Abstract
BACKGROUND: Acute and chronic stress is a risk factor for the development and progression of coronary artery disease. Increased arterial stiffness is an independent marker for cardiovascular disease. Cold pressor test (CPT) is known to be associated with substantial activation of the autonomic nervous system. OBJECTIVE: The aim of this study was to evaluate the effect of Phyllanthus emblica extract on cold pressor stress test induced changes on cardiovascular parameters and aortic wave reflections in healthy human subjects. MATERIALS AND METHODS: This was a double-blind, placebo-controlled, crossover study. Participants were randomized to receive either two capsules of P. emblica extract 250 mg (containing aqueous extract of P. emblica, highly standardized by high-performance liquid chromatography to contain low molecular weight hydrolysable tannins emblicanin-A, emblicanin-B, pedunculagin and punigluconin) or two capsules of placebo twice daily for 14 days. Pharmacodynamic parameters such as heart rate, augmentation pressure, augmentation index (AIx), subendocardial viability ratio (SEVR), radial and aortic blood pressure (BP) were recorded before and after CPT at baseline and end of treatment. After washout period of 14 days, subjects crossed over to the other treatment and the same test procedure was repeated again. Safety assessments were done at baseline and at the end of treatment. RESULTS: A total of 12volunteers completed the study. Compared with baseline and placebo, P. emblica extract produced a significant decrease of mean percent change in the indices of arterial stiffness (AIx, radial and aortic BP) and increase in SEVR, an index of myocardial perfusion with CPT. Both treatments were well-tolerated and no serious adverse events were reported. CONCLUSION: Proprietary P. emblica extract, showed a significant decrease in cold pressor stress test induced changes on aortic wave reflections.