ABSTRACT
BACKGROUND/AIMS: Among irritants causing gastric ulcer, Helicobacter pylori (H. pylori) might be pivotal, after which eradication became essential way in either inhibiting ulcerogenesis or preventing ulcer recurrence. Since threonine is essential in either mucus synthesis or cytoprotection, we hypothesized that the dietary threonine from Corynebacterium glutamicum (C. glutamicum) can mitigate the cytotoxicity of H. pylori infection.MATERIALS AND METHODS: RGM-1 cells were challenged with 100 multiplicity of infection H. pylori for 6 hours, during which threonine alone or combination with Corynebacterium sp. was administered and compared for anti-Helicobacter, anti-inflammation, anti-oxidative, and cytoprotective actions.RESULTS: Threonine alone or combination of threonine and C. glutamicum yielded significant bacteriostatic outcomes. The increased expressions of interleukin (IL)-1β, IL-8, Cox-2, and iNOS mRNA after H. pylori infection were significantly decreased with either threonine alone or the combination of threonine and C. glutamicum. The elevated expressions of NF-kB, HIF-1a, and c-jun after H. pylori infection were all significantly decreased with the combination of threonine and broth from C. glutamicum (P < 0.05), leading to significant decreases in 2′,7′-dichlorofluorescein-diacetate (P < 0.01). Tracing further host antioxidative response, the attenuated expression of heme oxygenase-1, Nrf2, and dehydrogenase quinone-1 after H. pylori infection was significantly preserved with combination of threonine and C. glutamicum. H. pylori infection led to significant increases in apoptosis accompanied with Bcl-2 decreases and Bax increases, while the combination of threonine and C. glutamicum significantly attenuated apoptosis, in which attenuated EGF, TGF-β, and VEGF were significantly regulated, while β-catenin did not change.CONCLUSIONS: Threonine synthesized from C. glutamicum significantly alleviated the cytotoxicity of H. pylori in gastric epithelial cells.