In Vitro Antioxidant Activities of Methanolic Extracts of Caesalpinia volkensii Harms., Vernonia lasiopus O. Hoffm., and Acacia hockii de Wild

Abstract

Oxidative stress is the result of the disparity between pro-oxidants and antioxidants in an organism, and it is important in the pathogenesis of several degenerative disorders, such as arthritis, Alzheimer's, cancer, and cardiovascular diseases. Free radicals can damage biomolecules, such as nucleic acids, lipids, proteins, polyunsaturated fatty acids, and carbohydrates, and the DNA leading to mutations. The use of antioxidants is effective in delaying the oxidation of biomolecules. Antioxidants are complexes found in the food that can retard or deter oxidation by preventing the initiation and propagation of oxidizing chain reactions. Medicinal plants have been used for centuries by man to manage diseases and have a host of antioxidant complexes. Traditionally, Caesalpinia volkensii, Vernonia lasiopus, and Acacia hockii have folkloric remedies against associated oxidative stress-mediated complications. However, the upsurge in its use has not been accompanied by scientific validations to support these claims. In this study, in vitro antioxidant activity of Caesalpinia volkensii, Vernonia lasiopus, and Acacia hockii collected from Embu County (Kenya) were determined by radical scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical in addition to ferric reducing antioxidant power analyzed against that of L-ascorbic acid as the standard. The obtained results revealed remarkable antioxidant activities of the studied plant extracts as evidenced by the low IC50 and EC50 values. These antioxidant activities could be due to the presence of antioxidants phytochemicals such as flavonoids, phenols, terpenoids, and saponins among others. Therefore, the therapeutic potential of this plant could be due to their antioxidant properties. This study recommends bioassay of the extracts against oxidative stress-related disorders for development of phytomedicine with antioxidant properties.