Anti-infective and Anti-inflammatory Properties of Portulaca oleracea L.

Portulaca oleracea L. (Portulacaceae) is used traditionally in many parts of Africa, Asia and Australia to treat infections, wounds, animal bites and bleeding. Though there has been some scientific investigations on some of its folkloric uses, not all of these claims or practices have been scientifically proven. This study seeks to investigate the antimicrobial, antioxidant and anti-inflammatory activities of methanol extract of leaf and aerial parts of P. oleracea. The extract was screened for antimicrobial activity using the agar well diffusion method. Minimum inhibitory concentration (MIC) was determined by the micro-dilution method against typed strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and clinical strains of Streptococcus pyogenes and Candida albicans. The antioxidant activity of the extract was determined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. Anti-inflammatory activity of the extract at doses of 100, 200 and 400 mg/kg body weight, were determined by carrageenan-induced footpad oedema in 7-day-old chicks. The preliminary phytochemical screening of P. oleracea revealed the presence of tannins, terpenoids, alkaloids, glycosides, sterols and saponins. The methanol extract showed antimicrobial activity against S. aureus, S. pyogenes, E. coli, P. aeruginosa and C. albicans with MIC values of 12.5, 12.5, 50.0, 50.0 and 50.0 mg/mL respectively. It also showed significant dose dependent anti-inflammatory activity at 100 (p<0.05), 200 (p<0.01) and 400 (p<0.01) mg/kg body weight. Methanol extract of the leaf and aerial parts of P. oleracea showed antimicrobial, antioxidant and antiinflammatory activities and these pharmacological properties may justify the folkloric uses of the plant.