Anti-Helicobacter pylori Activity of Larrea divaricata cav (jarilla) Extracts

VEGA AE; DAVICINO R; STEGE P; CASALI Y; MICALIZZI B

San Luis

Congreso; Cuyo Biology Society XXI Annual Scientific Meeting, 10 th Aniversary of Biocell; 2003

Sociedad de biología de cuyo

The development of resistance against clarithromycin (CLA) and metronidazole (MTZ) during treatment of Helicobacter pylori in­fection is a predominant cause of therapeutic failure. The search for new drugs that can serve as alternatives is thus very important. Larrea divaricata Cav (jarilla) (Zygophyllaceae) is a plant used in folk medicine for the treatment of microbial infections and tumours. The aim of this study was to evaluate the antimicrobial activity of decoction (D) and simulated digestion (SD) of jarilla against one H. pylori reference strain and six clinical isolates. Antibacterial activity was assayed by the agar dilution method. Serial dilutions of CLA and MTZ ranging from 128 to 0.008 mg/L. Extract con­centrations of 20 t0 100 mg/mL were prepared in Mueller-Hinton agar supplemented with 7% horse blood. The MIC was recorded as the lowest concentration of drugs inhibiting visible growth. All clini­cal isolates were CLA resistant and one was MTZ resistant. Com­plete inhibition in vitro was achieved by 79.3 mg/mL of SD and 100 mg/mL of D; however, 71.4% (5/7) of strains were inhibited al 85.3 mg/mL of decoction. The results indicate that Larrea divaricata Cav. may be a source of compounds with a therapeutic potential against H. pylori resistant and sensitive strains.