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.

Keywords:

• antioxidant
• membrane-stabilisation
• proteinase inhibition
• Telfairia occidentalis
• Moringa oleifera
• Hibiscus sabdariffa

Public Interest Statement

The global burden of cardiovascular disease conditions remains a paramount issue. Many epidemiological studies have established strong nexus between antioxidant and anti-inflammatory mechanism. Many antioxidant compounds have been indicated to possess important anti-inflammatory activity because reactive oxygen species known to react with cellular components and damaging the DNA and proteins causing cellular and tissue injury are forestalled at the onset. The excessive generation of the reactive oxygen species can overwhelm the biological system and induce other conditions such as premature aging, cancer, diabetes and atherosclerosis. On the basis of this, the antioxidant and anti-inflammatory studies were conducted on the common edible plants. This study revealed that Hibiscus sabdariffa, Telfairia occidentalis, Moringa oleifera and Ocimum gratissimum are potential natural antioxidant sources with high anti-inflammatory activities. The incorporation of such natural antioxidants in foods, drinks and nutraceuticals affords a green and sustainable means of health management especially in the developing nations.

Additional information

Notes on contributors

L. Kambizi

ACHRI is an acronym for African Centre for Herbal Research Ilorin. The centre is domiciled at the Central Research Laboratory building of the University of Ilorin, Ilorin, Nigeria. It was established by the U6 initiative for development comprising six funding African Universities namely; Cape Peninsula University of Technology, South Africa; Jaramogi Oginga Odinga University of Science and Technology, Kenya; Kwara State University, Malete, Nigeria; University of Cape Coast Ghana; University of the Gambia, Banjul, Gambia; and University of Ilorin, Ilorin, Nigeria. The centre is envisioned to conduct relevant research on African flora, organise workshops, collate research proposals for funding, advice Government on issues related to exploitation of African herbal resources and maintain the research laboratory. Scientists from these Universities form the basic network of researchers involved in ACHRI research. However, the centre is committed to regional and international research collaborations. The Director, Prof. Kambizi L. and Coordinator, Prof. Bakare-Odunola M.T. currently guide the affairs and research activities of ACHRI.