Immunomodulatory activities of oat β-glucan in vitro and in vivo

Abstract

Previous studies have shown that β-glucans extracted from yeast or fungi potentiate immune responses. In the present study, the immunomodulatory activities of β-(1→3, 1→4)-glucan, derived from oats, were investigated. The ability of oat β-glucan (OβG) to stimulate IL-1 and TNF-α release from murine peritoneal macrophages and the murine macrophage cell line P338D1, was assessed. In vitro stimulation of macrophages with OβG resulted in the production of IL-1 in a dose and time-dependent manner, whereas only small amounts of TNF-α could be detected in the culture supernatants. OβG also induced the production of IL-2, IFN-γ and IL-4 secretion in a dose-dependent manner in cultured spleen cells. The intraperitoneal administration of OβG in mice resulted in the accumulation of leucocytes, predominantly macrophages, in the peritoneal cavity. Furthermore, OβG was tested for its ability to enhance non-specific resistance to a bacterial challenge in mice. Survival of mice challenged with Staphylococcus aureus was enhanced by a single intraperitoneal administration of 500 μg of OβG 3 days prior to bacterial challenge. In conclusion, these studies demonstrated that OβG possesses immunomodulatory activities capable of stimulating immune functions both in vitro and in vivo.