Lactoferrin and desferrioxamine are ineffective in the treatment of Helicobacter pylori infection and may enhance H. pylori growth and gastric inflammation in mice.

AIMS: To evaluate the efficacy of bovine lactoferrin (BLf), recombinant human lactoferrin (rHLf) and desferrioxamine against Helicobacter pylori in vitro and in mice and also to determine whether BLf or rHLf alter gastric inflammation. METHODS AND RESULTS: In vitro: Broth dilution susceptibility tests were performed using different concentrations of desferrioxamine, BLf and rHLf. Murine trials: In the prevention trial, C57BL/6 female mice were treated with BLf or rHLF, and then infected with the SS1 strain of H. pylori. In the treatment trial, mice were gavaged with either BLf, rHLf or desferrioxamine. In addition, gastric myeloperoxidase activity (MPO) was measured to assess gastric inflammation. Desferoxamine was found to have a direct bactericidal effect, while BLf and rHLf only partially suppressed H. pylori growth in vitro. However, in both prevention and treatment trials all three forms of treatment failed to reduce H. pylori load in mice. Gastric MPO activity and H. pylori load were noted to be higher with lactoferrin treatments. CONCLUSIONS: Our study does not support the use of BLf or rHLF in the treatment of human H. pylori infection. Interestingly, H. pylori growth and gastric inflammation appear to be enhanced by lactoferrin treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: The mouse model is ideal for testing novel H. pylori eradicating agents.

Short-term zinc supplementation attenuates Helicobacter felis-induced gastritis in the mouse.

BACKGROUND: Mucosal damage by H. pylori infection is mainly caused by neutrophils producing large quantities of reactive oxygen species (ROS). Metallothionein (MT) an intracellular, low-molecular, cysteine-rich protein, which is inducible by dietary zinc (Zn), has been implicated in sequestering ROS. This study examines the effects of Zn supplementation on Helicobacter colonisation and associated gastritis and the relationship with gastric MT levels. METHODS: C57Bl/6 mice were inoculated with either 10(8) H. pylori or H. felis and were infected for 4 weeks or 6 and 12 weeks, respectively. Mice infected with H. pylori (4 weeks) or H. felis (6 weeks) were treated with either Zn acetate (ZnA; 1 mg/ml), or Zn sulphate (ZnSO4; 5 mg/ml) for 2 weeks with 0.1 ml oro-gastric gavage twice daily. H. pylori load and H. felis colonisation density were determined by culture and microscopy, respectively. MT levels and H. felis-induced gastritis were also determined. RESULTS: Zn treatment showed no significant difference in Helicobacter load and gastric MT, however, ZnSO4 treatment showed a significant (p<0.05) increased in gastric MT in H. felis infected mice. Both Zn-treated groups showed a significant (p<0.05) difference in gastritis score in the antrum of the stomach within the basal and submucosal compartments compared to H. felis-infected controls. CONCLUSIONS: We found that H. felis-induced gastritis can be attenuated by short-term treatment of Zn. This observation suggests that Zn alone may be effective for the suppression of gastric mucosal inflammation induced by Helicobacter.