Application of baicalin as SGLT2 inhibitor in treatment of diabetic heart failure

Abstract

The invention belongs to the technical field of biological medicine, and particularly relates to application of baicalin serving as an SGLT2 inhibitor to treatment of diabetic heart failure. The invention provides the baicalin as a natural SGLT2 inhibitor stimulant for the first time, and the baicalin is used for improving ejection fraction retention heart failure and diabetes related cardiovascular diseases. Molecular docking proves that the binding energy (-9.1 kcal / mol) of the baicalin and the SGLT2 is equivalent to that of phlorizin, and the structural similarity reaches 51.54%. Animal experiments show that 50 mg / kg / day of baicalin can significantly reduce the weight of a classical diabetes model mouse induced by high fat-STZ (Sequence Tagliflozin) by 8.73%, p < t >, 0.01, postprandial blood sugar by 22.7% in 60 min and cardiac hypertrophy indexes by heart weight / weight ratio reduction, p < t >, 0.001, and improve the left ventricular ejection fraction by 21.3%, and has no statistical difference from empagliflozin (EMPA, SGLT-2 inhibitor on the market in China in 2017) in effect. The invention provides a novel natural medicine scheme for HFpEF treatment.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and specifically relates to the use of scutellaria baicalensis as an SGLT2 inhibitor in the treatment of diabetic heart failure. Background Art

[0002] With the onset of an aging population, health issues among the elderly, particularly major chronic cardiovascular diseases, have become a major public health concern. Heart failure with preserved ejection fraction (HFpEF) has been a research hotspot and trend in recent years. HFpEF patients are often elderly and have impaired cardiac function. Currently, there are no effective targeted therapeutics available. The causes, pathogenic mechanisms, diagnosis, and treatment of the disease are less clear than those for HFrEF. Internationally renowned clinical medical journals, including the New England Journal of Medicine (NEJM) and The Lancet, have reported that multiple clinical study data support the claim that competitive inhibitors of the proximal sodium-glucose cotransporter 2 (SGLT-2) in the renal tubule inhibit renal glucose reabsorption, thereby achieving weight loss and lowering blood glucose levels for cardiovascular protection. Therefore, SGLT-2 inhibitors may be a promising option for improving heart failure symptoms and cardiac function in patients with HFpEF. Phlorizin is a natural compound found in the root bark of apple trees. It belongs to the dihydrochalcone class. Phlorizin is the earliest discovered natural SGLT-2 inhibitor.

[0003] Baicalin is a flavonoid isolated and extracted from the dicotyledonous plant Scutellaria baicalensis (Lamiaceae). It is a pale yellow powder at room temperature with a bitter taste. It is poorly soluble in methanol, ethanol, and acetone, slightly soluble in chloroform and nitrobenzene, and nearly insoluble in water, but soluble in hot acetic acid. Baicalin has multiple biological and pharmacological effects, including antibacterial, diuretic, cholesterol-lowering, antithrombotic, asthma-relieving, heat-purging and detoxifying, hemostatic, tocolytic, anti-allergic, and cardiovascular protective properties. It also exhibits anti-inflammatory and antioxidant properties.

[0004] The prior art CN110327360A discloses the application of baicalin in the preparation of drugs for treating silicosis. Baicalin can effectively inhibit the rate of silicotic fibrosis and actively seek new targets for the treatment of pulmonary fibrosis. Baicalin has an antagonistic effect on the formation of silicotic pulmonary fibrosis and can be effectively used in the application of drugs for the treatment of silicosis.

[0005] Prior art CN101638423A discloses phlorizin derivatives having the general structural formula (1), which have the effect of inhibiting SGLT2. This type of compound is easy to prepare and can be used to treat metabolic diseases such as diabetes and its complications.

[0006] Considering that huanglingsuan and phlorizin share many similar properties, such as diuretic, anti-inflammatory, cholesterol-lowering, and cardiovascular protective effects, we propose that huanglingsuan may become a natural novel SGLT2 inhibitor mimetic, which, by inhibiting SGLT-2, could improve heart failure symptoms in HFpEF patients, achieving healthy aging and cardiac rehabilitation. Summary of the Invention

[0007] The present invention first provides the use of huanglingsuan as an SGLT2 inhibitor in the preparation of a drug for treating heart failure with preserved ejection fraction (HFpEF). The chemical formula of huanglingsuan is C21H18O11.

[0008] In certain embodiments, the drug comprises huanglingside and a pharmaceutically acceptable carrier, and the dosage form is an oral preparation or an injection.

[0009] The present invention also provides a method for improving diabetic heart failure, comprising administering a therapeutically effective amount of scutellaria baicalensis to a patient, with a dosage ranging from 10 to 100 mg / kg / day.

[0010] In certain embodiments, the heart failure is manifested by an increased heart weight / body weight ratio (HW / BW) or a decreased left ventricular ejection fraction (LVEF).

[0011] In certain embodiments, the huanglingin reduces blood glucose and cardiac afterload by inhibiting SGLT2.

[0012] The present invention also provides a pharmaceutical composition for treating HFpEF, comprising a combination of huanglingside and empagliflozin.

[0013] In certain embodiments, the mass ratio of huanglingside to empagliflozin is 1:0.1–10.

[0014] The present invention also provides the use of scutellaria baicalensis in preparing a medicine for alleviating myocardial cell hypertrophy.

[0015] The present invention also provides the use of scutellaria baicalensis in the preparation of a medicament for reducing the heart weight / body weight ratio (HW / BW).

[0016] The present invention also provides the above-mentioned application or method, wherein the patient is a diabetic patient with HFpEF.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: By mimicking the mechanism of SGLT2 inhibitors, Huanglingsuan achieves the triple effects of weight loss, blood sugar reduction, and cardiovascular protection, providing a safe, natural alternative treatment for HFpEF and diabetic heart failure, particularly for elderly patients. These effects are comparable to those of the active control drug, empagliflozin. Huanglingsuan is derived from a natural plant extract, offering the advantages of low toxicity and high biocompatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A comparison diagram of the three-dimensional structures of phlorizin and scutellarin; red: phlorizin; beige: scutellarin.

[0019] Figure 2 This figure shows that huanglingsuan has a weight loss effect on high-fat-fed mice similar to that of the SGLT2 inhibitor empagliflozin.

[0020] Figure 3 The results of the OGTT experiment showed that huanglingside has a similar hypoglycemic effect profile to the SGLT2 inhibitor empagliflozin.

[0021] Figure 4 Figure 3 (A) Heart weight / body weight ratio (HW / BW) of mice; (B) average cardiomyocyte surface area (CSA) of mouse hearts.

[0022] Figure 5 These are the various indicators of cardiac function testing in mice: LVEF, LVFS, LVIDs, LVIDd, LVESV, and LVEDV.

[0023] Figure 6 Pathological staining of mouse heart cross-sectional tissue sections: HE staining in the upper row, WGA staining (cardiomyocyte area) in the lower row. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1: Similarity Analysis of Phlorizin and Huanglingin (1) Chemical formula Phlorizin: C21H24O10: It is formed by the combination of phlorizin and β-D-glucoside. Ring A has two hydroxyl groups (2', 4'), as shown in formula a.

[0026] Huanglingside: C21H18O11: It is formed by the combination of baicalein and glucuronide. Ring A has no hydroxyl group, and ring B has three hydroxyl groups (5, 6, 7), as shown in formula b.

[0027] (2) In the two-dimensional structure, phlorizin is an O-glycosidic bond, scutellarin is a C-glycosidic bond, and the carboxylic acid group increases water solubility.

[0028] (3) The three-dimensional structures of the two Figure 1 As shown, red: phlorizin; beige: scutellarin (4) Physical and chemical properties are shown in Table 1; Table 1. Physical and chemical properties (5) Molecular docking SGLT2: phlorizin: -9.1 kcal / mol, scutellarin: -9.1 kcal / mol.

[0029] SGLT1: phlorizin: -8.4 kcal / mol, scutellarin: -8.3 kcal / mol.

[0030] (6) Similarity quantification Based on topological fingerprint and Tanimoto similarity method: 51.54% (7) Conclusion The only difference between huanglingside and phlorizin is the sugar group, and the two have great similarities in two-dimensional and three-dimensional structures.

[0031] Huanglingin may serve as a new natural small molecule SGLT inhibitor, and its value has not yet been reported.

[0032] Example 2 This study investigated baicalin as a novel natural small molecule mimetic of the SGLT2 inhibitor. Using the clinically available empagliflozin (EMPA, an SGLT-2 inhibitor launched in China in 2017) as a positive control, the study examined the effects of baicalin on weight loss, blood sugar reduction, and cardiovascular protection in a mouse model of diabetes. Eight- to 10-week-old male C57BL / 6J mice were randomly divided into a high-fat diet (60% Kcal, HFD) plus streptozotocin (STZ) group, an HFD plus STZ plus baicalin (50 mg / kg / day) group, and an HFD plus STZ plus empagliflozin (10 mg / kg / day) group. After two weeks of high-fat diet, the mice in each group were fasted and given an intravenous injection of STZ (100 mg / kg). High-fat diet was then continued for 12 weeks (n=5). The weight changes of mice were recorded once every two weeks on average; the blood glucose concentration of mice was measured 2 hours after meal (OGTT); the heart weight / body weight ratio (HW / BW) of mice was calculated at the experimental endpoint; the changes in various indicators of left ventricular cardiac function of mice were examined by cardiac ultrasound; and the differences in myocardial cell hypertrophy were observed by pathological staining.

[0033] The experimental endpoint results showed that administration of 50 mg / kg / day of Baicalin could significantly reduce the average body weight of mice in the high-fat STZ group ( Figure 2 At the end of 12 weeks, the body weight (BW) of mice in the Baicalin group was 8.73% lower than that of mice in the high-fat-fed group (HFD+STZ+Baicalin vs. HFD+STZ (BW: 36.6±0.69 vs. 40.1±1.60, p<0.01). There was no statistically significant difference in weight loss between the Baicalin group and the Empagliflozin EMPA group (HFD+STZ+Baicalin vs. HFD+STZ+EMPA (BW: 36.6±0.69 vs. 35.67±1.27, p>0.05). These results suggest that Baicalin has a similar weight-reducing effect on high-fat-fed mice as the SGLT2 inhibitor Empagliflozin.

[0034] Example 3: Effect of Huanglingsucoside on Blood Glucose HFD+STZ is a classic model of type 2 diabetes. Therefore, we tested the fasting blood glucose and 2-hour postprandial blood glucose concentrations of each group of mice ( Figure 3 Results showed that both fasting and two-hour postprandial blood glucose levels in the scutellariae-treated group were significantly lower than those in the HFD+STZ group. Specifically, 60 and 90 minutes after the meal, scutellariae-treated mice experienced a 22.7% and 23.1% decrease in instantaneous blood glucose levels, respectively, compared to the HFD+STZ group, demonstrating an effect similar to that observed in EMPA.

[0035] Example 4: Effects of Huanglingsuan on the Heart After the mice were anesthetized and killed, their hearts were weighed and the heart weight / body weight ratio (HW / BW) was measured. It was found that the HW / BW value of the mice in the baicalin-treated group was significantly lower than that in the HFD+STZ group (p<0.001). At the same time, pathological examination revealed that the myocardial hypertrophy caused by diabetes was significantly reduced (cardiac cell surface area CSA: HFD+STZ+Baicalin vs. HFD+STZ, 381.76±14.17 vs. 447.16±20.51, p<0.001), suggesting that baicalin can significantly alleviate cardiac remodeling in diabetic mice ( Figure 4 ).

[0036] At the end of the experiment, 12 weeks after HFD feeding, we evaluated left ventricular function after scutellaria baicalensis treatment using cardiac ultrasound. The results suggest that scutellaria baicalensis effectively improves cardiac function in high-fat-fed type 2 diabetic mice (HFD+STZ), as evidenced by a 21.3% increase in left ventricular ejection fraction (LVEF) and a 25.5% increase in left ventricular fractional shortening (LVFS). There were no statistically significant differences between the scutellaria baicalensis-treated and EMPA-treated groups. Scutellaria baicalensis significantly attenuated HFD+STZ-induced systolic and diastolic dilatation (systolic: 2.73±0.09 vs. 3.38±0.08, p<0.0001; diastolic: 3.85±0.19 vs. 4.39±0.06, p<0.001). Furthermore, scutellaria baicalensis treatment significantly improved left ventricular end-systolic volume (LVESV) and end-diastolic volume (LVEDV) after HFD+STZ induction. Figure 5 ).

[0037] At the end of the experiment, mice were anesthetized and killed. The hearts were collected and paraffin-embedded after 4% paraformaldehyde. Serial sections (5 μm) were made along the short axis of the heart along the papillary muscle. HE and WGA staining showed that myocardial hypertrophy in the scutellarin-treated group was significantly improved compared with that in the HFD+STZ group, as evidenced by a decrease in myocardial cell surface area. There was no significant difference between the scutellarin-treated group and the EMPA-treated positive control group ( Figure 6 ).

[0038] In summary, the patent of this invention verifies a new type of flavonoid natural small molecule - huanglingside, which has similar effects to SGLT2 inhibitors in weight loss, blood sugar control and treatment of diabetic myocardial hypertrophy, and is a very potential Chinese herbal medicine therapeutic agent.

[0039] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. Use of huanglingsuan as an SGLT2 inhibitor in the preparation of a drug for treating heart failure with preserved ejection fraction (HFpEF), characterized in that: The chemical formula of huanglingsuan is C 21 H 18 O 11 .

2. The use according to claim 1, characterized in that The medicine comprises scutellaria baicalensis and a pharmaceutically acceptable carrier, and the dosage form is an oral preparation or an injection.

3. A method for improving diabetic heart failure, characterized in that: The method comprises administering to the patient a therapeutically effective amount of scutellaria baicalensis in a dosage range of 10-100 mg / kg / day.

4. The method according to claim 3, wherein The heart failure is manifested by an increased heart weight / body weight ratio (HW / BW) or a decreased left ventricular ejection fraction (LVEF).

5. The method according to claim 3, wherein Huanglingin reduces blood glucose and cardiac afterload by inhibiting SGLT2.

6. A pharmaceutical composition for treating HFpEF, characterized in that: The pharmaceutical composition comprises a combination of huanglingside and empagliflozin.

7. The composition according to claim 6, wherein The mass ratio of huanglingside to empagliflozin is 1:0.1–10.

8. Application of huanglingsuan in the preparation of drugs for alleviating myocardial hypertrophy.

9. Application of huanglingsuan in the preparation of drugs for reducing heart weight / body weight ratio (HW / BW).

10. The use or method according to any one of claims 1 to 9, characterized in that: The patients are diabetic patients with HFpEF.

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