Abstract: The aim of this study was to investigate the synergistic effect of a recently discovered strain Lactobacillus casei Qian (LC-Qian) and geniposide on the prevention of ethanol-induced gastric injury in mice. LC-Qian (0.5 × 108 CFU/kg mb) was mixed with geniposide (50 mg/kg mb), and LC-Qian (0.5 × 108 CFU/kg mb) and geniposide (50 mg/kg mb) were also used separately to protect against HCl/ethanol induced gastric injury and to compare their preventive effects. LC-Qian combined with geniposide (the combination group) diminished the gastric lesion area and gastric secretion volume and raised the pH of the gastric juice to a level close of that of the control group and significantly different from that in the model group. The combination treatment was also able to decrease the serum levels of cytokines such as interleukin-6 (IL-6), IL-12, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), motilin (MOT), substance P (SP), and endothelin-1 (ET-1) but increase the levels of somatostatin (SS) and vasoactive intestinal peptide (VIP) as compared to the model group. The combination group showed higher NO contents in serum, heart, liver, kidney and stomach in comparison to the model group, but their levels were lower than those in the normal group. As indicated by reverse transcription polymerase chain reaction (RT-PCR) assay, the combination treatment could increase the mRNA expression levels of neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS) and inhibitor kappa B-α (IκB-α), and decrease the mRNA expression levels of inducible nitric oxide synthase NOS (iNOS) and nuclear factor kappa B (NF-κB) as compared to the model group. These expression levels in the combination group were similar to those of the normal group. From these results, it can be concluded that the combination treatment has the best preventive effects against gastric injury and LC-Qian could enhance the preventive effect of geniposide against gastric injury. Therefore, this combination treatment could be used as a new way method for the prevention of gastric injury.

Key words: Lactobacillus casei Qian, ethanol, mRNA expression, mouse, stomach