Polysaccharides in cancer prevention: From bench to bedside

Abstract

Polysaccharides (PS) are one of the major classes of carbohydrate biomolecule found within living system. Current knowledge built on scientific rationale and anecdotal evidence over the years acknowledge therapeutic and health benefit effects of bioactive polysaccharides and PS-protein complex from medicinal mushrooms and botanical sources. Medicinal PS is also acknowledged as biological response modifiers substances that stimulate the body response to infection and disease. In related context of cancer therapy, efficacy of bioactive PS has been documented in preclinical models and found to reduce tumor growth and prolong survival by immune stimulation, apoptosis, and cell cycle arrest. The immunomodulating activity by PS includes activation of macrophage(s), natural killer (NK) cells, lymphocyte activated killer (LAK) cells, dendritic cells, tumor-infiltrating lymphocytes, and stimulated release of various cytokines including interferons, tumor necrosis factor, interleukins, and colony-stimulating factors by specific receptor-mediated (Toll-like receptor, dectin-1 and CR3) induction of gene expression. Many of the investigated PS from mushrooms and botanicals have proceeded to pharmaceutical-grade GMP products such as lentinan, schizophyllan/sizofiran/sonifilan, Krestin (polysaccharide-K), GanoPoly, astragalan, GCS-100, and PectaSol, with low toxicity and potent antitumor activity. In countries such as Japan, China, and Korea, pharmaceutical-grade bioactive PS have been introduced as an adjuvant alongside standard radio-and chemotherapy in cancer treatment. This chapter presents a succinct overview of some select bioactive PS derived from Basidiomycetes class of mushrooms (lentinan from Lentinus edodes, Krestin from Coriolus versicolor, schizophyllan from Schizophyllum commune, and Ganoderma sps) and few other botanical herbs (Angelica sinensis, Astragalus membranaceus, Panax ginseng, pectins, and modified citrus pectin) citing instances of preclinical test results and clinical efficacy outcome signifying their anticancer perspective either as monotherapy or combination therapy for future implementation either as chemopreventive or therapeutic regimen in clinic.