Rhamnus prinoides - A Basotho Medicinal Plant with Antioxidant and Antimicrobial Potential

Rhamnus prinoides finds therapeutic applications in traditional medicine in Southern Africa, which
include treating pulmonary tuberculosis (TB), pneumonia, gonorrhoea, muscular rheumatism, cleaning
the blood, bladder and kidneys. Hexane, chloroform, ethyl acetate and methanolic extracts from
leaves and stem-bark of R. prinoides have been evaluated for their antioxidant activity by 1,1-
diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The percentage values of radical of
scavenging activity of these extracts have been found to be in the range of 03.33±0.89 to
59.55±2.27% at various concentrations. The IC50 values of these extracts have been determined to be
in the range of 710.50 to >3000 μg mL-1. The positive control, ascorbic acid, showed an IC50 value of
<200 μg mL-1. Additionally, all these extracts have also been evaluated for their inhibitory effect
against six bacterial isolates viz. Escherichia coli (wild), Escherichia coli (H0157), Staphylococcus
aureus, Listeria monocytogens, Pseudomonas spp. and Serratia marcescens and two fungal isolates
viz. Penicillium digitatum and Candida albicans. The zones of inhibition have been found to be in the
range of 8.8±3.0 to 15.8±1.4 mm diameter against bacterial isolates and 10.3±1.8 to 14.3±2.5 mm
diameter against fungal isolates. The minimum inhibitory concentrations (MICs) of these extracts have
been found to be in the range of <31.25 to > 1000 μg/mL. Further studies on this plant will be useful to
commercialize products from this plant.