Carnosic Acid Inhibits Lipid Accumulation in 3T3-L1 Adipocytes Through Attenuation of Fatty Acid Desaturation

Abstract

Background:Excess body fat accumulation contributes to the development of metabolic disorders that can cause adverse health effects. Carnosic acid (CA), a major bioactive component of rosemary (Rosemarinus officinalis), has been suggested to possess anti-adipogenicproperties. The present study was conducted to elucidate the mechanism underlying the anti-adipogenic effects of CA. Methods:3T3-L1 pre-adipocytes were treated with CA (0.1, 1, and 10 μM) from day 0 to day 8 of differentiation. On day 8, biochemicalmarkers of lipid accumulation and the degree of fatty acid desaturation were measured. Results:Oil Red O staining results, triglyceride (TG) accumulation, and glycerol 3-phosphate dehydrogenase activity suggested that CAsignificantly inhibited lipid accumulation in 3T3-L1 adipocytes. CA significantly decreased mRNA expression of peroxisome proliferator-activated receptor-γ, sterol regulatory element-binding protein 1, and CCAAT/enhancer binding protein-αin a dose-dependent manner. Moreover, it decreased the ratio of both C16:1/C16:0 and C18:1/C18:0, with reduced expression of stearoyl CoA desaturase 1 mRNAand protein. Conclusions:These results suggest that CA efficiently suppressed adipogenesis in 3T3-L1 adipocytes and its action, at least in part, isassociated with the downregulation of adipogenesis-related genes and the fatty acid composition of TG accumulated in adipocytes.