基于代谢组学方法研究银耳多糖对非酒精性脂肪肝大鼠的干预作用

本实验通过脂肪乳诱导建立非酒精性脂肪肝(NAFLD)大鼠模型,造模后,银耳多糖组(TP)给予灌胃银耳多糖200 mg/kg,空白组和模型组给予灌胃水,连续灌胃28 d。末次给药后,全自动生化分析仪对血清中胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-c)、高密度脂蛋白胆固醇(HDL-c)、谷丙转氨酶(ALT)、谷草转氨酶(AST)和碱性磷酸酶(ALP)进行测定,苏木精-伊红染色观察肝脏组织病理形态改变。利用气相色谱-质谱获得空白大鼠、NAFLD大鼠和银耳多糖干预大鼠肝匀浆样品的代谢指纹图谱,通过模式判别方法结合代谢组网络数据库,初步确定银耳多糖干预NAFLD大鼠的生物标志物及作用通路,从代谢组学角度探究银耳多糖发挥降脂保肝功效的作用机制。结果表明:银耳多糖可明显降低NAFLD大鼠血清TC、TG、LDL-c、ALT、AST和ALP水平,增加HDL-c水平,并可降低NAFLD大鼠肝脂肪蓄积,减轻肝脏的脂肪变性程度。其作用机制与调节12种生物标志物(苹果酸、山梨醇、甘氨酸、D-葡萄糖醛酸、延胡索酸、D-葡萄糖、柠檬酸、D-核糖、丙酸、辛二酸、顺-乌头酸和乙酰乙酸)所对应的6条主要代谢通路(酮体的合成和代谢,乙醛和二羧酸代谢,抗坏血酸和醛酸代谢,甘氨酸、丝氨酸和苏氨酸代谢,TCA循环和丁酸代谢),使其向正常状态转变有关,从而缓解NAFLD大鼠代谢紊乱的症状,发挥降脂保肝功效。

Intervention of Tremella Polysaccharides on Non-alcoholic Fatty Liver Rats Based on Metabolomics Method

A nonalcoholic fatty liver(NAFLD)rat model was established by fat emulsion. After modeling,the Tremella polysaccharides group(TP)was intragastrically administered with Tremella polysaccharides of 200 mg/kg,the control group and the model group were intragastrically administered with water for 28 days. At the end of administering,biochemical analyzer was used to measure serum total cholesterol(TC),triglyceride(TG),low density lipoprotein cholesterol(LDL-c),high-density lipoprotein cholesterol(HDL-c),alanine aminotransferase(ALT),aspartate aminotransferase(AST)and alkaline phosphatase(ALP). Hematoxylin-eosin staining was used to observe the pathological changes of liver tissue. Gas chromatography-mass spectrometry technology was used to obtain the metabolic fingerprints of liver homogenate samples from control group,NAFLD group and Tremella polysaccharides group. The pattern identification method combined with metabolic network database was used to determine the biomarkers in order to explore the metabolomics mechanism of Tremella polysaccharides on NAFLD rats. The results showed that Tremella polysaccharides could decrease the levels of serum TC,TG,LDL-c,ALT,AST and ALP,increase the level of HDL-c on NAFLD rats. Furthermore,Tremella polysaccharides could reduce the liver fat accumulation and decrease the degree of fatty degeneration in liver of NAFLD rats. Tremella polysaccharides showed obvious hepatoprotective effect on NAFLD rats. The mechanism was related to regulate 12 biomarkers(malic acid,sorbitol,glycine,D-glucuronic acid,fumaric acid,D-glucose,citric acid,D-ribose,propionic acid,suberic acid,and cis-aconitic acid)and 6 major metabolic pathways(synthesis and degradation of ketone bodies,glyoxylate and dicarboxylate metabolism,ascorbate and aldarate metabolism,glycine,serine and threonine metabolism,and TCA cycle)back to normal levels.