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

Previous studies have shown that beta-glucans extracted from yeast or fungi potentiate immune responses, In the present study, the immunomodulatory activities of beta-(1-->3, 1-->4)-glucan, derived from oats, were investigated, The ability of oat beta-glucan (O beta G) to stimulate IL-1 and TNF-alpha release from murine peritoneal macrophages and the murine macrophage cell line P338D1, was assessed, In vitro stimulation of macrophages with O beta G resulted in the production of IL-1 in a dose and time-dependent manner, whereas only small amounts of TNF-alpha could be detected in the culture supernatants. O beta G also induced the production of IL-2, IFN-gamma and IL-4 secretion in a dose-dependent manner in cultured spleen cells, The intraperitoneal administration of O beta G in mice resulted in the accumulation of leucocytes, predominantly macrophages, in the peritoneal cavity, Furthermore, O beta G 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 mu g of O beta G 3 days prior to bacterial challenge, In conclusion, these studies demonstrated that O beta G possesses immunomodulatory activities capable of stimulating immune functions both in vitro and in vivo.