Effects of capsaicin on lipid catabolism in 3T3-L1 adipocytes

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a pungent ingredient of red peppers, and has been reported to reduce body weight gain and adiposity in rodents. The present study investigated the effects of capsaicin on lipid catabolism in differentiated 3T3-L1 adipocytes. Capsaicin decreased the intracellular lipid content in a concentration-dependent manner. The release of glycerol into the medium was increased by the addition of capsaicin. The mRNA levels of genes involved in lipid catabolism such as hormone sensitive lipase (HSL), carnitine palmitoyl transferase-Iα (CPTI-α) and uncoupling protein 2 (UCP2) were up-regulated significantly. These results suggest that capsaicin exerts its lipolytic action by increasing the hydrolysis of triacylglycerol in adipocytes, and that these effects are mediated at least partially by regulation of the expression of multiple genes that are involved in the lipid catabolic pathway, such as HSL and CPT-Iα, and those involved in thermogenesis such as UCP2.