Effects of berberine on lipid metabolism and vitamin D receptor as well as insulin-induced gene 2 gene expression of rabbits / 中草药

ABSTRACT

Objective: To investigate the effects of berberine on lipids metabolism of hyper-lipidemic rabbits and to explore whether its mechanism was involved in the vitamin D receptor (VDR) gene and insulin-induced gene 2 (Insig-2) gene expressions in adipose. Methods: Forty male New Zealand white rabbits were randomly divided into five groups normal diet (ND), high-fat diet (HFD); high-fat diet + pretreatments of either Fenofibrate (30 mg/kg) or berberine low dose (28 mg/kg, BLD), and berberine high dose (112 mg/kg, BHD) groups. The serum TC, TG, LDL-C, HDL-C, ApoA1, ApoB, and LPa in each different treated rabbit group were determined after 8-week administration. The mRNA expressions of VDR and Insig-2 in adipose tissue were quantified by RT-PCR. Results: Compared with normal diet group, the serum TC, TG, LDL-C, ApoB, and LPa in high fat diet group obviously elevated (P < 0.05), while ApoA1 obviously descend (P < 0.05). Compared with the high fat diet group, the levels of serum TC, TG, LDL-C, ApoB, and LPa in berberine treated group were significantly decreased (P < 0.05), while ApoA1 was elevated obviously (P < 0.05). The result of RT-PCR demonstrated that the mRNA expressions of VDR and Insig-2 in high fat diet group were significantly higher than those of the normal diet group (P < 0.05), and the VDR and Insig-2 mRNA expressions were significantly up-regulated by berberine (P < 0.05), especially in BLD. Conclusion: Berberine could significantly decrease the levels of blood lipids of the hyperlipidemic rabbits, the mechanism may be related to elevating the expressions of VDR and Insig-2 gene.