Strain differences in the cytotoxic activity and TNF production of murine macrophages stimulated by lentinan.

The effect of lentinan, a glucan type immunomodulatory polysaccharide was studied on the antitumor cytotoxicity and on the TNF secretion of peritoneal macrophages in inbred H-2 congeneic mouse strains under in vivo and in vitro conditions. The cytotoxic activity and TNF secretion of murine macrophages was found to be elevated by lentinan in vitro and in vivo conditions. The effectiveness of lentinan to induce cytotoxicity and TNF secretion was highly influenced by the genotype of the host.

Antitumor and immunological activity of lentinan in comparison with LPS.

Lentinan manifests marked antitumor and antimetastatic activity in numerous tumor/host systems, and prevents chemical and viral carcinogenesis. Modulation of immune or vascular functions by lentinan is involved in its antitumor effects. The impact of lentinan on the functions of macrophages is distinct from that of LPS.

Stimulation of microbicidal host defence mechanisms against aerosol influenza virus infection by lentinan.

The ability of polysaccharide immunomodulator lentinan to stimulate non-specific resistance against respiratory viral infections was investigated. Significant protection was conferred by lentinan administered intranasally before lethal influenza virus infection and could be corroborated by a reduction of the lung virus titres. Since the lung is the target organ of influenza virus infection, lentinan was also administered by the intravenous route.

Recent progress in immunopharmacology and therapeutic effects of polysaccharides.

Lentinan, a (1----3)-beta-D-glucan with (1----6)-beta-D-glucopyranoside branches and its related polysaccharides have marked antitumour activity in allogeneic, syngeneic and autochthonous primary hosts, suppress chemical and viral oncogenesis, and prevent cancer recurrence or metastasis after surgery. Results of the clinical application of lentinan have proven prolongation of life-span of the patients with advanced and recurrent stomach, colorectal and breast cancer with only little toxic side effect. These polysaccharides also increase host resistance to various kinds of bacterial, viral and parasitic infections including AIDS.