Antioxidant and anti-inflammatory effects of <i>Blighia unijugata</i> Baker aril protein-rich extract

The study investigated the in vitro oxidative-stress-mitigating effect and anti- inflammatory potential of the soluble protein of the arils of Blighia unijugata in order to establish possible use in inflammatory therapy. Air-dried Blighia unijugata aril was pulverized into powder, defatted using petroleum ether, and homogenized in Phosphate Buffer Saline. The homogenate was centrifuged, and the supernatant was subjected to ammonium sulphate fractionation. The precipitate was thoroughly dialyzed, dialysate was freeze-dried, and termed partially purified Blighia unijugata aril protein extract (ppBUAPE). The antioxidant potential of the protein-rich extract was investigated using DPPH, H2O2 scavenging activity, and FRAP. The ability of ppBUAPE to inhibit protease (trypsin) and lipoxygenase activities, as well as its antihemolytic property, was investigated to elucidate its mechanism of inflammatory treatment. The protein extract possessed antioxidant potential. The extract scavenged both radical (DPPH) and non-radical (H2O2) oxidants. Its DPPH scavenging activity, as shown by half-maximal inhibitory concentration (IC50) of 0.84 ± 0.18 mg/ml, was significantly lower than standard (ascorbic acid) IC50 of 0.22 ± 0.06 mg/ml, while H2O2 scavenging ability (IC50 of 96.06 ± 5.39 µg/ml) was comparable to standard (IC50 of 96.46 ± 8.21 µg/ml) potential. It displayed low iron-reducing power. Protein extracts inhibited trypsin and lipoxygenase activities with IC50 of 27.53 µg/ml and 1.56 mg/ml, respectively. ppBUAPE displayed a dose-dependent antihemolytic activity comparable to that of diclofenac (standard). The research provides in vitro evidence for the oxidative-stress mitigating and anti-inflammatory effects of the ppBUAPE.