Momordica charantia (Bitter Melon) Reduces Systemic and Adipose Tissue Inflammation in High-Fat Diet (HFD)-Fed Mice

Rising incidences of chronic inflammatory diseases such as obesity, has led to an increased use of alternative medicine. Ayurvedic medicine, Momordica charantia (bitter melon, BM) reduces total body and adipose tissue weights in mice fed with high-fat diet (HFD). During obesity, circulating monocyte chemoattractant protein-1 (MCP-1) increases adipose tissue macrophage (ATM) infiltration mediating low-grade systemic and tissue-specific inflammation; however, resident ATM secretes anti-inflammatory cytokines. Since BM reduced plasma levels of MCP-1 in mice fed HFD+BM, we hypothesized that BM would improve HFD-associated inflammation. Adipose tissue and blood were collected after 16 weeks from C57BL/6 male mice fed with 1) control diet with 4.8% fat, 2) control diet + 1.5% lyophilized BM (w/w), 3) HFD with 58% fat, and 4) HFD + BM. Results indicate that BM significantly lowered plasma levels of pro-inflammatory cytokines and chemokines. Similarly, markers of adipose tissue differentiation (peroxisome proliferator-activated receptor gamma, PPARγ) and inflammation (F4/80, interleukin-1 beta, IL-1β, MCP-1 and nuclear factor-kappaB1, NFκB1) were also reduced. Overall, BM lowered both systemic and adipose tissue inflammation in HFD-fed mice. These studies will help to identify molecular targets to prevent obesity-associated inflammation. Such studies are important as they offer low-cost alternatives for developing countries and lower health-care costs for standard long-term care in developed countries. [Public Health Service grants (R21AT003719) National Center for Complementary and Alternative Medicine, (G12 RR003061) Research Centers in Minority Institutions, and (2T34GM007684) Minority Access to Research Careers Program, National Institutes of Health.]