Anti-Inflammatory Effects of Momordica charantia (Bitter Melon) in Adipose Tissue of Mice Fed a High-Fat Diet

Abstract

Alternative therapies are of interest due to increasing incidences of chronic low-grade inflammatory diseases such as obesity. Momordica charantia (bitter melon, BM), has been demonstrated to reduce total body and adipose tissue weights in mice fed a high-fat diet (HFD). During obesity, elevated levels of monocyte chemo attractant protein-1 (MCP-1) recruit macrophages to infiltrate adipose tissues. Infiltrated macrophages mediate low-grade systemic and tissue-specific inflammation. We hypothesized that BM would reduce HFD-associated inflammation due to decreased plasma levels of MCP-1 found in mice fed HFD+BM. For 16 weeks, C57BL/6 male mice were treated with 1) control diet (4.8% fat), 2) control diet + BM (1.5% lyophilized powder, w/w), 3) HFD (58% fat), and 4) HFD + BM. Several inflammatory gene expressions from visceral adipose tissues were measured by quantitative real-time PCR (qPCR). Results suggest that BM reduced mRNA expression of macrophage infiltration (F4/80 and MCP-1), inflammatory (interleukin-1 beta, IL-1β, nuclear factor-kappaB1, NF-κB1, and toll-like receptor 4, TLR4), and adipose tissue differentiation (peroxisome proliferator-activated receptor gamma, PPARγ) markers. Overall, BM lowered adipose tissue inflammation in HFD-fed mice. Findings from this research could potentially be used to determine molecular targets of BM to alleviate obesity-induced 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, NIH.]