Antihypertensive effect of methanol leaf extract of Azadirachta indica was mediated through suppression of renal caspase 3 expressions on Nω‐Nitro‐L‐Arginine Methyl Ester (L‐NAME) induced hypertension

Abstract

In the last two decades, the incidence of hypertension has increased significantly both in developed and developing countries. Moreover, hypertension is known as a major risk factor in the development of cardiovascular diseases. Azadirachta indica Adr Juss (AI) known as neem, has been used traditionally for the treatment of various cardio‐metabolic diseases such as type 2 diabetes, obesity and hypertension. This study investigated the possible antihypertensive effects of the methanol leave extract of Azadirachta indica on Nω‐nitro‐L‐arginine methyl ester (L‐NAME) induced hypertension in Wistar rats. Fifty rats were selected into five groups, ten animals in each group, for this study. Group A (Control) received only clean water; group B received L‐NAME at 40 mg/kg; groups C and D were administered Azadirachta indica at 100 and 200 mg/kg, respectively, with L‐NAME at 40 mg/kg; and group E received enalapril at 25 mg/kg and L‐NAME at 40 mg/kg. All administrations were done for 21 days consecutively. Treatment with L‐NAME led to significant (p <0.05) increases in systolic, diastolic, mean arterial blood pressure and markers of oxidative stress in hypertensive rats. Immunohistochemistry showed increased renal expressions of Caspase‐3 in hypertensive rats compared to the control. Treatment with methanol leaf extract of Azadirachta indica caused significant improvement in antioxidant defense systems, reduction in markers of oxidative stress, restoration of blood pressure parameters and suppression of renal caspase‐3 expressions when compared to enalapril, standard antihypertensive drug. This study suggests that Azadirachta indica leaf extract can exert antihypertensive effect on L‐NAME induced elevation of blood pressure.