Acute Toxicity, Antioxidant and Vasodilatory Properties of Sclerocarya birrea (A. rich.) Hochst (Anacardiaceae) Trunk Bark’s Aqueous Decoction

Sclerocarya birrea (S. birrea) is a medicinal plant of the Anacardiaceae family used to treat various diseases, including high blood pressure. The plant has many biological activities, including antidiabetic, anti-inflammatory, and antihypertensive effects. This study aimed to determine the acute toxicity, antioxidant, and vasodilator activities of S. birrea trunk bark extracts. HPTLC carried out phytochemical testing of the lyophilized aqueous decoction (DAL) of the trunk bark of S. birrea. The vasodilation effect of the DAL extract of the trunk bark of S. birrea was studied ex vivo with DMT 620M myography. The phytochemical study revealed the presence of flavonoids, tannins, saponins, steroids, and triterpenes in the DAL extract. Evaluation of the vascular reactivity showed that this extract caused vasodilation of the thoracic aorta in NMRI mice, both in the presence of endothelium alone, in the presence of L-Nitro Arginine Methyl Ester (L-NAME), and the absence of endothelium. The effective concentrations of 50% (EC50) of DAL extract were (266.36±65.12 µg/mL, 365.57±97.54 µg/mL, and 592.43±78.05 µg/mL, respectively. As a preventive measure, this extract reduced the vasoconstriction of the mouse aorta ring by 58.04±0.60% compared to U46619 alone. This study reported the presence of secondary metabolites of interest, such as phenols, flavonoids, tannins, saponins, steroids, and triterpenes, and the vasodilation effect of the DAL extract of S. birrea. These results provide scientific evidence for its use in traditional medicine to treat high blood pressure.