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Abstract
Alstonia boonei has long been used in traditional medicine on various health conditions such as,
cardiovascular conditions, though its precise vasorelaxant mechanism remains unclear. Hypertension, often linked to vascular smooth muscle hyper contraction and endothelial dysfunction, is a leading cardiovascular risk. While conventional anti hypertensive target these pathways, they can have side
effects, high costs, and limited accessibility, prompting interest in medicinal plants as alternative therapies. This study evaluated the vasorelaxant effect of Alstonia boonei extracton rat thoracic aorta
rings precontracted with KCl and norepinephrine. Thoracic aortae were isolated from Wistar rats and sectioned into3–4 mm rings, mounted in a 25 mL organ bath at 37°C with continuous aeration (95%O₂,5%CO₂), and equilibrated under 1 g resting tension. Contractions were induced with 80mM KCl or 1 μM norepinephrine to establish baselines. The extract was then administered cumulatively, and vascular responses were recorded via Power Lab. Relaxation was expressed as a percentage of the initial contraction, with data analyzed using Graph Pad Prism (mean ± SEM, P < 0.05). The extract induced concentration-dependent relaxation in aortic rings precontracted with both KCl and norepinephrine, suggesting inhibition of voltage-dependent calcium channels and attenuation of receptor-mediated contraction. These findings support the vasorelaxant potential of Alstonia boonei and provide a mechanistic rationale for its ethnomedicinal use in hypertension. The study highlights its promise as a natural source of vasorelaxant compounds, though further work is needed to isolate active constituents, elucidate molecular pathways, and assess long-term therapeutic effect.
cardiovascular conditions, though its precise vasorelaxant mechanism remains unclear. Hypertension, often linked to vascular smooth muscle hyper contraction and endothelial dysfunction, is a leading cardiovascular risk. While conventional anti hypertensive target these pathways, they can have side
effects, high costs, and limited accessibility, prompting interest in medicinal plants as alternative therapies. This study evaluated the vasorelaxant effect of Alstonia boonei extracton rat thoracic aorta
rings precontracted with KCl and norepinephrine. Thoracic aortae were isolated from Wistar rats and sectioned into3–4 mm rings, mounted in a 25 mL organ bath at 37°C with continuous aeration (95%O₂,5%CO₂), and equilibrated under 1 g resting tension. Contractions were induced with 80mM KCl or 1 μM norepinephrine to establish baselines. The extract was then administered cumulatively, and vascular responses were recorded via Power Lab. Relaxation was expressed as a percentage of the initial contraction, with data analyzed using Graph Pad Prism (mean ± SEM, P < 0.05). The extract induced concentration-dependent relaxation in aortic rings precontracted with both KCl and norepinephrine, suggesting inhibition of voltage-dependent calcium channels and attenuation of receptor-mediated contraction. These findings support the vasorelaxant potential of Alstonia boonei and provide a mechanistic rationale for its ethnomedicinal use in hypertension. The study highlights its promise as a natural source of vasorelaxant compounds, though further work is needed to isolate active constituents, elucidate molecular pathways, and assess long-term therapeutic effect.
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