花椒精有效成分对高脂膳食大鼠脂质代谢的影响

EFFECTS OF ACTIVE INGREDIENTS OF ZANTHOXYLUM OLEORESIN ON LIPID METABOLISM IN RATS FED HIGH FAT DIET

目的研究花椒精有效成分对高脂膳食大鼠脂质代谢的影响及作用机制。方法用高脂饲料饲喂大鼠,并分别给与花椒精和含花椒精组相同剂量的花椒挥发油及花椒麻素灌胃4w后,检测大鼠血脂、肝脂及粪便中胆汁酸和中性固醇含量;用RT-PCR法检测肝脏及回肠中与脂质代谢相关基因m RNA的表达。结果与模型组相比,花椒精和花椒麻素组显著降低大鼠血清及肝脏中胆固醇(TC)和甘油三酯(TG)(P<0.05),增加粪便中胆汁酸及中性固醇含量(P<0.05),有效下调肝脏和回肠中3-羟基-3-甲基-戊二酰Co A还原酶(HMG-Co A R)及回肠胆盐转运蛋白(ASBT)等基因m RNA表达(P<0.05),显著上调肝脏7α–羟化酶(CYP7A1)及回肠法尼酯受体(FXR)m RNA表达(P<0.01);花椒挥发油组可显著降低大鼠血清及肝脏TG水平(P<0.05),增加粪便中性固醇含量,但增加了肝脏TC和减少粪便中胆汁酸含量,下调肝脏CYP7A1和HMG-Co A还原酶m RNA表达,上调肝脏和回肠FXR m RNA表达(P<0.05)。结论花椒精、花椒挥发油及花椒麻素对高脂膳食大鼠脂质代谢紊乱均有良好的改善作用,其中花椒麻素效果最佳,其可能机制与上调肝脏中胆固醇分解、下调胆固醇合成及回肠胆汁酸重吸收的相关基因表达有关。

Objective To explore the effects of active ingredients of Zanthoxylum oleoresin on lipid metabolism in rats fed a high diet and the potential mechanisms. Methods The hyperlipidemic rat model was induced by a high fat diet and rats were divided into model group Zanthoxylum oleoresin group and the groups treated with essential oil and alkylamide in Zanthoxylum oleoresin group. After four weeks, all of the rats were sacrificed, and the serum and hepatic lipids, bile acids and neutral steroid in feces were detected. The mRNA expression levels of the genes involved in lipid metabolism were assessed by real-time PCR. Results Compared with model group, the concentration of cholesterol and triglycerides in plasma and liver of Zanthoxylum oleoresin and alkylamide group rats were significantly reduced, and bile acids and neutral steroid concentrations in feces were significantly increased. The mRNA level of 3-hydroxyl-2methylglutaryl CoA reductase（HMG-CoA R） and ileal sodium-dependent bile acids transporter（ASBT） were significantly inhibited, while the mRNA expression of 7α-hydroxylase（CYP7A1） and farnesoid X receptor（FXR） were obviously up-regulated by Zanthoxylum oleoresin and alkylamide. The concentration of triglycerides in blood and liver were obviously reduced, but bile acids and neutral steroid concentrations in feces were increased by essential oil. The mRNA level of 7α-hydroxylase（CYP7A1） and 3-hydroxyl-2methylglutaryl CoA reductase（HMG-CoA R） were significantly down-regulated, while the mRNA expression of farnesoid X receptor（FXR） in liver and ileal was obviously up-regulated in essential oil group rats. Conclusion Zanthoxylum oleoresin, essential oil and alkylamide could ameliorate abnormal lipid metabolism in rats fed a high fat diet, and alkylamide group was much more effective among all groups. The underlying mechanism is due to up-regulated expressions of cholesterol synthesis genes, down-regulated expressions of cholesterol catabolism and ileal reabsorption of bile acids genes.