Methods: In the current study, a transcriptome investigation was performed to explore the mechanism underlying the biofilm dispersal of P. aeruginosa after the exposure to Trigona honey.
Results: Microarray analysis of the Pseudomonas biofilm treated by 20% Trigona honey has revealed a down-regulation of 3478 genes among the 6085 screened genes. Specifically, around 13.5% of the down-regulated genes were biofilm-associated genes. The mapping of the biofilm-associated pathways has shown an ultimate decrease in the expression levels of the D-GMP signaling pathway and diguanylate cyclases (DGCs) genes responsible for c-di-GMP formation.
Conclusion: We predominantly report the lowering of c-di-GMP through the down-regulation of DGC genes as the main mechanism of biofilm inhibition by Trigona honey.
MATERIALS AND METHODS: The well-diffusion method, minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) techniques were employed to investigate the putative antibacterial activity of Malaysian monofloral honey from Koompassia excelsa (Becc.) Taub (Tualang), Melaleuca cajuputi Powell (Gelam) and Durio zibethinus Murr. (Durian). Honey samples were tested against Staphylococcus aureus ATCC6518 and ATCC25923, Staphylococcus epidermidis ATCC12228, Enterococcus faecium LMG16192, Enterococcus faecalis LMG16216 and ATCC29212, Escherichia coli ATCC25922, Salmonella enterica serovar Typhimurium ATCC14028 and Klebsiella pneumoniae ATCC13883.
RESULTS: Marked variations were observed in the antibacterial activity of these honey samples. Durian honey failed to produce substantial antibacterial activity, whereas Tualang and Gelam honey showed a spectrum of antibacterial activity with their growth inhibitory effects against all of the tested bacterial species including vancomycin-resistant enterococci (VRE).
CONCLUSION: Present findings suggested Gelam honey possesses highest antibacterial effect among the tested Malaysian honey samples.
DESIGN AND SETTINGS: Prospective randomized placebo-controlled study. Subjects were recruited from an otolaryngology clinic in 2 tertiary referral centers in the East coast of Peninsular Malaysia. The study period ranged from April 2010-April 2011.
METHODS: Forty AR patients were divided equally into a case group and a control group. All the subjects received a daily dose of 10 mg of loratadine for 4 weeks. The case group ingested 1 g/kg body weight of honey daily in separate doses for the 4-week period. The control group ingested the same dose of honey-flavored corn syrup as placebo. AR symptoms were scored at the start, week 4, and week 8 of the study.
RESULTS: There were no significant differences between the mean total symptom score of the case and the control groups at the start of the study. At week 4, both groups showed progressive improvement in the symptoms; at week 8, only the case group showed a continuous improvement in the symptom score. Only the group that ingested honey showed a significant improvement in individual AR symptoms. The improvement persisted for a month after the cessation of the treatment.
CONCLUSION: Honey ingestion at a high dose improves the overall and individual symptoms of AR, and it could serve as a complementary therapy for AR.