Antioxidant and hypocholesterolaemic effects of Terminalia arjuna tree-bark powder: a randomised placebo-controlled trial.
OBJECTIVE: To evaluate the antioxidant and hypocholesterolaemic effects of Terminalia arjuna tree bark (a popular cardiotonic substance in Indian pharmacopoeia) and to compare it with a known antioxidant, vitamin E, we performed a randomized controlled trial. METHODS: One hundred and five successive patients with coronary heart disease (CHD) presenting to our centre were recruited and using a Latin-square design divided into 3 groups of 35 each. The groups were matched for age, lifestyle and dietary variables, clinical diagnosis and drug treatment status. None of the patients was on lipid-lowering drugs. Supplemental vitamins were stopped for one month before study began and American Heart Association Step II dietary advice was given to all. At baseline, total cholesterol, triglycerides, HDL and LDL cholesterol and lipid peroxide estimated as thiobarbituric acid reactive substances (TBARS) were determined. Group I received placebo capsules; Group II vitamin E capsules 400 units/day; and Group III received finely pulverized T. arjuna tree bark-powder (500 mg) in capsules daily. Lipids and lipid peroxide levels were determined at 30 days follow-up. RESULTS: Response rate in various groups varied from 86% to 91%. No significant changes in total, HDL, LDL cholesterol and triglycerides levels were seen in Groups I and II (paired t-test p > 0.05). In Group III there was a significant decrease in total cholesterol (-9.7 +/- 12.7%), and LDL cholesterol (-15.8 +/- 25.6%) (paired t-test p < 0.01). Lipid peroxide levels decreased significantly in both the treatment groups (p < 0.01). This decrease was more in vitamin E group (-36.4 +/- 17.7%) as compared to the T. arjuna group (-29.3 +/- 18.9%). CONCLUSIONS: Terminalia arjuna tree bark powder has significant antioxidant action that is comparable to vitamin E. In addition, it also has a significant hypocholesterolaemic effect.