Abstract:
Mangrove plants Avicennia marina, Bruguiera sexangula, Derris trifoliata, Excoecaria
agallocha, Lumnitzera racemosa and Rhizophora apiculata were used to obtain plant
extracts by grinding and sequential Soxhlet extraction method. Plant extracts were
obtained from mature leaves, immature leaves, shoot and bark of above selected
mangrove plants. In sequential Soxhlet extraction method, plant extracts were obtained
in petroleum ether, chloroform, ethyl acetate, ethanol and water. The antibacterial
activity of these mangrove plant extracts was tested against antibiotic-resistant bacterial
species of Staphylococcus sp. and Proteus sp. The degree of antibacterial activity was
assayed by measuring the length of inhibition zone in millimeters. Ethanol extracts were
found to be much more effective on both bacterial strains than aqueous extracts in
grinding procedure. In Soxhlet extraction method, almost all plant extracts could inhibit
growth of Staphylococcus sp more than Proteus sp. Among the plant extracts, the most
clear antibacterial activity was observed extracts of L. racemosa against both bacterial
strains. Soxhlet extracts of fresh plant materials and charcoal treated Soxhlet plant
extracts of L. racemosa were able to inhibit both bacterial strains more than those of
dried Soxhlet extracts of plant materials and untreated Soxhlet plant extracts.
Antibacterial activity of plant extracts of both fresh and dried plant materials had been
reduced for both bacterial strains with the time after extraction. The biological active
compounds in plant extracts will be isolated, purified and characterized using
chromatographic methods and known spectroscopic techniques.
