Evaluation of antimicrobial and urease inhibitory activities of Aristolochia argentina on Helicobater pylori strains

SALINAS IBAÑEZ AG, ; ARISMENDI SOSA AC, ; CORTIÑAS TI, ; PAREDES J, ; SOSA A; VEGA AE

Ljubljana

Congreso; XXVth International Workshop on Helicobacter and Related Bacteria in Chronic Digestive Inflammation; 2012

European Helicobacter Study Group

Helicobacter pylori survives and persists in human stomach due to the urease enzime, which provides the alkaline microenvironment. Antibiotic therapy can kill planktonic cells of H. pylori, however they are not effective in cells within a biofilm. The increase of antibiotic resistance demands the search for alternative strategies. Aristolochia argentina, is used in folk medicine for gastrointestinal disorders in Cuyo, Argentina. The aim of this study was to evaluate antimicrobial activity of A. argentinae extract on planktonic and established H. pylori sessile cells and their urease inhibitory activity. The minimum inhibitory concentration (MIC) of A. argentina was assayed by agar dilution method using serial dilutions in range of 64 at 0.032 mg/ml. The H. pylori strains, NCTC11638 and five clinical isolates were assayed. The effect of 1.5 mg/ml A. argentina extract on H. pylori adhered to an abiotic surface was determined using plate counting; the morphologic changes were observed by optical microscopy and urease expression was determined by RT-PCR. A. argentina showed activity against H. pylori with MICs between 2 to 16 mg/ml. In established biofilms, the extract decreased biofilm biomass (p≤ 0.05), induced 100% H. pylori coccoid forms and inhibited the urease expression after 26 h of treatment. A. argentina could be a new strategy for an effective therapy againts H. pylori infection due to its antimicrobial activities on H. pylori planktonic and sessile cells and the inhibition of urease expression at low concentrations.