Antioxidant activity and phytochemical analysis of extracts from Ximenia caffra: A Swazi medicinal plant

Abstract

Ximenia caffra is used in traditional Swazi medicine to treat various ailments, which include malaria, stomachache, fever, cough, infertility, dysentery, diarrhea and syphilis. The present study was aimed to evaluate the antioxidant potential, determine the IC50 values and phytochemicals analyses of hexane, chloroform, ethyl acetate, acetone and methanol extracts obtained separately from leaves and stem bark of X. caffra. The combination of maceration and hot solvent extraction techniques were used to obtain various extracts. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay was employed to assess the antioxidant potential and determine the IC50 values of these extracts. Phytochemical analysis of these extracts was conducted by methods described in literature. The extracts from leaves, stem-bark and positive control (ascorbic acid) exhibited radical scavenging potential in the ranges of 3.79±0.02-74.79±0.01%, 3.05±0.01-75.16±0.01% and 26.70±0.03-82.59±0.03%, respectively at a concentration range of 200-3000 µg/mL. The IC50 value of positive control was found to be 976.66 µg/mL and the IC50 values of extracts from leaves and stem-bark were found to be in the ranges of 1136.88-1375.41 and 1077.08-2554.62 µg/mL, respectively. Additionally, phytochemcials such as alkaloids, steroids, phenols, flavonoids, saponins, glycosides, coumarins, carbohydrates, proteins, tannins, terpenoids, and phlobatannins were detected in these extracts but their distributions were varied. From this study, we concluded that various extracts obtained from leaves and stem-bark of X. caffra exhibited significant radical scavenging potential at higher concentrations and showed a weak to moderate radical scavenging potential at lower concentrations. Additionally, various classes of phytochemicals were detected in these extracts.