title: Anti-microbial principles of selected remedial plants from Southern India.
abstract: OBJECTIVE
  To 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).
  
  
  METHODS
  We 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.
  
  
  RESULTS
  Compared 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.
  
  
  CONCLUSIONS
  We 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.
authors.affiliation: Centre for Cellular and Molecular Biology, Hyderabad 500 007, India.
authors.forename: Rao G
authors.initials: RG
authors.lastname: Tirupathi
authors.forename: Babu K
authors.initials: BK
authors.lastname: Suresh
authors.forename: Kumar J
authors.initials: KJ
authors.lastname: Ujwal
authors.forename: P
authors.initials: P
authors.lastname: Sujana
authors.forename: A Veerabhadr
authors.initials: AV
authors.lastname: Raoa
authors.forename: A S
authors.initials: AS
authors.lastname: Sreedhar
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D035163:Bombax / Q000737:chemistry*; D015169:Colony Count, Microbial; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects*; D007194:India; D008826:Microbial Sensitivity Tests; D031625:Morus / Q000737:chemistry*; D031701:Piper / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts
keywords: Anti-microbial activity; Bombax ceiba; Escherichia coli; Growth inhibition; Minimum inhibitory concentration; Morus alba; Piper betel; Pseudomonas aeruginosa; Staphylococcus aureus