Estudio in vitro e in vivo sobre los mecanismos involucrados en el posible papel protector de la vitamina c en el desarrollo de la obesidad

Résumé

Antioxidant-based treatments emerge as interesting approaches to counteract fat accumulation in obesity. In the present work, a vitamin C (VC) supplementation of a high fat diet significantly prevented a weight gain and adiposity increase induced by this diet in rats after 56 days, fact related with insulin-sensitivity improvement and lower apelin gene expression. At 14 days, VC supplementation prevented a lipolytic response increase of isolated adipocytes, and a locomotor activity reduction induced by high fat intake. Ex vivo studies showed direct inhibitory effects of VC on glucose/lipid metabolism, expression/secretion of leptin, and on reactive oxygen species (ROS) production of isolated adipocytes from lean rats. Also, VC incubation modulated the expression of other proteins involved in obesity-related processes, such as adipocyte differentiation, inflammation, insulin signaling and apoptosis. Furthermore, VC protected against toxicity induced by high glucose incubations on adipocytes isolated from lean, but not from obese rats. Additionally, lowering effects induced by VC were observed on glucose/lipid metabolism and on expression/secretion of apelin and leptin in adipocytes either from lean or obese animals. Finally, coculture studies using macrophages and adipocytes evidenced lowering effects of VC incubation on inflammatory related variables that were induced by the coculture establishment. Interestingly, VC reduced the apelin expression that was highly induced in the coculture. In summary, several systemic and direct effect of VC over variables related to obesity establishment has been described, suggesting that the antioxidant properties of this molecule could be involved in a possible protective effect against a high fat intake induced adiposity.