Gastric oxidative stress and hemorrhagic ulcer in Salmonella typhimurium-infected rats.

Infection of Salmonella typhimurium (Salmonella typhi) can lead to various organ diseases. This research first proposed that Salmonella typhi-infection could result in gastric oxidative stress and hemorrhagic ulcers that were ameliorated by ofloxacin, lysozyme chloride and several antioxidants, including exogenous glutathione (GSH), allopurinol and dimethylsulfoxide (DMSO). Male Wistar rats were given intrajejunally the live culture of Salmonella typhi [1 x 10(10) colony-forming unit (CFU)/rat] and followed by deprivation of food for 36 h. Age-matched control rats received vehicle only. Rat stomachs were irrigated for 3 h with either normal saline or a simulated gastric juice containing 100 mM HCl, 17.4 mM pepsin and 54 mM NaCl. Infection of Salmonella typhi produced an aggravation of ulcerogenic factors, including enhancing gastric acid back-diffusion, mucosal lipid peroxide generation and hemorrhagic ulcer as well as an attenuation of mucosal GSH level. Intragastric irrigation of gastric juice caused further aggravation of these gastric biochemical parameters. This exacerbation of ulcerogenic factors was abolished by pretreatment of ofloxacin and lysozyme chloride. Antioxidants, such as reduced GSH, allopurinol and DMSO also produced significant (P<0.05) amelioration of gastric damage in Salmonella typhi-infected rats. In conclusion, infection of Salmonella typhi substantially caused gastric oxidative stress and disruption of gastric mucosal barriers, consequently resulted in gastric hemorrhagic ulcerations that were effectively ameliorated by ofloxacin, lysozyme chloride and various antioxidants.