In vitro assessment of the antimicrobial effect of leaf and stem extracts of a
commonly used plant –
Alchornea cordifolia
was carried out on 10 bacteria and 5 fungi. Five
solvents– chloroform, methanol, ethanol, petroleum ether and water were used for extraction.
Chloroform extract from leaf and stem resulted in the highest zone of inhibition against the
test bacteria (33 – 56mm). Ethanol extracts showed inhibition zone ranging between 10 –
14mm; methanol extract showed inhibition zone of 13 – 21mm only for the leaf extract.
Petroleum ether extract of only the stem resulted in inhibition of the test bacteria (10 –
15mm). Leaf and stem water extracts did not result in any zone of inhibition. Only chloroform
extracts from both leaf and stem resulted in fungal growth inhibition ranging from 22 – 60mm
(leaf) and 14 – 40mm (stem).
Staphylococcus haemolyticus
was most sensitive to leaf
chloroform extracts (50mm), followed by
E. coli
(49mm); while
Salmonella
sp. was the most
sensitive to stem extracts (56mm).
Rhizopus
sp. was the most sensitive to both chloroform
leaf extracts (60mm) and stem extracts (40mm) out of the 5 fungi screened. The highest
minimum inhibition concentration (MIC) of 0.125mg/ml was obtained from the leaf
chloroform extract on
Pseudomonas
sp. The implication of the findings was discussed.