體外和體內研究蓮蓬萃取物抵抗乙醯胺基苯酚誘導肝損傷之保護作用

乙醯胺基苯酚(acetaminophen, APAP)是一種廣為使用的解熱鎮痛藥物。若APAP使用過量，將導致嚴重的肝損傷(liver injury)甚至造成急性肝衰竭。蓮蓬(lotus seedpod)為傳統中藥材，經研究顯示其富含多酚(polyphenol)物質且具有抗氧化、抗輻射與抗癌活性之作用，然而於保護肝臟方面之研究較少。本篇研究將透過體外與體內實驗探討蓮蓬水萃物(lotus seedpod extracts, LSE)對於APAP所誘導肝損傷之護肝作用及其分子機制作深入探討。首先於細胞實驗中，以APAP誘導人類肝細胞株HepG2細胞損傷，LSE或其主要所含的成分-表沒食子兒茶素(epigallocatechin，EGC)隨劑量增加可降低APAP對於肝細胞的傷害並提高細胞存活率。另外APAP誘導肝細胞凋亡(apoptosis)若有LSE或EGC介入可減少細胞凋亡之發生，其主要是經由抑制細胞凋亡之內在、外在與ASK 1/JNK訊息傳遞路徑進而達到抗細胞凋亡之作用。LSE亦可降低APAP所誘導的發炎調控蛋白iNOS的表現。動物實驗則以BALB/c小鼠每週給予兩次APAP (i.p.; 400 mg/kg)注射誘導肝臟損傷，並分別餵食1%與2% LSE共為期9週。實驗結果顯示，在血液生化數值方面，與APAP組相較，LSE試驗組其肝發炎指標(GOT、GPT)、三酸甘油酯(TG)與血清中發炎因子(IL-6和IL-1β)皆有顯著降低之趨勢。於肝臟抗氧化酵素方面，APAP注射會使小鼠glutathione (GSH)含量降低，但在餵食1% LSE組可顯著回復GSH含量且提升抗氧化酵素catalase和GRd活性。以西方墨點法分析肝臟中細胞凋亡相關蛋白，結果顯示LSE與NAC亦可減少因APAP所誘發的caspase-3、8、9蛋白表現。綜觀以上研究結果，LSE具有減少APAP所誘導肝臟細胞凋亡之效用，於未來可能具有治療藥物性肝損傷之潛力。

關鍵字

乙醯胺基苯酚；肝損傷；蓮蓬萃取物；表沒食子兒茶素；細胞凋亡；發炎

並列摘要

Acetaminophen (APAP) is one of the most widely used analgesic and antipyretic drug in the world. APAP overdose will lead to severe liver injury and have potential to result in acute liver failure. Lotus seedpod, a traditional herbal, is rich in polyphenol and has been shown to possess antioxidant, radioprotective and anti-cancer activities. However, there were no significant reports on the hepatoprotective effect of LSE. In this study, we examined the hepatoprotective role of lotus seedpod extracts (LSE) in vitro and in vivo. Firstly, LSE or its main compound epigallocatechin (EGC) dose-dependently improved the survival of human hepatocyte HepG2 cells from APAP-induced loss of viability. LSE or EGC showed potential in reducing APAP-induced occurrence of apoptosis confirmed by morphological and biochemical features, including an increase in the distribution of hypodiploid phase, apoptotic bodies formation and caspases activation. Molecular data showed that antiapoptotic effects of LSE or EGC might be mediated via intrinsic, extrinsic and ASK 1/JNK apoptotic signaling pathways. Further data showed that LSE inhibited the APAP-induced the protein expression of iNOS. In vivo study, the BALB/c mice were supplemented with or without LSE (1% and 2%) during the 9-week treatment period in the presence or absence of APAP (i.p.; 400 mg/kg) twice per week. Our investigation demonstrated that LSE treatments significantly decreased the serum levels of the hepatic enzyme markers GOT and GPT, and triglyceride (TG) induced by APAP. LSE also inhibited the serum levels of inflammatory cytokines (IL-6 and IL-1β) during APAP treatment. LSE at 1% significantly restored the decrease in glutathione (GSH) content and elevated the levels of antioxidant enzymes, including catalase and glutathione reductase (GRd), in the liver. Western blotting data demonstrated that LSE and N-acetylcysteine (NAC) inhibited the expression of caspase -3, -8, -9 in APAP-induced liver injury. Our data imply that LSE reduced APAP-induced hepatocytes apoptosis, and these findings may open interesting perspectives to the strategy in treatment of liver injury.

並列關鍵字

acetaminophen ； liver injury ； lotus seedpod extract ； epigallocatechin ； apoptosis ； inflammation

參考文獻

48. Wu CH, Yang MY, Chan KC, Chung PJ, Ou TT, Wang CJ.

69. Portt L, Norman G, Clapp C, Greenwood M, Greenwood MT.

1. Fainboim L, Cherñavsky A, Paladino N, Flores AC, Arruvito L. Cytokines and chronic liver disease. Cytokine & growth factor reviews. 2007; 18:143-157.

2. Sherlock S and Dooley J. Diseases of the liver and biliary system. 2008: John Wiley & Sons.

4. Thomson AW and Knolle PA. Antigen-presenting cell function in the tolerogenic liver environment. Nature Reviews Immunology. 2010; 10: 753-766.

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體外和體內研究蓮蓬萃取物抵抗乙醯胺基苯酚誘導肝損傷之保護作用

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