Effects of β-carotene and α-tocopherol on the levels of tissue cholesterol and triglyceride in hypercholesterolemic rabbits

Male New Zealand white rabbits were made hypercholesterolemic by feeding an atherogenic diet (0.5% cholesterol, 3% peanut oil, and 3% coconut oil) with and without β-carotene (25 mg/kg body weight given intravenously twice weekly) and/or α-tocopherol (0.5% of diet) for 8 weeks. Rabbits treated with combined β-carotene and α-tocopherol had significantly lower cholesterol contents in liver, heart, and plasma than control animals; heart and plasma cholesterol contents were also significantly lower in animals treated with β-carotene than in controls. Treatment with both antioxidants significantly increased triglyceride contents of liver and triceps, but not heart and plasma. Rabbits given both β-carotene and α-tocopherol had significantly lower values for tissue α-tocopherol than animals treated with α-tocopherol only, and significantly higher values for tissue β-carotene than animals treated with β-carotene only. Atherosclerotic lesion areas in the aortic arch, thoracic aorta, and abdominal aorta were positively correlated (r = 0.36-0.42) with plasma cholesterol concentrations and negatively correlated (r = -0.340.60) with plasma, liver, triceps, and heart α-tocopherol levels. Moderate levels of α-tocopherol supplementation with or without β-carotene may have a beneficial effect on tissue cholesterol contents and on the development of aortic atherosclerotic lesions in rabbits fed an atherogenic diet.