Abstract
Chronic gastrointestinal diseases due to Helicobacter pylori and resistance to conventional antibiotics by these bacteria are a growing problem worldwide. Native biodiversity from Mesoamerica might provide leads for new compounds for the safe treatment of this infection. The aim of this research was to investigate the inhibitory activity against H. pylori of extracts from 16 native species traditionally used for the treatment of chronic gastrointestinal disorders (Acalypha guatemalensis, Capsicum annuum, Cordia dentata, Lippia graveolens, Petiveria alliacea, Phlebodium pseudoaureum, Piper jacquemontianum, Rauvolfia tetraphylla, Salvia lavanduloides, Senna alata, Simarouba glauca, Smilax domingensis, Solanum nigrescens, Tagetes lucida, Vernonia deppeana and Wigandia urens). Plant samples were collected from the field, shade-dried, ground, extracted by percolation with 70% ethanol, and concentrated to dryness by rotary evaporation. Extractable yield from plant materials varied from 5% in C. annuum fruit to 34% in S. nigrescens aerial parts. Activity against three clinical isolates of H. pylori (strains 62, 64, 68) was evaluated by Müller-Hinton agar dilution method with 5% sheep red blood cells and incubated for 7 days at 37°C in a microaerophilic environment, as stated by Clinical and Laboratory Standards Institute (CLSI), using clarithromycin for validation of the method. Minimal inhibitory concentration (MIC) was demonstrated in the positive extracts by the same procedure. Significant inhibitory activity (p=0.0312) was detected against H. pylori in the ethanol extracts of leaves of Cordia dentata and Solanum nigrescens (MIC 100 μg/ml). Bioguided fractionation will help in elucidating the chemical composition responsible for this activity, suggesting its use as a potential lead for drug development or for preparation of a phytotherapeutical product
