To investigate the hypolipidemic effects of gypenosides granules and its combination with lipitor, a model of hyperlipidaemia C57BL/6J mice was established by high-fat diet feeding for 4 weeks. The mice were randomly divided into blank group, model group, lipitor group(10 mg/kg of lipitor), low dose group(90 mg/kg of gypenosides granules), medium dose group(120 mg/kg of gypenosides granules), high dose group(180 mg/kg of gypenosides granules)and the combination group(180 mg/kg of gypenosides granules and 10 mg/kg of lipitor). After 4 weeks of continuous administration, the contents of serum lipid indexes, serum ALT, AST and apolipoprotein B(ApoB)were measured. The liver tissues of mice were observed by H&E staining. The expression levels of key factors involved in hepatic cholesterol metabolism were observed by RT-PCR and Western blot methods, such as adenosine triphosphate combined box transporter A1(ABCA1), liver X receptor(LXRα), cholesterol 7 alpha hydroxylase(CYP7A1)and type BΙ scavenger receptor(SR-BΙ). The results revealed that gypenosides granules significantly decreased the mice body weight, total abdominal fat area and the level of serum total cholesterol(TC). The combination group showed a more significant reduction in TC level than the other administration groups. Moreover, gypenosides granules treatment remarkably increased the protein expression of ABCA1 and up-regulated the mRNA expression of ABCA1, CYP7A1 and SR-BI. The above results suggest that gypenosides granules can significantly reduce blood lipid contents, and the combination therapy with lipitor show better the lipid-lowering effect. Meanwhile, gypenosides granules can decrease the level of serum transaminase. Preliminary exploration suggests the lipid-lowering mechanism of gypenosides granules may be involved in cholesterol reversal to regulate the level of TC.

To investigate the hypoglycemic effects of ethyl acetate extract of Alismatis Rhizoma (AREEA) on type 2 diabetes mellitus,the model of type 2 diabetic rats was induced by high-fat diet feeding for 4 weeks and then intraperitoneal injection of a low dose of streptozotoin (STZ).Rats without the above-mentioned treatment were selected as the normal control group.The diabetic rats were randomly divided into 5 groups:the model control group,low doses (20 mg/kg),medium doses (50 mg/kg),high doses (100 mg/kg) of AREEA groups and positive control-metformin group (100 mg/kg).After four weeks,oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed,respectively.12 hours after the last administration,the levels of serum glucose,glycated hemoglobin(HbA1 c),insulin (Ins),total cholesterol (TC),triglyceride (TG),high density lipoprotein (HDL-C),low density lipoprotein (LDL-C),superoxide dismutase (SOD),malondialdehyde (MDA),glutathione (GSH-Px),tumor necrosis factor-or (TNF-α),interleukin-6 (IL-6),insulin-mediated tyrosine of IRS-1 and Akt phosphorylation in adipose tissue were determined.In addition,the pathological changes of pancreas were examined.After administration for 4 weeks,all doses of AREEA significantly reduced the fasting blood glucose of type 2 diabetic rats (P ＜0.05).In the high doses group of AREEA,the levels of GLU,HbA1c,TC,TG,MDA,TNF-α and IL-6 in serum were decreased significantly,and the levels of SOD and GSH-Px were increased (P ＜ 0.05).These results suggest that AREEA has the therapeutic effect on type 2 diabetes-related symptoms by metabolic regulation of glucose and lipids.

The research of triterpenoids on hypoglycemic and anti-diabetic activities have made great progress. Findings indicated that triterpenoids could reduce blood glucose via different mechanisms, including increasing insulin secretion, enhancing insulin sensitivity, promoting glucose uptake by activation of AMP-activated protein kinase(AMPK), decreasing glycogenolysis and gluconeogenesis, and inhibiting protein tyrosine phosphates 1B(PTP1B), α-glycosidase, aldose reductase(AR)and dipeptidyl peptidase-4(DPP-4). This article reviews the hypoglycemic effects and mechanisms of triterpenoids, providing the reference for further research and development of triterpenoids.