Thymol reduces oxidative stress, aortic intimal thickening, and inflammation-related gene expression in hyperlipidemic rabbits.

Atherosclerosis plays a key role in the development of cardiovascular diseases, and is often associated with oxidative stress and local inflammation. Thymol, a major polyphenolic compound in thyme, exhibits antioxidant and anti-inflammatory properties. In this study, we measured the in vitro antioxidant activity of thymol, and investigated the effect of thymol on high-fat-diet-induced hyperlipidemia and atherosclerosis. New Zealand white rabbits were fed with regular chow, high-fat and high-cholesterol diet (HC), T3, or T6 (HC with thymol supplementation at 3 mg/kg/d or 6 mg/kg/d, respectively) for 8 weeks. Aortic intimal thickening, serum lipid parameters, multiple inflammatory markers, proinflammatory cytokines, and atherosclerosis-associated indicators were significantly increased in the HC group but decreased upon thymol supplementation. In summary, thymol exhibits antioxidant activity, and may suppress the progression of high-fat-diet-induced hyperlipidemia and atherosclerosis by reducing aortic intimal lipid lesion, lowering serum lipids and oxidative stress, and alleviating inflammation-related responses.