aurapten and Obesity

Inflammation plays a key role in obesity-related pathologies such as insulin resistance and type 2 diabetes. Hypertrophied adipocytes trigger the enhancement of macrophage infiltration and the release of various proinflammatory factors in obese adipose tissue. In this study, we examined whether auraptene, a citrus-fruit-derived compound, could suppress the production of inflammatory factors that mediate the interaction between adipocytes and macrophages.. Experiments using a co-culture system of 3T3-L1 adipocytes and RAW264 macrophages showed that auraptene reduced the production of nitric oxide and tumor necrosis factor-α. In RAW264 macrophages, auraptene also suppressed the inflammation induced by either LPS or the conditioned medium derived from 3T3-L1 adipocytes. In addition, auraptene inhibited the phosphorylation of the p38 mitogen-activated protein kinase and suppressed the production of proinflammatory mediators in activated macrophages.. Our findings indicate that auraptene exhibits anti-inflammatory properties by suppressing the production of inflammatory factors that mediate the interaction between adipocytes and macrophages, suggesting that auraptene is a valuable food-derived compound with a potential to attenuate chronic inflammation in adipose tissue and to improve obesity-related insulin resistance.

Topics: 3T3-L1 Cells; Adipocytes; Adipose Tissue; Animals; Anti-Inflammatory Agents; Cell Line, Tumor; Chemokine CCL2; Citrus; Coculture Techniques; Coumarins; Culture Media, Conditioned; Fruit; Inflammation; Insulin Resistance; Lipopolysaccharides; Macrophages; Mice; Nitric Oxide; Obesity; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Plant Extracts; Tumor Necrosis Factor-alpha

Dietary polyphenols are important potential chemopreventive natural agents. Other agents, such as citrus compounds, are also candidates for cancer chemopreventives. They act on multiple key elements in signal transduction pathways related to cellular proliferation, differentiation, apoptosis, inflammation, and obesity. This short review article provides our findings of preclinical studies on potential chemopreventive activities of dietary citrus compounds, auraptene, collinin, and citrus unshiu segment membrane (CUSM), using clitis- and obesity-related colon tumorigenesis models. Dietary feeding with auraptene and collinin at dose levels of 0.01% and 0.05% significantly lowered the incidence (50-60% reduction) and multiplicity (67-80% reduction) of colonic adenocarcinomas induced by azoxymetahene [AOM, single intraperitoneal injection of 10 mg/kg body weight (bw)] and dextran sodium sulfate (1% in drinking water). Anti-inflammatory potency of aurapene and collinin may contribute to the effects. Administration with CUSM at 3 doses in diet significantly inhibited development of aberrant crypts foci induced by 5 weekly subcutaneous injections of AOM (15 mg/kg bw) in male db/db mice: 53% inhibition by 0.02% CUSM, 54% inhibition by 0.1% CUSM, and 59% inhibition by 0.5% CUSM. CUSM treatment also decreased serum level of triglycerides. Our findings suggest that certain citrus materials are capable of inhibiting clitis- and obesity-related colon carcinogenesis.

Topics: Animals; Azoxymethane; Citrus; Colitis; Colonic Neoplasms; Coumarins; Cyclooxygenase 2; Interleukin-1beta; Mice; NF-kappa B; Nitric Oxide Synthase Type II; Obesity; Precancerous Conditions; Tumor Necrosis Factor-alpha