Effect of silymarin, the seed extract of cultivated and endemic Silybum marianum (L.) Gaertn., on serum lipid levels and atherosclerosis development in hypercholesterolemic rabbits

Backgrond: Silymarin, the seed extract of Silybum marianum (L.) Gaertn., contains flavonolignan compounds with powerful anti-oxidant properties. The favourable effects of herbal medicine with ant-ioxidant properties on lipid profile have been reported in several experimental studies. Objective: The aim of this research was to investigate the effects of cultivated and endemic silymarins and levostatin with ant-ioxidant properties on serum lipoproteins levels and atherosclerosis development in hypercholesterolemic rabbits. Method: Hypercholesterolemic foods were fed to 5 groups of 8 rabbits, each for 60 days. One group negative control, second group received levostatin (10mg/kg) and other two groups received cultivated and endemic silymarins (200 mg/kg) daily one hour before feeding. The last group did not receive any drugs (positive control). The fasting blood total cholesterol, LDL and HDL-cholesterol and triglyceride levels were determind before starting the experiments and also after 30 and 60 days during the study. At the end of the study rabbits were killed and the extent of aortic atherosclerotic plaque were determined. Results: Results showed that, levostatin, cultivated and endemic silymarins caused a significant decrease in fasting serum cholesterol and LDL-cholesterol compared to control group. HDL-cholesterol increased and triglyceride level was significantly decreased in cultivated and endemic silymarins treated groups, as compared to positive control group. In addition, atherosclerotic plaque development was significantly decreased in levostatin, cultivated and endemic silymarins treated groups. Conclusion: Treatment of hypercholesterolemic rabbits with levostatin, cultivated and endemic silymarins showed favourable effects on serum lipid profile, as well as atherosclerotic plaque development