Antibacterial, Antifungal and Phytochemical Activities of some Medicinal Plants from Zimbabwe

Abstract

Twenty eight (28) methanol crude extracts from fourteen (14) medicinal plants commonly used by communities and traditional medical practitioners in treating sexually transmitted diseases were selected after an ethno-botanical survey of five districts from Zimbabwe. Thin Layer Chromatography (TLC) and UV detection was used to confirm their phytochemical groups. Tannins (89 %), saponins (82 %) and flavonoids (61 %) were the commonest phytochemical groups found. Agar well diffusion assay method was used to screen for their antibacterial and antifungal activities by measuring the zone of inhibition. Most extracts were moderately active against Streptococcus aureus and Streptococcus Group A but relatively inactive against Escherichia coli and Pseudomonas aeruginosa. The root extract of Terminalia sericea (10 mg/ml) was the most active inhibiting the growth of Staphylococcus aureus (7.88±0.48 mm) compared with reference amoxicillin (10 μg) (9.00 ± 0.41 mm) and 10.00±0.82 mm against P. aeruginosa, compared with reference gentamicin (10 μg) (7.00±0.40 mm). The root extract of Warbugia salutaris was the most active against Candida albicans (10.00±0.82 mm) compared with the reference miconazole (10 μg) (10.00±0.41 mm) and amphotericin B (10 μg) (6.35±0.50 mm) and against Aspergillus niger (8.25±0.50 mm) compared with reference miconazole (10 μg) (10.00±0.81 mm) and amphotericin B (10 μg) (6.75±0.58 mm).