Effect of Gymnema sylvestre extract in high-fat diet induced metabolic disorders

Abstract

Obesity rates has greatly increased in modern societies and this is related to various metabolic diseases such as diabetes, liver steatosis, chronic inflammation and adiposity. Currently, an energy imbalance between calorie consumption and expenditure by high-fat diet(HFD) is considered as a major cause of obesity. Being an important issue in the modern public health, many studies have been conducted to find its precaution. In particular, natural products having biological activities have been used for anti-obesity and antidiabetic agents. Gymnema sylvestre extract (GS), a dicotyledonous medicinal herb belonging to the family of Asclepiadaceae, is a woody climber found in tropical Africa, India and China. Its main active compound is gymnemic acid, and several experimental studies of GS have been performed by using its properties. Many scientific studies of GS, however, have been performed using mutant mice or STZ-treated diabetic models, and the administration method was mostly oral. Therefore, the objective of this study is to evaluate anti-obesity and antidiabetic effects of GS through feeding mixed food and correlated analysis of insulin resistance, dysfunction of the liver and adipose tissue in C57BL/6J mice. Male C57BL/6J mice were divided into 5 groups, comprising a normal chow fed group, high-fat diet fed group and high-fat diet plus GS in different doses (100, 250 and 500 mg/kg body weight), and feeding food for 8 weeks. As a result, GS significantly decreased the body weight, liver and adipose tissue weight, and improved insulin resistance and impaired glucose level. In addition, the level steatosis and inflammation of the liver and adipose tissue were decreased. In summary, this results support relationships among insulin resistance, liver steatosis,, adiposity and cytokine level such as leptin and adiponectin, and confirmed the mechanism by amylase activity of GS. Further mechanism studies are needed to investigate anti-obesity and antidiabetic effects for in vivo model.