In vitro screening of Annona Reticulata l. pericarp for antimicrobial activity

Unripe and ripe pericarp extracts of Annona reticulata Linn. fruits were investigated for their in vitro antimicrobial properties against three gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus), gram-negative bacteria (Eschericia coli, Pseudomonas aeruginosa and Proteus vulgaris) and three fungal strains (Aspergillus flavus, Aspergillus niger and Penicillium chrysogenum). All the extracts showed activity against at least one strain of bacteria and fungi and the result shows there is significant differences (P<0.05) between the activities of extract on microorganism. The ethanol extract of unripe pericarp exhibited the highest inhibition activity against the growth of Eschericia coli (19.67 mm) which was higher than the zone of inhibition produced by ampicillin standard (15.33 mm). The MIC of unripe pericarp extracts ranged from 1.0–3.0 mg/ml inhibiting the growth of most of the gram-positive bacteria. Ethanol extract was found to be most potent, as it inhibited the three fungal strains at concentration ranging from 2.5–3.0 mg/ml. Also MIC for ethanol extract was the lowest (1.0 mg/ml) compared with other extracts. The obtained results indicated that the ethanol extract of unripe pericarp manifested significant antimicrobial activity. The results were promising and suggest that it can be used in treating diseases caused by the test organisms.