Application of naturally-sourced small molecule compound and pharmaceutical composition thereof in preparation of antimalarial drugs

Abstract

The invention discloses application of a naturally-sourced small molecule compound and a pharmaceutical composition thereof in preparation of antimalarial drugs, and belongs to the technical field of biological medicines. The small molecule compound is PHPP, the CAS number of the small molecule compound is 252205-23-5, and the structure of the small molecule compound is shown in the specification. According to the invention, the small molecule compound PHPP, which is a specific monomer component, is screened from natural products for the first time and is proved to have remarkable anti-malarial activity, and the cognitive blank of the anti-malarial application of the small molecule compound is filled up; the compound not only has an excellent in-vitro anti-malarial effect, but also has no obvious cytotoxicity under an effective concentration and is high in safety; more importantly, when the compound is combined with artemisinin, a remarkable synergistic effect can be generated, a brand new solution is provided for solving the problem of severe artemisinin drug resistance, and candidate lead compounds and combination schemes with wide prospects are provided for developing new-generation antimalarial drugs.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to the application of a naturally derived small molecule compound active ingredient and its pharmaceutical composition in the preparation of antimalarial drugs. Background Technology

[0002] Malaria is a parasitic disease caused by Plasmodium. The problem of drug resistance to antimalarial drugs is becoming increasingly prominent and has become the most serious challenge in the current malaria prevention and control work.

[0003] Currently, artemisinin-based combination therapy is the first-line antimalarial regimen recommended by the World Health Organization. However, the emergence and spread of artemisinin-resistant Plasmodium parasites in Southeast Asia and other regions, as well as widespread resistance to other classic drugs such as chloroquine, makes the development of novel, highly effective antimalarial drugs with unique mechanisms of action an urgent priority. Discovering antimalarial lead compounds with novel mechanisms of action from natural products is an important research direction for addressing the problem of Plasmodium resistance. Although some small molecule compounds from natural sources have been isolated and identified, their potential applications in the field of antimalarial therapy still require systematic research. Summary of the Invention

[0004] The present invention aims to screen small molecule compounds with antimalarial value from natural products, providing candidate lead compounds for the development of next-generation antimalarial drugs.

[0005] In a first aspect, the present invention provides the use of a naturally derived small molecule compound in the preparation of a drug for inhibiting the activity of Plasmodium falciparum, said small molecule compound being PHPP, with CAS number 252205-23-5 and molecular formula C2. 19 H 20 O5 has the following structure: .

[0006] Furthermore, the small molecule compound showed no significant toxicity to either HEK 293T cells or A549 cells.

[0007] Furthermore, the small molecule compound is used to prepare at least one of the following: a drug for inhibiting the activity of Plasmodium falciparum, a drug for inhibiting the activity of artemisinin-resistant Plasmodium, and a drug for inhibiting the activity of chloroquine-resistant Plasmodium.

[0008] Furthermore, the Plasmodium falciparum is the Plasmodium falciparum 3D7 strain, and the artemisinin-resistant Plasmodium is the artemisinin-resistant Plasmodium 3D7 strain. C580Y The chloroquine-resistant Plasmodium is the chloroquine-resistant Plasmodium Dd2 strain.

[0009] Furthermore, the small molecule compound exhibits antimalarial activity in vitro, and the small molecule compound shows an IC50 concentration against Plasmodium falciparum strain 3D7.50 The concentration of the small molecule compound was 8 μM to 9 μM, and its IC50 value against the chloroquine-resistant Plasmodium Dd2 strain was [missing value]. 50 The value is 6μM~7μM.

[0010] Furthermore, the small molecule compound is used to inhibit the growth and development of Plasmodium ring stage.

[0011] A second aspect of the present invention provides an antimalarial drug composition comprising: a first active ingredient, a second active ingredient, and a pharmaceutically acceptable carrier or excipient; wherein, The first active ingredient is the aforementioned small molecule compound; The second active ingredient is an artemisinin-like compound.

[0012] Furthermore, in drugs targeting the 3D7 strain of Plasmodium falciparum, the molar ratio of the first active ingredient to the second active ingredient is (2~10):0.005; in drugs targeting artemisinin-resistant Plasmodium falciparum 3D7... C580Y In the insect-derived drug, the molar ratio of the first active ingredient to the second active ingredient is (2~10):0.7.

[0013] Furthermore, the artemisinin-like compounds are selected from one or more of artemisinin, artesunate, artemether, and dihydroartemisinin.

[0014] A third aspect of the invention provides the use of the above-described antimalarial drug composition in the preparation of a medicament for the prevention and / or treatment of malaria.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: This invention is the first to screen and confirm that the specific monomer component of the small molecule compound PHPP has significant antimalarial activity from natural products, filling a gap in the understanding of the antimalarial use of this small molecule compound. This small molecule compound not only has excellent in vitro antimalarial effects, but also has no obvious cytotoxicity at effective concentrations and high safety. More importantly, the combination of this small molecule compound and artemisinin can produce a significant synergistic effect, providing a new solution to the serious problem of artemisinin resistance, and providing promising candidate lead compounds and combination schemes for the development of next-generation antimalarial drugs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1The graph shows the antimalarial activity of the naturally derived small molecule compound provided in Example 1 of this invention after 72 hours of in vitro treatment with Plasmodium falciparum 3D7 strain at two concentrations of 50 μM and 0.5 μM, and the cell viability of the naturally derived small molecule compound provided in Example 2 of this invention after treatment with RAW264.7 cells. Figure 2 This is a dose-response diagram showing the antimalarial activity of five screened small molecule compounds after gradient dilution in vitro against the Plasmodium falciparum 3D7 strain for 72 hours, as provided in Example 3 of the present invention. Figure 3 This describes the antimalarial effect of PHPP against the chloroquine-resistant parasite strain Dd2, as provided in Example 4 of the present invention. Figure 4 The results of the specific time of PHPP's inhibitory effect on the growth of Plasmodium falciparum in vitro culture stage provided in Example 5 of the present invention; Figure 5 The toxicity of PHPP to normal human cells and tumor cells provided in Embodiment 6 of the present invention; Figure 6 This describes the antimalarial effect of the combination of PHPP and artemisinin against the 3D7 strain of Plasmodium falciparum, as provided in Example 7 of this invention. Figure 7 The combination of PHPP and artemisinin provided in Example 7 of this invention is effective against artemisinin-resistant Plasmodium 3D7. C580Y The antimalarial activity of the insect strain; Figure 8 The qPCR experiment provided in Example 8 of this invention was used to verify the effect of the combined action of PHPP and artemisinin on the gene expression of Plasmodium. Detailed Implementation

[0018] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0019] In a first aspect, this invention provides the use of a naturally derived small molecule compound in the preparation of a drug for inhibiting the activity of Plasmodium falciparum, wherein the small molecule compound is PHPP, with CAS number 252205-23-5 and molecular formula C2. 19 H 20 O5 has the following structure: .

[0020] Understandably, although the compound PHPP is a known natural product, its application in antimalarial treatment, whether it has antimalarial activity, whether it can inhibit Plasmodium falciparum, inhibit drug-resistant Plasmodium, and whether it can synergize with artemisinin-based drugs, are all unknown.

[0021] This invention provides the first screening and confirmation from natural products that the specific monomer component PHPP, a small molecule compound, has significant antimalarial activity, filling a gap in our understanding of the antimalarial uses of this small molecule compound.

[0022] In some embodiments, PHPP showed no significant toxicity to either HEK293T or A549 cells.

[0023] Studies have found that PHPP not only has excellent antimalarial effects in vitro, but also shows no significant toxicity to HEK293T cells and A549 cells at effective concentrations, demonstrating high safety.

[0024] In some embodiments, PHPP can be used to prepare drugs that inhibit the activity of Plasmodium falciparum, drugs that inhibit the activity of artemisinin-resistant Plasmodium, and drugs that inhibit the activity of chloroquine-resistant Plasmodium. Specifically, the Plasmodium falciparum strain 3D7 is used for the Plasmodium falciparum strain in this embodiment of the invention, and the artemisinin-resistant Plasmodium strain 3D7 is used for the artemisinin-resistant Plasmodium. C580Y The strain used for chloroquine-resistant Plasmodium was the Dd2 strain.

[0025] In some embodiments, PHPP exhibits antimalarial activity in vitro. Experiments have confirmed that PHPP has an IC50 effect against Plasmodium falciparum strain 3D7. 50 The IC50 of PHPP against chloroquine-resistant Plasmodium Dd2 strain is 8 μM–9 μM. 50 The value is 6μM~7μM.

[0026] In some embodiments, PHPP is used to inhibit the growth and development of Plasmodium ring stage.

[0027] Specifically, this embodiment of the invention investigated the specific timing of PHPP's inhibitory effect on the growth of Plasmodium falciparum 3D7 in vitro culture. It found that PHPP had a significant impact on the development process starting from the ring stage of Plasmodium falciparum, resulting in developmental delay or even arrest. However, adding PHPP to the schizont stage did not have a significant effect.

[0028] A second aspect of this invention provides an antimalarial drug composition comprising: a first active ingredient, a second active ingredient, and a pharmaceutically acceptable carrier or excipient; wherein the first active ingredient is PHPP, and the second active ingredient is an artemisinin-based compound. Optionally, the artemisinin-based compound is selected from one, two, or more of artemisinin, artesunate, artemether, and dihydroartemisinin.

[0029] In some embodiments, in drugs targeting Plasmodium falciparum 3D7 strain, the molar ratio of the first active ingredient to the second active ingredient is (2~10):0.005; in drugs targeting artemisinin-resistant Plasmodium falciparum 3D7... C580Y In the insect-derived drug, the molar ratio of the first active ingredient to the second active ingredient is (2~10):0.7.

[0030] A third aspect of the present invention provides the use of the above-described antimalarial drug composition in the preparation of a medicament for the prevention and / or treatment of malaria.

[0031] Example 1: Screening of naturally derived small molecule compounds that can kill Plasmodium falciparum 3D7 strain in vitro using in vitro drug sensitivity tests. Example 1 screened 35 small molecule compounds from natural sources, including two natural plants: Dendrobium and Meconopsis.

[0032] In vitro drug susceptibility testing includes the following steps: (1) Synchronization of Plasmodium: Plasmodium was synchronized with 5% Sorbtiol to bring the parasite into the ring stage; (2) Determination of Plasmodium density: Take a portion of the blood from the synchronized parasites, prepare a blood smear for staining, and calculate the Plasmodium density; add an appropriate amount of red blood cells to adjust the density to 0.8%; (3) Preparation of insect blood suspension: Dilute insect blood with CM to prepare a 4% insect blood suspension; (4) Dilution of small molecule compounds: 35 extracts were diluted to 100 μM and 1 μM with CM, and after adding insect blood suspension, the final concentrations were 50 μM and 0.5 μM; (5) 96-well plate loading: Use a 96-well plate and add 50 µL of two different concentrations of diluent for each drug. Set up three wells for each concentration as a parallel control. (6) Positive control setup: The final concentration of chloroquine was set at 160 μM, and three parallel wells were set up as positive controls; (7) Addition of insect blood suspension: Add 50µL of insect blood suspension to each well; (8) Incubation: Place the 96-well plate in a sterile container containing a small amount of sterile water and incubate at 37°C for 72 hours; (9) Freezing and thawing: Place the 96-well plate in a -20°C freezer overnight, remove the 96-well plate from the freezer, and allow it to thaw naturally at room temperature; (10) Dye addition and incubation: Add 100µL of lysis buffer (0.2µL of SYBR Green I in 1mL of lysis buffer) to each well and incubate the 96-well plate in the dark for 1 hour; (11) Detection: Detection was performed using an ELISA reader (excitation wavelength 490nm, emission wavelength 530nm).

[0033] The results are as follows Figure 1 As shown, 35 naturally derived small molecule compounds were treated in vitro with Plasmodium falciparum strain 3D7 at two concentrations of 50 μM and 0.5 μM for 72 hours, and their antimalarial activity was tested. Among them, small molecule compounds 1, 2, 3, 4, 5, 7, 8, 30, and 31 showed better antimalarial effects.

[0034] Example 2: Cytotoxicity test of the naturally derived small molecule compounds screened in Example 1 Includes the following steps: (1) Cell suspension preparation: RAW264.7 cells were prepared into a cell suspension using culture medium and counted; (2) Cell seeding: Add 100 μL of cell suspension to each well of a 96-well plate, with the number of cells per well controlled at 5000, and incubate in a carbon dioxide incubator. (3) Cell culture and treatment: After overnight culture, when the cell adhesion rate reaches 80%~90%, set up 3 parallel control wells; add the corresponding small molecule compound to each well and continue incubation for 48 hours; (4) CCK-8 addition: After incubation, discard the liquid in the wells, add 100µL of fresh culture medium containing CCK-8 solution (made by mixing 10µL of CCK-8 solution with 90µL of culture medium) to each well, and put the 96-well plate back into the incubator for 2 hours; (5) Absorbance measurement: The absorbance of each well was measured at 450 nm using an ELISA reader; (6) Data analysis: GraphPad Prism software was used to process and analyze the experimental data.

[0035] The results are as follows Figure 1 As shown, small molecule compounds 2, 3, 5, and 7 exhibit significant cytotoxicity. Based on the in vitro drug sensitivity test results from Example 1, five small molecule compounds, 1, 4, 8, 30, and 31, were screened out.

[0036] Example 3: Inhibitory effect of five small molecule compounds screened in Example 2 on the growth of Plasmodium falciparum 3D7 strain during in vitro culture. (1) Synchronization of Plasmodium: Plasmodium was synchronized with 5% Sorbtiol to bring the parasite into the ring stage; (2) Determination of Plasmodium density: Take a portion of the blood from the synchronized parasites, prepare a blood smear for staining, and calculate the Plasmodium density; add an appropriate amount of red blood cells to adjust the density to 0.8%; (3) Preparation of insect blood suspension: Dilute insect blood with CM to prepare a 4% insect blood suspension; (4) Drug dilution: The five small molecule compounds were diluted to 200 μM with CM, and after being added to the insect blood suspension, the final concentration was 100 μM; (5) 96-well plate loading: Add 50 µL of small molecule compound to the first row using a pipette, and add 50 µL of medium to each of the remaining wells for a two-fold serial dilution; set up three wells for each concentration as a parallel control; (6) Positive control setup: The final concentration of chloroquine was set at 160 μM, and three parallel wells were set up as positive controls; (7) Addition of insect blood suspension: Add 50µL of insect blood suspension to each well; (8) Incubation: Place the 96-well plate in a sterile container containing a small amount of sterile water and incubate at 37°C for 72 hours; (9) Freezing and thawing: Place the 96-well plate in a -20°C freezer overnight, remove the 96-well plate from the freezer, and allow it to thaw naturally at room temperature; (10) Dye addition and incubation: Add 100µL of lysis buffer (0.2μL of SYBR Green I in 1mL of lysis buffer) to each well and incubate the 96-well plate in the dark for 1 hour; (11) Detection: Detection was performed using an ELISA reader (excitation wavelength 490nm, emission wavelength 530nm).

[0037] The results are as follows Figure 2 As shown in Table 1, after serial dilution of the five small molecule compounds, their antimalarial activity was detected in vitro on Plasmodium falciparum 3D7 strain for 72 hours. Among them, small molecule compound No. 8 (PHPP) showed the best antimalarial effect, and the corresponding dose-response curve showed its half-maximal inhibitory concentration (IC50). 50 The molecular weight is approximately 8.36 μM.

[0038] Table 1 IC50 values ​​for five small molecule compounds 50 Condition

[0039] Example 48: In vitro killing effect of small molecule compound (PHPP) on chloroquine-resistant strain Dd2 Includes the following steps: (1) Preparation of Plasmodium: Use 5% Sorbtiol to synchronize Plasmodium to make it in the ring stage; take some of the synchronized blood, prepare blood smears for staining, and calculate the density of Plasmodium; add an appropriate amount of red blood cells to adjust the density to 0.8%; dilute the blood with CM to make a 4% blood suspension. (2) In vitro antimalarial activity verification: Plasmodium was synchronized with 5% Sorbtiol to make the Plasmodium strain Dd2 in the circular stage; blood of some synchronized parasites was taken, blood smears were prepared and stained, and the density of Plasmodium was calculated. An appropriate amount of red blood cells was added to adjust the density to 0.8%; the parasite blood was diluted with CM to prepare a 4% parasite blood suspension; PHPP was diluted to 200 μM with CM and added to the parasite blood suspension, and the final concentration was 100 μM; chloroquine was used as a positive control group and the mixture was incubated in a 37℃ incubator for 72 hours; the antimalarial activity was detected by SYBR Green I staining method and detected by enzyme-linked immunosorbent assay (ELISA) with an excitation wavelength of 490 nm and an emission wavelength of 530 nm.

[0040] The results are as follows Figure 3 As shown, PHPP has an inhibitory effect on the growth of the chloroquine-resistant strain Dd2 of Plasmodium falciparum, IC50. 50 The value is 6.30 μM.

[0041] Example 58: Specific time of action of small molecule compound (PHPP) on the growth inhibition of Plasmodium falciparum 3D7 in vitro culture. (1) Synchronization treatment of Plasmodium: After two synchronizations with sorbitol, when the Plasmodium grows to the mature schizont stage, it is further synchronized by the 40%-70% Percoll-sorbitol gradient separation method; 3 hours later, it is synchronized again with sorbitol to ensure that the Plasmodium is in a highly consistent developmental stage; then, red blood cells are added to adjust the density of Plasmodium to 1% and prepare a Plasmodium suspension with a hematocrit of 2%; (2) PHPP treatment and observation: The malaria parasite suspension was added to the 24-well plate, and PHPP (final concentration of 25 μM) was added to the corresponding well every 8 hours. Blood smears were prepared and observed at the same time, continuing for 88 hours.

[0042] The results are as follows Figure 4As shown, after adding 25 µM PHPP, the development of highly synchronized parasites (starting from 0 hpi) was continuously assessed every 8 hours; once added, PHPP was maintained until the last time point of 80 hpi. PHPP was found to have a significant effect on the early growth and development of Plasmodium. The results indicate that PHPP significantly affects the developmental process starting from the ring stage of Plasmodium, showing developmental delays or even arrest; however, addition at the schizont stage had no significant effect, and merozoites were able to be released normally and invade new RBCs.

[0043] Cytotoxicity assay of small molecule compound (PHPP) in Example 68 Includes the following steps: (1) Preparation of cell suspension: Human normal cells (HEK 293T) and tumor cells (A549) were prepared into cell suspensions using culture medium and counted; the cell suspensions were added to 96-well plates, 100µL per well, with the cell count controlled at 5000 cells per well, and cultured in a carbon dioxide incubator; after overnight culture, when the cell adhesion rate reached 80%-90%, 6 parallel control wells were set up; the corresponding concentration of PHPP was added to each well and incubated for another 48 hours; (2) Results detection: After incubation, discard the liquid in the wells, add 100µL of fresh culture medium containing CCK-8 solution to each well, and put the 96-well plate back into the incubator for 2 hours; use an ELISA reader to measure the absorbance value of each well at 450nm; use GraphPad Prism 8 software to process and analyze the experimental data.

[0044] The results are as follows Figure 5 As shown, PHPP did not exhibit significant cytotoxicity against HEK 293T cells and A549 cells.

[0045] Example 78: Combined action of small molecule compound (PHPP) and artemisinin The synergistic antimalarial effect of PHPP and dihydroartemisinin (DHA) was verified, using Plasmodium falciparum 3D7 and artemisinin-resistant Plasmodium 3D7 as the malaria parasites. C580Y It includes the following steps: (1) Preparation of Plasmodium: Synchronize Plasmodium in the annular stage with 5% sorbitol. Synchronize Plasmodium in the late stage with 70%-40% percoll-sorbitol. Prepare 90% percoll-sorbitol in advance and dilute it to 70% and 40%. Wash with ICM, discard the supernatant, and resuspend the parasite blood in a 1:1 ICM / CM solution. Spread 3 mL of 70% percoll-sorbitol at the bottom of a 15 mL centrifuge tube and 40% percoll-sorbitol on top of 70% PS solution. Add the 40% percoll-sorbitol solution before centrifugation to prevent the two solutions from merging. Slowly spread the parasite blood on top of 40% PS solution. Collect the middle layer and bottom cells into two new test tubes and wash with ICM. After PS, remove the schizonts, add fresh red blood cells, and incubate for 3 hours. Synchronize again with 5% D-sorbitol and plate the cells intermittently. (2) Combined use of PHPP and DHA: When the drugs were plated, the test drugs (PHPP and DHA) were prepared at twice the working concentration in CM; 250µL was added to each well; after the plate was plated, 250µL of parasite blood suspension with a volume of 4% and a density of 1% was added; 6h after the plate was plated, the suspension was transferred to centrifuge tubes with a Pasteur pipette and washed twice with ICM; after washing, 1mL of CM and CM containing PHPP were added respectively to prepare a 2% volume and evenly distributed to 4 sub-wells, and cultured for 66h; the cells were counted by flow cytometry and smear.

[0046] The results are as follows Figure 6 and Figure 7 As shown: Figure 6 The concentrations of PHPP were 0 µM, 2.09 µM, 4.18 µM, and 8.36 µM, corresponding to DHA concentrations of 0 nM and 5 nM, respectively. Figure 6 A represents the combined results of PHPP and DHA for 6 hours. Figure 6 B represents the results of the combined use of PHPP for 72 hours and DHA for 6 hours, indicating that the survival rate of Plasmodium falciparum 3D7 strain was significantly reduced under the action of PHPP after the combined use of PHPP and DHA. Figure 7 The concentrations of PHPP were 0 µM, 2.09 µM, 4.18 µM, and 8.36 µM, corresponding to DHA concentrations of 0 nM and 700 nM, respectively. Figure 7 A represents the combined results of PHPP and DHA for 6 hours. Figure 7 B represents the results of combining PHPP for 72 hours with DHA for 6 hours, showing artemisinin-resistant Plasmodium 3D7. C580Y The survival rate of the parasite strains was also significantly reduced. The results indicate that the antimalarial effect was significantly enhanced when PHPP was used in combination with DHA.

[0047] Example 8: qPCR experiment to verify the effect of the combined action of small molecule compound 8 (PHPP) and artemisinin on Plasmodium gene expression. Includes the following steps: (1) Treatment of Plasmodium: Plasmodium was synchronized twice with 5% sorbitol at an interval of 40 h. After synchronization, PHPP was added at a concentration of 8.36 μM. The parasites were collected, and 3 volumes of erythrocyte lysis buffer were added. The mixture was mixed and allowed to stand at room temperature. The supernatant was completely aspirated, and the leukocyte precipitate was collected. 1 mL of TRIZOL was added, and the mixture was allowed to stand at room temperature for 5 min to fully lyse. The mixture was then incubated at 12000 rpm at 4℃ for 10 min, and the supernatant was collected. 200 µL of chloroform was added to each 1 mL of the supernatant, and the mixture was vigorously shaken and allowed to stand for 3 min-5 min to allow for natural phase separation. The uppermost colorless aqueous phase was transferred to a new tube, and an equal volume of cold isopropanol was added. The mixture was allowed to stand at room temperature for 10 min-20 min. The mixture was then incubated at 12000 rpm at 4℃ for 10 min, and the supernatant was discarded. The RNA settled at the bottom of the tube. 1 mL of TRIZOL was added to the RNA precipitate. Add 75% ethanol to the centrifuge tube and gently shake to suspend the precipitate; centrifuge at 5000-8000 rpm for 1-2 minutes at 4°C, discard the supernatant; let stand at room temperature for 1-2 minutes to air dry the precipitate; (2) Gene expression detection: Add 50µL of RNase-free water and gently tap the tube wall to dissolve RNA; detect RNA concentration and purity; reverse transcribe RNA into cDNA; select appropriate primers, add qPCR related solutions, prepare the system, and perform detection.

[0048] The results are as follows Figure 8 As shown, the addition of PHPP upregulated PI3K gene expression and activated the PI3K / AKT1 pathway. Studies have found that a small number of circular-stage Plasmodium parasites within erythrocytes enter a "dormant state," temporarily ceasing metabolic activity and evading artemisinin attack. The results indicate that PHPP prevents Plasmodium parasites from entering a dormant state by upregulating the PI3K gene (a signal that promotes growth and inhibits dormancy), thus synergizing with artemisinin. Based on the Bliss model, in Plasmodium falciparum 3D7, with PHPP treatment for 72 hours at a concentration of 8.36 μM and DHA concentration of 5 nM, the synergistic index was 41.2%. C580Y In the study, when PHPP was used for 72 hours at a concentration of 8.36 μM and DHA concentration was 700 nM, the synergistic index was 6.46%. This indicates that the combined use of PHPP and artemisinin has a synergistic effect on the inhibitory effect of Plasmodium falciparum strains.

[0049] It will be readily understood by those skilled in the art that the above-described advantageous methods can be freely combined and superimposed without conflict. The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. The use of a naturally derived small molecule compound in the preparation of a drug for inhibiting the activity of Plasmodium, characterized in that, The small molecule compound is PHPP, with a CAS number of 252205-23-5, a molecular formula of C 19 H 20 O5, as shown below: 。 2. The application according to claim 1, characterized in that, The small molecule compound showed no significant toxicity to either HEK 293T or A549 cells.

3. The application according to claim 1, characterized in that, The small molecule compound is used to prepare at least one of the following: drugs that inhibit the activity of Plasmodium falciparum, drugs that inhibit the activity of artemisinin-resistant Plasmodium, and drugs that inhibit the activity of chloroquine-resistant Plasmodium.

4. The application according to claim 3, characterized in that, the P. falciparum is P. falciparum 3D7 strain, and the artemisinin-resistant Plasmodium is artemisinin-resistant Plasmodium 3D7 strain C580Y the P. falciparum is P. falciparum Dd2 strain.

5. The application according to claim 4, characterized in that, The small molecule compound exhibits antimalarial activity in vitro, and its IC50 value against Plasmodium falciparum 3D7 strain is [not specified]. 50 The concentration of the small molecule compound was 8 μM to 9 μM, and its IC50 value against the chloroquine-resistant Plasmodium Dd2 strain was [missing value]. 50 The value is 6μM~7μM.

6. The application according to any one of claims 1-5, characterized in that, The small molecule compound is used to inhibit the growth and development of Plasmodium ring stage.

7. An antimalarial drug composition, characterized in that, include: The first active ingredient, the second active ingredient, and a pharmaceutically acceptable carrier or excipient; wherein... The first active ingredient is a small molecule compound as described in any one of claims 1-6; The second active ingredient is an artemisinin-like compound.

8. The antimalarial drug composition according to claim 7, characterized in that, In drugs targeting Plasmodium falciparum 3D7 strain, the molar ratio of the first active ingredient to the second active ingredient is (2~10):0.005; in drugs targeting artemisinin-resistant Plasmodium falciparum 3D7... C580Y In the insect-derived drug, the molar ratio of the first active ingredient to the second active ingredient is (2~10):0.

7.

9. The antimalarial drug composition according to claim 7 or 8, characterized in that, The artemisinin compounds are selected from one or more of artemisinin, artesunate, artemether, and dihydroartemisinin.

10. Use of the antimalarial drug composition according to any one of claims 7-9 in the preparation of a medicament for the prevention and / or treatment of malaria.

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