Effects of Astragalus polysaccharides on proliferation and differentiation of 3T3-L1 preadipocytes

Abstract

To observe the effects of Astragalus polysaccharides (APS) on the proliferation and differentiation of 3T3-L1 preadipocytes and to elucidate its possible mechanism. The proliferation of 3T3-L1 preadipocytes was detected by XTT method. Lipid droplets accumulated in cytoplasm of the differentiated preadipocytes were observed by using red O staining and quantified by colorimetry. The expressions of peroxisome proliferation activated receptor gamma (PPAR gamma) and CAAT/enhancer binding protein (C/EBP alpha) mRNAs and proteins were detected by real-time polymerase chain reaction (RT-PCR) and Western blotting respectively. APS at different concentrations (0.025-0.8 g/L) affected 3T3-L1 preadipocyte proliferation and differentiation dose-dependently. 3T3-L1 preadipocytes treated with 0.4 g/L APS had lots of lipid droplets in the cytoplasma, which were similar to cells treated with rosiglitazone (ROS). APS significantly increased the mRNA and protein expressions of PPAR gamma and C/EBP alpha (P<0.05, P<0.01, compared with the normal control group) in the course of 3T3-LI preadipocyte differentiation. APS can promote the proliferation of 3T3-L1 preadipocytes, enhance the accumulation of lipid drops, and increase the terminal differentiation of preadipocytes, which may be associated with its effects in increasing the expressions of PPAR gamma and C/EBP alpha mRNAs and proteins. The study suggests that APS has potential in the treatment of metabolic syndrome.