Obesity is an epidemic caused primarily by a pathological expansion of white adipose tissue (WAT). Obese adipose tissue gets infiltrated with proinflammatory macrophages contributing to the chronic low-grade inflammation associated with obesity. Agents with anti-inflammatory effects were shown to be beneficial in the prevention and treatment of metabolic diseases like obesity, diabetes mellitus and cardiovascular disease. The citrus-derived flavonoid naringenin (NAR) has been shown to have lipid lowering and anti-diabetic properties. In the current study, we determined the effect of NAR on human omental adipocyte differentiation and lipid accumulation. Post confluent adipocytes were supplemented with NAR and lipid content was quantitated using Nile Red dye based AdipoRedTM assay kit. Results indicated a dose-dependent effect of NAR on inhibiting lipid deposition in omental adipocytes cultured under adipogenic conditions. We further investigated the anti-inflammatory effects of NAR using RAW 264.7 cells, a murine macrophage cell line. We hypothesized that the anti-inflammatory effects of NAR are due to M2 polarization of macrophages and our results indicated that NAR upregulated the secretion of interleukin 10 (IL10), a signature cytokine for M2 polarization, in RAW264.7 cells in a dose dependent manner after 48 hr. We further demonstrated that NAR decreased the secretion of LPS-induced TNFα and IL6 levels. Thus, our studies in adipocytes and macrophages demonstrate NAR as a promising phytochemical with anti-obesity and anti-inflammatory effects making it a potential therapeutic agent for prevention and treatment of metabolic diseases including obesity and diabetes.
Available at: http://works.bepress.com/srujana_rayalam/65/