| dc.description.abstract | Antibiotic resistance is a global health concern that ultimately results in resistant
bacterial strains against common antibiotics. Therefore, it is an urgent need to
discover novel antibiotics of natural origin. Pteridophytes are a promising
alternative and in Sri Lanka, pteridophytes are almost unexplored area of study for
their medicinal properties. This study aims to evaluate the in-vitro antibacterial
activity of crude hexane, ethyl acetate, and methanol extracts of leaves, roots and
stems of five pteridophytes found in Sri Lanka namely Alsophila
walkerae, Sphaeropteris crinita, Pityrogramma calomelanos, Blechnum orientale and
Diplazium esculentum. The crude organic extracts were assayed using disc diffusion
method against two gram-positive (Staphylococcus aureus, Bacillus subtilis) and two
gram-negative (Pseudomonas aeruginosa, Escherichia coli) bacteria. The zones of
inhibitions were recorded after overnight incubation and mean values were
calculated based on the triplicated results. Gentamicin and 50% methanol were used
as the positive and negative controls respectively. According to the results, 29 out of
33 extracts were active against least for one bacterial strain. Thirteen extracts
inhibited the growth of S. aureus while 8 extracts were active against B.Subtilis. Two
plant extracts showed the activity against P. aeruginosa and 6 extracts were active
against E.coli. Methanolic root extract of S.crinita showed promising activity against
both Gram-negative and Gram-positive bacteria tested. Hexane extracts were
completely inactive. This study revealed that the pteridophytes are a good source of
phytochemicals with antibacterial activity. | en_US |
