ABSTRACT
BACKGROUND: To find out an alternative strategy to antibiotic usage against bacterial infection. MATERIALS AND METHODS: The purpose of this study is to describe the quorum-sensing (QS) inhibitory activity of edible plants and fruits against N-acyl-homoserine lactone (AHL)-mediated violacein production in Chromobacterium violaceum and virulence factor expression in Pseudomonas aeruginosa PAO1. RESULTS: Aqueous extracts of Ananas comosus (Bromeliaceae), Musa paradiciaca (Musaceae), Manilkara zapota (Sapotaceae) and Ocimum sanctum (Lamiaceae) were prepared and anti-QS activity of each extract was tested against AHL-mediated phenotypic expressions of C. violaceum and PAO1. Most of these extracts showed significant reduction in AHL-mediated violacein production in C. violaceum as well as pyocyanin pigment, staphylolytic protease, elastase production and biofilm formation in PAO1. However, these extracts were not inhibitory to bacterial growth, revealing that the QS inhibition by the extracts is not related to static or killing effects on the bacteria. CONCLUSIONS: The present study identified the anti-QS activity of A. comosus, M. paradiciaca, M. zapota and O. sanctum. An AHL-inactivating compound from these plant sources can be used as an alternative to antibiotic compounds to prevent AHL-mediated bacterial infection in higher organisms.
Subject(s)
Acyl-Butyrolactones/antagonists & inhibitors , Anti-Bacterial Agents/pharmacology , Chromobacterium/drug effects , Plant Extracts/pharmacology , Plants, Edible , Pseudomonas aeruginosa/drug effects , Quorum Sensing/drug effects , Ananas , Bacterial Proteins/metabolism , Biofilms/drug effects , Biofilms/growth & development , Caseins/metabolism , Chromobacterium/growth & development , Chromobacterium/physiology , Fruit , Indoles/metabolism , Manilkara , Metalloendopeptidases/metabolism , Metalloproteases/metabolism , Musa , Ocimum , Pancreatic Elastase/analysis , Pancreatic Elastase/metabolism , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/physiology , Pyocyanine/metabolism , Virulence Factors/metabolismABSTRACT
Honey and ghee are the two food substances used widely in our diet. In Ayurveda, it is quoted that heated honey and honey mixed with equal amount of ghee produce deleterious effects. Hence, it was of our interest to study the physicochemical characteristics and chemical constituents of heated honey and honey mixed with ghee, and their effect on daily food intake and organ weights of rats. The specific gravity of samples showed a significant decrease in honey and ghee samples heated to 140°C. The pH of honey heated to 140°C was elevated with a reduction in the specific gravity. There was a significant rise in hydroxymethyl furfuraldehyde (HMF) in 60º and 140°C heated honey samples. The browning and total antioxidant of honey mixed ghee samples was significantly higher when compared to ghee samples. Further, the authors have also evaluated the effects of consumption of heated honey, ghee, honey mixed with equal amount of ghee and heated honey mixed with heated ghee in rats. The feeding of heated honey and honey mixed with ghee for 6 weeks showed no significant change in the food intake, weight gain and relative organ weights. The study revealed that the heated honey mixed with ghee produces HMF which may cause deleterious effects.
