title: Plant-based hydrocarbon esters from Tragia involucrata possess antimicrobial and anti-inflammatory activities.
abstract: Antimicrobial and anti-inflammatory activities of hydrocarbon esters obtained from Tragia involucrata were evaluated by disk-diffusion (250 µg/ml), and broth-dilution (500-7.8 µg/ml), methods against bacteria. Among the compounds, shellsol showed the most potent activity against Burkholderia pseudomallei (KHW), Aeromonas hydrophila, Staphylococcus aureus, Bacillus subtilis, Streptococcus pyogenes, Klebsiella pneumoniae, Proteus mirabilis, and Streptococcus pneumoniae. Interestingly, vinyl hexylether was active against food-spoilage bacteria (Bacillus cereus and Proteus vulgaris), 2, 4-methyl hexane also exerted antimicrobial activity against K. pneumoniae, S. pyogenes, B. pseudomallei, Alcaligens viscolactis, and Pseudomonas aeruginosa. 2-methylnonane and 2, 6-dimethyl heptane showed only weak activity. For example, shellsol showed bacteriostatic effect (MIC of 7.8 µg/ml) against A. hydrophila, vinyl hexylether (MIC of 15.6 µg/ml) against P. mirabilis, and 2, 4-methyl hexane (MIC of 31.25 µg/ml) on B. pseudomallei. Cytotoxic effects of compounds were assayed in human skin and monkey kidney cells (62.5-2000 µg/ml) by an XTT assay. The vinyl hexylether, 2, 4-dimethyl hexane and shellsol did not show any toxicity up to 1000 µg/ml concentrations. The 2-methylnonane and 2, 6-dimethyl heptane induced morphological changes (e.g. cell disintegration and lysis) of both cell types at a 2000 µg/ml. The vinyl hexylether, 2, 4-dimethyl hexane and shellsol were devoid of toxic effects; however, 2-methylnonane induced weight loss and severe necrosis as evidenced by histopathological and serum biochemical analysis in rats. Interestingly, shellsol showed the maximum inhibition of carrageenan-induced, paw oedema in rats. In conclusion, findings of this study clearly indicate that biologically active hydrocarbon esters, such as shellsol, vinyl hexylether, and 2, 4-dimethyl hexane isolated from T. involucrata, may effectively control the growth of certain food-borne and food-spoilage pathogens.
authors.affiliation: Infectious Diseases Programme, MD4, 5 Science Drive 2, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore-117597. rperumalsamy@yahoo.co.uk
authors.forename: Ramar Perumal
authors.initials: RP
authors.lastname: Samy
authors.forename: Gautam
authors.initials: G
authors.lastname: Sethi
authors.forename: Vincent T K
authors.initials: VT
authors.lastname: Chow
authors.forename: Bradley G
authors.initials: BG
authors.lastname: Stiles
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002460:Cell Line; D004285:Dogs; D004952:Esters / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D000882:Haplorhini; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D008297:Male; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats
chemical_list: D000890:Anti-Infective Agents; D000893:Anti-Inflammatory Agents; D004952:Esters; D010936:Plant Extracts