In vitro inhibition of Helicobacter pylori urease with non and semi fermented Camellia sinensis.

PURPOSE: Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori. METHODS: Minimum inhibitory concentrations of nonfermented and semifermented C. sinensis methanol: water extracts were assessed by broth dilution method. Examination of the urease function was performed by Mc Laren method, and urease production was detected on 12% SDS polyacrylamide gel electrophoresis from whole cell and membrane bound proteins. RESULTS: Both extracts had inhibitory effects against H. pylori and urease production. At a concentration of 2.5 mg/ml of nonfermented extract and 3.5 mg/ml of semifermented extract the production of Ure A and Ure B subunits of the urease enzyme were inhibited completely. A concentration of 4 mg/ml of nonfermented and 5.5 mg/ml of semifermented extract were bactericidal for H. pylori. CONCLUSIONS: C. sinensis extracts, especially the nonfermented, could reduce H. pylori population and inhibit urease production at lower concentrations. The superior effect of nonfermented extract is due to its rich polyphenolic compounds and catechin contents.

[In vitro reduction in colonization of Streptococcus mutans by honey beeswax ethyl acetate extract]

Dental plaque is composed of bacterial derived extracellular polysaccharide known as glucan which is synthesized by Streptococcus mutans. Natural substances that could inhibit the plaque formation of the bacteria have a significant importance. This investigation has evaluated the honey beeswax extract effect on the Gft production, the key enzyme of S. mutans colonization factor for the first time. In this experimental study extraction of the sample conducted with ethyl acetate and methanol solutions in the Clevenger extractor. The ethyl acetate soluble fraction was separated in the first step and after the evaporation of the first solute, the 70% methanol as inactive solvent was added and the water mixture was used as a second solution, then materials were separated with dH[2]O. Minimum inhibitory concentration [MIC] of the honey beeswax extract was assessed by Broth diffusion method. Examination of cell adherence [Biofilm Inhibitory Concentration, BIC] was calculated by colony counts from surface scratching of glass slides in the bacterial media that supplied with 1% sucrose. Glucosyltransferase expression was detected by 15% SDS poly acrylamide gel electrophoresis. Concentration of 1mg/ml of ethyl acetate honey beeswax extract was inhibited completely biofilm and it was prevented the production of glucosyltransferase enzyme. The concentration of formation 6 mg/ml of the extract had bacteriostatic effect and 30 mg/ml concentration of this extract had bacteridicidal for S. mutans [P<0.01]. Thu sub-bacterial concentration honey beeswax extract was able to block the major enzyme that contributes to S. mutans biofilm formation