Evaluation of simvastatin antioxidant effects.

3-Hydroxy-3-methyl-coenzyme A reductase (HMG-CoA reductase) which transforms 3-hydroxy-3-methylglutaril-coenzyme A (HMG-CoA) in mevalonate, is the rate limiting enzyme in cholesterol biosynthesis. In our study, from HMG-CoA reductase's known inhibitors, we used simvastatin (ZOCOR), which is a semi synthetic derivative of the second generation. The study was performed on 25 subjects (12 men and 12 women) aged 33-67 yo, with hypercholesterolemia, which have received simvastatin, 10 mg daily for 8 months. Under treatment with simvastatin we obtained a significant decrease of total cholesterol (p < 0.0001) and an improvement of enzymatic antioxidant parameters: superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). In conclusion, simvastatin therapy determines a significant decrease in SOD, GPx, CAT, and an increase in CAT/SOD and GPx/SOD ratios.