Irradiated β-glucan enhances immune response to bacterial infection through CD4 and CD8 T-lymphocytes

Background: β-glucans are glucose polymers with a variety of stimulatory effects on the immune system. The objective of this study was to evaluate the immune-enhancing activities of low molecular weight gamma irradiated β-glucan (Iβ-g) extracted from Pleurotus ostreatus in response to Pseudomonas aeruginosa infection in rats. Materials and Methods: β-glucan (β-g) powder was exposed to 50 kGy of gamma radiation. For experimental study, healthy male rats were divided in six groups. Group I: did not receive any treatment. Group 2: infected group was injected once with P. aeruginosa. Group 3: were orally administrated with β-g for 15 days at a dose of 65 mg/Kg body weight/day. Group 4: were orally administrated with Iβ-g for 15 days at a dose of 65 mg/Kg body weight/day. Group 5: rats were treated with β-g and injected once with P. aeruginosa. Group 6: rats were treated with Iβ-g and injected once with P. aeruginosa. Rats were sacrificed 24 h post bacterial infection.Results: β-g and Iβ-g were characterized using FTIR spectra and SEM, showed breakdown of the glycosidic bonds with deformation and splittng of β-g molecule. Oral ingestion of β-g markedly enhanced the production of lymphocytes and leucocytes and CD8 compared to that of Iβ-g, although Iβ-g was more effective in stimulating CD4 count compared to that of β-g and ameliorated CD4/CD8 ratio. Iβ-g enhanced GPx and CAT activity, elevated zinc concentration in the blood compared to that of β-g, although both Iβ-g and β-g elevated GSH and caused no effect on MDA level in post infected groups. Conclusion: In conclusion Iβ-g improves antioxidant state and enhances immune system in particular CD4 count against bacterial infections which is an important marker of immune system.