The Chinese herbal medicine FTZ attenuates insulin resistance via IRS1 and PI3K in vitro and in rats with metabolic syndrome

Xuguang Hu,Man Wang,Weijian Bei,Zongyu Han,Jiao Guo

doi:10.1186/1479-5876-12-47

Abstract

BackgroundInsulin resistance plays an important role in the development of metabolic syndrome (MS). Fu Fang Zhen Zhu Tiao Zhi formula (FTZ), a Chinese medicinal decoction, has been used to relieve hyperlipidemia, atherosclerosis and other symptoms associated with metabolic disorders in the clinic.MethodsTo evaluate the effect of FTZ on insulin resistance, HepG2 cells were induced with high insulin as a model of insulin resistance and treated with FTZ at one of three dosages. Next, the levels of glucose content, insulin receptor substrate1 (IRS1) protein expression and phosphatidylinositol 3-kinase (PI3K) subunit p85 mRNA expression were measured. Alternatively, MS was induced in rats via gavage feeding of a high-fat diet for four consecutive weeks followed by administration of FTZ for eight consecutive weeks. Body weight and the plasma levels of lipids, insulin and glucose were evaluated. Finally, the expression of PI3K p85 mRNA in adipose tissue of rats was measured.ResultsOur results revealed that FTZ attenuated glucose content and up-regulated the expression of PI3K p85 mRNA and IRS1 protein in insulin-resistant HepG2 cells in vitro. Moreover, FTZ reduced body weight and the plasma concentrations of triacylglycerol, cholesterol, fasting glucose and insulin in insulin resistant MS rats. FTZ also elevated the expression of PI3K p85 mRNA in the adipose tissues of MS rats.ConclusionFTZ attenuated MS symptoms by decreasing the plasma levels of glucose and lipids. The underlying mechanism was attenuation of the reduced expression of PI3K p85 mRNA and IRS1 protein in both insulin-resistant HepG2 cells and MS rats.

Highlights

Insulin resistance plays an important role in the development of metabolic syndrome (MS)
Effect of Fu Fang Zhen Zhu Tiao Zhi formula (FTZ) on PI-3K p85 mRNA expression in insulinresistant HepG2 cells To evaluate the effect of FTZ on PI-3K p85 mRNA expression, total RNA was extracted from HepG2 cells, and real-time polymerase chain reaction (PCR) was performed
These results suggest that FTZ induces an insulin sensitizing effect on Insulin resistance (IR) cells through the up-regulation of PI-3K p85 mRNA expression in HepG2 cells (Figure 2)

Summary

Introduction

Insulin resistance plays an important role in the development of metabolic syndrome (MS). Fu Fang Zhen Zhu Tiao Zhi formula (FTZ), a Chinese medicinal decoction, has been used to relieve hyperlipidemia, atherosclerosis and other symptoms associated with metabolic disorders in the clinic. Hypertension and hypertriglyceridemia often occurred together [1] This author proposed the concept of X Syndrome, regarding insulin resistance as the primary characteristic of X Syndrome. Fu Fang Zhen Zhu Tiao Zhi formula (FTZ), for which a patent has been issued, is composed of eight medical herbs and has been proven clinically effective for the treatment of dyslipidemia [3,4]. Our previous study demonstrated that FTZ could reduce serum levels of total cholesterol (TC), triglycerides (TG) and lowdensity lipoprotein cholesterol (LDL-C) and increase the serum level of high-density lipoprotein cholesterol (HDL-C) in hyperlipidemic patients [5,6]. FTZ could improve serum lipid profile in high lipid diet induced hyperlipidemic rats by regulating the HMG-CoA reductase and CYP7A1 [9]

Methods

Results

Discussion

Conclusion