pylori strains isolated from gastric biopsies of subjects selleck chemicals attending an outpatient clinic in Southern Italy. Their clinical relevance has also been elucidated. Methods Almond skins Natural almond skins (NS) were prepared from Californian almonds by treatment with liquid nitrogen as previously reported [20]. In vitro digestion studies The protocol used to simulate digestion of natural almond skins under gastric
and duodenal conditions in vitro has been previously described [21]. Briefly, for the gastric digestion, 1.5 g of NS was suspended in 12.4 mL acidic saline (150 mM NaCl, pH 2.5) and readjusted to pH 2.5 with HCl. Phosphatidylcholine (Lipid Products, UK) vesicle suspension, pepsin (Sigma, UK) and gastric lipase analogue (Amano Enzyme, Japan)
were added so that the final concentrations were 2.4 mmol/L, 146 U/mL and 60 U/mL, respectively. Gastric digestion was performed in a shaking incubator (170 rpm, 37°C) for 2 h. For the simulated gastric plus duodenal digestion, the pH was raised to 6.5 by addition of NaOH and the following enzymes were added: α-chymotrypsin (Sigma, 5.9 U/mL), trypsin (Sigma, 104 U/mL), colipase (Sigma, 3.2 μg/mL), pancreatic lipase (Sigma, 54 U/mL), and α-amylase (Sigma, Momelotinib in vitro 25 U/mL) in the presence of sodium taurocholate (4 mmol/L) and sodium glycodeoxycholate (4 mmol/L). Gastric plus duodenal digestion was performed in a shaking incubator (170 rpm, 37°C) for 1 h. Almond skin extracts Polyphenol-rich extracts
from NS, NS post in vitro gastric digestion (NS G) and NS post in vitro gastric plus duodenal digestion (NS G + D) were prepared as previously described and their composition has been previously reported [21]. Patients, H. pylori strains and culture conditions Two reference American Type Culture Collection strains of H. pylori (ATCC 43504 and ATCC 49503) and thirty two clinical isolates recovered from Phospholipase D1 gastric biopsy samples of dyspeptic adults (23 women, 9 men; average age, 51 years) undergoing digestive endoscopy at the Endoscopy Unit of the Department of Internal Medicine of the University of Messina, Messina, Italy, were used in this study. None of the patients had previously undergone eradication therapy. All study subjects gave their informed consent and the study was approved by the local ethical committee (Comitato Etico Scientifico A.O.U. Policlinico “G. Martino” Messina, Italy). Diagnosis of peptic ulcer (PU) and non-ulcer dyspepsia (NUD) or gastritis was based on endoscopic examination of the stomach and duodenum. Biopsy samples were taken for each patient for culture. Isolates were derived from patients suffering from gastritis (n = 27; 84.37%), or NUD (n = 5; 15.62%). Gastric biopsy specimens for culture were placed in the sterile screw-capped tubes containing 0.5 ml sterile saline and transported to the microbiology laboratory within 2 h.