Tumoricidal Effects of β-Glucans: Mechanisms Include Both Antioxidant Activity Plus Enhanced Systemic and Topical Immunity

Abstract

A study to evaluate the mechanisms of tumoricidal activity resulting from orally administered extract of Agaricus blazei Murill (A. blazei) was performed in mice bearing syngeneic and xenogeneic tumors. Tumor regression was comparably seen in both syngeneic and xenogeneic tumor-bearing mice when administered oral extract preparations. In addition, in a murine syngeneic tumor model, oral administration of water-soluble extracts of A. blazei resulted in significant production of cytokines such as IFN-gamma, and TNF-alpha in peritoneal exudate cells, in parallel with the marked regression of tumor development. The water-soluble extracts also induced pronounced antioxidant activity in in vitro and in vivo assays using two different methods. These results indicate the A. blazei extract may enhance not only the immnunomodulatory effects that promote activity of peritoneal exudate cells for tumor regression but also potentially result in the direct destruction of tumor cells through its antioxidant activity.

Laminarin, a soluble beta-glucan, inhibits macrophage phagocytosis of zymosan but has no effect on lipopolysaccharide mediated augmentation of phagocytosis

“…In addition to their role as PAMPs, beta-glucans are also recognized as potent immunomodulators that enhance tumoricidal cytotoxic activity [9], increase neutrophil phagocytosis [10], and enhance macrophage antiviral resistance [11]. However, other studies report that beta-glucans have suppressive effects on macrophage activities, including phagocytosis of S. cerevisiae [12] and also suppression of zymosan phagocytosis [13].…”

Gut microbiota, the pharmabiotics they produce and host health

“…β-Glucan is a water-soluble fibre found in cereals, as well as in yeast, bacteria, algae and mushrooms (145) . The EPS β-glucan has been reported to have many health promoting properties, including immunomodulatory effects (146)(147)(148)(149) , lowering serum cholesterol levels (145,150) , antiosteoporotic (151) , antitumourigenic, anticytotoxic and antimutagenic effects (152,153) . Furthermore, oat β-glucan has also been associated with the ability to modulate satiety, thus controlling appetite (154,155) .…”

Association of Beta-Glucan Endogenous Production with Increased Stress Tolerance of Intestinal Lactobacilli

“…The EPS beta-glucan has been reported to have many healthpromoting properties, which include immunomodulatory effects (1,25,64,70), lowering serum cholesterol levels (63,76), and antiosteoporotic (55), antitumorigenic, anticytotoxic, and antimutagenic effects (24,42), as well as displaying prebiotic qualities (57). Curdlan, a bacterial 1,3-beta-D glucan, has been assessed for its safety in vitro and in vivo and is approved for use in numerous countries, including Japan and the United States, as a food additive (58).…”