評估乙醯胺基苯酚誘導慢性肝損傷之動物模式並以此模式探討七層塔精油之護肝功效

To Evaluate Hepatoprotective Activity of Ocimum gratissimum L. essential oil on a Chronic Acetaminophen-induced Liver Injury Animal Model

胡芳晴(Fang-Ching Hu)

指導教授 ： 沈立言

國立臺灣大學/生物資源暨農學院/食品科技研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.10522

摘要

根據行政院衛生署在2008年的資料統計中可見慢性肝疾病及肝硬化為國人的十大死因之一，而在十大癌症死因中，肝癌更位居第二位，而肝病所造成的併發症也造成極大的醫療支出，因此在台灣肝病的預防及治療可說是當務之急。肝臟是解毒代謝的重要器官，相對而言，國人因病毒、藥物或酒精毒性引起的肝損傷比率很高。乙醯胺基苯酚(acetaminophen, APAP)是臨床上常用的鎮痛解熱劑，每日建議量為1~4克，當一次服用大量時會導致肝臟損害，而其中毒機轉主要是因肝臟的Phase I代謝途徑中經CYP450氧化酶會產生有毒的中間產物N-acetyl-p-benzoquinoemine (NAPQI)，使肝貯存之glutathione (GSH)含量下降，並造成脂質過氧化而引起肝臟傷害。
而本研究欲建立APAP誘導SD大鼠肝損傷之模式，結果顯示以管餵(oral gavage)方式給予大鼠高劑量(3.5 g/kg bw)仍難以誘導，並與先前本實驗室所建立之APAP誘導Balb/c小鼠肝損傷模式加以比較評估後，由病理組織切片中發現小鼠模式較符合人體的病理進展，因此小鼠模式是較適合之動物模式。七層塔(Ocimum gratissimum L.)是台灣特有的民間草藥，有解毒、利尿、消炎的功能，並有抗脂質過氧化及抗氧化之功效，先前研究中發現，以適當濃度七層塔精油處理大白鼠初代肝細胞，能有效提升GSH相關之抗氧化與解毒代謝系統，因此本實驗藉由已建立之APAP誘導小鼠肝損傷之模式，評估七層塔精油之護肝功效與相關代謝途徑及探討可能的護肝有效成分。
由急性(600 mg APAP/kg bw, 腹腔注射後四小時犧牲)及慢性(400 mg APAP/kg bw, 腹腔注射每週兩次共四週)實驗結果顯示，以APAP誘導小鼠肝損傷會顯著提升血清中aspartate transferase (AST)及alanine transferase (ALT)值，同時嚴重耗損肝臟貯存之GSH含量，並造成肝臟抗氧化酵素glutathione peroxidase (GPx)、glutathione reductase (GRd)、superoxide dismutase (SOD)及catalase (CAT)活性顯著降低(p < 0.05)，也使肝臟解毒酵素glutathione S-transferase (GST)活性下降及cytochrome P450 2E1 (CYP2E1)氧化酶(oxidase)活性上升。而以管餵方式給予小鼠N-acetyl-L-cysteine (NAC)則能有效恢復APAP所造成之肝細胞傷害，且管餵給予2 mg/kg bw七層塔精油也有恢復酵素活性之趨勢。而管餵給予七層塔精油之主成分丁香酚(eugenol)則有類似於七層塔精油的效果，但效果較不顯著，推測七層塔中含有其他可與eugenol有護肝之加成效果的成分。此結果指出，七層塔精油可能具有發展為保健植物產品的潛力。

關鍵字

乙醯胺基苯酚 ； 動物模式 ； 七層塔精油 ； 抗氧化酵素 ； 丁香酚 ； 肝損傷

並列摘要

According to the 2008 report of Department of Health of Taiwan, liver cancer is the second of ten leading cancer deaths, and chronic liver disease and cirrhosis is the seventh of ten leading causes. Therefore hepatoprotective issue is very important in Taiwan. Acetaminophen (APAP) is a mild nonnarcotic, analgesic and antipyretic agent, and is effective and safe when consumed as recommended (1-4 g per day). However, APAP overdose will undergo oxidative conversion by Phase I reactions to the toxic metabolite N-acetyl-p-benzoquinoemine (NAPQI) and may increase the risk of hepatotoxicity. Ocimum gratissimum L. (OG; tree-basil) is an aromatic plant and has been used as a folk medicine in the treatment of hepatitis and cirrhosis in Taiwan. In this study, the applicable animal model by the comparison of SD rats and Balb/c mice was evaluated. Moreover, the hepatoprotective effects of OG essential oil at various concentrations on the serum and liver enzymes, hepatic inflammation, and pathological changes in APAP-intoxicated Balb/c mice were investigated. The experimental results showed that in acute liver injury, OG oil treatment decreased 600 mg/kg bw APAP-induced liver injury. The chronic liver injury results indicated that administration of 400 mg APAP/kg bw increased the aspartate transferase (AST) and alanine transferase (ALT) levels in mice serum along with the enhancement of hepatic lipid peroxidation. APAP also reduced antioxidant enzyme activities (GPx, GRd, SOD and CAT) and glutathione (GSH) level in the liver. Treatment with the 2 mg OG oil/kg bw significantly reversed these changes (p < 0.05). Besides, histopathological examination also revealed the protective nature of OG oil against APAP-induced necrotic change in the liver. The major compound of OG oil is eugenol. However, the treatment with eugenol had less hepatoprotective effects on APAP-induced liver damage compared with OG oil. The results suggest that the OG oil protects hepatic tissues against oxidative damages and can be used as an effective protector against APAP-induced hepatotoxicity.

並列關鍵字

acetaminophen ； animal model ； Ocimum gratissimum L. essential oil ； antioxidant enzymes ； eugenol ； liver damage

參考文獻

行政院衛生署。死因統計。2008。

周筱胤。建立乙醯胺基苯酚誘導小鼠肝損傷模式與探討大棗於小鼠肝損傷之護肝功效。國立台灣大學 食品科技研究所。2008。

邱顯喬。建立乙醯胺基苯酚誘導小鼠肝損傷模式並以此模式探討大蒜精油護肝功效。國立台灣大學 食品科技研究所。2008。

洪銓成。七層塔水萃取物保肝功能之評估。中山醫學大學 生化暨生物科技研究所。2006。

Abdel-Zaher, A. O.; Abdel-Rahman, M. M.; Hafez, M. M.; Omran, F. M. Role of nitric oxide and reduced glutathione in the protective effects of aminoguanidine, gadolinium chloride and oleanolic acid against acetaminophen-induced hepatic and renal damage. Toxicology 2007, 234, 124-134.