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Plants are the basis of traditional medicine system and have been the source of many of novel
drug components. Passiflora suberosa is used in Sri Lankan Ayurvedic system to treat many
diseases including diabetes. The objective of the present study was to evaluate phytochemical
constituent of different extracts and antimicrobial effect of methanol and aqueous extracts of
leaves of P. suberosa. Aqueous, methanol, chloroform and hexane extracts of leaves of P.
suberosa obtained under reflux conditions were subjected for phytochemical screening
according to previously established methods. Aqueous and methanol extracts of P. suberosa
leaves possessed more phytochemicals, thus those extracts were subjected for antimicrobial
study which was obtained using minimum inhibition assay as determined by agar well diffusion
method. Both methanol and aqueous extracts ranging from 6 μg/ml - 800 μg/ml were tested
against both gram positive (Bacillus subtilis, Staphylococcus aureus and Enterococcus
faecium) and gram negative bacteria (Pseudumonas aeruginosa, Salmonella typhimuriam and
Escherichia cloi) while Gentamicin was used as the standarded drug. The phytochemical
screening revealed the presence of saponins and anthraquinones in the chloroform extract,
alkaloids, saponins, and flavonoids in the hexane extract and alkaloids, unsaturated sterols,
triterpenes, saponins, flavonoids and tannins in both methanol and aqueous extracts.
Proanthocyanidin, which is a potent free radical scavenger, was observed only in the aqueous
extract. Further, only methanol extract was found to possess moderate activity against all the
tested bacterial strains. Highest concentration (800 μg/ml) of methanol extract showed widest
zone of inhibition (7 mm), indicating moderate activity against tested bacterial strains. In
contrast, the aqueous extract showed poor activity against tested bacterial strains. In
conclusion, results revealed the presence of bioactive natural compounds in aqueous and
mehtanolic extracts that may be used in the development of pharmaceutical products. Similarly,
preliminary studies on antimicrobial activity exhibited antimicrobial potential of methanol
extract, which could be used as future antimicrobial sources for natural therapies, food industry
