In-vitro antioxidant and anti-inflammatory activities of ethanol stem-bark extract of Blighia sapida K.D. Koenig

Blighia sapida (B. sapida) K.D. Koenig (Family Sapindaceae) is a branchless straight bole approximately 15 m in length. The study evaluated the antioxidant and anti-inflammatory activities of ethanol extract and fractions of B. sapida stem-bark using in vitro methods. Ethanol extract and its fractions were investigated for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), and quantitative phenolic and flavonoid contents. Anti-inflammatory activity was evaluated using albumin denaturation and membrane stabilization assays. The extract and its fractions exhibited radical scavenging and anti-inflammatory properties. The ethyl acetate fraction possessed maximum phenolic and flavonoid contents (136.67 ± 1.55 gallic acid equivalent mg/g and 75.76 ± 4.03 quercetin equivalent mg/g, respectively). Antioxidant studies revealed that the ethyl acetate fraction displayed superior activity with an IC(50) = 0.09 ± 0.03 mg/mL DPPH, and values of 146.96 ± 3.81 ascorbic acid equivalent (AAE) mg/g and 359.20 ± 4.98 AAE mg/g for FRAP and TAC, respectively. Furthermore, the anti-inflammatory activity was revealed by inhibition of heat-induced albumin denaturation and red blood cell membrane stabilization at concentrations of 200–1000 μg/mL and 50–250 μg/mL, respectively. The ethanol extract and fractions exhibited antioxidant and anti-inflammatory activities, with ethyl acetate fraction showing superior activity, which could be attributed to secondary metabolites, mainly phenolic compounds. Overall, the antioxidant and anti-inflammatory activities of B. sapida can be exploited by ethnomedicinal users.