| 摘要: | 非酒精性脂肪肝炎NASH (nonalcoholic steatohepatitis)屬於慢性脂肪肝疾病的一種。形成NASH的病理因素以two-hit”假說最廣為接受，first hit為脂肪堆積在肝臟，形成脂肪肝，second hit則為氧化壓力及發炎反應造成肝臟脂肪肝炎。毛木耳(學名:Auricularia polytricha)，與黑木耳同屬木耳科木耳屬，已有研究指出具有降血糖、降血漿中膽固醇、抗氧化及抗發炎的作用，因此本實驗探討毛木耳萃取物是否可以藉由改善NASH ”two-hit”假說而達到減輕NASH的肝損傷程度。本研究以四十隻六週齡之雄性Sprauge Dawley大白鼠為實驗動物，經適應後環境隨機分成五組，除對照實驗組之Control組及高脂飲食組(HFD)外，實驗組分為三組，HC組：餵食高脂飲食 8 週後給予Chow diet 4 週，LO組及HO組:餵食高脂飲食 8 週後，分別給予低劑量毛木耳萃取物 0.75％及高劑量毛木耳萃取物1.5％。實驗期間每週測量體重，實驗為期 12 週後犧牲採集血液及肝臟進行分析。結果顯示，餵食毛木耳萃取物可以顯著降低肝損傷指標(AST、ALT)，在first hit方面，降低血漿中葡萄糖含量改善胰島素阻抗，改善血脂代謝及游離脂肪酸含量（p<0.05），在肝臟方面高劑量毛木耳萃取物可以降低肝臟中膽固醇及三酸肝油酯含量（p<0.05），在Second hit方面降低了血漿及肝臟中的脂質過氧化作用及肝臟中的發炎反應（p<0.05），以肝臟病理組織切片觀察結果可知，毛木耳萃取物降低肝臟脂肪滴泡及發炎細胞含量，顯示具有改善肝損傷的效果。綜合以上結果顯示，毛木耳萃取物可以改善NASH動物模式中的”two-hit”假說而達到改善NASH的肝損傷程度。
The pathology leading to non-alcoholic steatohepatitis (NASH) is often characterized by the “two-hit” theory. The “first-hit” is triggered with obesity and insulin resistance, which causes excess hepatic lipid accumulation and hepatic steatosis. The steatotic liver is vulnerable to “second-hits,” which was mediated by inflammation and oxidative stress, resulting in lipid peroxidation then NASH. Auricularia polytricha is found to have therapeutic effects, including anti-inflammatory, antitumor, hypercholesterolemia, etc. The purpose of the study was to examine whether Auricularia polytricha extract （APE） improved liver damage in the animal model of NASH. 40 Male Sprague Dawley rats were randomly divided into five groups. Except the normal and high fat control group (control, HFD group), the experimental groups were fed with high fat diet for 8 weeks then divided into three groups by different amount of APE supplementation (0, 0.5, 1.5%) for 4 weeks. After 12 weeks of treatment, animals were sacrificed; blood samples and liver tissues were collected immediately for biological analysis. The results show that 1.5% APE significantly lowered plasma AST and ALT level and ameliorated hepatic steatosis and necroinflammation; In the first hit, APE improved the dyslipidemia, liver lipid metabolism and plasma free fatty acid level, as well as increased insulin sensitivity; In the aspect of second hit, 1.5% APE decreased the plasma and hepatic MDA content, liver inflammatory response then improved the antioxidant status. In conclusion, APE presents an effective improvement on liver damage of nonalcoholic steatohepatitis model. |
