七層塔萃取物對於氧化緊迫誘發神經退化之保護作用

七層塔 (Occimum Grastissimum L.; OGL) 是台灣常用民間保健草藥之一，具有許多抗氧化的成分。本實驗我們研究七層塔萃取物對於H2O2誘發神經退化的保護作用。實驗過程是利用PC12細胞為細胞模式，在處理不同濃度的H2O2 (0.5mM、1mM 和2mM) 前1小時先處理不同濃度的七層塔萃取物 (50μg/ml、125μg/ml、250μg/ml 和500μg/ml )，最後在指定時間下觀察結果。因為處理2mM H2O2 4小時後會有起泡 (blebbing) 現象，而0.5mM和1mM H2O2則未發現起泡，因此我們用0.5mM和1mM H2O2進行七層塔萃取物保護作用的研究。結果顯示0.5mM和1mM H2O2處理24小時後，都會造成細胞內接觸酵素活性　(catalase activity)　下降，然而只有1mM H2O2會降低細胞生存率。當預先處理七層塔萃取物時，這些現象會被恢復，而且有劑量依賴的現象。這些結果顯示七層塔萃取物可能有降低氧化傷害誘發神經退化的作用。

Ocimum Gratissimum L. (OGL), containing various antioxidative components, is usually used as one of popular health protective medicines in Taiwan. In this study, we investigated the protective effect of OGL extracts on the H2O2-induced neurodegeneration. By using PC12 cells as a cell model, after pretreatment with various doses of OGL (50μg/ml, 125μg/ml, 250μg/ml and 500μg/ml ) for 1 hour, we then treated various doses of H2O2 (0.5mM, 1mM and 2mM). Since the blebbing was observed in the 2mM H2O2–treated group after 4 hour treatment, but not in the other groups (0.5mM and 1mM H2O2-treated groups), we used these two doses (0.5mM and 1mM H2O2) for the subsequent protective examinations of OGL extracts. The results showed that although both 0.5mM and 1mM H2O2 inhibited the catalase activity after 24 hours treatment, only 1mM H2O2 decreased cell viability. When pretreated with OGL extracts, these phenomenon were recovered in a dose-dependent manner. These data indicated that the OGL extracts may have the protective effect in the oxidative stress-induced neurodegeneration.