Evaluation of Possible Fungitoxic and Antibacterial Activity of Some Local Plants

Abstract

The effects of water and methanol extracts of 19 Ghanaian plants belonging to12 families on some aspects of the physiology of five fungi (Scopulariopsis brevicaulis Aspergillus niger, A. flavus, Sclerotium rolfsii, Nigrospora sp.), and five bacterial species(Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella (Group C,), Escherichia coli(EPEC 0:43), E. coli (ETEC OK5)) were investigated in vitro in either liquid or agar mediumamended with varying dilutions (1:1 - 1:5 v/v) of the extracts.Scopulariopsis brevicaulis grew best at a temperature of 30°C and is being recorded forthe first time in soil from Ghana.Comparatively higher fungistatic effects were found in both the water and the methanolextracts of leaves of Cassia rolundifolia, Pergularia daemia, Ahernanthera pungens, Voacangaafricana, Launaea taraxacifolia, Tridax procumbens, Zanthoxylum xanthoxyloides, Oxaliscorniculata, Azadirachta indica, Desmodium triflorum, Euphorbia heterophylla and Crotalariaretusa (in decreasing order) when the five test fungi were cultured on solid agar medium.Vegetative growth of mycelial discs of test fungi (Scopulariopsis brevicaulis, Aspergillusniger, A. flavus, Sclerotium rolfsii, Nigrospora sp.) immersed in 1:1 v/v dilution of plantextracts for varying periods (1/4, 1/2, 1, 3, 12, 24, 48h) were variably depressed by the extractafter transfer to extract-free (Potato Dextrose Broth) medium. The longer the period ofimmersion, the greater the depression of vegetative growth.Oxalis corniculata showed the highest antibacterial activity among the eight plants (Oxaliscorniculata, Pergularia daemia, Desmodium triflorum, Ahernanthera pungens, Voacangaafricana, Cassia rolundifolia, Zanthoxylum xanthoxyloides, Azadirachta indica) tested; the inhibitory effect of 0. corniculata was akin to what was obtained when standard antibiotics (35 /xg/ml Streptomycin, 5 /xg/Chloramphenicol, 5 /xg/ml Oxytetracycline) were used.