title: The immunostimulating role of lichen polysaccharides: a review.
abstract: The immune system has capacity to suppress the development or progression of various malignancies including cancer. Research on the immunomodulating properties of polysaccharides obtained from plants, microorganisms, marine organisms, and fungi is growing rapidly. Among the various potential sources, lichens, symbiotic systems involving a fungus and an alga and/or a cyanobacterium, show promise as a potential source of immunomodulating compounds. It is well known that lichens produce an abundance of structurally diverse polysaccharides. However, only a limited number of studies have explored the immunostimulating properties of lichen polysaccharides. Published studies have shown that some lichen polysaccharides enhance production of nitrous oxide (NO) by macrophages and also alter the production levels of various proinflammatory and antiinflammatory cytokines (IL-10, IL-12, IL-1β, TNF-α, and IFN-α/β) by macrophages and dendritic cells. Although there are only a limited number of studies examining the role of lichen polysaccharides, all results suggest that lichen polysaccharides can induce immunomodulatory responses in macrophages and dendritic cells. Thus, a detailed evaluation of immunomodulatory capacity of lichen polysaccharides could provide a unique opportunity for the discovery of novel therapeutic agents.
authors.affiliation: Department of Biology, Brigham Young University, Provo, UT, 84602, USA; M. L. Bean Life Science Museum, Brigham Young University, Provo, UT, 84602, USA.
authors.forename: Gajendra
authors.initials: G
authors.lastname: Shrestha
authors.forename: Larry L
authors.initials: LL
authors.lastname: St Clair
authors.forename: Kim L
authors.initials: KL
authors.lastname: O'Neill
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D003713:Dendritic Cells / Q000187:drug effects; D006801:Humans; D016753:Interleukin-10 / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D053583:Interleukin-1beta / Q000276:immunology; D008011:Lichens / Q000737:chemistry*; D008264:Macrophages / Q000187:drug effects; D009569:Nitric Oxide / Q000276:immunology; D011134:Polysaccharides / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D053583:Interleukin-1beta; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D009569:Nitric Oxide
keywords: dendritic cells; immunostimulation; lichens; macrophages; natural products; polysaccharides