| 摘要: | 背景與目的：狼尾草（Pennisetum purpureum），俗稱牧草。紫色狼尾草則是由台南畜產試驗所改良的特殊品種，命名為狼尾草五號。該狼尾草含有高量花青素與多酚類且具有抗氧化的功效。近年來國人的十大死因肝病總是位列其中，而肝臟在人體扮演著代謝及解毒兩項重要角色，台灣酒精性肝炎的人數率逐年增加，且常會轉變成肝硬化及肝癌，因此肝臟疾病預防及延緩發生實為全民健康的重要課題；由於酒精性肝損傷與氧化壓力有著密切的關係，因此本研究以狼尾草餵食小鼠來探討其是否具有保護急性酒精性肝損傷的效應，以及對肝臟的解毒代謝酵素系統的影響情形。方法：第一部份以體外抗氧化試驗，探討狼尾草水萃取物的總抗氧化能力、清除DPPH能力、還原力、螯合亞鐵離子能力。第二部分為動物模式。本實驗採用25隻鼠齡七週大的C57BL/6J 雄性小鼠，隨機分成四組分別為控制組（CS, Control+Saline）、管餵酒精組 （CA, Control+Alcohol）、狼尾草組（PS, 5% Pennisetum +Saline）、狼尾草+管餵酒精組 （PA, 5% Pennisetum + Alcohol），飼養期四週，於犧牲前12小時管餵酒精(60% Alcohol, 10ml/Kg BW)或生理食鹽水。犧牲當天取得血液、肝臟，分析下列項目: 血漿Glutamic Pyruvic Transaminase （GPT）、LDH（Latate dehydrogenase）活性試驗，肝臟Catalase（CAT）、Superoxide Dismutase（SOD）、Glutathione Peroxidease（GPX）、Glutathione Reductase（GR）、glutathione S-transferase（GST）酵素活性，肝臟Glutathione（GSH）、Thiobarbituric Acid Reactive Substances （TBARS）濃度以及肝臟 Vit.E濃度、肝臟細胞色素P4503A、2E1蛋白質含量。結果：第一部份，狼尾草水萃取物在總抗氧化能力活性測試、清除DPPH能力、還原力、螯合亞鐵離子測定，隨樣品濃度上升數值也隨之提升。第二部分由Two-way ANOVA 統計得知，CA 組的 GPT、LDH 活性顯著高於 CS 組，顯示小鼠經酒精管餵後會誘導急性肝損傷。PA 組的 GPT 活性雖比 CA 組略有降低，但沒有顯著差異。在肝臟 GSH試驗中 PS 組比起 CS 組有顯著降低，但 PA 組與 CA 組比起 CS 組則沒有顯著差異。肝臟 TBARS 試驗中，四組濃度間並無顯著差異。而肝臟中抗氧化酵素活性 CAT、SOD、GST 在四組間並沒有顯著差異，在 GPX 中 PS組比起CS組有顯著降低，但 PA 組與 CA 組比起 CS 組則沒有顯著差異，而GR 則是 PS 組比起 CA 組有顯著上升。肝臟 Vit.E 濃度 CA 組、PS 組與PA組比起CS組都有顯著下降。肝臟 CYP3A 蛋白含量 PS 組與 PA 組比起 CS 組有顯著下降，但 CA 組比起 CS 沒有顯著差異。CYP2E1 蛋白含量於四組間都無顯著差異。結論：狼尾草水萃物具體外抗氧化能力。動物實驗中，經急性酒精誘導肝損傷後，狼尾草組的GPT值有降低的趨勢。狼尾草雖使肝臟中 GPX 活性與 GSH 濃度降低，但是對於肝臟脂質過氧化壓力方面並沒有造成顯著的差異。狼尾草組在肝臟Vit.E濃度及CYP3A 蛋白含量有顯著降低，顯示狼尾草會影響肝臟CYP3A 的 調節，而Vit.E 濃度與 CYP3A 間可能有相互影響的關係。
Background and Purpose: Pennisetum purpureum is commnly known as grass. Purple Pennisetum is a new species and has been named as Pennisetum 5th by the Tainan National Livestock Research Institute. Pennisetum contains high levels of anthocyanins and polyphenols which owning antioxidant effect. Nowadays, liver disease is one of the top ten causes of death for people in Taiwan. The alcoholic hapatitis and viral hepatitis which is increasing in Taiwan may then develop into liver cancer. Therefore, prevention of liver disease and protection of liver against oxidative stress is an important issue for the public health. Oxidative stress produced during alcohol metabolism causes liver cell injury. In this study, we would like to explore the protection effects of Pennisetum on acute alcoholic liver injury in mice, and the liver detoxification enzyme system was also measured. Methods: In part 1, the antioxidant effect of water extract of Pennisetum were measured in vitro. The Trolox equivalent antioxidant capacity（TEAC）, scavenging effect on 2,2-Diphenyl -1-picrylhydrazyl radicals , reducing power , chelating effects on ferrous ions were included. In part 2, the animal model was used to investigate the protection effects of Pennisetum. In the second part, 25 seven-weeks old C57BL/6J male mice were divided into four groups as the following: the control group (CS, Control + Saline,), alcohol group (CA, Control + Alcohol), PS group (5% Pennisetum + Saline,) and PA group ( 5% Pennisetum + Alcohol). All groups were fed for four-weeks. The alcohol (60% ethanol, 10ml/Kg BW) or saline were tube fed once 12 hours before sacrifice. Results: In part 1, all the antioxidant indicators measured showed an increasing effects as the concentration of Pennisetum extract increased. In the second part, The plasma activities of GPT and LDH in CA group were significantly higher than in CS group. This suggested that acute liver injury was induced in mice tube fed with alcohol. The GPT activity of the PA group was slightly lower than the CA group, but showed no significant difference. There were no significant differences among the four groups in TBARS levels and the antioxidant enzyme activities of CAT, SOD and GST in liver. The GPX activity and GSH levels in liver showed significantly lower in PS group than the CS group, but no significant differences among the PA, CA and CS group. The liver GR activity has a significant increase in the PS group than the CA group. The concentrations of liver Vit. E in CA group, PS group and PA group decreased significantly than in the CS group. In the PS and PA group, liver CYP3A protein content were significantly decreased when compared to the CS group. No significant differences were found in the CYP2E1 protein content among the four groups. Conclusion: Pennisetum extract showed antioxidant ability in vitro test. In animal model,Pennisetum feeding decreased the GPX activity and GSH concentration in liver, but showed no increase in liver lipid oxidation. There was no obvious protection effect of Pennisetum on acute ethanol-induced liver injury in mice. The inhibition of CYP3A protein expression was found by Pennisetum feeding. The interaction between Vit.E and CYP3A needs further investigation. |
