Comparative Evaluation of Conventional and Novel Extracts of Stem Bark of Terminalia arjuna for Antihypertensive Activity in BSO Induced Oxidative Stress based Rat Model

Background: Terminalia arjuna (TA) has been reported and explored traditionally for its cardiotonic properties while the mechanism of antihypertensive effect of TA has not been clearly reported. Method: The oxidative stress is a major cause for hypertension, hence different extracts of TA having variable marker yield were evaluated for their antihypertensive effect in buthionine sulfoxamine (BSO) induced oxidative stress based model. Soxhlet extraction (SE), room temperature extraction (RTE), microwave assisted extraction (MAE), and ultrasound assisted extraction (USAE) were quantitatively estimated for marker compounds arjunolic acid and arjunic acid through HPTLC. Results: The hypertension was induced using buthionine sulfoxamine (2 mmol/kg b.w.i.p.) and results suggested that the MAE and USAE showed better recovery of systolic blood pressure (110.33 +/- 0.10 and 118.33 +/- 0.10) and GSH level (3.62 +/- 0.07 nmoles/mL and 3.22 +/- 0.13 nmoles/mL), respectively as compared to the positive control group treated with ascorbic acid (Systolic BP: 119.67 +/- 0.10, GSH level: 3.11 +/- 0.10 nmoles/mL). The RTE and SE also showed a decrease in hypertension but were having moderate effect as compared with the standard positive control. Conclusion: The total percentage yield, the yield of the marker compounds arjunolic and arjunic acid, the IC50 values for antioxidant activity as well as the antihypertensive effect were in order: MAE>USAE>SE>RTE that suggested the role of biomarkers arjunolic acid and arjunic acid in reversing the effect of buthionine sulfoxamine.