Untitled

Abstract

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 highperformance 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.

Phytochemical Screening, Polyphenol and Flavonoid Contents, and Antioxidant and Antimicrobial Activities of Opilia amentacea Roxb. (Opiliaceae) Extracts

“…The results of the phytochemical screening partly corroborate those of previous studies on O. amentacea or O. celtidifolia [27,[44][45][46][47]. Secondary metabolites are bioactive compounds involved in the biological properties of plants [37] and their accumulation in O. amentacea crude ethanol extract could explain their medicinal properties. The detected chemical groups, including flavonoids, tannins, phenols, sterols, terpenes and reducing compounds, have been regularly reported in O. celtidifolia by several studies, despite the extraction process and solvent used [27,[44][45][46][47].…”

“…The total phenolic contents (TPCs) of the O. amentacea ethanol crude extracts (OCFe, OCET, OCER) were determined using the Folin-Ciocalteu spectrophotometric method according to a method previously described by Koala et al [37], with slight modifications. Phosphomolybdate reagent and sodium tungstate were reduced during phenol oxidation in alkaline medium to a mixture of tungsten blue and molybdenum.…”

“…The determination of the total flavonoid contents (TFCs) in the O. amentacea extracts was performed using the aluminum trichloride method with quercetin as a reference according to a method previously described by Koala et al [37], with slight modifications. The method evaluates all compounds reacting with aluminum chloride (AlCl3).…”

“…The antioxidant activity of O. amentacea extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging method [37]. The process is based on the capacity of plant extracts to scavenge the DPPH radical (DPPH • ) compared to Trolox in a doseresponse curve.…”

“…The process is based on the capacity of plant extracts to scavenge the DPPH radical (DPPH • ) compared to Trolox in a doseresponse curve. The DPPH radical absorbs visible light at a maximum wavelength of 517 nm and disappears upon reduction by an antioxidant compound [37].…”