| 摘要: | 台灣產石斛抗氧化活性及急性肝損傷保護作用
研究生 鄭承瑋
中國醫藥大學 藥學院 中國藥學研究所
中文摘要
本研究目的主要探討台灣的石斛品種(黃花石斛、櫻石斛、銅皮石斛)及有瓜石斛市售品的抗氧化活性以及對四氯化碳誘導的急性肝臟傷害的保護效果，首先我們以總多酚和類黃酮含量試驗來評估四種石斛活性成分含量的多寡，再以DPPH自由基清除試驗和還原力試驗以及亞鐵螯合能力試驗等三種抗氧化能力試驗來評估四種石斛的抗氧化活性，然後經由上述試驗結果,再選擇具有最佳抗氧化活性的石斛品種來探討其對四氯化碳誘導的急性肝損傷的保護效果，並測定catalase , SOD , GPX ,GSH , GR , GST及MDA，最後觀察其肝臟病理切片以探討石斛保護四氯化碳誘導急性肝損傷之機轉。
在多酚以及類黃酮試驗中，無論在總多酚或類黃酮項目上，有瓜石斛具有相對較多的含量，特別的是在總多酚含量上，次多品種為黃花石斛，而在類黃酮含量上，次多品種為銅皮石斛。
在體外抗氧化實驗(DPPH清除能力試驗、還原力試驗、亞鐵離子螯合能力試驗)中，以有瓜石斛抗氧化效果最佳，其次則為黃花石斛，雖然在亞鐵螯合試驗中有瓜石斛的螯合能力略低於櫻石斛，但是差異不大，因此我們選擇有瓜石斛和黃花時斛進行四氯化碳誘導急性肝損傷實驗。
黃花石斛和有瓜石斛對四氯化碳所引起血清GOT及GPT活性升高有皆顯著降低，並減少MDA濃度，此結果與病理切片結果一致。
黃花石斛和有瓜石斛可以提升因四氯化碳所減少抗氧化酵素(GPx, GR, GST, catalase與SOD)活性和抗氧化物質GSH濃度，綜合實驗結果，顯示黃花石斛及有瓜石斛皆具有抗氧化活性，兩者對四氯化碳誘導的急性肝臟損傷有保護作用，其保護機制可能經由提升自由基清除酵素的活性和GSH含量來達到保護效果。有瓜石斛價格便宜且功效佳，值得進一步深入探討其對慢性肝損傷的保護效果。
Anti-oxidative activity and acute liver injury protective effects of Dendrobium species in Taiwan
Cheng Wei Cheng
Graduate Institute of Chinese Pharmaceutical Sciense,
College of Pharmacy, China Medical University
Abstract
The aims of this study were intended to investigate the anti-oxidative activity, anti-oxidative substance content and hepatoprotective effect of four species of Herba Dendrobii [Dendrobium tosaense (DT), D. linawanum (DL),
D. moniliforme(DM), Ephemerantha fimbriata (EL)] in Taiwan. First, we estimated the contents of total flavonoid and total polyphenol in the four speciess. The anti-oxidative activities of the four species were determined using DPPH free radical scavenging assay, reduce power assay, ferrous metal-
chelating capacities assay in vitro. The hepatoprotective effect of DT and EL was determined using CCl4-induced acute liver injury. The activities of glutamate-oxalate-transaminase(GOT), glutamate-pyruvate-transaminase(GPT), superoxide dismutase(SOD), glutathione peroxidase(GPx), glutathione reductase
(GR), glutathione-S-transferase(GST), and the levels of glutathione(GSH) and malondialdehyde (MDA) were measured. The results were confirmed by histological examinations .
In anti-oxidative test in vitro, the results shown that DT possessed the better anti-oxidative activity than the others and was similar with EF. When mice were treated with CCl4 in the absence of DT and EF, the activities of GOT and GPT, and MDA levels were increased, while the activities of antioxidant enzymes (SOD, GPx, Catalase, GR, GST) were decreased. When the mice were treated with CCl4 in the presence of DT and EF, the activities of sGOT and sGPT, and MDA levels were significantly decreased, while the activities of antioxidant enzymes, and the GSH level were increased. The above results were confirmed by histological examinations. DT and EF contained polyphenol and flavonoid.
These results suggested that DT and EF possess anti-oxidative activity and protect against CCl4-induced acute liver injury in mice by increasing theanti-oxidant enzymes activities and GSH level. |
