Dietary oxidized cholesterol increases expression and activity of antioxidative enzymes and reduces the concentration of glutathione in the liver of rats.
An experiment was conducted with rats to investigate the effect of dietary oxidized cholesterol on the antioxidant status. Four groups of male, growing Sprague-Dawley rats received diets containing unoxidized or oxidized cholesterol (5 g/kg diet) with either coconut oil or salmon oil as dietary fat (100 g/kg diet) for 5 weeks. The oxidized cholesterol preparation consisted of 7 g of various cholesterol oxidation products and 93 g of unmodified cholesterol per 100 g preparation. No significant amounts of oxysterols were detected in the unoxidized cholesterol-supplemented diets. As parameters of the antioxidant status activities, mRNA concentrations of several antioxidative enzymes and the concentrations of glutathione were measured. Rats fed the diets containing oxidized cholesterol had significantly higher mRNA concentrations of glutathione peroxidase (p < 0.001) and superoxide dismutase (p < 0.01), a significantly higher activity of glutathione peroxidase (p < 0.001), and significantly lower concentrations of total (p < 0.05) and reduced glutathione (p < 0.01) in the liver than rats fed diets containing unoxidized cholesterol. These effects were independent of the dietary fat. In conclusion, the study suggests that dietary oxidized cholesterol stresses the antioxidant defense system in rats.
Ringseis
Robert
R
Institute of Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
Eder
Klaus
K
D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000737:chemistry; D002791:Cholesterol, Dietary / Q000008:administration & dosage / Q000494:pharmacology*; D000074263:Coconut Oil; D005395:Fish Oils / Q000008:administration & dosage; D005954:Glucosephosphate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000008:administration & dosage; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D002791:Cholesterol, Dietary; D005395:Fish Oils; D010938:Plant Oils; D012333:RNA, Messenger; C030341:salmon oil; D002784:Cholesterol; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D005978:Glutathione; D000074263:Coconut Oil