10th U6+ Consortium of African Universities International Conference

Garcinia kola Heckel (Clusiaceae) is an important African medicinal plant traditionally used for the management of diseases associated with oxidative stress. This study evaluated the phytochemical composition and in vitro antioxidant activities of solvent fractions of Garcinia kola seeds. Dried seeds were extracted successively with n-hexane, dichloromethane (DCM), ethyl acetate, ethanol and aqueous. Total phenolic content (TPC), total flavonoid content (TFC) and total tannin content (TTC) were determined using standard spectrophotometric methods and expressed as gallic acid equivalents (mg GAE/g extract), quercetin equivalents (mg QE/mL) and catechin equivalents (mg CE/g extract), respectively. Antioxidant activity was evaluated using DPPH and ABTS radical scavenging assays, ferric reducing antioxidant power (FRAP), and the phosphomolybdenum assay (PMA). The ethyl acetate fraction contained the highest TPC (2.331 ± 0.001 mg GAE/g extract) and TFC (0.372 ± 0.037 mg QE/mL), whereas the n-hexane fraction exhibited the highest TTC (119.5 ± 10.2 mg CE/g extract). The ethanol fraction demonstrated the greatest DPPH radical scavenging activity (76.99 ± 0.47%), while the ethyl acetate fraction showed the highest ABTS radical scavenging activity (97.34 ± 0.22%). The DCM fraction exhibited the strongest reducing capacity in both the FRAP assay (1.235 ± 0.030 mg Fe(II) equivalent/g extract) and the phosphomolybdenum assay (0.887 ± 0.019 mg EDTA equivalent/g extract). Antioxidant activities generally increased with extract concentration and varied among solvent fractions. Garcinia kola is a rich source of phytochemicals with significant antioxidant potential. The ethyl acetate fraction was particularly enriched in phenolic and flavonoid compounds and exhibited excellent free radical scavenging activity, whereas the DCM fraction possessed the highest reducing power. These findings support the potential application of Garcinia kola as a natural source of antioxidant compounds for nutraceutical and pharmaceutical development.