<i>In vitro</i> antioxidant and antidiabetic potentials of the seed, bark and whole pod of okra (<i>Abelmoschus esculentus</i> (L.) Moench): A comparative study

Abstract

Okra is an indigenous vegetable consumed for its sliminess and nutritional benefits. The aim of this study was to assess and compare the in vitro antioxidant, and antidiabetic activities of the seed, bark and whole pod of okra. The total phenolic and total flavonoid contents of the different parts were evaluated according to standard methods. The antioxidant capacity was assessed using the 1,1-diphenyl-2-picrylhdrazyl (DPPH), hydroxyl (OH), and 2,2-azino-bis (3-ethylbenzthiazoline-6-sulphoric acid) (ABTS) radical scavenging assays, ferric reducing antioxidant power (FRAP) assay, and ferrous ion-induced lipid peroxidation assay using standard procedures. The in vitro antidiabetic activity was evaluated using the α-amylase, and α-glucosidase inhibitory assays. The whole okra pod exhibited a significantly higher total phenolic content (5.0 mg GAE/g) and enhanced radical scavenging activity compared to both the seed and bark of the pod (p < 0.05). Although, the seed had a higher content of total flavonoid (2.23 mg QE/g) than the bark and whole pod, the bark and whole pod of okra showed a higher ferric reducing antioxidant power than the seed. Similarly, the whole pod showed a higher lipid peroxidation inhibition, and higher α-glucosidase inhibitory activity than the bark and seed of the pod. In order to enjoy all the nutritional and pharmacological benefits associated with okra consumption, it is recommended that no part of the pod should be considered a waste.