Abstract

Temnocalyx obovatus is widely found in many areas in Zimbabwe, Nigeria and Zambia where it is used to treat a variety of ailments. Phenolic compounds in T. obovatus assessed by Folin-Ciocalteu method varied from 1.18 to 2.89 mg tannic acid g^-1. Acetone extract showed the greatest flavonoids, flavonols and proanthocyanidins content 5.12, 4.13 and 3.07 mg catechin g^-1respectively. 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH^.) scavenging effect, Ferric reducing ability and egg lipid peroxidation inhibition assays were adopted to evaluate antioxidant activity. Acetone extracts exhibited the greatest antioxidant activity for all the assays, followed by methanol extracts. Hexane extracts showed the weakest activity. Correlation studies showed that antiradical activity is explained more by flavonols and proanthocyanidins (73%) and flavonoids (71%) and weakly by phenolic contents (43%). The results revealed significant phenolic capacity and antioxidant potential of T. obovatus to warrant its use as a source of antioxidants. It can be added to foods, such as, meat and soups for enhancement of nutritional content and promotion of health.

Key words: Antioxidant activity, phenolics, T. obovatus.