ABSTRACT
@#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.
ABSTRACT
@#The purpose of this study was to investigate the hypoglycemic effect and the safety of medicinal formula composed of Cyclocarya paliurus and Mulberry leaves. An experimental diabetic rat model was established by high energy diet plus small dosage of auoxan(ALX). At the same time, each group rats were given distilled water(blank and model), metformin(Met), Cyclocarya paliurus aqueous extract(CP), Mulberry leaves aqueous extract(ML)and the different proportions of aqueous extract mixtures of Cyclocarya paliurus and Mulberry leaves(CM1, CM2 and CM3), respectively. Fasting blood glucose(FBG), OGTT, TC, TG, LDL-C, HDL-C, insulin and liver and kidney function related index were gauged to evaluate the hypoglycemic effect and the safety of samples. The results showed that FBG level of the rats in CM1, CM2 and CM3 groups decreased 21. 64%, 16% and 12. 55%, respectively, comparing with that of model group. Moreover, FBG, glucose tolerance and pancreatic tissue morphology were remarkably improved in CM1 group. TC and LDL-C levels of rats in ML and CM3 groups decreased significantly compared with the those of Model group(P< 0. 05), which showed ML and CM3 were beneficial to regulate the blood lipid level in diabetic rats. Furthermore, all the administration groups had no adverse effect on liver function index. The down regulation of kidney function index of CP, ML, CM1, CM2 and CM3 groups comparing with model group indicated that Cyclocarya paliurus and Mulberry leaves could alleviate the injury of liver and kidney. Our results demonstrated that the medicinal formula composed of Cyclocarya paliurus and Mulberry leaves were favorable to reduce blood glucose and can regulate lipid metabolism without liver and kidney toxicity.
ABSTRACT
@#To investigate the effect and possible mechanisms of triterpenic acid-enriched fraction from Cyclocarya paliurus(TAE)on glucagon secretion in insulin-resistance pancreatic α cells, the model of insulin resistance in αTC1-6 cells was induced by long term exposure to high glucose. Experimental groups were divided as follow: control(5. 5 mmol/L glucose), model(25 mmol/L), TAE(1, 5, 10 μg/mL), and TAE(10 μg/mL)plus wortmannin(10 nmol/L)group. The supernatant and lysate of treated cells were collected to determine glucagon secretion by ELISA kit. The mRNA and protein abundance of IRS-1, PI3K and Akt were measured by qPCR and Western blot analysis. Results showed that TAE could not only significantly reduce glucagon secretion induce by high glucose in a dose-dependent manner, but also remarkably increased the mRNA and protein abundance of IRS-1, PI3K and Akt in αTC1-6 cells. However, these effects of TAE were reversed by PI3K inhibitor wortmannin. In conclusion, it suggested that TAE could improve the insulin resistance induced by high glucose in pancreatic α cells which may be related with the activation of IRS-1/PI3K/Akt signaling pathway.
ABSTRACT
To investigate the therapeutic effects of triterpenoids from Cyclocarya paliurus on non-alcoholic fatty liver disease (NAFLD),the model of NAFLD in HepG2 cells was induced by free fatty acids (FFAs). Cytotoxicity of the triterpenoids from C. paliurus was determined by MTT method,and the effects of triterpenoids without cytotoxicity on intracellular triglyceride (TG)and superoxide dismutase (SOD)were detected by the kits. Data indicated that compound 4 [2α,3α,23-trihydroxy-12,20 (30)-dien-28-ursolic acid,TUA]had hypolipidemic and antioxidant activities. After being treated with TUA and FFAs for 24 h,the intracellular lipid content was observed using Oil Red O staining,and intracellular TG,malondialdehyde (MDA ),SOD and reactive oxygen species (ROS)levels were determined by the assay kits. The protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2),heme oxygenase-1 (HO-1 )and NAD (P)H quinone oxidoreductase 1 (NQO-1 )were measured by Western blot. The results showed that TUA significantly increased SOD activity,and decreased intracellular TG, ROS and MDA levels in FFAs-induced HepG2 cells. Moreover,TUA dramatically improved Nrf2,NQO-1 ,and HO-1 expression. However,the dramatic increase in TG,ROS,MDA levels and the reduction in SOD,NQO-1 and HO-1 expression following Nrf2 inhibitor brusatol treatment were observed. In conclusion,these results suggest that TUA has the therapeutic effect on NAFLD which may be associated with Nrf2 activation.