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

Male New Zealand rabbits were made hypercholesterolemic by feeding an atherogenic diet (0.5% cholesterol, 3% peanut oil, and 3% coconut oil) with or without β-carotene (25 mg/kg BW given IV twice weekly) and/or α-tocopherol (0.5% of diet). Treatment groups were α-tocopherol (AT), β-carotene (BC), AT+BC, and control (CN). Livers of BC + AT rabbits were significantly lower in cholesterol content than other animals while BC + AT and BC had significantly higher triglyceride content than AT and CN animals. Triceps muscle cholesterol and triglyceride content were significantly higher in AT+BC than other groups. Heart muscle cholesterol content were significantly lower in BC+AT and BC groups than other animals and triglyceride content of all groups were similar. Cholesterol and triglyceride contents were positively correlated in triceps and heart muscles but not liver. Liver α-tocopherol levels were positively correlated and β-carotene levels negatively correlated with liver cholesterol content. Plasma cholesterol concentrations were positively correlated with cholesterol content of heart muscle, and plasma triglyceride concentrations negatively correlated with triglyceride levels in triceps and heart muscles. Plasma α-tocopherol contentration was positively correlated with α-tocopherol content of liver and triceps muscle, while plasma β-carotene concentration was positively correlated with β-carotene content of liver, triceps muscle, and heart muscle. Aortic atherosclerotic lesion areas were positively correlated with plasma cholesterol levels. Lesion areas were negatively correlated with α-tocopherol levels in plasma, liver, triceps muscle, and heart muscle. Moderate levels of supplementation with α-tocopherol or β-carotene plus α-tocopherol may have a beneficial effect on decreasing aortic atherosclerotic lesions in rabbits fed high-fat high-cholesterol diets.