Berberine inhibits SREBP-1-related clozapine and risperidone induced adipogenesis in 3T3-L1 cells

Weight gain is a common and potentially serious complication associated with the treatment of second generation antipsychotics such as clozapine and risperidone. Increased peripheral adipogenesis via the SREBP-1 pathway could be one critical mechanism responsible for antipsychotic drug-induced weight gain. Berberine, a botanical alkaloid, has been shown in our previous studies to inhibit adipogenesis in cell and animal models. MTT was used to determine the cytotoxic effects of clozapine and risperidone in combination with berberine. Differentiation of 3T3-L1 cells was monitored by Oil-Red-O staining and the expression of SREBP-1 and related proteins was determined by real-time RT-PCR and western blotting. The results showed that neither clozapine nor risperidone, alone or in combination with berberine had significant effects on cell viability. Eight days treatment with 15 μM clozapine increased adipogenesis by 37.4% and 50 μM risperidone increased adipogenesis by 26.5% during 3T3-L1 cell differentiation accompanied by increased SREBP-1, PPARγ, C/EBPα, LDLR and Adiponectin gene expression. More importantly, the addition of 8 μM berberine diminished the induction of adipogenesis almost completely accompanied by down-regulated mRNA and protein expression levels of SREBP-1-related proteins. These encouraging results may lead to the use of berberine as an adjuvant to prevent weight gain during second generation antipsychotic medication.