Use of IDO1 inhibitor albiflorin or / and paeoniflorin in immunotherapy for cancer comorbid with depression

Abstract

Disclosed are use of an indole 2,3-dioxygenase (IDO1) inhibitor albiflorin (paeoniflorin), or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of albiflorin in the immunotherapy for cancer comorbid with depression, cancer immunopotentiation therapy, and a method for improving the survival quality of cancer patients. Albiflorin (paeoniflorin), or a pharmaceutically acceptable salt thereof, or an extract or a pharmaceutical composition containing a therapeutic amount of albiflorin (paeoniflorin) serves as a potentiator of cancer immunotherapy. By means of multiple mechanisms for resisting chronic stress, relieving emotional distress, regulating circadian rhythm, mitigating intestinal flora disequilibrium, inhibiting overactivation of IDO1, and correcting metabolic abnormalities, treatment of cancer comorbid with depression is potentiated synergistically, especially the immunotherapy for cancer comorbid with depression.

Description

Use of IDO1 inhibitors paeoniflorin and / or paeoniflorin in cancer immunotherapy for depression comorbidity Technical Field

[0001] This invention belongs to the field of biomedicine and relates to the IDO1 inhibitor paeoniflorin and / or paeoniflorin, which can alleviate emotional distress (ED), regulate circadian rhythm, and enhance the body's immune function by improving gut microbiota-tryptophan metabolism, thereby enhancing the immunotherapy of depression and comorbid cancer through multiple mechanisms in a synergistic and systemic manner. Background Technology

[0002] In recent years, the following groundbreaking discoveries have been made regarding the pathogenesis of cancer and immunotherapy:

[0003] I. Improving emotional distress (ED) can significantly enhance the efficacy of cancer immunotherapy.

[0004] Emotional stress (ED) is prevalent among cancer patients. Studies show that 33%–77.2% of lung cancer patients report experiencing symptoms of depression / anxiety. This negative emotion severely impairs the body's immune function and promotes the formation of an immunosuppressive tumor microenvironment. Increasingly, research suggests that individual psychological factors are also important potential factors in cancer treatment management, directly affecting treatment outcomes. Despite this understanding, clinical evidence regarding the correlation between emotional stress and the efficacy of immune checkpoint inhibitors (ICIs) is insufficient. Therefore, prospective clinical research findings are urgently needed to confirm this association. In recent years, this question has received a clear answer. For example, a paper published in *Nature Medicine* (IF: 82.9, May 13, 2024) by Professor Wu Fang's team from the Cancer Center of Xiangya Second Hospital, Central South University, entitled "Association between pretreatment emotional distress and immune checkpoint inhibitor response in non-small-cell lung cancer patients." This cohort study included 227 patients. The study found that among patients with advanced non-small cell lung cancer (NSCLC) receiving first-line immunotherapy, those experiencing emotional stress had their median progression-free survival halved (7.9 months vs. 15.5 months), with lower objective response rates and a higher risk of disease-related death. The study found that from the moment of cancer diagnosis, negative emotions such as depression, anxiety, sadness, and fear can begin to affect patients, and these emotional disturbances can severely impact tumor development. The secretion of glucocorticoids (GCs) and adrenergic hormones under emotional stress can damage the immune system and severely interfere with tumor immunotherapy. Therefore, "alleviating emotional stress in cancer patients may become a new perspective for enhancing cancer immunotherapy, and its application is not limited to advanced NSCLC. Other anti-cancer treatments, such as targeted therapy, can also benefit."

[0005] For example, a research team from Johns Hopkins University published a research paper titled "Chronic Stress Hormones Promote Metastasis of Diffuse Large B-Cell Lymphoma via Extracellular Trap NETs" in *Cancer Cell* (IF: 38.5, April 10, 2024). This study revealed that "emotional stress exposure promotes metastasis by releasing glucocorticoids (GCs), which in turn induce neutrophils to form NETs, ​​creating a microenvironment conducive to cancer cell metastasis." The research team found that emotional stress (ED) increased the metastasis rate of cancer cells in mice by 2–4 times. Simultaneously, emotional stress (ED) alters the normal diurnal rhythm of neutrophils and, through GC release, leads to increased NET formation, promoting the metastasis of diffuse large B-cell lymphoma.

[0006] For example, Ivan E. de Araujo, Hao Chang, and Wenwen Han from the Max Planck Institute for Biocontrol at the Icahn School of Medicine at Mount Sinai published a paper in Cell (IF: 66.8, August 1, 2024) entitled "Stress-sensitive neural circuits alter the gut microbiota through duodenal glands," which was the first to discover that psychological stress impairs immunity by affecting the gut microbiota. The study showed that the Brunner gland in the duodenum promotes the proliferation of lactobacilli in the gut via the vagus nerve, thereby activating the host's immune function and synergistically fighting inflammation and cancer. Chronic stress (i.e., emotional stress, ED) inhibits the brain-vagus nerve circuit (CeA-DMV-BG↓), thereby reducing the number of lactobacilli (↓) and leading to a decline in human immune function (↓).

[0007] The above research provides new insights into synergistic cancer immunotherapy through anti-stress, anti-depression, reduction of psychological stress, alleviation of anxiety, inhibition of excessive GC release, improvement of gut microbiota to promote the proliferation of probiotics such as lactic acid bacteria. Individual psychological factors are also a potentially important factor in cancer treatment and management.

[0008] II. Negative Impacts of Existing Antidepressants on Cancer Immunotherapy

[0009] Contrary to most people's expectations, the use of existing antidepressants can impair cancer treatment, particularly negatively impacting cancer immunotherapy, resulting in shorter survival times and reduced quality of life for patients taking these medications. Research in this area is as follows:

[0010] A paper titled "Use of antidepressants versus survival outcomes in cancer patients receiving immune checkpoint inhibitor therapy: a systematic review and meta-analysis" published in The Lancet Oncology (IF: 54.433) in October 2021 showed that researchers conducted a systematic review and meta-analysis of the survival outcomes of 10,337 cancer patients in different countries and regions who used antidepressants and received immune checkpoint inhibitor therapy. The study found that patients who used antidepressants after starting cancer immune checkpoint inhibitor therapy (ICI) had significantly shorter overall survival (OS) and progression-free survival (PFS) than those who did not use antidepressants (OS was shortened by 19% and PFS by 13%).

[0011] In January 2023, Professor Scott Gettingeer's team at Yale University School of Medicine published a research paper titled "Antidepressant Use and Survival Outcomes in Cancer Patients: A National Cohort Study" in *JAMA Oncology* (IF: 33.00). This large-scale cohort study, using data from the National Cancer Database, aimed to assess the relationship between antidepressant use and overall survival in cancer patients. The study included over 300,000 adult cancer patients, 10% of whom used antidepressants after cancer diagnosis. The results showed that patients who used antidepressants after the start of cancer treatment had a significantly shorter overall survival (OS).

[0012] There are many similar studies, such as: a paper titled "Antidepressant use and survival outcomes in cancer patients treated with ICI: an observational cohort study" published in The Lancet Psychiatry (IF: 27.08) in April 2023; a paper titled "Antidepressant use during immune checkpoint inhibitor therapy and survival in cancer patients" published in The Lancet Oncology (IF: 54.43) in June 2023; and a paper titled "Antidepressant use after ICI initiation and mortality in cancer patients" published in JAMA Oncology (IF: 33.00) in July 2023. These studies generally yielded similar results: antidepressants significantly impacted cancer immunotherapy, with patients using these medications experiencing significantly shorter overall survival and progression-free survival compared to those not using antidepressants.

[0013] III. IDO1 inhibitors possess both antidepressant and immunomodulatory / anticancer functions.

[0014] Current research has found that some antidepressants can significantly enhance the efficacy of cancer immunotherapy, such as IDO1 inhibitors.

[0015] In April 2017, at the American Association for Cancer Research (AAAR) Annual Meeting, NewLink presented research findings that attracted considerable attention from researchers. In a phase 2017 clinical trial, the combination of the IDO1 inhibitor indoximod and the immune checkpoint inhibitor Keytruda (Merck) demonstrated significant efficacy in the treatment of advanced melanoma. The overall response rate in 60 melanoma patients treated with the indoximod / Keytruda combination therapy was as high as 52%, significantly higher than the 33% achieved with Keytruda alone (52% vs. 33%); moreover, the disease control rate of this combination therapy was as high as 73%.

[0016] A research paper titled "Preclinical study of IDO1 inhibitors for the treatment of depression," published in *Science* (IF: 63.71) in November 2019, found that the immunotherapy drug IDO1 inhibitor INCB024360 can improve depressive-like behavior in CUMS model mice, enhance cognitive and social abilities, and effectively treat depression comorbid with cancer (Note: INCB024360 is a drug developed by Inset Therapeutics for the treatment of advanced solid tumors and lymphomas).

[0017] In August 2024, Academician Li Lanjuan's team from the First Affiliated Hospital of Zhejiang University published a research paper entitled "Tryptophan Metabolism and Disease" in *Cell Metabolism* (IF: 31.9). This study explored tryptophan metabolism from multiple perspectives, including gut microbiota, tryptophan metabolites, key enzymes, receptor ligands, and the combination of inhibitors with other drugs for treatment. They discovered that inhibiting the activity of the IDO1 enzyme can have antidepressant effects and promote cancer immunotherapy. "As an independent agent, IDO / TDO inhibitors can improve the efficacy of traditional anticancer drugs and can serve as a synergist for cancer immunotherapy."

[0018] The inventors of this invention discovered, based on a large-sample clinical cohort study:

[0019] 1) Cancer patients with emotional distress (ED) have a relatively low overall objective response rate to immunotherapy, a 18.4% reduction in the absolute value of the 2-year overall survival rate, and a worse quality of life. Therefore, a comprehensive study integrating clinical psychological and biological multidimensional factors can lead to the following conclusion: improving emotional stress (ED) in cancer patients and combating depression and anxiety may become a new perspective for improving the overall efficacy of cancer treatment, especially enhancing cancer immunotherapy (ICI).

[0020] 2) Overall, existing antidepressants (SSRIs and tricyclic antidepressants, etc.) do not help improve cancer immunotherapy. On the contrary, they increase the risk of disease and death and shorten the survival time of patients. Therefore, the value of antidepressants in cancer treatment should not be judged solely from the perspective of relieving emotional stress. Instead, we should analyze the positive and negative effects of physiological and psychological factors on tumor treatment and the health of the host from multiple perspectives, and systematically study the overall effect of antidepressants on cancer immune checkpoint inhibitor therapy. In this way, we can develop a new generation of antidepressants with better performance and better comprehensive benefits that can truly enhance the precision immunotherapy of tumors.

[0021] Cancer is a complex systemic disease closely related to psychological and emotional stress. Individual psychological factors are also a potentially important factor in cancer treatment, rehabilitation, and management. In order to improve the overall effectiveness of cancer treatment and reduce the negative impact on patients' quality of life and health, it is urgent to develop a new generation of systemic enhanced cancer immunotherapy drugs and methods.

[0022] Summary of the Invention

[0023] The purpose of this invention is to address the technical problems existing in the treatment of depression, cancer, and cancer comorbid with depression, and to provide the application of the IDO1 inhibitor paeoniflorin (or paeoniflorin), its pharmaceutically acceptable salt, or extracts or compositions containing therapeutic amounts of paeoniflorin (or paeoniflorin) in adjuvant cancer immunotherapy. The IDO1 inhibitor paeoniflorin (or paeoniflorin) of this invention improves gut microbiota-tryptophan metabolism, relieves emotional distress (ED), regulates circadian rhythms, enhances the body's immune function, and systematically enhances the use of immunotherapy for cancer comorbid with depression.

[0024] To achieve the objectives of this invention, the technical solution adopted is as follows:

[0025] This invention provides an IDO1 inhibitor, paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, for use in cancer treatment by improving gut microbiota-tryptophan metabolism, relieving emotional stress (ED), restoring circadian rhythm, and enhancing human immune function, with synergistic effects through multiple mechanisms. Preferably, it is used in the treatment of cancer with depression, and more preferably in the immunotherapy of cancer with depression.

[0026] The IDO1 inhibitor paeoniflorin (paeoniflorin) of the present invention can be used for both cancer treatment and cancer immunotherapy, especially to enhance immunotherapy for cancer comorbid with depression.

[0027] In particular, the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is formulated into pharmaceuticals, health foods, dietary supplements, functional foods or beverages, or gummies for cancer treatment, preferably for cancer immunotherapy, more preferably for immunotherapy of cancer comorbid with depression, and for improving the quality of life of patients.

[0028] The present invention also provides the use of paeoniflorin, an IDO1 inhibitor, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in cancer treatment by improving gut microbiota-tryptophan metabolism, relieving emotional stress (ED), restoring circadian rhythm, and enhancing human immune function, with synergistic effects through multiple mechanisms, preferably in the treatment of cancer with depression, and more preferably in the immunotherapy of cancer with depression.

[0029] In particular, the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is formulated into pharmaceuticals, health foods, dietary supplements, functional foods or beverages, or gummies for cancer treatment, preferably for cancer immunotherapy, more preferably for immunotherapy of cancer comorbid with depression, and for improving the quality of life of patients.

[0030] The present invention also provides the use of the IDO1 inhibitor paeoniflorin and / or paeoniflorin, or a pharmaceutically acceptable salt thereof, in adjuvant cancer therapy; and the use of a combination of the IDO1 inhibitor paeoniflorin and / or paeoniflorin, or a pharmaceutically acceptable salt thereof, with immune checkpoint inhibitors such as PD-1 / PD-L1, in enhancing cancer therapy, preferably in cancer immunotherapy, and more preferably in immunotherapy for cancer comorbid with depression.

[0031] In particular, the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in combination with immune checkpoint inhibitors such as PD-1 / PD-L1, is used to treat rectal cancer or rectal cancer comorbid with depression, or for use in nCRT treatment of colorectal cancer; the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in combination with immune checkpoint inhibitors such as PD-1 / PD-L1, is used to treat rectal cancer or rectal cancer comorbid with depression, or for use in nCRT treatment of colorectal cancer.

[0032] In particular, the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is used to treat cancer comorbid with depressive disorders, or to improve the quality of life and prognosis of cancer patients with circadian rhythm disorders, sleep disorders, and gut microbiota dysbiosis; the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is used to treat cancer comorbid with depressive disorders, or to improve the quality of life and prognosis of cancer patients with circadian rhythm disorders, sleep disorders, and gut microbiota dysbiosis.

[0033] In particular, the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is used for the treatment of tumors comorbid with type 2 diabetes, preferably for the treatment of tumors comorbid with type 2 diabetes and associated with depressive disorder.

[0034] The present invention also provides a method for cancer immunomodulatory therapy and improving the quality of life of cancer patients, comprising administering to the patient an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or an extract containing a therapeutic dose of paeoniflorin; or comprising administering to the patient an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or an extract containing a therapeutic dose of paeoniflorin.

[0035] The present invention also provides a method for cancer immunomodulatory therapy and improving the quality of life of cancer patients, comprising administering to the patient an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or a combination of an extract containing a therapeutic dose of paeoniflorin and immune checkpoint inhibitors such as PD-1 / PD-L1; or comprising administering to the patient an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or a combination of an extract containing a therapeutic dose of paeoniflorin and immune checkpoint inhibitors such as PD-1 / PD-L1.

[0036] The present invention relates to the use of paeoniflorin (or / and paeoniflorin) or a pharmaceutically acceptable salt thereof, an IDO1 inhibitor, for the purpose of relieving emotional stress (ED), enhancing immune system function, and enhancing immunotherapy for depression comorbid with cancer through multiple mechanisms.

[0037] The IDO1 inhibitor paeoniflorin (or / and paeoniflorin) of the present invention, or a pharmaceutically acceptable salt thereof, or a white peony extract containing a therapeutic amount of paeoniflorin (or / and paeoniflorin), inhibits the secretion of hormones such as glucocorticoids (GCs) and prostaglandin E2 (PGE2) by inversely regulating the hyperactive HPA axis, thus exhibiting anti-stress, antidepressant, and anti-anxiety effects, inhibiting IDO1 overactivation, promoting the activity of the endogenous melatonin system, correcting circadian rhythm disorders, improving gut microbiota balance, enhancing the body's immune system function, and providing multi-mechanism systemic synergistic immunotherapy for depression comorbid with cancer.

[0038] This invention provides the use of the IDO1 inhibitor paeoniflorin (or / and paeoniflorin) or a pharmaceutically acceptable salt thereof, in combination with a PD-1 / PD-L1 immune checkpoint inhibitor in the immunotherapy of cancer comorbid with depression.

[0039] In particular, the choice of PD-1 / PD-L1 immune checkpoint inhibitors, such as Merck's Keytruda, enhances the efficacy of immunotherapy for cancer patients with depression and improves their quality of life.

[0040] This invention provides the application of the IDO1 inhibitor paeoniflorin (or / and paeoniflorin) in the prevention and treatment of colorectal cancer comorbid with depression.

[0041] This invention provides the use of the IDO1 inhibitor paeoniflorin (or / and paeoniflorin) or a pharmaceutically acceptable salt thereof, in combination with a PD-1 / PD-L1 immune checkpoint inhibitor in the immunotherapy of rectal cancer with depression.

[0042] IDO1 inhibitors paeoniflorin (or / and paeoniflorin) not only have a direct tumor-suppressing effect on colorectal cancer cells, but also improve gut microbiota by reducing Bacteroides abundance, downregulating the Bacteroides / Firmwallis ratio in the patient's gut, enhancing the anti-cancer efficacy of PD-1 / PD-L1 immune checkpoint inhibitors, and especially enhancing neoadjuvant chemoradiotherapy (nCRT) for the treatment of colorectal cancer.

[0043] This invention provides the use of the IDO1 inhibitor paeoniflorin (or paeoniflorin), or a pharmaceutically acceptable salt thereof, in the treatment of type 2 diabetes comorbid with cancer, preferably in the immunotherapy of type 2 diabetes comorbid with depression and cancer.

[0044] IDO1 inhibitor paeoniflorin (or paeoniflorin) is used as an inhibitor of dipeptidyl peptidase-4 (DPP-4) inducing type 2 diabetes for the treatment of type 2 diabetes comorbid with cancer, especially for immunotherapy in patients with type 2 diabetes and cancer comorbid with depression.

[0045] This invention provides paeoniflorin (or / and paeoniflorin), or extracts containing therapeutic amounts of paeoniflorin (or paeoniflorin) (e.g., total paeoniflorin of Paeonia lactiflora), or compositions containing therapeutic amounts of paeoniflorin (or paeoniflorin) (e.g., peony and licorice formula, peony and astragalus formula), as dietary supplements, health foods, foods, beverages, or functional gummies for relieving emotional stress (ED), improving the gut microenvironment, enhancing immune system function, and assisting in cancer immunotherapy.

[0046] The present invention provides a method for enhancing immunotherapy for cancer comorbid with depression, comprising administering to a patient an effective dose of paeoniflorin (or / and paeoniflorin), or an extract containing a therapeutic dose of paeoniflorin (or / and paeoniflorin), or a composition containing a therapeutic dose of paeoniflorin (or / and paeoniflorin).

[0047] Compared with the prior art, the present invention has the following advantages and benefits:

[0048] This invention utilizes a multi-omics approach, from a systems medicine perspective, combining bio-psychological markers to conduct a comprehensive study on the effects of paeoniflorin in relieving emotional stress (ED) and enhancing the immunotherapy of cancer comorbid with depressive disorders. It was found that paeoniflorin (or / and paeoniflorin) has different pathways and performance advantages in improving gut microbiota-tryptophan metabolism compared to SSRIs such as fluoxetine. By integrating multiple mechanisms of action of therapeutic targets (IDO, TDO, KMO, TPH, etc.) on the tryptophan metabolism pathway and the internal and external environment of cancer comorbid with depression, a holistic bio-psychological systemic therapeutic effect is achieved. This makes it an excellent synergist for combination therapy with next-generation immunotherapeutic drugs (such as PD-1 inhibitors like Keytruda, from Merck).

[0049] Guided by the concept of "systems medicine" reflecting new scientific understanding, this invention comprehensively and deeply explores the multifactorial and complex nature of cancer as a systemic disease, including factors such as tumor occurrence and development, tumor microenvironment, interaction with the body's immune system, metabolic abnormalities, circadian rhythm disorders, emotional and psychological stress, and gut microbiota dysbiosis. Through the systematic integration of the multiple functions of the natural monomeric compounds paeoniflorin and paeoniflorin, this invention forms a "next-generation mechanism-guided therapeutic drug and treatment plan," which significantly enhances the immunotherapy of cancer comorbid with depression, improves the quality of life and prognosis of patients with cancer comorbid with depression, and enhances their physical condition.

[0050] This invention discovers:

[0051] 1. Emotional stress (ED) can cause hyperactivity of the HPA axis, leading to a sustained over-secretion of glucocorticoids (CORT) and adrenaline in cancer patients. This negatively impacts the body's immune system function, thus hindering cancer immunotherapy. Paeoniflorin (or / and paeoniflorin), along with SSRIs such as fluoxetine, can inversely regulate the hyperactive HPA axis, inhibiting excessive CORT secretion, thus providing anti-stress, anti-depression, and alleviating emotional stress (ED) in cancer patients. Therefore, paeoniflorin (or / and paeoniflorin) can enhance the efficacy of cancer immunotherapy and strengthen anti-cancer immune response.

[0052] 2. Emotional stress (also known as emotional stress-induced erectile dysfunction) leads to increased prostaglandin 2 (PGE2), which inhibits CD3+. + T cells enable stem cells CDB + T cells and CDB infiltrating the tumor + The inability of T cells to proliferate leads to mitochondrial dysfunction, ultimately resulting in ferroptosis. A recent study published in *Nature* confirms that prostaglandin E2 is a major anti-cancer agent that inhibits T cell proliferation within tumors. The paeoniflorin (or / and paeoniflorin) of this invention enhances tumor immunotherapy and immunotherapy by inhibiting the PGE2 signaling pathway.

[0053] 3. Emotional stress (ED) can cause abnormalities in the tryptophan metabolism pathway, leading to the overactivation of IDO1. This overactivation degrades tryptophan, creating a microenvironment of tryptophan deficiency in the body, which in turn induces the occurrence and development of diseases such as depression and cancer. As a key molecule inducing immune tolerance in tumor cells, high expression of IDO1 leads to local tryptophan depletion in cells, inducing T cells to arrest in the G1 phase, thereby inhibiting T cell proliferation. Paeoniflorin (or / and paeoniflorin) inhibits the overactivation of IDO1 and, when combined with immunotherapeutic drugs such as PD-1 inhibitors (e.g., Merck's Keytruda), can synergistically prevent tumor immune escape and enhance the efficacy of cancer immunotherapy. In contrast, existing first-line antidepressants such as fluoxetine and other SSR1s not only lack this function but may even further activate IDO1, thus severely weakening cancer immunotherapy.

[0054] 4. Emotional stress (ED) can induce gut microbiota dysbiosis, increasing the abundance of Bacteroides (B) and decreasing the abundance of Firmicutes (F), thus increasing the B / F ratio and inducing drug resistance in tumor treatment (a paper published in Cancer Cell by Academician Zhan Qimin's team at Peking University Cancer Hospital on December 23, 2022, showed that "common Bacteroides in the gut can promote drug resistance in nCRT treatment of rectal cancer through nucleotide synthesis"). The paeoniflorin (or / and paeoniflorin) of this invention improves gut microbiota balance, reduces the abundance of Bacteroides (B) and increases the abundance of Firmicutes (F), and decreases the B / F ratio, thereby correcting drug resistance in cancer cells and enhancing the efficacy of tumor immunotherapy. Existing SSR1 class antidepressants such as fluoxetine do not possess this function; on the contrary, they exacerbate gut microbiota dysbiosis and disrupt tumor immunotherapy.

[0055] 5. Emotional stress (ED) can disrupt circadian rhythms, increasing the risk of cancer. Disruptions in circadian rhythm genes and insufficient sleep promote tumor growth by enhancing fatty acid oxidation (FAO). Furthermore, overactivation of ACSL enzymes (long-chain fatty acid A synthase) increases the stemness of cancer cells, further promoting tumor growth. The number and phenotype of immune cells in the tumor microenvironment are influenced by circadian rhythms. (A paper titled "Circadian Rhythm-Influenced Tumor Infiltration and CD8+ T Cell Function Determine the Efficacy of Immunotherapy," published in *Cell* on May 8, 2024, by Christoph Scheiermann's research team at the Department of Pharmacology and Immunology, University of Geneva, Switzerland, illustrates this point.) This invention relates to a new generation of immunomodulatory anticancer synergist, paeoniflorin, which promotes the function of the endogenous melatonin system, improves circadian rhythm, enhances sleep quality, and enhances the immunotherapy of tumors by regulating the expression of clock factor mRNAs such as Ngfr, Nr1d1, and Dbp. In contrast, antidepressants such as fluoxetine do not have this function, and some may even further disrupt circadian rhythm, cause sleep disorders, and interfere with cancer immunotherapy.

[0056] 6. SSRIs and other antidepressants may induce drug-induced metabolic syndrome (Mets). During cancer immunotherapy (CIC), the use of SSRIs such as fluoxetine can affect cancer immunotherapy and shorten overall survival (OS). Another potentially important factor contributing to this negative effect is the potential for these drugs to induce drug-induced metabolic syndrome (Mets). For example, fluoxetine increases the risk of obesity, dyslipidemia, type 2 diabetes, and cardiovascular disease. The paeoniflorin (or / and paeoniflorin) of this invention can be used to prevent and treat comorbid cancer and depressive disorders, including metabolic syndrome, and can be used for weight loss, correction of dyslipidemia, and reduction of the risk of type 2 diabetes and cardiovascular diseases.

[0057] 7. Paeoniflorin inhibits DAAO. The new generation of immune anticancer enhancer, paeoniflorin, has an in vivo metabolite of benzoic acid. By inhibiting DAAO activity, it prevents the decomposition of D-serine in the tumor microenvironment, increases the release of tumor antigens, thereby inhibiting the growth and survival of tumor cells and improving the immune anticancer efficacy of PD-1 / PD-L1 blockade therapy. Attached Figure Description

[0058] Figure 1A shows the effect of paeoniflorin of the present invention on IDO1 in the hippocampus of chronically stressed rats (CUMS) detected by Western blotting.

[0059] Figure 1B is a bar chart showing the effect of paeoniflorin on IDO1 in the hippocampus of chronically stressed rats (CUMS).

[0060] Figures 1A and 1B show: Control group, CUMS model group, Albiflorin group, and Fluoxetine (FLX) group; # indicates an increase compared to the CUMS group (p<0.05), ## indicates a significant increase compared to the CUMS group (p<0.01), and ** indicates a significant decrease compared to the CUMS group (p<0.01).

[0061] Figure 2 is a metabolic pathway diagram of the paeoniflorin of the present invention, which has the effects of antidepressant and regulation of circadian rhythm by downregulating the kynurenic acid-quinolinic acid metabolic pathway and upregulating the serotonin-melatonin metabolic pathway.

[0062] Figure 3 shows the PLS-DA analysis of rat intestinal flora metabolism. The analysis shows that there is a significant difference in intestinal flora metabolism between the CUMS group and the normal control group. The paeoniflorin administration of the present invention helps the intestinal flora to restore normal metabolism.

[0063] Figure 4 shows the PLS-DA analysis of rat gut microbiota metabolism. The analysis indicates that fluoxetine caused the gut microbiota of CUMS rats to be further away from the normal control group, and the results show that fluoxetine further disrupts gut microbiota metabolism.

[0064] Figure 5 shows the VIP analysis results of gut microbiota metabolism in the CUMS group and the normal control group. Among the top 20 metabolites with significant differences between the two groups, 16 metabolites were significantly decreased. (For the top 20 metabolites, VIP > 1.5 indicates a significant difference.)

[0065] Figure 6 shows the results of VIP analysis of rat intestinal flora metabolism. The VIP analysis results show that the overall metabolism of intestinal flora in the paeoniflorin group was significantly improved compared with that in the CUMS group, mainly manifested by increased bile acid content, increased amino acid and vitamin content, indicating that paeoniflorin significantly upregulated the beneficial metabolism of intestinal flora.

[0066] Figure 7 shows the results of VIP analysis of rat gut microbiota metabolism. The VIP analysis results indicate that fluoxetine significantly downregulated gut microbiota metabolism. The levels of all 25 (100%) most significantly different metabolites in rat feces were not only reduced but also lower than those in the CUMS group, indicating that fluoxetine exacerbated the disruption of the metabolic balance of gut microbiota.

[0067] Figure 8 shows the relative abundance of bacterial species at the family level in the blank control group, CUMS model group, fluoxetine group, and paeoniflorin group (the top 10 species with the highest abundance).

[0068] Figure 9 shows the B / F ratio of Bacteroides to Firmicutes in rat feces. Paeoniflorin reduced the B / F ratio in the feces of the CUMS group (p<0.05).

[0069] Figure 10 shows the results of LEFSe assay for the enrichment of gut microbiota in rats. Among them, the prominent gut microbiota in the paeoniflorin group is the probiotic Lactobacillus (Figure 10B); the prominent gut microbiota in the CUMS group and the fluoxetine group is Prevotellaceae (Figure 10A, Figure 10C).

[0070] Figure 11 shows the GO enrichment analysis of differentially expressed genes in biological processes. The analysis results show that the top 16 significantly different sequences of the differentially expressed genes between the paeoniflorin group and the CUMS group were enriched in the GO enrichment of biological processes. The edges between the two biological processes in the chord diagram represent the common genes between them.

[0071] Figure 12 shows the significant associations between differentially expressed genes involved in circadian rhythms and aromatic monoamines and their related metabolites in rat hippocampus; the color of the lines in the figure represents positive (red) or negative (blue) correlations. The thickness of the lines corresponds to the coefficient r value; the higher the r value, the thicker the line. Detailed Implementation

[0072] The present invention will be further illustrated below with specific implementation examples. However, the following implementation examples are merely illustrative of the invention and are not intended to limit the scope of the invention.

[0073] Example 1: The inhibitory effect of paeoniflorin, the immune-anticancer systemic potentiator of the present invention, on the hyperactive HPA axis glucocorticoid (CORT) and prostaglandin E2 (PGE2) in chronically stressed (CUMS) rats (↓).

[0074] First, an unpredictable long-term mild stress experiment (CUMS) was conducted. Except for a normal control group, all groups received randomly designed CUMS stimulation. Drug administration began on day 29 after successful modeling of the stress stimulus and lasted for 7 days. Then, following the instructions of the ACTHCLIA, CRHCLIA, CortCLIA, TestoELISA, PGE2, and BDNF kits, the levels of ACTH, CRH, CortCLIA, and BDNF in the hippocampus and plasma of male rats, as well as the concentrations of Testo and PGE2 in plasma, were measured to detect the effect of paeoniflorin on the HPA axis function in rats.

[0075] The immune-anticancer systemic potentiator paeoniflorin (Alb) and the positive control drug fluoxetine (FLX) of this invention have a significant reverse regulatory effect (↓) on the elevated levels of glucocorticoids (CORT) and prostaglandin E2 (PGE2) in the plasma of chronically stressed (CUMS) rats with hyperactive HPA axis, bringing them back to normal.

[0076] HPA functional indicators (ACTH, BDNF, CORT, CRH, PGE2) in the plasma of rats in each group were measured, and the results are shown in Table 1. The groups included a blank control group (control), a model group (CUMS), fluoxetine (FLX, positive drug control group), and high, medium, and low dose groups of albiflorin (Alb).

[0077] Table 1: Effects of paeoniflorin and fluoxetine on plasma CORT and PGE2 in CUMS rats

[0078] ## Compared with the control group, p<0.01; * Compared with the model group, p < 0.05. ** Compared with the model group, p < 0.01

[0079] Chronic stress caused by persistent emotional stress (ED) induces hyperactivity of the HPA axis, leading to the continuous over-secretion of glucocorticoids (CORT) and adrenergic hormones in cancer patients. This negatively impacts the body's immune system function and hinders immunotherapy for tumors. Paeoniflorin and other SSRIs (antidepressants) such as fluoxetine, by inversely regulating the hyperactive HPA axis, reduce the secretion of glucocorticoids (CORT) and prostaglandin E2 (PDE2), thus relieving stress, depression, and emotional stress (ED) in cancer patients, thereby enhancing the efficacy of cancer immunotherapy.

[0080] Example 2: The regulatory effect of paeoniflorin, the immune-anticancer systemic potentiator of the present invention, on IDO overexpression (↑) and melatonin receptor (MT1) decrease (↓) induced by a chronic stress rat model (CUMS).

[0081] After successful establishment of the chronic stress model using the Unpredictable Long-Term Mild Stress Experiment (CUMS), Western blotting was used to detect IDO and MT1 in the hippocampus of rats in each group (i.e., blank control group, model group (CUMS), fluoxetine (FLX, positive drug control group), and high, medium and low dose groups of albiflorin (Alb). The results are shown in Table 2, Figures 1A and 1B.

[0082] In the hippocampus of rats in a chronic stress model (CUMS), IDO expression was significantly increased (↑), while melatonin receptor MT1 expression was significantly decreased (↓). After 7 days of administration of paeoniflorin (7 mg / day), IDO expression in the rat hippocampus was significantly inhibited (↓) (P<0.01), while melatonin receptor MT1 expression in the rat hippocampus was significantly increased (↑) (P<0.01). Conversely, the positive control drug fluoxetine further promoted IDO enzyme activity in the rat hippocampus (↑) (P<0.05) and decreased melatonin receptor MT1 expression (↓) (P<0.01).

[0083] Table 2: Effects of IDO and MT1 in the hippocampus of CUMS rats (Mean±SE)

[0084] # This indicates an increase of p<0.05 compared to the model group; ## This indicates an increase of p<0.01 compared to the model group; ** This indicates a decrease of p<0.01 compared to the model group.

[0085] As shown in Figure 2, in the hippocampus of CUMS rats, the serotonin synthesis pathway was inhibited, while the kynuric acid metabolism pathway was upregulated (↑), leading to a decrease in serotonin levels (↓), which in turn triggered depression and cancer. This study found that after administration of paeoniflorin, the levels of kynuric acid and quinolinic acid in the hippocampus of rats were significantly lower than in the CUMS group (↓), indicating a downregulation of the kynuric acid metabolism pathway in the hippocampus. Meanwhile, the levels of serotonin and melatonin in the hippocampus were significantly increased (↑), indicating that paeoniflorin of this invention promotes an upregulation of the serotonin metabolism pathway (↑).

[0086] Improving tryptophan metabolism abnormalities caused by chronic stress, inhibiting IDO1 overactivation, restoring the body's circadian rhythm, and promoting the function of the body's immune system are among the main mechanisms of action of paeoniflorin, the systemic synergist for immunotherapy and anticancer therapy of this invention, in treating depression and enhancing cancer immunotherapy. Conversely, experiments have shown that although fluoxetine can have antidepressant effects, its mechanism of action differs from that of paeoniflorin, the systemic synergist for immunotherapy and anticancer therapy of this invention. Fluoxetine cannot reduce tryptophan metabolism by inhibiting IDO activity and thus cannot regulate immunosuppression in the tumor microenvironment, nor can it correct circadian rhythm abnormalities by regulating the function of the endogenous melatonin system. Therefore, fluoxetine not only lacks the function of enhancing cancer immunotherapy but may even produce certain negative effects.

[0087] Example 3: Multivariate PLS-DA analysis showed that paeoniflorin, the systemic synergist for immune anticancer activity of the present invention, significantly improved the metabolic balance of intestinal flora in CUMS rats.

[0088] Chronic stress (CUMS) disrupts gut microbiota metabolism, and "gut microbes affect the therapeutic efficacy of PD-1 / L1 immunotherapy for cancer." This embodiment employs targeted metabolomics to simultaneously measure 430 common gut microbiota metabolites with important physiological and biochemical functions. These 430 metabolites are distributed across 46 key gut microbiota metabolic pathways.

[0089] PLS-DA multivariate analysis was performed on the intestinal flora metabolites of rats in each group, and the results are shown in Figure 3-4; VIP analysis was performed, and the results are shown in Figure 4-7.

[0090] 1. PLS-DA multivariate analysis showed that CUMS disrupted gut microbiota metabolism. Paeoniflorin, the immune anticancer systemic potentiator of this invention, was administered for 7 days, which restored the gut microbiota metabolism of CUMS rats to the direction of the normal control group, almost completely overlapping with the normal group, indicating that paeoniflorin helps to restore normal gut microbiota metabolism (Figure 3). Fluoxetine had the opposite effect, causing the gut microbiota metabolism of CUMS rats to deviate further from the normal state, and the gut microbiota metabolism was further damaged or changed (Figure 4).

[0091] 2. This invention explored the differences in gut microbiota metabolism between CUMS rats and the normal group through VIP analysis. It found that among the Top 25 metabolites with significant differences in gut microbiota metabolism between CUMS rats and the normal group, 16 metabolites were significantly reduced in CUMS rats, as shown in Figure 5.

[0092] 3. Administration of the immune-anti-cancer systemic potentiator paeoniflorin of the present invention can significantly upregulate the metabolism of intestinal flora, mainly manifested by an increase in the content of bile acids, short-chain fatty acids, amino acids and vitamins, suggesting that paeoniflorin significantly upregulates the beneficial metabolism of intestinal flora, thereby restoring the normal function of intestinal flora, as shown in Figure 6.

[0093] 4. After administration of fluoxetine, intestinal flora metabolism was further inhibited. The levels of all 25 most significant metabolites in rat feces were significantly reduced in the fluoxetine group and lower than in the CUMS group. This suggests that fluoxetine exacerbates the beneficial metabolism of intestinal flora in chronically stressed rats and severely disrupts the metabolic balance of intestinal flora. This is one of the important reasons why fluoxetine is not suitable for treating cancer comorbid depression, as shown in Figure 7.

[0094] Example 4: 16S rDNA method studies demonstrated that paeoniflorin, the systemic synergist for immune anticancer activity of the present invention, can significantly restore the species balance of the intestinal flora in CUMS rats.

[0095] This invention uses the 16S rDNA method to sequence the species of gut microbiota in CUMS rats.

[0096] 16S rDNA, as a characteristic nucleic acid sequence revealing biological species, is considered the most suitable indicator for cell series development and classification identification. The detection results are shown in Table 3 and Figures 8-9.

[0097] Table 3: Top 10 most abundant species at the family level and relative abundance (%) of AKK bacteria

[0098] ↑: The relative abundance of bacterial species increased in the model group compared with the normal control group; ↓: The relative abundance of bacterial species decreased in the model group compared with the normal control group; ↑: The relative abundance of bacterial species increased in the paeoniflorin group compared with the model group; ↓: The relative abundance of bacterial species decreased in the paeoniflorin group compared with the model group.

[0099] The results in Table 3 show that the top 10 species with the highest abundance at the family level are: 1. Prevotellaceae, 2. Lactobacillusaceae, 3. Bacteroidetes S24-74, Trichophytonceae, and 5. Ruminococciaceae. Among these, Prevotellaceae was significantly higher in feces of CUMS rats than the normal control group (↑), while the abundance of other species and AKK bacteria was lower than that of the normal control group to varying degrees (↓).

[0100] As shown in Figure 8, the new generation of immune anticancer synergist paeoniflorin group of this invention can improve the intestinal flora disorder of CUMS rats, significantly downregulate the abundance of Prevotellaceae (↓), and increase the abundance of Lactobacillusceae (including Lactobacillus johnsonii, which is used to treat colon cancer) (↑), Bacteroidetes S24-7 (↑), Trichophytonceae (↑), and Ruminococcus (↑), which is beneficial to enhance anti-stress, anti-depression and immune anticancer effects.

[0101] As shown in Figure 9, 16S rDNA metagenomic analysis revealed that the diversity of gut microbiota in CUMS rats was significantly lower than that in the normal control group. Bacteroides (B) abundance was increased (↑), Firmicutes (F) abundance was decreased (↓), and the B / F ratio was increased (↑). This gut microbiota dysbiosis increases drug resistance in colorectal cancer and hinders immunotherapy for colorectal cancer. Oral administration of paeoniflorin can reduce the B / F ratio (↓), bringing it close to normal, thus contributing to cancer immunotherapy.

[0102] Therefore, the paeoniflorin glycoside, an immune anticancer systemic synergist of the present invention, not only helps to combat chronic stress and depression by improving the balance of intestinal flora, but also helps to enhance the immunotherapy of cancer, especially the immunotherapy of colorectal cancer.

[0103] Example 5: Determination of intestinal microbiota enriched species using the LEFSe method

[0104] The intestinal flora enriched in the paeoniflorin group of this invention's new generation of immune-boosting and anti-cancer synergistic agents are Lactobacillus, while the intestinal flora enriched in the fluoxetine group are Prevotellaceae.

[0105] The LEFSe method was used to determine the species of intestinal flora enriched in the CUMS group, fluoxetine group, and paeoniflorin group. The results are shown in Figure 10.

[0106] 1. As shown in Figure 10A, CUMS group: Compared with the blank control group, the CUMS group showed that the bacterial species were Bacteroides at the class level, Bacteroidetes at the order level, and Prevotellaceae at the family level.

[0107] 2. As shown in Figure 10C, in the fluoxetine group, the bacterial markers at the family level highlighted Prevostidae, the same as in the CUMS group. This suggests that fluoxetine cannot restore the normal gut microbiota of CUMS patients, therefore, it is not suitable for treating cancer-related comorbid depression. (Note: Prevostidae can influence the occurrence and development of cancer by regulating the host's immune system, metabolic pathways, and intestinal metabolites. In November 2023, a paper published in *Gut* by Professor Fang Jingyuan's team from the Affiliated Hospital of Shanghai Jiao Tong University School of Medicine found that the abundance of Prevostidae in the feces of rectal cancer patients was significantly higher than that of normal individuals. In addition, the study also found that Prevostidae can produce some pro-inflammatory substances, such as hydrogen sulfide and trimethylamine, which may damage the host's intestinal mucosa and promote the growth and metastasis of cancer cells.)

[0108] 3. As shown in Figure 10B, in the paeoniflorin group: the prominent bacterial species at the family level are Lactobacilliales and Lactobacilliaceae (including Lactobacillus johnsonii, which has been clinically proven to be beneficial in the treatment of colorectal cancer). (Note: Metabolites of intestinal flora Lactobacillus, including indole substances such as IPA and short-chain fatty acids such as lactic acid, acetic acid, and propionic acid, can inhibit tumor growth and metastasis by improving immune function and enhance the anti-cancer immune capacity of PD-1 / L-1 checkpoint inhibitors.)

[0109] Example 6: Enrichment Study of Biological Processes in Gene Ontology (GO)

[0110] Through RNA-Seq transcriptomics analysis, the paeoniflorin of this invention enhances cancer immunotherapy by regulating circadian rhythms through inhibiting IDO1 and promoting the expression of clock factors such as Ngfr, Nr1d1, and Dbp.

[0111] Gene Ontology (GO) is an international standard classification system for gene function.

[0112] Genes showing significant alterations in the hippocampus of rats treated with paeoniflorin, obtained from RNA-Seq transcriptome analysis, were enriched using GO biological processes. Among the Top 16 significantly enriched GO sequences, two (Circadian rhythm and Rhythmic process) were associated with biological rhythms, as shown in Figure 11.

[0113] Figure 12 shows that the analysis results indicate a significant correlation between circadian rhythms and genes related to monoamines and their derivative metabolites. These data suggest that depression and sleep disorders may share common pathophysiological mechanisms.

[0114] The results further showed that the expression of clock factors such as Ngfr, Nr1d1, and Dbp was negatively correlated with the level of kynurenine in hippocampal tissue (Figure 12). Hippocampal metabolomics analysis suggested that paeoniflorin exerts its antidepressant effect by reducing IDO1 expression in hippocampal tissue, inhibiting the kynurenine metabolic pathway, enhancing the body's immune system function, and contributing to the immunomodulatory and anticancer efficacy of PD-1 / L1 immune checkpoint inhibitors. Its mechanism of action is as follows:

[0115] I. The present invention provides a systemic synergist for immune anticancer activity, paeoniflorin, which inhibits the expression of IDO1 in hippocampal tissue, suppresses the production of kynurenine, and increases the secretion of serotonin.

[0116] II. The immune anticancer systemic synergist paeoniflorin of the present invention increases dopamine and melatonin, which are closely related to circadian rhythms and sleep, in the hippocampus of CUMA rats by regulating the expression of clock genes (Ngfr, Nr1d1, Dbp), thereby regulating circadian rhythms, restoring them to normal, and alleviating sleep disorders caused by CUMA.

[0117] Third, the systemic synergist paeoniflorin of this invention, an immune anticancer agent, improves sleep disorders and decreased immune function caused by CUMS, enhances the body's immune function by regulating biological rhythms, and assists the immunotherapeutic efficacy of PD-1 / L1 immune checkpoint inhibitors against cancer.

[0118] Research has found that the expression levels of clock genes (Ngfr, Nr1d1, Dbp) can affect the function of the immune system, thereby influencing tumor development and progression. For example, the expression level of the Nr1d1 gene affects the activity of T cells, impacting the effectiveness of tumor immunotherapy; the expression level of the Dbp gene affects the activity of macrophages, influencing tumor immune escape.

[0119] Some SSRIs, such as fluoxetine, do not have these functions. Instead, they may exacerbate circadian rhythm disorders and sleep disturbances, thereby reducing the function of the human immune system and affecting the immunotherapy of tumors. This is consistent with the results of clinical treatment data analysis.

[0120] Example 7: Effects of total paeoniflorin glycosides (paeoniflorin content ≥15%) on the HPA axis in chronically stressed rats

[0121] Unpredictable Long-Term Mild Stress (CUMS) experiment was conducted. Except for the normal control group, all groups received randomly designed CUMS stimulation. Drug administration began on day 29 after successful modeling of stress stimulation and lasted for 7 days. Then, the serum CORT concentration of male rats in each group was measured according to the instructions of the ACTHCLIA, CRHCLIA, CortCLIA, TestoELISA, PGE2, and BDNF kits. The results are shown in Table 4.

[0122] Table 4. Effects of total paeoniflorin on serum CORT in chronically stressed rats.

[0123] Compared with the model group, *P<0.05, **P<0.01

[0124] The results showed that CORT levels were elevated in the chronic stress rat model, with a significant difference compared to the control group (P≤0.01). Administration of the positive control drug fluoxetine and total paeoniflorin (paeoniflorin content ≥18%) significantly reduced CORT levels (P≤0.05).

Claims

1. The use of paeoniflorin, an IDO1 inhibitor, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in cancer treatment by improving gut microbiota-tryptophan metabolism, relieving emotional stress (ED), restoring circadian rhythm, enhancing human immune function, and through a synergistic effect of multiple mechanisms, preferably in the treatment of cancer with depression as a comorbidity, and more preferably in the immunotherapy of cancer with depression as a comorbidity.

2. The use according to claim 1, characterized in that, The IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is formulated into pharmaceuticals, health foods, dietary supplements, functional foods or beverages, or gummies for cancer treatment, preferably for cancer immunotherapy, more preferably for immunotherapy of cancer comorbid with depression, and for improving the quality of life of patients.

3. The use of paeoniflorin, an IDO1 inhibitor, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in cancer treatment by improving gut microbiota-tryptophan metabolism, relieving emotional stress (ED), restoring circadian rhythm, enhancing human immune function, and through a multi-mechanism synergistic effect, preferably in the treatment of cancer with depression as a comorbidity, and more preferably in the immunotherapy of cancer with depression as a comorbidity.

4. The use according to claim 3, characterized in that, The IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is formulated into pharmaceuticals, health foods, dietary supplements, functional foods or beverages, or gummies for cancer treatment, preferably immunotherapy for cancer, more preferably immunotherapy for cancer comorbid with depression, and to improve the quality of life of patients.

5. Use of the IDO1 inhibitor paeoniflorin and / or paeoniflorin, or a pharmaceutically acceptable salt thereof, in adjuvant cancer therapy; use of the IDO1 inhibitor paeoniflorin and / or paeoniflorin, or a pharmaceutically acceptable salt thereof, in combination with immune checkpoint inhibitors such as PD-1 / PD-L1, in enhancing cancer therapy, preferably in cancer immunotherapy, and more preferably in immunotherapy for cancer comorbid with depression.

6. The use as described in any one of claims 1-4, characterized in that, The IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in combination with immune checkpoint inhibitors such as PD-1 / PD-L1, is used to treat rectal cancer or rectal cancer comorbid with depression, or for use in nCRT treatment of colorectal cancer; the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, in combination with immune checkpoint inhibitors such as PD-1 / PD-L1, is used to treat rectal cancer or rectal cancer comorbid with depression, or for use in nCRT treatment of colorectal cancer.

7. The use as described in any one of claims 1-4, characterized in that, The IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is used to treat cancer comorbid with depressive disorders, or to improve the quality of life and prognosis of cancer patients with circadian rhythm abnormalities, sleep disorders, and gut microbiota dysbiosis; the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is used to treat cancer comorbid with depressive disorders, or to improve the quality of life and prognosis of cancer patients with circadian rhythm abnormalities, sleep disorders, and gut microbiota dysbiosis.

8. The use as described in any one of claims 1-4, characterized in that, The IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt thereof, or an extract or composition containing a therapeutic amount of paeoniflorin, is used for the treatment of tumors comorbid with type 2 diabetes, preferably for the treatment of tumors comorbid with type 2 diabetes and associated with depressive disorder.

9. A method for enhancing cancer immunotherapy and improving the quality of life of cancer patients, characterized in that, This includes administering an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or extract containing a therapeutic dose of paeoniflorin; or administering an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or extract containing a therapeutic dose of paeoniflorin.

10. A method for cancer immunomodulatory therapy and improving the quality of life of cancer patients, characterized in that it includes administering to the patient an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or a combination of an extract containing a therapeutic dose of paeoniflorin and an immune checkpoint inhibitor such as PD-1 / PD-L1; or it includes administering to the patient an effective dose of the IDO1 inhibitor paeoniflorin, or a pharmaceutically acceptable salt and / or a combination of an extract containing a therapeutic dose of paeoniflorin and an immune checkpoint inhibitor such as PD-1 / PD-L1.

Images