ETD

• cetylated fatty acids
• gastritis
• Helicobacter
• infection

Helicobacter pylori (H. pylori) is the major cause of inflammation damaging the gastric mucosal barrier. First-line treatment regimens for H. pylori infection typically include a combination of two or more antibiotics and an acid suppressive agent, however, these are not always effective in eradicating the infection. Therefore, new therapeutic strategies are needed, particularly those targeting inflammation. Based on the cytoprotective and lubricant properties of cetylated fatty acids (CFAs), we hypothesized that these may have therapeutic effects by protecting the gastric mucosa from H. pylori-induced inflammation.
To test this hypothesis, we performed in vitro bactericidal assays using different concentrations of CFAs (0-10%) against H. pylori strains B128 7.13 and 26695. Additionally, in an in vivo study, C57BL/6 mice (n=30) were divided into 3 groups and treated by oral gavage with either Helicobacter felis (n=20) or Brain Heart Infusion broth as a control (n=10). At 4 weeks post-infection (pi), mice were treated once daily for 7 days with CFAs (283 mg/kg) or corn oil. At 5-weeks pi (1 day post-treatment) and 9-weeks pi (1 month post treatment), mice were euthanized, and stomachs, spleens and sera collected. Serum anti-H. felis IgG levels were measured by ELISA. Stomach tissues were histologically analyzed in a blinded fashion for inflammation (Hematoxylin and Eosin staining) and H. felis colonization (Giemsa staining). Parietal cells numbers were quantified by immunofluorescence, mucosal thickness was measured, and acidic mucins were analyzed by Alcian-PAS staining. Mice body, stomach and spleen weights were recorded. The macroscopic morphology of stomach and spleen samples was evaluated. Gastric expression levels of TNF, IL1β and IL6 were analyzed by qPCR.
Viable counting assays revealed a dose-dependent bacteriostatic effect of CFAs against H. pylori, with 5% CFAs being sufficient to eliminate bacterial growth in vitro. In vivo, anti-H. felis IgG serum antibodies were significantly elevated in infected animals at 1 month post-treatment but not at 1 day post-treatment when compared with uninfected mice. Infected animals had significantly increased inflammatory scores compared with the uninfected group, but no differences were observed between CFAs-treated mice and corn oil-treated animals. Colonization levels were significantly increased in infected mice compared to uninfected groups, although no statistical difference was observed between the CFA-treated and corn oil-treated groups Although parietal cell numbers were reduced in all H. felis-infected groups compared to uninfected mice, CFAs-treated mice exhibited higher parietal cell numbers than corn oil-treated mice. Gastric mucosal thickness was significantly increased in CFAs-treated animals at 1 day post-treatment compared to uninfected controls, with a mild but significant increase also observed at 1 month post-treatment. Furthermore, CFAs treatment was associated with increased levels of acidic mucins in the gastric mucosa of infected mice. No significant differences were observed in body, stomach or spleen weights between groups, nor were any macroscopic differences evident. qPCR analysis showed reduced expression of all examined proinflammatory cytokines in CFAs-treated animals at 1 day post-treatment compared to uninfected group.
In conclusion, this study identifies CFAs as a potential therapeutic agent for the treatment of Helicobacter-induced chronic gastritis, demonstrating bacteriostatic activity, suppression of proinflammatory cytokines, and enhancement of gastric mucosal repair. These findings warrant further investigation into the molecular mechanisms and translational potential of CFAs in the treatment of gastric inflammation.