酒精攝取所誘導之高同半胱胺酸血症與酒精性肝臟損傷 相關性之探討

Studies on the relationship between alcohol consumption induced hyperhomocysteinemia and alcoholic liver injury

陳雅琳(Ya-Ling Chen)

指導教授 ： 楊素卿

臺北醫學大學/公共衛生暨營養學院/保健營養學研究所/博士(2011年)

https://doi.org/10.6831/TMU.2011.00106

摘要

中文摘要
本研究藉由動物實驗及臨床試驗來探討酒精攝取所誘導之高同半胱胺酸血症與酒精性肝臟疾病之相關性。在動物試驗方面，將雄性Wistar大白鼠分為對照組 (C)、葉酸及維生素B12組 (CV)、酒精組 (E) 及酒精添加葉酸及維生素B12組 (EV) 四組。其中C組及CV組給予正常液體飼料，而E組及EV組給予酒精液體飼料，CV組及EV組於飼料中添加10倍大白鼠基本需要量之葉酸及維生素B12。於實驗第十六週後E組大白鼠血漿同半胱胺酸濃度較C組顯著增加，而血漿葉酸濃度卻顯著降低。另外，E組大白鼠肝臟纖維化指標matrix metalloproteinase-2 (MMP-2) 濃度較C組顯著增加，且血漿同半胱胺酸濃度與肝臟MMP-2濃度呈正相關性。由病理切片與評分可知E組大白鼠有明顯之肝臟纖維化現象。此外E組大白鼠肝臟cytochrom P450 2E1 (CYP2E1) 蛋白質表現量顯著增加，顯示攝取酒精使體內之氧化壓力提高。大白鼠攝取酒精液體飼料並添加葉酸及維生素B12後，與酒精組相比其血漿同半胱胺酸濃度顯著降低，葉酸濃度顯著增加，且肝臟MMP-2濃度及CYP2E1蛋白質表現量亦顯著降低，病理切片結果亦無明顯之纖維化現象。由此推測酒精液體飼料添加葉酸及維生素B12可能可以藉由抑制血漿同半胱胺酸濃度增加，而降低肝臟MMP-2濃度及CYP2E1表現量，進而改善酒精所導致之肝臟損傷的現象。在臨床試驗方面，由國泰醫院肝臟中心及台東馬階醫院分別招募50位及27位酒精性肝臟疾病患者，並徵求年齡及性別相配對之健康受試者作為對照組，共49位。於空腹8小時後抽取患者及健康受試者之血液樣本進行分析。結果顯示，酒精性肝臟疾病患者與健康對照組相比其肝功能指標血漿aspartate aminotransferase (AST)顯著增加，而血漿high density lipoprotein-cholesterol (HDL-C) 及low densitiy lipoprotein-cholesterol (LDL-C) 濃度顯著降低。另外，酒精性肝臟疾病患者血漿同半胱胺酸及維生素B12濃度較健康對照組顯著增加。在抗氧化狀態方面，酒精性肝臟疾病患者紅血球還原態及氧化態麩醯胺酸比值顯著降低，且脂質過氧化物含量顯著增加。綜合以上結果，由動物實驗及臨床試驗可知攝取酒精會造成血漿中同半胱胺酸濃度顯著增加及葉酸濃度顯著降低。由動物試驗可知，大白鼠攝取酒精液體飼料會導致肝臟產生纖維化現象，推測可能與血中同半胱胺酸濃度增加有關，而補充葉酸及維生素B12可使血中同半胱胺酸濃度明顯降低且改善肝纖維化的現象。
關鍵詞: 酒精性肝臟疾病、同半胱胺酸、葉酸、維生素B12、肝臟纖維化

關鍵字

酒精性肝臟疾病 ； 同半胱胺酸 ； 葉酸 ； 維生素B12 ； 肝臟纖維化

並列摘要

Abstract
The purpose of this study is to realize the relationship between alcohol consumption induced hyperhomocysteinemia and alcoholic liver injury. In the animal study, the effect of folate and vitamin B12 on ethanol consumption was investigated. Male Wistar rats weighing about 180 g were divided into four groups: an ethanol (E) group fed an ethanol liquid diet; a control (C) group pair-fed an isoenergetic diet without ethanol; an ethanol and vitamin (EV) group fed an ethanol-containing diet, which was supplemented with folate (10 mg/kg body weight/d) and vitamin B12 (0.5 mg/kg body weight/d); and a control and vitamin (CV) group fed an isoenergetic diet without ethanol, which was supplemented with folate (10 mg/kg body weight/d) and vitamin B12 (0.5 mg/kg body weight/d). After 16 weeks, the plasma homocysteine concentration in the E group was significantly higher than those in the other three groups. The plasma folate concentration in the E group was significantly lower than those in the other three groups. And the hepatic matrix metalloproteinase-2 (MMP-2) concentration in the E group was significantly higher than those of the C and EV groups. Furthermore, the plasma homocysteine concentration at the 16th week and hepatic MMP-2 concentration showed a significant positive correlation in rats of each group. In addition, pathological evidence of liver fibrosis was only observed in group E. Furthermore, hepatic cytochrom P450 2E1 (CYP2E1) protein expression in group E increased significantly. These results suggest that combined treatment of folate and vitamin B12 can alleviate alcoholic liver injury which may be related to normalization of the plasma homocysteine level. In the clinical trial, we comprised 50 patients with alcoholic liver disease (ALD) recruited from Liver Unit, Cathay General Hospital, Taiwan and 27 patients with ALD recruited from Mackay Memorial Hospital Taitung Branch. Forty-nine age- and gender-matched healthy adults served as the control group in this study. Venous blood of each subject was drawn into EDTA-containing tubes after 8 h overnight fasting. The plasma aspartate aminotransferase (AST) activity in patients with ALD were significantly higher than those of the control group. Besides, lower plasma high density lipoprotein-cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C) concentrations were observed in patients with ALD. The plasma homocysteine level is significantly higher in patients with ALD. However, vitamin B12 concentrations were significantly higher in patients with ALD when compared than that in the control group. Furthermore, the erythrocytic reduced glutathione/oxidized glutathione (GSH/GSSG) ratio in patients with ALD was lower than that in the control group, while the plasma thiobarbituric acid reactive substance (TBARS) concentration was higher in patients with ALD than that in the control group, which indicates the increased oxidative stress was occurred in patients with ALD. Taken together, chronic ethanol exposure leads to hyperhomocysteinemia and lower plasma folate concentration. And rats with alcohol consumption induced hepatic fibrosis and it might be related to the increasing of plasma homocysteine. However, combined treatment of folate and vitamin B12 can decrease alcohol-induced hyperhomocysteinemia and meliorate hepatic fibrosis in rats.
keyword: alcoholic liver disease、homocysteine、folate、vitamin B12、fibrosis

並列關鍵字

alcoholic liver disease ； homocysteine ； folate ； vitamin B12 ； fibrosis

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