Terminalia arjuna improves cardiovascular autonomic neuropathy in streptozotocin-induced diabetic rats

The present study was designed to examine the therapeutic potential of Terminalia arjuna bark extract in improving cardiovascular autonomic neuropathy in Streptozotocin (STZ)-induced diabetic Wistar Albino rats. The baroreflex was evaluated by measuring the changes in heart rate with changes in arterial blood pressure induced by bolus injections of phenylephrine (vasoconstrictor) and sodium nitroprusside (vasodilator). T. arjuna bark extract, Rosuvastatin and Insulin were tested/administered therapeutically in rat model of uncontrolled diabetes. After 8 weeks of STZ administration, the reflex bradycardia and tachycardia response to hypertension and hypotension, respectively, were impaired in the diabetic group. The reflex bradycardia improved significantly after 1 month treatment of T. arjuna while the reflex tachycardia could not improve. The decreased body weight, heart rate, blood pressure and raised blood sugar in diabetic rats were not improved by T. arjuna therapy. Rosuvastatin treatment exerted similar effects while Insulin improved all the parameters. Further T. arjuna, Rosuvastatin and Insulin significantly reduced oxidative stress and inflammatory cytokine levels in diabetic rats. Results suggest that T. arjuna bark extract improves the altered baroreflex sensitivity in diabetic rats possibly through maintaining endogenous antioxidant enzyme activities and decreasing cytokine levels.