Evaluation of Antibacterial Activities of medicinal Plants

Abstract

In this study, antibacterial activities of 9 different medicinal plants were tested against 10common pathogenic bacterial species. Medicinal plants were selected on the basis of their common use among the differentethnic groups for common disorder. The selected medicinal plants wereAcorus calamus,Aegle marmelos, Asparagus racemosus, Holarrhena antidysenterica, Mimosa pudica,Terminalia bellirica, Terminalia chebula, Tinospora cordifolia and Woodfordiafruticosa. These medicinal plants were subjected to solvent extraction using hot solventof increasing polarity into 3 fractions viz: hexane, ethylacetate and methanol usingsoxhlet apparatus. After removing the solvent under reduced pressure, residues weresuspended separately in DMSO. The highest yield was obtained in methanol fraction ofTerminalia chebula(46.1%) while lowest in hexane fraction of Asparagus racemosus(0.7%). The bacteria selected for the study were Staphylococcus aureus, Escherichia coli,Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris,Pseudomonas aeruginosa, Salmonella Typhi, Salmonella Paratyphi A and Shigelladysenteriae. Out of nine tested plants, four plant extracts (44%) showed activity against at least five ormore test bacteria and 5 plant extracts (56%) were active against three or less than threebacteria. None of the tested plants extracts were active against all the tested bacteria.Asparagus racemosuswas the least effectiveagainst the tested bacterial species. Plants extracts showed significant antibacterial activity towards Gram positive bacteriathan Gram negative bacteria.Staphylococcus aureuswas the most susceptible bacteriabeing sensitive to 18 fractions from 8 medicinal plants.Proteus vulgariswas the mostresistance bacteria being resistance to all selected plants. Largest ZOI (31 mm) wasproduced by ethylacetate fraction of Terminalia belliricawhile lowest MBC of 3.12mg/ml was shown by ethylacetate fraction ofT. belliricaagainstE. coli. Key words: Medicinal plants, Antibacterial activity, Plant extracts