Effect of (+) and (-) hydroxycitric acid sterio-isomers present in natural products in counteracting insulin resistance

Abstract

Metabolic syndrome is a cluster of cardiovascular and metabolic risk factors that include impaired glucose metabolism and obesity. The use of nutraceuticals is an ideal choice for controlling this disorder. The aim of the present study is to investigate the effect (-) hydroxycitric acid present in garcinia fruit rind and (+) hydroxycitric acid present in hibiscus calyx on metabolic syndrome and compare it to that of metformin. Metabolic syndrome was induced in rats by ingestion of high fat high fructose (HFHF) diet for 90 days. Metformin (500 mg/Kg animal b.wt.), garcinia (1000 mg/Kg animal b.wt.) and hibiscus (250 mg/Kg animal b.wt) were orally administered throughout the last 30 days of the HFHF diet regimen. Both garcinia and hibiscus were effective in reducing serum blood glucose and insulin levels. The effect of garcinia on blood glucose was comparable to that of metformin, while the effect of hibiscus on insulin and HOMA-IR was comparable to that of metformin. Both were able to reduce serum leptin level. All treated groups showed a significant decrease in total cholesterol level. Only hibiscus was able to normalize liver function while garcinia failed to reduce the elevated liver function. As a conclusion we would recommend the use of hibiscus over garcinia to overcome the adverse effects of metabolic syndrome.