Asian Pacific Journal of Tropical Biomedicine  2011;1(4):298-305

doi:10.1016/S2221-1691(11)60047-6

Anti-microbial principles of selected remedial plants from Southern India.

Rao G TIRUPATHI 1 ; Babu K SURESH ; Kumar J UJWAL ; P SUJANA ; A Veerabhadr RAOA ; A S SREEDHAR

Affiliations

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Keywords

Anti-microbial activity; Bombax ceiba; Escherichia coli; Growth inhibition; Minimum inhibitory concentration; Morus alba; Piper betel; Pseudomonas aeruginosa; Staphylococcus aureus

Country

China

Language

English

MeSH

Abstract

OBJECTIVETo examine the anti-bacterial activity of leaf extracts of Morus alba L. (Moraceae) and Piper betel L. (Piperaceae), and seed extracts of Bombax ceiba L. (Borabacaceae).

METHODSWe have partially purified plant extracts by solvent extraction method, and evaluated the effect of individual fractions on bacterial growth using Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) bacterial strains.

RESULTSCompared with Morus and Bombax fractions, Piper fractions showed significant growth inhibition on all the three types of bacteria studied. The EtOAc-hexane fractions of Piper leaves exhibited significant anti-bacterial activity with minimum inhibitory concentrations (MIC) of 50 µg/mL culture against both gram-positive and gram-negative bacteria. The EtOAc-fractions I, II, and IV inhibited bacterial colony formation on soft agar in addition to growth inhibition. A combination treatment of piper fractions with ampicillin resulted in significant growth inhibition in E. coli and P. aeruginosa, and combination with anticancer drug geldanamycin (2µg/mL) showed selective growth inhibition against P. aeruginosa and S. aureus. Three major compounds, i.e., eugenol, 3-hexene-ol and stigmasterol, were primarily identified from Piper betel leaf extractions. Among the individual compounds, eugenol treatment showed improved growth inhibition compared with stigmasterol and 3-hexene-ol.

CONCLUSIONSWe are reporting potential anti-bacterial compounds from Piper betel against both gram-positive and gram-negative bacteria either alone or in combination with drug treatment.