香瓜茄葉水萃物對於酒精性脂肪肝之影響

Protective effect of aqueous extract from Solanum muriactum Ait Leaf on Alcoholic Fatty Liver

陳秉辰(Bing-Chen Chen)

指導教授 ： 徐成金

中山醫學大學/健康管理學院/營養學研究所/碩士(2016年)

摘要

人體攝入的酒精大多經由肝臟代謝，過量的酒精攝取會導致酒精性肝臟疾病。其致病機轉與酒精代謝所產生的氧化壓力、內毒素和發炎因子有關。因此若能藉由飲食因子降低身體的氧化壓力或慢性發炎或許有助於降低酒精引起的肝臟損傷。香瓜茄是澎湖特有農作物，坊間相傳其對於糖尿病與高血壓有幫助。本實驗室先前的研究發現，香瓜茄果實萃取物能藉由降低糖尿病小鼠體內氧化壓力及發炎反應來改善糖尿病，但對於香瓜茄葉是否也具有改善氧化壓力及抗發炎效果是值得觀察的研究。因此本實驗以Lieber-DeCarli酒精液態飼料誘發小鼠酒精性脂肪肝，並輔以高劑量及低劑量香瓜茄葉水萃物，探討香瓜茄葉水萃物之護肝效果。實驗結果顯示，餵食香瓜茄葉水萃物能有效降低小鼠血清中肝功能指數天門冬胺酸轉胺酶（Aspartate transaminase; AST）及丙胺酸轉胺酶（Alanine transaminase; ALT），對於血清中三酸甘油脂、總膽固醇的含量也有下降之功效。在肝臟組織切片也觀察到餵食低劑量及高劑量香瓜茄葉水萃物均能改善酒精誘發的肝臟脂肪堆積。此外，香瓜茄葉水萃物也提升了小鼠肝臟中抗氧化酵素麩胱甘肽過氧化酶（Glutathione peroxidase; GPx）、過氧化氫酶 (Catalase; CAT）及超氧歧化酶（Superoxide dismutase; SOD）之活性，並降低小鼠肝臟中脂質過氧化產物( Thiobarbituric acid reactive substances; TBARs)及發炎因子TNF-α、IL-6。最後以西方墨點法追蹤小鼠肝臟中脂質代謝相關蛋白SREBP、p-AMPK、 Fatty acid synthesis、Acetyl-CoA carboxylase、PPAR-α，發現餵食香瓜茄葉水萃物能減少SREBP-1、Fatty acid synthesis、Acetyl-CoA carboxylase的表現量，並提高PPAR-α及p-AMPK，促進肝臟中脂質β-氧化。由上述實驗結果顯示，香瓜茄葉水萃物能藉由提升抗氧化機制，降低發炎反應並調控肝臟中脂肪合成，達到改善酒精性脂肪肝之功效。

關鍵字

香瓜茄葉 ； 酒精性脂肪肝 ； 脂質生成 ； 抗氧化

並列摘要

Ingested ethanol is metabolized by liver through various pathways. Chronic alcohol intake leads to alcoholic liver disease (ALD). The pathogenesis of ALD is related to oxidative stress, endotoxins, and cytokines. Solanum muricatum Ait (pepino) is a popular fruit in Penghu, Taiwan. Residents in Penghu consider it as a folk medicine to treat diabetes and hypertension. Our previous study indicated that the aqueous extract from pepino was able to attenuate diabetic progression via its anti-oxidative and anti-inflammatory effects. However, the anti-oxidative and anti-inflammatory effects of pepino leaf in preventing ALD remain unknown. In our present study, Lieber-DeCarli ethanol-containing liquid diet was used to induce alcoholic hepatic injury in C57BL/6 mice. The hepato-protective effects and mechanisms of aqueous extract prepared from pepino leaf (AEPL) were examined. Our results showed that AEPL significantly reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol and triglyceride levels in plasma. Moreover, AEPL significantly elevated the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione content compared to the ethanol-fed group. AEPL also decreased the level of thiobarbituric acid relative substances, interleukin-6, and tumor necrosis factor-alpha in liver. Western blot data indicated that AEPL activated hepatic p-AMPK、PPAR-α and inhibited the activities of lipogenic enzymes such as ACC, SREBP-1c and fatty acid synthase. Our present study suggests that AEPL could protect liver against ethanol-induced oxidative injury and lipid accumulation.

並列關鍵字

Pepino leaf aqueous extract ； Alcoholic fatty liver ； Lipid synthesis ； Anti-oxidative

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