In Vitro Study on the Antioxidant Potentials of the Leaves and Fruits of Nauclea latifolia

This study was carried out to investigate the in vitro antioxidant potentials of the leaves and fruits of Nauclea latifolia, a straggling shrub or small tree, native to tropical Africa and Asia. Hot water extracts of the leaves and fruits of Nauclea latifolia were assessed for their total polyphenolic, flavanol, and flavonol contents as well as 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, ferric reducing antioxidant power (FRAP), Trolox equivalence antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays. The aqueous extract of the leaves was found to contain higher level of total polyphenols (11.63 ± 0.023 mg GAE/g), flavanol (1.45 ± 0.10 mg CE/g), and flavonol (2.22 ± 0.37 mg QE/g) than the extract of the fruits with values of 1.75 ± 0.02 mg GAE/g (total polyphenol), 0.15 ± 0.01 mg CE/g (flavanol), and 1.00 ± 0.13 mg QE/g (flavonol). Similarly, the aqueous extract of the leaves also exhibited higher DPPH (IC(50) 20.64 mg/mL), FRAP (86.10 ± 3.46 μmol AAE/g), TEAC (94.83 ± 3.57 μmol TE/g), and ORAC (196.55 ± 0.073 μmol TE/g) than the extract of the fruits with DPPH (IC(50) 120.33 mg/mL), FRAP (12.23 ± 0.40 μmol AAE/g), TEAC (12.48 ± 0.21 μmol TE/g), and ORAC (58.88 ± 0.073 μmol TE/g). The present study showed that Nauclea latifolia has strong antioxidant potentials with the leaves demonstrating higher in vitro antioxidant activities than the fruits.