Antioxidant activity of the inflorescents of Vernonia calvoana growing in Yakurr Local Government Area of Cross River State, Nigeria
Vernonia calvoana is an indigenous green leafy vegetable that grows around the Cameroons and the southern part of Nigeria. This study was designed to evaluate the phytochemical and antioxidant activity of V. calvoana inflorescents using the following methods: 1, 1 – diphenyl-2-picrylhydrazyl radical (DPPH), Ferric reducing/antioxidant power (FRAP), 2, 2–azobis-3-ethyl benzothiolin-6-sulphonic acid (ABTS), anti-lipid, superoxide, phosphomolybdate and ascorbic acid assay. The result showed significantly high saponins, alkaloids and polyphenols at (p<0.05). Oxalates, cyanates, phytates, tannins, terpenoids, steroids, anthraquinones, flavonoids and sesquiterpene lactones were found in trace amounts. The assay indicated strong free radical scavenging activity, including ABTS, anti-lipid, superoxide, phosphomolybdate activities of the inflorescents. However, the percentage antioxidant capacity was low in the inflorescents using FRAP, whereas the antioxidant capacity increased with increase in concentration compared to the ascorbic acid standard. Moreover, the inflorescents were found to show stronger antioxidant activity (137.0+6.86) compared to ascorbic acid (79.44%).We therefore conclude that V. calvoana inflorescents could serve as source strong diatary antioxidants.
Running Title: Vernonia calvoana inflorescents in Calabar
Keywords: Vernonia calvoana, antioxidant activity and nutraceuticals