Cantwell H, Devery R
School of Biological Sciences, Dublin City University, Dublin, Ireland.
Cell Biol Toxicol. 1998 Dec;14(6):401-9. doi: 10.1023/a:1007595527176.
Suspension cultures of isolated rat hepatocytes were used to investigate whether 7-ketocholesterol and cholestane-3beta,5alpha,6beta-triol exert oxidative stress in cells as manifested by increased lipid peroxidation and the induction of the antioxidant enzymes catalase, glutathione peroxidase and superoxide dismutase. The oxysterols were found to increase the levels of both superoxide dismutase and catalase and to have variable effects on glutathione peroxidase activity. Increased lipid peroxidation was not observed, indicating that the endogenous antioxidant defense system was capable of protecting against any oxidative stress that might otherwise by exerted by 7-ketocholesterol or cholestane-3beta,5alpha,6beta-triol. Covi-ox, a natural tocopherol blend reduced the effects of both oxysterols on the antioxidant enzymes. A concurrent reduction in the production of thiobarbituric acid-reactive substances in Covi-ox-treated cells is indirect evidence that reactive oxygen species were produced by oxysterols in hepatocyte suspension cultures.
利用分离的大鼠肝细胞悬浮培养物来研究7-酮胆固醇和胆甾烷-3β,5α,6β-三醇是否会在细胞中引发氧化应激，其表现为脂质过氧化增加以及抗氧化酶过氧化氢酶、谷胱甘肽过氧化物酶和超氧化物歧化酶的诱导。发现氧化甾醇会增加超氧化物歧化酶和过氧化氢酶的水平，并对谷胱甘肽过氧化物酶活性产生不同影响。未观察到脂质过氧化增加，这表明内源性抗氧化防御系统能够抵御7-酮胆固醇或胆甾烷-3β,5α,6β-三醇可能引发的任何氧化应激。天然生育酚混合物Covi-ox可降低两种氧化甾醇对抗氧化酶的影响。在经Covi-ox处理的细胞中，硫代巴比妥酸反应性物质产生的同时减少间接证明了氧化甾醇在肝细胞悬浮培养物中产生了活性氧。
