RESUMEN
BACKGROUND AND OBJECTIVE: The problems of bacterial diseases in aquaculture are primarily controlled by antibiotics. Medicinal plants and herbs which are seemed to be candidates of replacements for conventional antibiotics have therefore gained increasing interest. Current study was performed to investigate the presence of phytochemical constituents, antibacterial activities and composition of antibacterial active compounds in methanolic extract of local herb, Piper betle . METHODOLOGY: Qualitative phytochemical analysis was firstly carried out to determine the possible active compounds in P. betle leaves methanolic extract. The antibacterial activities of major compounds from this extract against nine fish pathogenic bacteria were then assessed using TLC-bioautography agar overlay assay and their quantity were determined simultaneously by HPLC method. RESULTS: The use of methanol has proved to be successful in extracting numerous bioactive compounds including antibacterial compounds. The TLC-bioautography assay revealed the inhibitory action of two compounds which were identified as hydroxychavicol and eugenol. The $-caryophyllene however was totally inactive against all the tested bacterial species. In this study, the concentration of hydroxychavicol in extract was found to be 374.72±2.79 mg g-1, while eugenol was 49.67±0.16 mg g-1. CONCLUSION: Based on these findings, it could be concluded that hydroxychavicol and eugenol were the responsible compounds for the promising antibacterial activity of P. betle leaves methanolic extract. This inhibitory action has significantly correlated with the amount of the compounds in extract. Due to its potential, the extract of P. betle leaves or it compounds can be alternative source of potent natural antibacterial agents for aquaculture disease management.
Asunto(s)
Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Infecciones Bacterianas/veterinaria , Eugenol/análogos & derivados , Enfermedades de los Peces/tratamiento farmacológico , Peces/microbiología , Metanol/química , Piper betle/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Solventes/química , Animales , Antibacterianos/aislamiento & purificación , Bacterias/crecimiento & desarrollo , Bacterias/patogenicidad , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/microbiología , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Eugenol/aislamiento & purificación , Eugenol/farmacología , Enfermedades de los Peces/microbiología , Pruebas de Sensibilidad Microbiana , Fitoterapia , Extractos Vegetales/aislamiento & purificación , Plantas MedicinalesRESUMEN
AIMS: The purpose of this study was to search for a novel quorum sensing inhibitor and analyse its inhibitory activity. METHODS AND RESULTS: Quorum sensing inhibition was monitored using the Tn-5 mutant, Chromobacterium violaceum CV026. Vanilla beans (Vanilla planifolia Andrews) were extracted using 75% (v/v) aqueous methanol and added to C. violaceum CV026 cultures. Inhibitory activity was measured by quantifying violacein production using a spectrophotometer. The results have revealed that vanilla extract significantly reduced violacein production in a concentration-dependent manner, indicating inhibition of quorum sensing. CONCLUSIONS: Vanilla, a widely used spice and flavour, can inhibit bacterial quorum sensing. SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggest that the intake of vanilla-containing food materials might promote human health by inhibiting quorum sensing and preventing bacterial pathogenesis. Further studies are required to isolate specific substances from vanilla extract acting as quorum sensing inhibitors.