Tauroursodeoxycholic acid reduces damaging effects of taurodeoxycholic acid on fundus gastric mucosa

Tauroursodeoxycholic Acid Inhibits Nuclear Factor Kappa B Signaling in Gastric Epithelial Cells and Ameliorates Gastric Mucosal Damage in Mice

Background/Aims

Previous studies have reported the protective effects of tauroursodeoxycholic acid (TUDCA) on gastric epithelial cells in some animal models, but the precise mechanisms are unclear. This study examined the effects of TUDCA on NF-κB signaling in gastric epithelial cells. Moreover, the protective effects of TUDCA in experimental gastritis models induced by ethanol and NSAID were evaluated and compared with ursodeoxycholic acid (UDCA).

Methods

After a pretreatment with TUDCA or UDCA, human gastric epithelial MKN-45 cells were stimulated with tumor necrosis factor (TNF)-α to activate NF-κB signaling. A real-time PCR (RT-PCR) for human interleukin (IL)-1 mRNA was performed. An electrophoretic mobility shift assay (EMSA) and immunoblot analyses were carried out. In murine models, after a pretreatment with TUDCA or UDCA, ethanol and indomethacin were administered via oral gavage. Macroscopic and microscopic assessments were performed to evaluate the preventive effects of TUDCA and UDCA on murine gastritis.

Results

A pretreatment with TUDCA downregulated the IL-1α mRNA levels in MKN-45 cells stimulated with TNF-α, as assessed by RT-PCR. As determined using EMSA, a pretreatment with TUDCA reduced the TNF-α-induced NF-κB DNA binding activity. A pretreatment with TUDCA inhibited IκBα phosphorylation induced by TNF-α, as assessed by immunoblot analysis. TUDCA attenuated the ethanol-induced and NSAID-induced gastritis in murine models, as determined macroscopically and microscopically.

Conclusions

TUDCA inhibited NF-κB signaling in gastric epithelial cells and ameliorated ethanol- and NSAID-induced gastritis in murine models. These results support the potential of TUDCA for the prevention of gastritis in humans.

The Unexpected Uses of Urso- and Tauroursodeoxycholic Acid in the Treatment of Non-liver Diseases

Tauroursodeoxycholic acid (TUDCA) is the taurine conjugate of ursodeoxycholic acid (UDCA), a US Food and Drug Administration–approved hydrophilic bile acid for the treatment of certain cholestatic liver diseases. There is a growing body of research on the mechanism(s) of TUDCA and its potential therapeutic effect on a wide variety of non-liver diseases. Both UDCA and TUDCA are potent inhibitors of apoptosis, in part by interfering with the upstream mitochondrial pathway of cell death, inhibiting oxygen-radical production, reducing endoplasmic reticulum (ER) stress, and stabilizing the unfolded protein response (UPR). Several studies have demonstrated that TUDCA serves as an anti-apoptotic agent for a number of neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and Huntington's disease. In addition, TUDCA plays an important role in protecting against cell death in certain retinal disorders, such as retinitis pigmentosa. It has been shown to reduce ER stress associated with elevated glucose levels in diabetes by inhibiting caspase activation, up-regulating the UPR, and inhibiting reactive oxygen species. Obesity, stroke, acute myocardial infarction, spinal cord injury, and a long list of acute and chronic non-liver diseases associated with apoptosis are all potential therapeutic targets for T/UDCA. A growing number of pre-clinical and clinical studies underscore the potential benefit of this simple, naturally occurring bile acid, which has been used in Chinese medicine for more than 3000 years.

Preventive effect of hydrotalcite on stress ulcer in rats after acute brain trauma

AIM: To study the role of bile reflux in the stress ulcer in rats after acute brain trauma, and to investigate the preventive role of Hydrotalcite (Talcid) to the stress ulcer.

METHODS: An animal model was established by Allen's method with modification. 128 male Wistar rats were divided randomly into four groups: Group I (n = 32): stress ulcer group, rats suffered from acute brain trauma without therapy; Group II (n = 32): normal control group, rats with sham operation; Group III (n = 32): Talcid group, rats suffered from acute brain trauma with Talcid administration; Group IV (n = 32): normal saline (NS) group, rats suffered from acute brain trauma with NS administration. Each group was divided into four subgroups of 1 h, 3 h, 6 h, and 24 h after the trauma (n = 8, for each subgroup). The rats in groups III and IV received Talcid and NS by gavage respectively before the operation for three days (Talcid: 500mg/kg.weight/day, NS: 1.5 mL/kg. weight/day). The bile acid concentration in the stomach and blood, the PH value and ulcer index (UI) were assayed, and the histology of gastric mucosa was analysed.

RESULTS: The concentration of gastric bile acid in group I was higher than that of group II at each time point (P <0.05, P <0.01); The damage of gastric mucosa was serious (P <0.05); and it showed a positive correlation between them (r = 0.05, P <0.01). But there was no difference in the blood bile acid and PH value. The histology showed corresponding changes. The concentration of gastric bile acid in group III was lower than that of group Ⅳ at each time point (P <0.01); The PH value at 1 h, 3 h, 6 h was higher but UI was lower at 6 h, 24 h in group III (P <0.01). There was a linear relationship between the gastric bile acid concentration or PH value and UI (r = 0.43, r = 0.52, P <0.01). The damage was ameliorated obviously in group III.

CONCLUSION: The bile reflux plays an important role in the stress ulcer after acute brain trauma. It shows a potential correlation between the extent of bile reflux and gastric mucosa damage. As a new combined bile acid drug, hydrotalcite can effectively prevent the occurrence of stress ulcer after acute brain trauma.