- 學位論文
諾麗果之安全性及護肝與對於血脂影響之評估研究
Evaluations of safety, hepato-protection and effects on blood lipids of Noni fruit
摘要
本研究第一部分是以諾麗果汁作為實驗材料，探討其安全性及對四氯化碳誘導之大白鼠肝損傷的修復功能。結果顯示，以17.5 ml/kg諾麗果汁餵食Wistar鼠2週，對其肝腎功能皆無不良影響。且在此劑量下，能夠顯著增加大白鼠肝臟中麩胱甘肽總量 (total glutathione) 及還原態麩胱甘肽 (reduced glutathione) 的含量。而於8週的四氯化碳誘導肝損傷實驗中，Wistar鼠隨機分為六組，分別為正常組、CCl4 (0.5 ml/隻) 組、CCl4+silymarin (200mg/kg) 組、CCl4＋0.175 ml/kg諾麗果汁組、CCl4＋1.75 ml/kg諾麗果汁組及CCl4＋17.5 ml/kg諾麗果汁組，每天給予試驗品及每週一、四給予四氯化碳誘導其肝損傷。於第2週時，諾麗果汁三組尚具護肝能力，其AST、ALT活性顯著低於CCl4組。但於犧牲當週時，僅剩CCl4＋17.5 ml/kg諾麗果汁組之AST活性顯著低於CCl4組。而在肝臟抗氧化酵素SOD (superoxide dismutase)、catalase及GPx (glutathione peroxidase) 活性方面，CCl4組之活性皆顯著低於正常組。而諾麗果汁三組之SOD活性，則與正常組無顯著差異。至於肝臟中抗氧化物質方面，諾麗果汁三組之氧化態麩胱甘肽(oxidized glutathione, GSSG) 含量皆顯著低於CCl4組。且CCl4＋1.75 ml/kg諾麗果汁組及CCl4＋17.5 ml/kg諾麗果汁組之氧化壓力指標GSH/GSSG比值皆顯著高於CCl4組。由肝臟病理切片結果發現，CCl4＋0.175 ml/kg諾麗果汁組及CCl4＋17.5 ml/kg諾麗果汁組其肝細胞壞死程度顯著較CCl4組輕微。以上結果顯示，諾麗果汁可提升CCl4誘導之肝損傷大鼠之肝臟抗氧化能力及減少肝細胞之壞死。 本研究第二部分是以諾麗果汁冷凍乾燥粉末作為實驗材料，探討其對於高糖高脂誘導之倉鼠脂質代謝異常的影響。將十五隻倉鼠分為五組，分別為正常飲食組、高脂飲食 (High fat diet, HFD) 組、HFD+0.25%Noni組、HFD+0.5%Noni組及HFD+1%Noni組。7週的高糖高脂飲食確實使倉鼠之肝臟組織及腹部內臟脂肪組織重量較正常飲食組別顯著增加。而其血中三酸甘油酯及膽固醇含量亦較正常飲食組顯著上升。而同時攝食諾麗果汁冷凍乾燥粉末之高脂飲食組別，與高脂飲食組間並無顯著差異。由結果推測，諾麗果汁對於改善在高糖高脂飲食下所造成的血中三酸甘油酯及膽固醇上升，似乎沒有效果。但攝食諾麗果汁冷凍乾燥粉末之高脂飲食組別，其肝腎功能指數與正常飲食組間無顯著差異。推測此三劑量對倉鼠肝腎功能無不良影響產生。綜合以上，由本研究可知，諾麗果汁能夠藉由提升體內抗氧化能力而降低四氯化碳所引起的肝細胞壞死程度，但於降血脂方面，似乎沒有效果。
並列摘要
The aim of this study was to evaluate the safety and liver protection against carbon tetrachloride (CCl4) induced liver injury of Noni juice in rats. The results showed that 17.5 ml/kg Noni juice didn’t have adverse effects on liver and kidney in rats. The total glutathione and the reduced glutathione content in liver in rats treated with 17.5 ml/kg Noni juice were significantly increased as compared to control. In the CCl4-induced liver injury experiment, Wistar rats were administrated orally with Noni juice everyday (0.175, 1.75, and 17.5 ml/kg) and CCl4 (0.5ml/rat) twice a week for 8 weeks. CCl4 increased the AST and ALT levels in serum as compared with control group. Co-treatment with 17.5 ml/kg Noni juice decreased the AST level as compared with CCl4-treated group. CCl4 also significantly (p<0.05) decreased the activities of SOD, catalase, and GPx (glutathione peroxidase) and increased the GSSG content in liver as compared with control group. Co-treatment with Noni juice (0.175, 1.75 and 17.5 ml/kg) significantly increased the SOD activity and decreased the GSSG content as compared with CCl4-treated group. And the GSH/GSSG ratios in Noni juice-treated groups were also significantly increased as compared with CCl4- treated group. Liver histopathological results showed that Noni juice (0.175 and 17.5 ml/kg) reduced the necrotic cells induced by CCl4 in rats. The data suggest that oral administration with Noni juice for 8 weeks increased the level of antioxidants and decreased the extent of liver injury induced by CCl4 in rats. In the other part of this experiment, the effects of freezing dried powder of Noni fruit on lipid metabolism in hamsters fed with high fat diet were evaluated. 15 hamsters were divided into 5 groups and gave them the modified diet according to PMI#5001 for 7 weeks. The high fat diet contained 15% coconut oil, 5% soy bean oil and 0.1% cholesterol. The three experimental groups contained 0.25%, 0.5% and 1% freezing dried powder of Noni fruit. It showed that HFD significantly increased the weights of liver and abdominal visceral adipose tissue as compared with control group. The levels of serum triglyceride and cholesterol were also significantly increased. Three doses of freezing dried powder of Noni fruit neither decreased the weight of liver and abdominal visceral adipose tissue nor reduced the levels of serum triglyceride and cholesterol. However, the levels of AST, ALT, BUN and creatinine showed no difference between three experimental groups and control group. It suggested that freezing dried powder of Noni fruit didn’t have adverse effects on liver and kidney in hamsters. In summary, the present study showed that Noni fruit could increase the level of antioxidants in liver and reduce the necrotic cells that were induced by CCl4 in rats. It also showed that freezing dried powder of Noni fruit didn’t have influence on hypolipidemia.