基于尿液代谢组学的土三七诱导大鼠肝损伤的机制研究

Mechanism study on Gynura segetum induced liver injury in rats based on urine metabonomics

目的:采用代谢组学技术检测土三七干预后大鼠尿液中内源性代谢物的变化,分析土三七诱导大鼠肝脏损伤的可能机制。方法:12只SD大鼠,随机分为对照组和土三七组,每组6只。土三七组大鼠灌胃给予7.5 g·kg-1·d-1土三七水煎液,对照组大鼠灌胃给予等体积纯净水,连续给药14 d。末次给药后,代谢笼收集大鼠尿液,并分离大鼠血清和肝脏组织。生化分析仪检测血清ALT、AST、TBIL和TG水平; HE染色后光镜下观察肝组织病理形态学变化。液质联用(LC-MS)技术检测尿液样本,主成分分析评价组间代谢谱差异,筛选并鉴定差异性代谢物,分析代谢通路。结果:与对照组比较,土三七组大鼠血清ALT、AST和TBIL水平显著增高(P<0.05,P<0.01); HE染色结果显示,土三七组大鼠肝组织结构破坏,细胞排列紊乱,有炎性细胞浸润。代谢组学分析显示,组间代谢谱差异明显,尿液样本中共鉴定出马尿酸、苯丙氨酸、N-甲基烟酰胺、氧化三甲胺等40个差异代谢物,涉及缬氨酸、亮氨酸和异亮氨酸生物合成,苯丙氨酸、酪氨酸和色氨酸生物合成,苯丙氨酸代谢,烟酸和烟酰胺代谢,Vit B2代谢等主要代谢通路。结论:土三七诱导大鼠肝脏损伤,其机制可能与苯丙氨酸生物合成和代谢、烟酸和烟酰胺代谢、Vit B2代谢等有关。

Objective: To detect the changes of urinary endogenous metabolites in rats treated with Gynura segetum based on metabonomics,and analyze the possible mechanism of Gynura segetum induced liver injury in rats. Methods: 12 SD rats were randomly divided into the control group and Gynura segetum group,6 rats in each group. The rats in the Gynura segetum group were treated with decoction of Gynura segetum at daily dose of 7.5 g/kg by intragastric administration,while the rats in the control group were treated with pure water at equal volume,with a course of 14 days. After the last administration,the urine of rats was collected by metabolic cage,and the serum and liver tissues were separated. The serum levels of ALT,AST,TBIL and TG were detected by biochemical analyzer. HE staining was used to observe the pathological changes of liver tissue under light microscope. The urine samples were detected by liquid chromatography-mass spectrometry( LC-MS). Principal component analysis was used to evaluate the differences of metabolic profiles between the two groups,the differential metabolites were screened and identified,and the metabolic pathways were analyzed. Results:Compared with the control group,the serum levels of ALT,AST and TBIL were increased significantly( P<0.05,P<0.01). HE staining showed that the liver tissue structure of rat in Gynura segetum group was destroyed,the cells arranged irregularly,and the inflammatory cell infiltration was observed. Metabonomics analysis showed that there were significant differences in metabolic profiles between the two groups. A total of 40 differential metabolites,such as hippuric acid,phenylalanine,N-methylnicotinamide and trimethylamine oxide,were identified in urine samples,involving valine,leucine and isoleucine biosynthesis,phenylalanine,tyrosine and tryptophan biosynthesis,phenylalanine metabolism, nicotinic acid and nicotinamide metabolism, Vit B2 metabolism and other major metabolic pathways.Conclusion: Gynura segetum can induce liver injury in rats,which may be related to phenylalanine biosynthesis and metabolism,nicotinic acid and nicotinamide metabolism,Vit B2 metabolism.