Original Articles
Joy Nwakaego Chinweze, Hillary
Abstract
The phytochemical and antioxidant activity of the ethanolic extracts of stem bark of Psorospermum febrifugum and Harungana madagascariensis were carried out to assess the potential of these extracts as antioxidant agents. The antioxidant potentials of both extracts were assessed using l,l-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, Ferric Reducing Antioxidant Power (FRAP) and Total Antioxidant Capacity (TAC). P. febrifugum extract was richer in flavonoids (898 ± 2.17 mg QE/g), tannins (44.91 ± 0.18 mg GAE/g), phenols (40.26 ± 0.05 mg GAE/g), and alkaloids (530.00 ± 13.61 mg CE/g), than H. madagascariensis extract (flavonoids, 706.38 ± 2.17 mg QE/g, tannins, 42.46 ± 0.41 mg GAE/g, phenols, 26.17 ± 0.23 mg GAE/g and alkaloids, 457.87 ± 5.05 mg CE/g). P. febrifugum extract (IC50 = 0.74 ± 0.02 μg/mL and 1865.42 mg GAE/g) had a better antioxidant activity than H. madagascariensis (0.82 ± 0.05 μg/mL and 1601.92 mg GAE/g) in the free radical scavenging activity and total antioxidant capacity respectively. However, H. madagascariensis extract showed greater ferric reducing antioxidant power (321.069 μmol Fe2+/g) than P. febrifugum extract (266.687 μmol Fe2+/g) and gallic acid standard (220.391 μmol Fe2+/g) at 1000 μg/mL concentration. The extract’s vitamin (A, C and E) contents showed that vitamin A is higher in P. febrifugum while vitamins C and E were higher in H. madagascariensis.