Effects of single-dose morning and evening administration of pravastatin on antioxidant markers in cholesterol-fed rabbits

BACKGROUND Accurate timing of statin administration is considered important to obtain the best hypolipidemic effect. Pravastatin is one of the currently prescribed hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, and was chosen in this study to evaluate its antioxidant effect when administered as a single daily dose in the morning versus evening in cholesterol-fed rabbits. METHODS This 12-week study was performed in New Zealand rabbits, divided into four groups (n = 6 each), ie, normocholesterolemic controls; cholesterol 1% diet, nontreated ; cholesterol 1% diet treated with pravastatin in the morning; and cholesterol 1% diet treated with pravastatin in the evening. Plasma total cholesterol levels, superoxide dismutase enzyme levels in erythrocyte lysates, thiobarbituric acid-reactive substance content, catalase, and glutathione enzyme activity in liver homogenates from the tested rabbits were measured. RESULTS Both morning and evening treatment with pravastatin significantly improved all the measured antioxidant markers in comparison with nontreated cholesterol-fed rabbits. However, results obtained with evening dosing were better than with morning dosing. CONCLUSION The antioxidant profile of pravastatin is better when the drug is administered in the evening rather than in the morning.