Hypoglycemic Activity and the Potential Mechanism of the Flavonoid Rich Extract from Sophora tonkinensis Gagnep. in KK-Ay Mice

Biological Activities and Secondary Metabolites from Sophora tonkinensis and Its Endophytic Fungi

The roots of Sophora tonkinensis Gagnep., a traditional Chinese medicine, is known as Shan Dou Gen in the Miao ethnopharmacy. A large number of previous studies have suggested the usage of S. tonkinensis in the folk treatment of lung, stomach, and throat diseases, and the roots of S. tonkinensis have been produced as Chinese patent medicines to treat related diseases. Existing phytochemical works reported more than 300 compounds from different parts and the endophytic fungi of S. tonkinensis. Some of the isolated extracts and monomer compounds from S. tonkinensis have been proved to exhibit diverse biological activities, including anti-tumor, anti-inflammatory, antibacterial, antiviral, and so on. The research progress on the phytochemistry and pharmacological activities of S. tonkinensis have been systematically summarized, which may be useful for its further research.

Disclosing targets and pharmacological mechanisms of total bioflavonoids extracted from Selaginella doederleinii against non-small cell lung cancer by combination of network pharmacology and proteomics

ETHNOPHARMACOLOGICAL RELEVANCE

Previously, the total bioflavonoids extract from Selaginella doederleinii (SDTBE) presented favorable in vitro and in vivo activities against non-small cell lung cancer (NSCLC), hinting at its medicinal potential. However, up to nowadays, targets and integrative action mechanisms of SDTBE are still not very clear, which presents an obstacle to the development of herbal medicine.

AIM OF THE STUDY

The present study aimed to disclose the potential targets and integrative action mechanism of SDTBE against NSCLC.

MATERIALS AND METHODS

A system pharmacology-based strategy including target fishing, network pharmacology analysis and molecular docking were applied to predict the potential targets and pathways for the seven main active ingredients in SDTBE. A proteomics study was subsequently performed for validating the affected pathways and possible targets. Western blot assay, mouse xenograft tumor model and immunofluorescence assays were used to further confirm the key targets and integrative action mechanisms of SDTBE against NSCLC.

RESULTS

By system pharmacology, it was inferred that SDTBE could mainly act on mitogen-activated protein kinase (MAPK) and PI3K-AKT signaling pathways by targeting epidermal growth factor receptor (EGFR), protein kinase B (AKT) and mitogen-activated or extracellular signal-regulated protein kinase (MEK), which was validated by proteomics results, and further confirmed in vitro and in vivo by Western blot and immunofluorescence assays.

CONCLUSION

SDTBE targeting multi-targets including EGFR, AKT and MEK could exert its anti-NSCLC effect mainly via MAPK and PI3K-AKT signaling pathways.

Davidones F and G, Two Novel Flavonoids from Sophora davidii (Franch.) Skeels

An unprecedented novel flavanone davidone F (1) with a seven-membered ring side chain, and a novel flavanonol davidone G (2), along with 11 known flavonoids, were isolated from the ethyl acetate fraction of Sophora davidii (Franch.) Skeels. Their planar structures were established by UV, IR, HRESIMS, 1D and 2D NMR data. The relative configurations of 1 and 2 were determined by calculation of NMR chemical shift values, the absolute configuration of 1 and 2 were assigned by comparing their experimental and calculated electronic circular dichroism (ECD) spectra. Moreover, compounds 1–13 were screened for the translocation activity of glucose transporter 4 (GLUT-4), and the fluorescence intensity was increased to the range of 1.56 and 2.79 folds. Compounds 1 and 2 showed moderate GLUT-4 translocation activity with 1.64 and 1.79 folds enhancement, respectively, at a concentration of 20 μg/mL.

The hypoglycemic effect of freeze-dried fermented mulberry mixed with soybean on type 2 diabetes mellitus

Mulberry has significant hypoglycemic effect and can be used as an auxiliary food for people with type 2 diabetes. However, it is rich in carbohydrate and cannot be consumed directly by diabetic patients. In the study, we fermented the mulberry to reduce the content of glucose and fructose, and added the soybean to reduce the loss of probiotics during fermentation and then determined its hypoglycemic effect. We induced type 2 diabetes mellitus (T2DM) mice by streptozotocin and measured its blood glucose, serum biochemistry, hepatic and pancreatic histopathology, and the diversity of the gut microbiota. After 5 weeks of oral DFMS administration, the glucose tolerance was improved significantly in T2DM mice. Furthermore, there were also significant increases in superoxide dismutase activity and glutathione concentration, and marked reductions in the concentrations of malondialdehyde and free fatty acids. Moreover, DFMS also prevented histopathological changes and the increases in the activities of alanine transaminase and aspartate transaminase. DFMS treatment also markedly increased the richness of the gut microbial community. The abundance of Bacteroidetes was increased, and those of Proteobacteria, Escherichia-Shigella, and Lactobacillus were reduced. In summary, DFMS has a clear hypoglycemic effect in mice with T2DM.

Cassia Abbreviata Enhances Glucose Uptake and Glucose Transporter 4 Translocation in C2C12 Mouse Skeletal Muscle Cells

Background.

This study aim at assessing C. abbreviata aqueous extracts for its potential to exhibit anti-diabetic activity in skeletal muscle cells. In addition to the toxicological and glucose absorption studies, the action of C. abbreviata extracts on some major genes involved in the insulin signaling pathway was established.

Methods.

The in vitro cytotoxic effects C. abbreviata was evaluated on muscle cells using the MTT assay and the in vitro glucose uptake assay conducted using a modified glucose oxidase method described by Van de Venter et al. (2008). The amount of GLUT-4 on cell surfaces was estimated quantitatively using the flow cytometry technique. Real time quantitative PCR (RT-qPCR) was used to determine the expression of GLUT-4, IRS-1, PI3 K, Akt1, Akt2, PPAR-γ.

Results.

Cytotoxicity tests revealed that all extracts tested at various concentrations were non-toxic (LC₅₀ > 5000). Aqueous extracts of leaves, bark and seeds resulted in a dose-dependent increase in glucose absorption by cells, after 1 h, 3 h and 6 h incubation period. Extracts of all three plant parts had the best effect after 3 h incubation, with the leaf extract showing the best activity across time (Glucose uptake of 29%, 56% and 42% higher than untreated control cells after treatment with 1 mg/ml extract at 1 h, 3 h and 6 h, respectively). All extracts, with the exception 500 µg/ml seed extract, induced a two-fold increase in GLUT-4 translocation while marginally inducing GLUT-10 translocation in the muscle cells. The indirect immunofluorescence confirmed that GLUT-4 translocation indeed occurred. There was an increased expression of GLUT-4, IRS1 and PI3 K in cells treated with insulin and bark extract as determined by the RT-qPCR.

Conclusion.

The study reveals that glucose uptake involves GLUT-4 translocation through a mechanism that is likely to involve the upstream effectors of the PI3-K/Akt pathway.

Antidiabetic effect of a flavonoid-rich extract from Sophora alopecuroides L. in HFD- and STZ- induced diabetic mice through PKC/GLUT4 pathway and regulating PPARα and PPARγ expression

HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE

Sophora alopecuroides L. is a traditional ethnopharmacological plant, which is widely used in traditional Chinese medicine and Mongolian and Uighur medicine to ameliorate "thirst disease".

AIM OF THE STUDY

This study aimed to investigate the antidiabetic activities and mechanisms of a flavonoid-rich extract from Sophora alopecuroides L. (SA-FRE) both in vivo and vitro.

MATERIALS AND METHODS

The main six chemical constituents of SA-FRE were elucidated based on an off-line semi-preparative liquid chromatography nuclear magnetic resonance (LC-NMR) protocol. Myc-GLUT4-mOrange-L6 cell models and mouse model with diabetes induced by high-fat diet combined with STZ injection were respectively adopted to investigate the antidiabetic effects of SA-FRE both in vitro and vivo.

RESULTS

In vivo, 4-week treatment of SA-FRE ameliorated hyperglycemia, dyslipidemia, and insulin resistance in diabetic mice. Mechanically, SA-FRE regulated PPARα and PPARγ expression in white adipose tissue (WAT) and liver, thereby ameliorating dyslipidemia. Moreover, SA-FRE increased the phosphorylation of PKC and further stimulated the GLUT4 expression in WAT and skeletal muscle, thus increasing the glucose utilization in vivo. In vitro, 50 μg/mL SA-FRE increased GLUT4 translocation to about 1.91-fold and glucose uptake to 1.82-fold in L6-myotubes. SA-FRE treatment increased the GLUT4 expression at both gene and protein levels. Furthermore, only Gö6983, a PKC inhibitor, reversed the SA-FRE-induced GLUT4 translocation and expression at the gene and protein levels.

CONCLUSIONS

Generally, SA-FRE ameliorated hyperglycemia, dyslipidemia, and insulin resistance partly through activating PKC/GLUT4 pathway and regulating PPARα and PPARγ expression.

A Review of Pharmacological and Toxicological Effects of Sophora tonkinensis with Bioinformatics Prediction

Sophora tonkinensis Gagnep. (ST) (Fabaceae) is distributed chiefly in south-central and southeast China and Vietnam. In traditional Chinese medicine theory, the root and rhizome of ST are toxic and mainly used in the treatment of pharyngeal and laryngeal diseases. Modern studies provide new insights into the pharmacological and toxicological aspects of ST. The pharmacological and toxicological properties of ST were reviewed in this paper based on the literature from Google Scholar and CNKI, and the bioinformatics platforms were applied to explore the pharmacological and toxicological potentials of ST. The results of the literature analysis showed that ST has hepatoprotective, immunomodulatory, and anticancer effects and produces obvious toxicity to the liver and nervous and cardiovascular system. The results of bioinformatics showed that the compounds from ST may be applied to the treatment of cancer and digestive and nervous system diseases and show the possibility to cause hematotoxicity, neurotoxicity, and immunotoxicity. The present review demonstrates that attention should be paid to the potential toxicity of ST in the treatment of diseases and provides the reference for the subsequent pharmacological toxicological studies on the mechanism and chemical basis of ST.

Antidiabetic effects of a lipophilic extract obtained from flowers of Wisteria sinensis by activating Akt/GLUT4 and Akt/GSK3β

Background

Type 2 diabetes mellitus is primarily caused by insulin resistance (IR) in insulin-sensitive tissues, including liver, white adipose tissues (WAT), and skeletal muscles. Discovering nutritious foods with antidiabetic effects is of great significance. Numerous published reports indicated that protein kinase B (Akt) and glucose transporter 4 (GLUT4) play crucial roles in ameliorating IR and diabetic symptoms.

Objective

In the present study, antidiabetic effects and the potential mechanism of action of WS-PE (a lipophilic extract from edible flowers of Wisteria sinensis) were explored with L6 cells in vitro and in high-fat diet (HFD) + Streptozocin (STZ)-induced diabetic mice in vivo.

Design

In vivo, HFD + STZ-induced diabetic mice were used as diabetic models to investigate the potential antidiabetic and antidyslipidemic activities. In vitro, a novel GLUT4 translocation assay system was established to evaluate the potential effects of WS-PE on GLUT4 translocation. Western blot analysis was adopted to investigate the molecular mechanisms of WS-PE both in vivo and in vitro.

Results

vitro, WS-PE increased glucose uptake by stimulating GLUT4 expression and translocation, which were regulated by Akt phosphorylation. In vivo, the WS-PE treatment ameliorated the hyperglycemia, IR, and dyslipidemia and reversed hepatic steatosis and pancreatic damage in diabetic mice. The WS-PE treatment increased GLUT4 expression by Akt activation in WAT and skeletal muscle. Akt activation stimulated GSK3β phosphorylation in liver and skeletal muscles, indicating that WS-PE showed regulatory effects on glycogen synthesis in liver and skeletal muscles.

Conclusion

These in vitro and in vivo results indicated that the WS-PE treatment exerted antidiabetic effects by activating Akt/GLUT4 and Akt/GSK3β.

A biflavonoid-rich extract from Selaginella moellendorffii Hieron. induces apoptosis via STAT3 and Akt/NF-κB signalling pathways in laryngeal carcinoma

Selaginella moellendorffii Hieron. (SM), a perennial evergreen plant, has been used in the treatment of acute infectious hepatitis, thoracic and hypochondriac lumbar contusions, systemic oedema and thrombocytopaenia. However, the role of a biflavonoid-rich extract from SM (SM-BFRE) in anti-larynx cancer has rarely been reported. In this study, the in vitro and in vivo anti-laryngeal cancer activity and potential mechanisms of SM-BFRE were investigated. An off-line semipreparative liquid chromatography-nuclear magnetic resonance protocol was carried out to determine six biflavonoids from SM-BFRE. In vitro, MTT assay revealed that SM-BFRE inhibited the proliferation of laryngeal carcinoma cells. A wound healing assay indicated that SM-BFRE suppressed the migration of laryngeal cancer cells. Hoechst 33 258 and Annexin V-FITC/PI double staining assays were performed and verified that SM-BFRE induced apoptosis in laryngeal carcinoma cells. The Hep-2 bearing nude mouse model confirmed that SM-BFRE also exhibited anticancer effect in vivo. In addition, Western blot analysis demonstrated that SM-BFRE exerted its anti-laryngeal cancer effect by activating the mitochondrial apoptotic pathway and inhibiting STAT3 and Akt/NF-κB signalling pathways. All results suggested that SM-BFRE could be considered as a potential chemotherapeutic drug for laryngeal cancer.

Antidiarrheal activity of methanol extract of Sophora tonkinensis in mice and spasmolytic effect on smooth muscle contraction of isolated jejunum in rabbits

Context: In China, the herb Sophora tonkinensis Gagnep. (Fabaceae, ST) (Committee of National Pharmacopeia. 2015) exhibits anti-inflammatory, antitumor, and antiviral effects. However, to date, there have been few studies on its gastrointestinal effect. Objective: The gastrointestinal effect of the methanol extract of ST rhizome (STR) was evaluated. Materials and methods: Study was conducted from February to December 2018. In vivo, antidiarrheal activity of STR (125, 250 and 500 mg/kg; orally) in castor oil-induced diarrheal mice was studied. In vitro, the effects of STR (0.01-10 mg/mL) on the isolated tissue preparations of rabbit jejunum were also investigated, the rabbit jejunum stripes were pre-contracted with Ach (10^-5M), K⁺ (60 mM) and tested in the presence of STR, the possible spasmolytic effect was analyzed in the pretreatment of the jejunum preparations with STR or verapamil in Ca²⁺-free high-K⁺ (60 mM) solution containing EDTA. Results: STR (125, 250 and 500 mg/kg) exhibited antidiarrheal activity. STR (0.01-10 mg/mL) completely relaxed spontaneously contracting, Ach (10^-5M) and high K⁺ (60 mM) induced contracted jejunum with an EC₅₀ value of 0.66 (0.49-0.96), 0.39 (0.28-0.44) and 0.17 (0.10-0.21), similar to verapamil. Concentration-response curves of CaCl₂ could be significantly moved to the right and down in the presence of STR (0.3, 1 mg/mL). Discussion and conclusions: Results suggest the presence of antidiarrheal activity and spasmolytic effects of STR, possibly mediated through Ca²⁺ channel blocking activity, providing the pharmacological basis for its traditional uses in gastrointestinal disorders.

Neferine Promotes GLUT4 Expression and Fusion With the Plasma Membrane to Induce Glucose Uptake in L6 Cells

Glucose transporter 4 (GLUT4) is involved in regulating glucose uptake in striated muscle, liver, and adipose tissue. Neferine is a dibenzyl isoquinoline alkaloid derived from dietary lotus seeds and has multiple pharmacological effects. Therefore, this study investigated neferine’s role in glucose translocation to cell surface, glucose uptake, and GLUT4 expression. In our study, neferine upregulated GLUT4 expression, induced GLUT4 plasma membrane fusion, increased intracellular Ca²⁺, promoted glucose uptake, and alleviated insulin resistance in L6 cells. Furthermore, neferine significantly activated phosphorylation of AMP-activated protein kinase (AMPK) and protein kinase C (PKC). AMPK and PKC inhibitors blocked neferine-induced GLUT4 expression and increased intracellular Ca²⁺. While neferine-induced GLUT4 expression and intracellular Ca²⁺ were inhibited by G protein and PLC inhibitors, only intracellular Ca²⁺ was inhibited by inositol trisphosphate receptor (IP₃R) inhibitors. Thus, neferine promoted GLUT4 expression via the G protein-PLC-PKC and AMPK pathways, inducing GLUT4 plasma membrane fusion and subsequent glucose uptake and increasing intracellular Ca²⁺ through the G protein-PLC-IP₃-IP₃R pathway. Treatment with 0 mM extracellular Ca²⁺ + Ca²⁺ chelator did not inhibit neferine-induced GLUT4 expression but blocked neferine-induced GLUT4 plasma membrane fusion and glucose uptake, suggesting the latter two are Ca²⁺-dependent. Therefore, we conclude that neferine is a potential treatment for type 2 diabetes.

Preparative Purification of Total Flavonoids from Sophora tonkinensis Gagnep. by Macroporous Resin Column Chromatography and Comparative Analysis of Flavonoid Profiles by HPLC-PAD

For the full development and utilization of Sophora tonkinensis Gagnep., this study was primarily intended to established a simple and efficient approach for the preparative purification of total flavonoids from S. tonkinensis by macroporous resin column chromatography (MRCC). The adsorption and desorption characteristics of the total flavonoids on ten macroporous resins were first studied, and AB-8 resin was chosen as the most suitable, and the adsorption data were best fitted to the pseudo-second-order kinetics model and Langmuir isotherm model. Furthermore, the technological parameters for the purification of the total flavonoids were optimized using column chromatography. After a sample one-step purification procedure, the content of the total flavonoids increased by about 4.76-fold from 12.14% to 57.82%, with a recovery yield of 84.93%. In addition, the comparative analysis of the flavonoid extracts before and after purification was performed by high-performance liquid chromatography coupled with photodiode-array detection (HPLC-PAD). The results showed that the contents of six major flavonoids in the purified product were all higher than before the purification. Therefore, the AB-8 MRCC established in this work was a promising method for the industrial-scale purification of the total flavonoids from S. tonkinensis.

Anti-diabetic activity of canophyllol fromCratoxylum cochinchinense(Lour.) Blume in type 2 diabetic mice by activation of AMP-activated kinase and regulation of PPARγ

Our results indicated that CNPL exhibits anti-diabetic effects in KK-Ay miceviaactivating AMP-activated kinase and regulating PPARγ.

Ethanolic Extract of Folium Sennae Mediates the Glucose Uptake of L6 Cells by GLUT4 and Ca2

In today’s world, diabetes mellitus (DM) is on the rise, especially type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance. T2DM has high morbidity, and therapies with natural products have attracted much attention in the recent past. In this paper, we aimed to study the hypoglycemic effect and the mechanism of an ethanolic extract of Folium Sennae (FSE) on L6 cells. The glucose uptake of L6 cells was investigated using a glucose assay kit. We studied glucose transporter 4 (GLUT4) expression and AMP-activated protein kinase (AMPK), protein kinase B (PKB/Akt), and protein kinase C (PKC) phosphorylation levels using western blot analysis. GLUT4 trafficking and intracellular Ca²⁺ levels were monitored by laser confocal microscopy in L6 cells stably expressing IRAP-mOrange. GLUT4 fusion with plasma membrane (PM) was observed by myc-GLUT4-mOrange. FSE stimulated glucose uptake; GLUT4 expression and translocation; PM fusion; intracellular Ca²⁺ elevation; and the phosphorylation of AMPK, Akt, and PKC in L6 cells. GLUT4 translocation was weakened by the AMPK inhibitor compound C, PI3K inhibitor Wortmannin, PKC inhibitor Gö6983, G protein inhibitor PTX/Gallein, and PLC inhibitor U73122. Similarly, in addition to PTX/Gallein and U73122, the IP3R inhibitor 2-APB and a 0 mM Ca²⁺-EGTA solution partially inhibited the elevation of intracellular Ca²⁺ levels. BAPTA-AM had a significant inhibitory effect on FSE-mediated GLUT4 activities. In summary, FSE regulates GLUT4 expression and translocation by activating the AMPK, PI3K/Akt, and G protein–PLC–PKC pathways. FSE causes increasing Ca²⁺ concentration to complete the fusion of GLUT4 vesicles with PM, allowing glucose uptake. Therefore, FSE may be a potential drug for improving T2DM.

Insulin Mimetic Properties of Extracts Prepared from Bellis perennis

Diabetes mellitus (DM) and consequential cardiovascular diseases lead to millions of deaths worldwide each year; 90% of all people suffering from DM are classified as Type 2 DM (T2DM) patients. T2DM is linked to insulin resistance and a loss of insulin sensitivity. It leads to a reduced uptake of glucose mediated by glucose transporter 4 (GLUT4) in muscle and adipose tissue, and finally hyperglycemia. Using a fluorescence microscopy-based screening assay we searched for herbal extracts that induce GLUT4 translocation in the absence of insulin, and confirmed their activity in chick embryos. We found that extracts prepared from Bellis perennis (common daisy) are efficient inducers of GLUT4 translocation in the applied in vitro cell system. In addition, these extracts also led to reduced blood glucose levels in chicken embryos (in ovo), confirming their activity in a living organism. Using high-performance liquid chromtaography (HPLC) analysis, we identified and quantified numerous polyphenolic compounds including apigenin glycosides, quercitrin and chlorogenic acid, which potentially contribute to the induction of GLUT4 translocation. In conclusion, Bellis perennis extracts reduce blood glucose levels and are therefore suitable candidates for application in food supplements for the prevention and accompanying therapy of T2DM.

Antidiabetic Activity of a Flavonoid-Rich Extract From Sophora davidii (Franch.) Skeels in KK-Ay Mice via Activation of AMP-Activated Protein Kinase

The present study was undertaken to investigate the hypoglycemic activity and potential mechanisms of action of a flavonoid-rich extract from Sophora davidii (Franch.) Skeels (SD-FRE) through in vitro and in vivo studies. Four main flavonoids of SD-FRE namely apigenin, maackiain, leachianone A and leachianone B were purified and identified. In vitro, SD-FRE significantly promoted the translocation and expression of glucose transporter 4 (GLUT4) in L6 cells, which was significantly inhibited by Compound C (AMPK inhibitor), but not by Wortmannin (PI3K inhibitor) or Gö6983 (PKC inhibitor). These results indicated that SD-FRE enhanced GLUT4 expression and translocation to the plasma membrane via the AMPK pathway and finally resulted in an increase of glucose uptake. In vivo, using a spontaneously type 2 diabetic model, KK-Ay mice received intragastric administration of SD-FRE for 4 weeks. As a consequence, SD-FRE significantly alleviated the hyperglycemia, glucose intolerance, insulin resistance and hyperlipidemia in these mice. Hepatic steatosis, islet hypertrophy and larger adipocyte size were observed in KK-Ay mice. However, these pathological changes were effectively relieved by SD-FRE treatment. SD-FRE promoted GLUT4 expression and activated AMPK phosphorylation in insulin target tissues (muscle, adipose tissue and liver) of KK-Ay mice, thus facilitating glucose utilization to ameliorate insulin resistance. Regulation of ACC phosphorylation and PPARγ were also involved in the antidiabetic effects of SD-FRE. Taken together, these findings indicated that SD-FRE has the potential to alleviate type 2 diabetes.

Anti-diabetic activity of a polyphenol-rich extract from Phellinus igniarius in KK-Ay mice with spontaneous type 2 diabetes mellitus

The present study investigated the anti-diabetic activity and potential mechanisms of the polyphenol rich extract from Phellinus igniarius (PI-PRE) in vitro and in vivo. Four main phenolic compounds of PI-PRE were purified and identified as 7,8-dihydroxycoumarin, 3,4-dihydroxybenzalacetone, 7,3'-dihydroxy-5'-methoxyisoflavone and inoscavin C by the off-line semipreparative liquid chromatography-nuclear magnetic resonance protocol. In vitro, PI-PRE stimulated GLUT4 translocation by 2.34-fold and increased glucose uptake by 1.73-fold in L6 cells. However, the selective AMP-activated protein kinase (AMPK) inhibitor, compound C, completely reversed the PI-PRE-induced GLUT4 translocation. In vivo, KK-Ay mice treated with PI-PRE for four weeks had lower fasting blood glucose levels, as well as other blood-lipid indexes, compared with the vehicle control group. Mechanistic studies showed that the expressions of p-AMPKα and GLUT4 were significantly increased by treatment with PI-PRE in L6 cells. In KK-Ay mice, the expression of p-AMPKα was enhanced in the liver and skeletal muscle, and the expression of GLUT4 was increased in skeletal muscle. These findings suggest that PI-PRE possesses potential anti-diabetic effects including improving glucose tolerance, reducing hyperglycemia, and normalizing insulin levels. These effects are partly due to the activation of GLUT4 translocation via the modulation of the AMPK pathway.

Hypoglycemic Potential of Aqueous Extract of Moringa oleifera Leaf and In Vivo GC-MS Metabolomics

Moringa oleifera Lam. (family; Moringaceae), commonly known as drumstick, have been used for centuries as a part of the Ayurvedic system for several diseases without having any scientific data. Demineralized water was used to prepare aqueous extract by maceration for 24 h and complete metabolic profiling was performed using GC-MS and HPLC. Hypoglycemic properties of extract have been tested on carbohydrate digesting enzyme activity, yeast cell uptake, muscle glucose uptake, and intestinal glucose absorption. Type 2 diabetes was induced by feeding high-fat diet (HFD) for 8 weeks and a single injection of streptozotocin (STZ, 45 mg/kg body weight, intraperitoneally) was used for the induction of type 1 diabetes. Aqueous extract of M. oleifera leaf was given orally at a dose of 100 mg/kg to STZ-induced rats and 200 mg/kg in HFD mice for 3 weeks after diabetes induction. Aqueous extract remarkably inhibited the activity of α-amylase and α-glucosidase and it displayed improved antioxidant capacity, glucose tolerance and rate of glucose uptake in yeast cell. In STZ-induced diabetic rats, it produces a maximum fall up to 47.86% in acute effect whereas, in chronic effect, it was 44.5% as compared to control. The fasting blood glucose, lipid profile, liver marker enzyme level were significantly (p < 0.05) restored in both HFD and STZ experimental model. Multivariate principal component analysis on polar and lipophilic metabolites revealed clear distinctions in the metabolite pattern in extract and in blood after its oral administration. Thus, the aqueous extract can be used as phytopharmaceuticals for the management of diabetes by using as adjuvants or alone.

Quantitative Analysis, Extraction Optimization, and Biological Evaluation of Cudrania tricuspidata Leaf and Fruit Extracts

Cudrania tricuspidata Bureau (Moraceae) shows numerous pharmacological effects and has been used in traditional herbal remedies for inflammation, gastritis, tumors, and liver diseases. However, no validated analytical method for the standardization and optimization of the biological properties of C. tricuspidata preparations has been reported. We developed and validated a reverse-phase high-performance liquid chromatography (HPLC) method for the separation and quantification of active markers. Ethanolic extracts of C. tricuspidata leaves were prepared and evaluated for chemical profiles and biological activities. The 80% ethanolic extract demonstrated the greatest antioxidant activity and phenolic content, while the 100% ethanolic extract had the greatest total flavonoid content and xanthine oxidase (XO) inhibitory activity. The validated HPLC method confirmed that chlorogenic acid, rutin, and kaempferol were present in C. tricuspidata leaf extracts. We postulated that the antioxidant and anti-hyperuricemic/gout effects of C. tricuspidata extract could be attributed to these marker compounds. Our results suggested that the flavonoid-rich fraction of the leaf extract may be utilized for the treatment and prevention of hyperuricemia-related diseases, and the validated method and marker compounds could be applied for the quality control of C. tricuspidata preparations.

Anti-diabetic activity of stigmasterol from soybean oil by targeting the GLUT4 glucose transporter

The present study investigated the anti-diabetic activity and potential mechanism of stigmasterol (SMR), which is a kind of phytosterols derived from the edible soybean oil in vitro and in vivo. SMR displayed a mild GLUT4 translocation activity by 1.44-fold in L6 cells. L6 cells were treated with different concentration of SMR, showing significant effects on the enhancing glucose uptake. SMR administrated orally to the KK-Ay mice significantly alleviated their insulin resistance and oral glucose tolerance with reducing fasting blood-glucose levels and blood lipid indexes such as triglyceride and cholesterol. Moreover, the GLUT4 expression in L6 cells, skeletal muscle and white adipose tissue had been also enhanced. In this paper we conclude that, stigmasterol seems to have potential beneficial effects on the treatment of type 2 diabetes mellitus with the probable mechanism of targeting GLUT4 glucose transporter included increasing GLUT4 translocation and expression.

Activity of Isoliensinine in Improving the Symptoms of Type 2 Diabetic Mice via Activation of AMP-Activated Kinase and Regulation of PPARγ

This study was designed to explore the effects and mechanism of isoliensinine (isolie) from embryos of Nelumbo nucifera on type 2 diabetes and dyslipidemia in vivo and in vitro. The in vitro study showed that isolie increased the GLUT4 translocation by 2.5-fold in L6 cells. Furthermore, after 4 weeks of treatment, the in vivo biochemical study indexes revealed that isolie had a positive effect on decreasing serum insulin level (42.2 ± 5.10 vs 55.7 ± 6.33 mU/L, P < 0.05) and reducing fast blood glucose (9.4 ± 1.5 vs 18.7 ± 2.3 mmol/L, P < 0.001) and body weight (37.8 ± 2.9 vs 46.9 ± 5.4 g, P < 0.05) compared with the KK-Ay model mice. Isolie treatment led to significant increases in GLUT4 proteins (∼2.7-fold in skeletal muscle and ∼2.4-fold in WAT) and phosphorylated AMP-activated protein kinase (∼1.4-fold in skeletal muscle, ∼3.1-fold in WAT, and ∼2.3-fold in liver). However, isolie caused a significant decrease in lipogenesis protein expressions of PPARγ and SREBP-1c, and decreased the activity of ACC by increasing the phospho-ACC level. Our findings showed that isolie has the potential to alleviate type 2 diabetes associated with hyperlipidemia in KK-Ay mice. Regulation of GLUT4, SREBP-1c, PPARγ, AMPK phosphorylation, and ACC phosphorylation is implicated in the antidiabetic effects of isolie.

Network Pharmacology Studies on the Bioactive Compounds and Action Mechanisms of Natural Products for the Treatment of Diabetes Mellitus: A Review

Diabetes mellitus (DM) is a kind of chronic and metabolic disease, which can cause a number of diseases and severe complications. Network pharmacology approach is introduced to study DM, which can combine the drugs, target proteins and disease and form drug-target-disease networks. Network pharmacology has been widely used in the studies of the bioactive compounds and action mechanisms of natural products for the treatment of DM due to the multi-components, multi-targets, and lower side effects. This review provides a balanced and comprehensive summary on network pharmacology from current studies, highlighting different bioactive constituents, related databases and applications in the investigations on the treatment of DM especially type 2. The mechanisms related to type 2 DM, including α-amylase and α-glucosidase inhibitory, targeting β cell dysfunction, AMPK signal pathway and PI3K/Akt signal pathway are summarized and critiqued. It suggests that the network pharmacology approach cannot only provide a new research paradigm for natural products, but also improve the current antidiabetic drug discovery strategies. Furthermore, we put forward the perspectives on the reasonable applications of network pharmacology for the therapy of DM and related drug discovery.