CONTEXT: Cranberry juice has long been recognized in folk medicine as a 
therapeutic agent, mainly in urinary tract infections. Its proposed mechanism of 
action is antiadhesion of bacteria.
OBJECTIVE: Investigation of the potential antiadhesion effect of nondialyzed 
material of cranberry (NDM) via its influence on secretion, gene expression, and 
promoter activity of the fructosyltransferase (FTF), which is among the 
extracellular enzymes associated with dental biofilm formation and pathogenesis 
of oral bacteria.
MAIN OUTCOME MEASURES: Secretion of FTF from Streptococcus mutans, in the 
presence of NDM, was measured by immunoblotting and confocal scanning laser 
microscopy. Its influence on ftf gene expression was determined by reverse 
transcription followed by real-time RT-PCR. The luciferase assay was used to 
detect bioluminescence expressed by the ftf promoter activity of bacteria 
exposed to NDM.
RESULTS: NDM at concentrations between 0.2/mL and 1mg/mL significantly (P<.05) 
decreased secretion of extracellular FTF, as well as down-regulated ftf 
expression in a dose-dependent manner. NDM also markedly reduced the luciferase 
activity under the ftf promoter.