香椿萃取物對於內毒素誘發RAW264.7細胞氧化性傷害和細胞自噬表現的影響評估

Effects of TS Extracts on the Oxidative Stress and Autophagy in the RAW264.7 Cell Line Induced by Lipopolysaccharide

張華程(Hua-Cheng Chang)

指導教授 ： 蔡麗玉

高雄醫學大學/健康科學院/醫學檢驗生物技術學研究所/碩士(2014年)

摘要

研究背景：敗血症是加護病房中導致死亡的主要原因之一，過去的研究顯示，敗血症會伴隨著細胞內氧化壓力的上升，同時自噬作用是細胞面對壓力的反應機制，在敗血症的情況下或許對於細胞具有保護的作用。香椿（Toona Sinensis）在過去的研究顯示具有多種生物活性，其中包括了抗氧化的功用。因此，在本篇實驗我們選用香椿的天然萃取物來探討抗氧化物對於敗血症細胞模型中氧化壓力以及細胞自噬的影響。
實驗方法：本篇實驗使用RAW264.7細胞株給予細菌內毒素刺激作為敗血症的模型。探討在事先給予香椿萃取物的情況下，對於此敗血症細胞模型超氧陰離子生成、脂質過氧化物的累積、過氧化氮、二氧化氮、一氧化氮的釋放、還原態及氧化態穀胱甘肽（GSH/GSSG）的濃度、抗氧化酵素（GPx、GRx和SOD）的活性以及蛋白質iNOS、GST-Pi、p-mTOR(S2448)、p-mTOR(S2481)、mTOR、HMGB1、Beclin-1和LC3 Ⅱ的表現。
實驗結果：在香椿事先給予的情況下，敗血症細胞模型中可以有效降低超氧陰離子的生成、脂質過氧化物的累積、過氧化氮、二氧化氮、一氧化氮的釋放、氧化態穀胱甘肽的濃度、抗氧化酵素的活性、以及抑制蛋白質iNOS和p-mTOR(S2448)的表現，而蛋白質HMGB1和Beclin-1的表現則是上升，另外LC3 II的生成以及消耗也有促進的現象。
結論：香椿對於RAW264.7細胞株的敗血症細胞模型可以有效降低細胞內氧化壓力的程度並且促進細胞自噬作用的表現，藉此達到保護細胞的效果。

關鍵字

香椿 ； 氧化性傷害 ； 細胞自噬 ； 敗血症

並列摘要

Background: Sepsis is a leading cause of mortality in intensive care units. Previous studies have point out that sepsis is accompanied by increased oxidative stress. Autophagy is a cellular response to stress and would play a beneficial role during sepsis. Toona Sinensis (TS) possess a variety of biological activities, including antioxidant. Therefore, we select TS extracts to investigate the influence of antioxidants on the biological effect of sepsis.
Methods: RAW 264.7 cells were pretreated with various concentrations of TS extracts in the presence or absence of LPS. The levels of superoxide anion, MDA, NO2, NO3, NO, GSH, GSSG, the activities of GPx, GRx, SOD in the cell were determined. The protein expressions of iNOS, GST-Pi, p-mTOR(S2448), p-mTOR(S2481), mTOR, HMGB1, Beclin-1and LC3 Ⅱ were assayed.
Results: Under the exposure to LPS, pretreating with TS extracts decreasing the O2- generations, MDA levels, productions of NO2, NO3, NO, GSSG levels, activities of GPx, GRx, SOD ,and the expressions of iNOS and p-mTOR(S2448), increasing the expressions of HMGB1 and Beclin-1, and accelerating the LC3 II production and consumption.
Conclusion: The pre-supplementation of TS extracts could prevent cell damage from LPS exposure through decreasing the oxidative stress, and increasing autophagy in the RAW264.7 sepsis model.

並列關鍵字

Toona Sinensis ； oxidative stress ； autophagy ； sepsis

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