High-Performance Thin-Layer Chromatography Phytochemical Profiling, Antioxidant Activities, and Acute Toxicity of Leaves Extracts of Lannea velutina A. Rich

Leaves of Lannea velutina are used to treat several human pathologies, such as high blood pressure (HBP) and oxidative stress. Rich in bioactive components that promote prevention and therapy, herbal medicines are affordable and have no adverse effects. This work aims to evaluate the phytochemical profile, antioxidant activity, and acute toxicity of water, methanol, ethyl acetate, dichloromethane, and hexane leaf extracts of L. velutina by using suitable experimental paradigms. This shrub's leaves include sterols, saponosides, flavonoids, and tannins, as revealed by a high-performance thin-layer chromatography (HPTLC) profile. The methanol extract exhibited a significant highest total phenolic (533.9 ± 5.05 mg GAE/g DW), flavonoid (59.4 ± 0.6 mg QE/g DW), and condensed tannins (86.9 ± 0.05 CE/g DW) content compared with ethyl acetate and aqueous extracts. By using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capability experiment, the methanol extract demonstrated the highest antioxidant activity (AAI = 2.60) among the other extracts. There was a strong association between flavonoid concentration and hydrophilic antioxidant activity (r = 0.96). The acute oral toxicity test of ethyl acetate, methanol, and aqueous extracts on mice was evaluated by using Economic Cooperation and Development (OECD) guidelines 423. All investigated extracts exhibit a lethal dose (LD50) estimated higher than 2000 mg/kg body weight. This study constitutes a solid scientific basis that could justify the traditional uses of the leaves of L. velutina as a natural source of phenolic compounds for high blood pressure management.