2, 2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging potential and phytochemical analysis of extracts from Berchemia zeyheri: A Swazi medicinal plant

Berchemia zeyheri has been used in traditional medicine to treat various conditions which include cough, vomit, diarrhea, dysentery, headache, backache, anemia, rectal ulcers and gastrointestinal issues. The objectives of the present study were to evaluate radical scavenging potential, determine IC50 values and analyze phytochemical compositions of various solvent extracts obtained from leaves and stem-bark of B. zeyheri. The combination of maceration and hot solvent extraction techniques were used to obtain various extracts from the leaves and stem-bark of B. zeyheri. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay was used to evaluate the radical scavenging potential and determine of IC50 values of various extracts and positive control (ascorbic acid). Phytochemical analysis was performed using established methods reported in literature. The radical scavenging potential of positive control, various extracts obtained from leaves and stem-bark were found to be in the ranges of 58.44±0.01-87.84±0.01%, 22.05±0.01-64.98±0.02% and 13.88±0.01-70.22±0.01%, respectively at a concentration range of 200-3000 µg/mL. The IC50 value of positive control was found to be < 200 µg/mL. The methanol extract from leaves and ethyl acetate extract from stem-bark showed lowest IC50 values of 1513.30 and 1228.59 µg/mL, respectively. Various classes of phytochemicals were detected in these extracts which include glycosides, carbohydrates, saponins, proteins, phlobatannins. phenolics, flavonoids, tannins, coumarins, steroids, terpenoids and alkaloids. From this study, we concluded that B. zeyheri showed significant radical scavenging potential at higher concentrations and showed a weak to moderate radical scavenging potential at lower concentrations. Additionally, B. zeyheri possessed various classes of phytochemicals.