餵食炸油對天竺鼠肝中cytochrome P450及其他解毒酵素活性之影響

Effects of Deteriorated Frying Oil on Liver Cytochrome P450 and Other Detoxifying Enzymes Activity in Guinea Pigs

張鳳珍(Feng-Chen Chang)

指導教授 ： 劉珍芳

臺北醫學大學/公共衛生暨營養學院/保健營養學研究所/碩士(1997年)

摘要

本研究的目的欲探討餵食炸油於無法合成維生素C的天竺鼠時，對天竺鼠體內解毒酵素系統的影響。將新鮮黃豆油在200±5℃下油炸薯條，每天油炸6小時，連續4天共油炸24小時，作為實驗用炸油。將新鮮油、炸油分別以15％重量混入不含維生素C的純化飼料，再分別添加300ppm維生素C作為F300、D300組的飼料，餵養剛離乳之雄性天竺鼠，共為期17週。結果顯示，炸油組(D300)生長及攝食效率較差，血漿及肝腎組織中維生素C含量均明顯低於F300組，而肝、腎組織中TBARS(Thiobarbituric acid reactive substances)含量較高。餵食炸油之天竺鼠肝中UDP-Glucuronyl-Transferase(UGT)活性高於新鮮油組，Glutathione S-Transferase(GST)活性於兩組間則沒有差異。且炸油組肝微粒體中cytochrome P450含量明顯增加；cytochrome P450相關酵素：NADPH-cytochrome c reductase活性亦明顯高於新鮮油組。在測定異構酉每特性方面，代表CYP1A1的EROD之活性以炸油組較高，代表CYP2B的PROD之活性則沒有差異。但經由SDS-PAGE及Western immunoblotting之檢定，發現CYP1A1 isoform之表現於炸油組及新鮮油組間並無顯著地差異。由上述結果推測，餵食炸油會消耗天竺鼠體內維生素C，並可增加（誘發）天竺鼠肝中解毒酵素系統相關酵素之活性，但為何種cytochrome P450之異構酉每仍須進一步地探討。

並列摘要

The purpose of this study is to investigate the effect of deteriorated frying oil (DFO) on the liver detoxifying enzyme system of guinea pigs. DFO sample was obtained by flying potato chips in soybean oil under 200±5℃ for 24 hours. Fifteen male weaning guinea pigs were fed 15% DFO or fresh soybean oil supplemented with 300 ppm ascorbic acid diet for 12 weeks. It was shown that guinea pigs fed the DFO diet (D300) had worse growth and lower feed efficiency than in the control (F300). The contents of vitamin C in plasma, liver and kidney of D300 were lower than the the control (F300). Besides, the contents of TBARS (Thiobarbituric acid reactive substance) in liver and kidney of D300 were higher than F300. The activity of liver UGT (UDP-Glucuronyl-Transferase) of D300 was higher than F300 and there was no difference between two groups in GST (Glutathione-S-Transferase) activity. By the way, the content of total cytochrome P450 (CYP450) and the activity of NADPH-cytochrome c reductase of D300 were increased significantly. In the detection of characterisitics of cytochrome P450 isozyme, the activity of EROD (Ethoxyresorufin O-deethylase) which presents CYP1A1 was higher in D300 than in F300. There was no difference in the activity of PROD (Pentoxyresorufm O-dealkylase) which presents CYP2B between two groups. However, it was founded that the amount of CYP1A01 isoform of D300 did not differ apparently from it of F300 through the SDS-PAGE and western immunoblotting. Our results demonstrated that the activities of relative enzymes in the liver detoxifying enzymes system of guinea pigs could be induced by DFO feeding, but it needs the advanced research to identify the major type of cytochrome P450 isozyme which works under this condition.

並列關鍵字

Deteriorated frying oil ； guinea pig ； cytochrome P450 ； ascorbic acid ； UDP-Glucuronyl-Transferase