Effects of Bitter Melon and Toll-Like Receptor (Tlr) 4 on Glucose and Lipid Parameters in Mice Fed a High Fat Diet

Abstract

Bitter Melon (Momordica charantia, MC) has been investigated for its hypoglycemic and hypolipidemic effects and its ability to reduce adiposity in animal models and clinical trials. This study examined the effect of MC on glucose and lipid homeostasis in an animal model of diet-induced obesity (DIO). Additionally, fatty acids can activate toll-like receptor (TLR) 4 signaling pathway resulting in an inflammatory state which may contribute to insulin resistance associated with DIO. It has been reported that the loss of TLR 4 protected against dietary fat-induced inflammation and insulin resistance. TLR 4 mutant (C3H/HeJ) and wild-type mice (C57BL/6) were randomly assigned to four dietary treatment groups for eight weeks; control (10% calories from fat), high fat (HF, 60% calories from fat), HF + 1% MC, and HF + 10% MC. C3H/HeJ strain exhibited significantly higher body weight, body fat, and lipid levels in response to a high fat diet when compared to the C57BL/6 strain. However, C3H/HeJ strain had significantly lower area under the curve after a glucose tolerance test, plasma fructosamine and free fatty acid in comparison to the C57BL/6 strain. Animals fed the HF + 10% MC also exhibited improved blood glucose control.