- 學位論文
探討龍眼花水萃物對倉鼠血脂之影響
Investigation of the Effect of Longan Flower Water Extract on Blood Lipids in Hamsters
摘要
高血脂症與動脈粥樣硬化發展之進程息息相關。依據我國103年國人十大死因統計顯示，心臟疾病、腦血管疾病以及高血壓性疾病分別高居第二、第三及第八順位，其與血脂異常和動脈粥樣硬化關係密切。近年來，許多相關文獻指出，龍眼花具有調節血糖、改善胰島素阻抗及抗氧化之現象。因此，本研究欲對龍眼花是否具調節血脂作用作進一步探討。 實驗設計將雄性黃金敘利亞倉鼠分為四組：B 組餵飼一般商業飼料，為基礎組；C 組餵飼高油脂高膽固醇飼料，為控制組；L 組餵飼高油脂高膽固醇飼料並同時每天灌食 250 mg/kg BW 龍眼花水萃物；H 組餵飼高油脂高膽固醇飼料並同時每天灌食 500 mg/kg BW 龍眼花水萃物。實驗為期八週，期間測量體重及記錄攝食量，並收集禁食血清測定三酸甘油酯、總膽固醇、高密度脂蛋白膽固醇與低密度脂蛋白膽固醇濃度等數值。實驗期結束，收集檢體測定相關生化指標和膽固醇代謝相關蛋白之表達。 研究結果顯示，C 組之禁食血清及肝臟中三酸甘油酯與總膽固醇含量、血清低密度脂蛋白膽固醇佔總膽固醇之比例 (LDL-C/TC) 與血清 TBARS 含量均顯著高於 B 組，且血清高密度脂蛋白膽固醇佔總膽固醇之比例 (HDL-C/TC) 與 B 組相比顯著較低，顯示高油脂高膽固醇飲食成功誘發高血脂症，並增加體內氧化壓力。在食材處理組部分，L 組血清 TBARS 含量雖與 C 組無顯著差異，但與 B 組相比亦無顯著差異。而 H 組倉鼠之禁食血清及肝臟中總膽固醇含量與血清 LDL-C/TC 均顯著低於 C 組，且血清 HDL-C/TC 與 C 組相比也顯著提高；在血清 TBARS 含量部分，H 組雖與 C 組無顯著差異，亦與 B 組差異。此外，經膽固醇代謝相關蛋白質表現量分析發現，L 組 SREBP2 蛋白質表現量顯著低於 C 組，且 HMGCR 蛋白質表達雖與 C 組無顯著差異，但與 B 組亦無顯著差異。而高劑量龍眼花水萃物之給予則可減少 SREBP2 及 HMGCR之表達，並顯著提升 AMPK 之表現量。推測龍眼花水萃物透過調節膽固醇生合成路徑中 SREBP2、HMGCR 及 AMPK 之表達，進而減少禁食血清與肝臟中總膽固醇含量。綜上所述，龍眼花水萃物具改善高膽固醇血症之功效，同時也有降低體內氧化壓力之潛力。
並列摘要
Hyperlipidemia is highly related to the progress of Atherosclerosis. According to the statistical result of Taiwan top 10 causes of death in 2014, heart disease, cerebrovascular disease, and hypertensive disease is at NO.2,3 and 8 respectively. These three diseases are closely related to dyslipidemia and Atherosclerosis. In recent years, many related pieces of research have pointed out that Longan flower has the ability to improve not only blood glucose level but also insulin resistance and antioxidation. In this way, this research intends to find out the further effect of Longan flower on adjusting blood lipids. The experiment divided male Golden Syrian hamsters into 4 groups: Group (B) was fed with normal chow diet as basal group; Group (C) was fed with high fat high cholesterol diet as control group; Group (L) was fed with high fat high cholesterol diet, and was tube feeding 250mg/kg BW Longan flower water extract as well; Group (H) was fed with high fat high cholesterol diet and was tube feeding 500mg/kg BW Longan flower water extract as well. The experiment lasted for 8 weeks, body weight and food intake were measured routinely during the experiment, fasting serum was collected to measure TG, TC, HDL, LDL and other related data. After the experiment, correlative organs were harvested to measure biochemical levels and expression levels of proteins that are involved in cholesterol metabolism. The results show the TG, TC, LDL-C/TC levels in fasting serum and TBARS level in serum of Group (C) are highly above those of Group (B), and HDL-C/TC level in Group (C) is lower than Group (B), indicating the successfully induce of hyperlipidemia and raise of oxidative stress of Group (C). In Longan flower treatment groups, Group (L)’s serum TBARS level shows no significant difference to not only Group (C) but also Group B. Meanwhile, Group (H)’s both TC levels in fasting serum and liver and LDL-C/TC level in serum are significantly lower than Group (C), HDL-C/TC level is higher than Group (C) in a remarkable way. When it comes to serum TBARS section, although Group (H) doesn’t show a significant difference with Group (C), it also shows no difference with Group (B). What’s more, after working on related protein expression of cholesterol metabolism, SREBP2 level of Group (L) is much lower than Group (C) and HMGCR protein level shows no difference to both Group (B) and Group (C). On the other hand, high level of Longan flower water extract can lower the expression of SREBP2 and HMGCR, it can also improve AMPK expression greatly. In this way, an assumption is made that Longan flower reduce the TC levels in both fasting serum and liver by affecting SREBP2, HMGCR and AMPK expression in cholesterol biosynthesis pathway. To conclude, Longan flower water extract has the ability to improve hyperlipidemia and the potential to lower oxidative stress in the body.