Phytochemical constituents and <i>in vitro</i> antioxidant activity of methanolic extract of <i>Tetracarpidium conophorum</i> (African walnut) seeds

Abstract

This study evaluated the total phenolics, proanthocyanidins, and flavonoids contents as well as the antioxidant activity of the methanolic extract of Tetracarpidium conophorum seeds. The extract of T. conophorum was evaluated for its phytochemical constituents such as alkaloids, tannins, flavonoids and steroidal glycosides and its in vitro antioxidant activities using 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay and reducing power assay. The total phenolic, proanthocyanidin, flavonol and flavonoid contents were determined using standard methods. The methanolic extract of T.conophorum has 50% inhibitory concentration (IC₅₀) value for radical scavenging activity of 0.41mg/mL which was significantly higher than that of vitamin E (0.13mg/mL). The extract has a significantly higher concentration of total phenols, proanthocyanidin and flavonoids compared to their various standards respectively. T.conophorum has the potential for use as natural antioxidants against free radical damage.