Anti-Helicobacter pylori effects of IgY from egg york of immunized hens

Abstract

Effects of egg york containing IgY specific for Helicobacter pylori on the bacterial growth and intragastric infection were investigated in comparison with a proton-pump inhibitor pantoprazole. For in vitro anti-bacterial activity test, H. pylori (1×10(8) CFU/mL) was incubated with a serially diluted IgY for 3 days. As a result, IgY fully inhibited the bacterial growth at 16 mg/mL, which was determined to a minimal inhibitory concentration. In vivo elimination study, male C57BL/6 mice were infected with the bacteria by intragastric inoculation (1×10(8) CFU/mouse) 3 times at 2-day intervals, and 2 weeks later, orally treated twice a day with 50, 100, 200 or 500 mg/kg IgY for 18 days. After the final administration, biopsy sample of the gastric mucosa was assayed for the bacterial identification via urease, oxidase, catalase, nitrate reduction and H(2)S tests in addition to microscopic examination for mucosal inflammation. In CLO kit test, 75, 50, 12.5 and 12.5% of the animals revealed positive reaction following treatment with 50, 100, 200 and 500 mg/kg IgY, respectively, resulting in a superior efficacy at 200 mg/kg than 30 mg/kg pantoprazole that displayed 75% elimination. The CLO test results were confirmed by bacterial identification. Microscopic examination revealed that H. pylori infection caused severe gastric mucosal inflammation, which were not observed in the CLO-negative mice following treatment with IgY or pantoprazole. Taken together, IgY inhibited the growth of H. pylori, and improved gastritis and villi injuries by eliminating the bacteria from the stomach. The results indicate that IgY could be a good candidate overcoming tolerance of antibiotics for the treatment of H. pylori-mediated gastric ulcers.

Keywords: CLO test; Helicobacter pylori; gastric inflammation; immunoglobulin Y (IgY); minimal inhibitory concentration (MIC).

Figure 1

Representative microscopic findings of the gastric mucosa of mice infected with H. pylori followed by treatment with IgY (50-200 mg/kg) or pantoprazole (30 mg/kg). Note the degeneration and sloughing of villi (A) and submocosal inflammatory cell infiltration (B) in vehicle group, in comparison with light sloughing of villi at a low (50 mg/kg) dose of IgY (C) and near-normal features at high doses of IgY (D, 100 mg/kg; E, 200 mg/kg) or pantoprazole (F, 30 mg/kg).