Evaluation Of Possible Fungitoxic And Antibacterial Activity Of Some Local Plants

ABSTRACT The effects of water and methanol extracts of 19 Ghanaian plants belonging to 12 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 medium amended 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 for the first time in soil from Ghana. Comparatively higher fungistatic effects were found in both the water and the methanol extracts of leaves of Cassia rolundifolia, Pergularia daemia, Ahernanthera pungens, Voacanga africana, Launaea taraxacifolia, Tridax procumbens, Zanthoxylum xanthoxyloides, Oxalis corniculata, Azadirachta indica, Desmodium triflorum, Euphorbia heterophylla and Crotalaria retusa (in decreasing order) when the five test fungi were cultured on solid agar medium. Vegetative growth of mycelial discs of test fungi (Scopulariopsis brevicaulis, Aspergillus niger, A. flavus, Sclerotium rolfsii, Nigrospora sp.) immersed in 1:1 v/v dilution of plant extracts for varying periods (1/4, 1/2, 1, 3, 12, 24, 48h) were variably depressed by the extract after transfer to extract-free (Potato Dextrose Broth) medium. The longer the period of immersion, the greater the depression of vegetative growth. Oxalis corniculata showed the highest antibacterial activity among the eight plants (Oxalis corniculata, Pergularia daemia, Desmodium triflorum, Ahernanthera pungens, Voacanga africana, 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.