Vascular Smooth Muscle Modulatory Effects of Ethanol Stem Extracts of Terminalia Glaucescens on L-NG-Nitro Arginine Methyl Ester-Induced Hypertensive Male Wistar Rats

Terminalia glaucescens contains bioactive compounds that promote vasorelaxation and inhibit smooth muscle contraction induced by phenylephrine and potassium chloride (KCl) in vascular tissues. This study evaluated the vascular effects of ethanol stem extract of T. glaucescens (ESET) in L-NG-nitro arginine methyl ester (L-NAME)-induced hypertensive male Wistar rats. Seven groups of 6-week-old rats were used: normotensive control (Group 1), normotensive+ESET (Group 4), L-NAME-only hypertensive (Group 3), L-NAME+ramipril (5mg/kg) (Group 2), L-NAME+ESET (150 mg/kg and 250 mg/kg; Groups 5 and 6 respectively), and ESET pre-treatment before L-NAME (Group 7). Histological analysis showed that ESET protected cardiac tissue from hypertensive damage. Additionally, ESET modulated SMA responses by reducing contractions to phenylephrine and KCl, and enhancing acetylcholine-induced vasorelaxation. These findings suggest that ESET exerts antihypertensive and endothelial-protective effects, likely via NO-mediated pathways and antioxidant activity.