Antioxidant polyphenols extracted from Avocado epicarp (Persea americana var. Hass) inhibit Helicobacter pylori urease [Los polifenoles antioxidantes extraídos del epicarpio de Palta (Persea americana var. Hass) inhiben la ureasa de Helicobacter pylori]
Chavez F.,University of Concepción |
Aranda M.,University of Concepción |
Garcia A.,Laboratorio Of Patogenicidad Bacteriana |
Pastene E.,University of Concepción
Boletin Latinoamericano y del Caribe de Plantas Medicinales y Aromaticas | Year: 2011
Chronic infection by Helicobacter pylori produce chronic gastritis leading to other more severe pathologies as peptic ulcer and gastric adenocarcinoma. New anti-H. pylori agents has been found in natural products, particularly polyphenols. The inhibition of enzymes such us urease appears to be an interesting strategy by which polyphenols could limit the colonization by H. pylori. From the exocarp of Persea americana (avocado fruit), we obtain a procyanidin-rich extract with a 77% of gallic acid equivalents (GAE). Such procyanidins derived from epicatechin. with a mean degree of polymerization DPm = 6.10. The antioxidant capacity was assessed by different methods as TEAC-DPPH, TEAC-CUPRAC, TEAC-FRAP, TEAC-crocin. The extract shown inhibitory activity against H. pylori urease with an IC50 = 1.02 μg GAE/mL. In order to obtain clusters of procyanidins with different molecular weights, avocado peel extract was fractioned. A clear relation between the molecular size of procyanidins and their urease inhibitory activity was observed. © 2011 Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas.
PubMed | Laboratorio Of Patogenicidad Bacteriana
Type: Journal Article | Journal: Investigacion clinica | Year: 2012
Vaginitis is a common gynecologic disorder. It is due to several causes, some even unknown. Bacteroides fragilis is the most important anaerobe in clinical bacteriology, some strains of this group are notable for being enterotoxigenic and they have been associated with intestinal and extraintestinal syndromes. They have recently been isolated from patients with vaginitis. The purpose of this study was to investigate a possible association of enterotoxigenic B. fragilis with infectious vaginitis. 265 samples of vaginal exudate were processed, 202 from symptomatic patients and 63 healthy women. The identification of the microorganisms was carried out by conventional methods. In 31.2% of symptomatic patients were identified: Gardnerella vaginalis, Mobiluncus, Candida albicans, Mycoplasma hominis, Ureaplasma urealyticum and Streptococcus agalactiae. B. fragilis was identified in 27 symptomatic patients and 5 healthy women. These strains were cultivated in liquid medium and incubated during 48 h at 36 degrees C in anaerobe chambers. Supernatant activity was assayed in HT-29 cells. Eighteen B. fragilis strains isolated from symptomatic patients were enterotoxigenic, because induced alterations in target cell morphology. It was not identified in healthy women (P < 0.05). 77.7% of enterotoxigenic B. fragilis strains were not associated with other specific pathogens. This fact suggests that enterotoxigenic B. fragilis could be a cause for vaginitis. The effect of enterotoxin on E-cadherin of vaginal epithelium could facilitate invasion and its possible pathogenic role in the vagina. This is the first report that associates enterotoxigenic Bacteroides fragilis as a possible cause of infectious vaginitis.