Abstract:
This study investigated the antimicrobial effect of air potato (Dioscorea bulbifera) leaf
extracts on somepathogenic microorganisms. Air potato (Dioscorea bulbifera) is a species of
yam (Discoreaceae) family. Different extracts were obtained by using ethanol,
petroleum-ether and distilled water and 100 grams of different prepared Air potato leaves
(dropped, yellow, fresh) powder were soaked in 1000ml of the solvents for 72 hours.The
crude extracts were concentrated through rotatory evaporation.Escherichia coli, Salmonella
typhi, Proteus vulgari, Pseudomonas aeruginosa, Streptococcus pneumonia,Staphylococcus
aureus, Candida albicans and Aspergillus nigerwere obtained from Microbiology Laboratory,
University College Hospital, Ibadan, and Lagos University Teaching Hospital (LUTH),
Nigeria.In this study, the antimicrobial activity of air potato (Dioscorea bulbifera) leaves
(dropped, fresh, yellow) extractswere investigated against these pathogens. All extracts of
Dioscorea bulbifera inhibited the growth of the tested bacterial isolates with the dropped leaf
showing the highest potency against the bacteria, while none of the leaf extracts inhibited the
growth of the tested fungi at 1000 mg/ml. Ethanolic extracts have high potency against the
tested bacteria.Salmonella typhi, Proteus vulgaris andPseudomonas aeruginosahave zones of
inhibition greater than 15 mm withNitrofurantoin, while Streptococcus pneumoniae
andStaphylococcus aureus were susceptive to cotrimonazole. The minimum inhibitory
concentration of ethanol, petroleum ether and aqueous extracts of air potato (Dioscorea
bulbifera) required to totally eradicate the growth of tested bacteria was determined ranging
from 62.5-250 mg/ml for ethanolic extracts; from 125-500 mg/ml for petroleum ether and
from 125mg/ml to 1000mg/ml for aqueous extracts.The leaf extracts were purified using
chloroform, methanol and ethyl acetate.Phytochemical analysis showed the presence of
flavonoids, tannins, saponins, and carbohydrates.
