Antihypertensive Potential of Azadirachta indica Methanolic Leaf Extract in Salt-induced Hypertensive Rat Model

Hypertension is a condition arising from persistently elevated blood pressure, leading to severe complications, including death. Factors such as high salt consumption and family history predispose individuals to hypertension. Azadirachta indica (AI) has shown potential in reducing high blood pressure, irregular heart rhythms, and abnormal heartbeats. This study aimed to assess the antihypertensive effect of Azadirachta indica methanolic leaf extract (AIMLE) on salt-induced hypertension in albino rats. The study involved 25 healthy male albino rats (150 - 250g), divided into five groups (A-E, n=5). Group A received normal salt feed and water (vehicle), group B received high-salt feed (HSF), group C received HSF and 500 mg/kg AIMLE, group D received HSF and 1000 mg/kg AIMLE, and group E received HSF and 10 mg/kg Nifedipine. Systolic (SBP) and diastolic (DBP) blood pressures were measured using the tail cuff method. Antidiuretic hormone (ADH) and Angiotensin-Converting Enzyme (ACE) levels were analyzed using ELISA methods. Nitric Oxide, Potassium, Bicarbonate, and Sodium were assayed using the colorimetric method. Administration of HSF caused a significant (p <0.05) progressive increase in SBP and DBP after 8 weeks when compared with the normal control. However, treatment with the serial doses of AIMLE resulted in a significant (p <0.05) dose dependent decrease in SBP, DBP and serum nitric oxide concentrations as well as decrease in serum levels of ACE, ADH, potassium, bicarbonate, and sodium ions when compared with untreated HSF group, after 8 weeks. These findings suggest that Azadirachta indica leaf extract may offer a natural remedy for managing hypertension.

Key Words: Azadirachta indica, ADH, Salt induced hypertension, Antidiuretic, ACE