Antibacterial, Antioxidant and Anti-inflammatory Properties of Margaritaria discoidea, a Wound Healing Remedy from Ghana

Abstract

Margaritaria discoidea (Baill.) Müll Arg. (Euphorbiaceae), has folkloric use in the treatment of wounds and skin infections. We report on the antibacterial, antioxidant and anti-inflammatory effects of the leaves and stem bark of Margaritaria discoidea. A 70% ethanolic extract of the various plant parts were tested for antibacterial activity using the agar well diffusion and micro dilution assays. Free radical scavenging, total antioxidant and phenol content were estimated. Using the carrageenan-induced foot pad oedema in chicks, the anti-inflammatory activity of the extract was assessed. The bark extract gave the higher activity with a zone of inhibition of 16.33 ± 0.88 mm against Bacillus subtilis. The MIC's for the bark extracts ranged from 500 µg/mL to over 1000 µg/mL against the test organisms. However, the leaf extract had no activity against all organisms tested. The leaf and bark extracts demonstrated free radical scavenging activity yielding IC50 values of 0.0185 and 0.0181 mg/mL respectively. In the total antioxidant assay, ascorbic acid equivalents ranged from 0.49 mg/g in the bark to 0.56 mg/g in the leaf. Both extracts had high phenolic content correlating with their antioxidant activity. The extracts showed significant anti-inflammatory activity. The ED50s of the leaf and bark extracts were 12.20 and 8.27 mg/kg body weight respectively. The results were comparable to those of diclofenac and dexamethasone, the reference drugs used in this study. On the basis of the antimicrobial, antioxidant and antiinflammatory activities observed for both extracts, the ethnomedicinal use of the plant in the mamagement of wounds and skin infections is supported.