Mechanistic Clues in the Cardioprotective Effect of Terminalia Arjuna Bark Extract in Isoproterenol-Induced Chronic Heart Failure in Rats

The present study demonstrated prophylactic and therapeutic potential of Terminalia arjuna bark extract in isoproterenol (ISO)-induced chronic heart failure (CHF). Fifteen days after injection of ISO (85 mg/kg twice at an interval of 24 h, s.c), rats showed decline in maximal rate of rise and fall of left ventricular pressure (LV (dP/dt)(max) and LV (dP/dt)(min)), cardiac contractility index (LV (dP/dt)(max)/LVP), cardiac output and rise in LV end-diastolic pressure. CHF rats showed a significant increase in serum creatine kinase isoenzyme-MB (CK-MB) and malondialdehyde levels, as well as fall in the activities of superoxide dismutase, reduced glutathione. Altered lipid profile and increased level of cytokine tumour necrosis factor-alpha (TNF-alpha) along with histological changes in heart were also observed in CHF rats. T. arjuna bark extract (500 mg/kg, p.o) treatment prior and 15 days after ISO injection significantly attenuated cardiac dysfunction and myocardial injury in CHF rats. Cardioprotective action of T. arjuna was comparable to fluvastatin, a synthetic drug. The results suggest that T. arjuna bark extract has a significant prophylactic and therapeutic beneficial effect on protection of heart against ISO-induced CHF possibly through maintaining endogenous antioxidant enzyme activities, inhibiting lipid peroxidation and cytokine levels.