Proteinease inhibition, membrane stabilization, antioxidant and phytochemical evaluations of leaves, seeds and calyces of four selected edible medicinal plants

Abstract The aqueous extracts of the edible parts of four common medicinal plants (Hibiscus sabdariffa, Telfairia occidentalis, Moringa oleifera and Ocimum gratissimum) readily consumed as food or supplements in many African settings are examined for some of their acclaimed pharmacological activities and possible potential associated risks. The classes of phytochemicals present are examined qualitatively and quantitatively, while the antioxidant activities were determined using three assays which include 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS) and hydrogen peroxide (H2O2) assays. The anti-inflammatory activities were also examined using proteinase inhibitory assays and red blood cell membrane stabilisation assays. Both the antioxidant and anti-inflammatory activities of the plants indicated that the plants have potentials for applications in foods and nutraceuticals that can be used for the management of various ailments and diseases. However, the consumption of H. sabdariffa leaf should be highly regulated as the extract exhibited reduced cell membrane stabilisation activities at increased concentrations.