Fruits of mulberry (Morus alba L.) belonging to the Moraceae family have been widely used for therapeutic purposes in Asian countries for centuries. Adipocyte differentiation has often been a target of anti-obesity strategies because obesity is caused not only by hypertrophy of adipocytes, but also by adipocyte hyperplasia(Reference Caro, Dohm and Pories1). The 3T3-L1 cell line is commonly used as an adipocyte differentiation model system for investigation of molecular mechanisms that regulate adipogenesis(Reference Jae Eun and Jie2). This study was performed to investigate the effects of ethanol extract and fractions of M. alba L. on adipocyte differentiation in 3T3-L1cells. The anti-adipogenic effect of M. alba L. extracts was examined for its effect on the anti-adipocyte differentiation of 3T3-L1 cells by Oil red O staining assay. The lipolysis effect of M. alba L. was measured by glycerol releases assay.
Values are means for three independent experiments. Mean values were significantly different from those for MDI group (ANOVA, followed by Duncan test): *P<0.05, †P<0.01.
Treatment of 3T3-L1 cells with ethanolic extracts of M. alba decreased adipocyte differentiation in a dose-dependent manner (A). Most of the tested fractions exhibited anti-adipogenic effects except for butanol and water-soluble fractions. The ethylacetate-soluble fraction was found to have the greatest inhibitory effect, as indicated by suppression of the lipid accumulation by 38.5% in response to treatment with 100 μg/ml.
On other hands, glycerol secretion decreased in treated-concentration of hexan and chloroform-soluble fraction. The low secretion level of glycerol is not an expected result because it was thought that adipocyte reducing effects are caused by lipolysis. The results indicate that M. alba L. is a possible candidate for regulating lipid accumulation in obesity.
