Anti-tumor activity of polysaccharides obtained from Leucocalocybe mongolica using solid-state fermentation

Abstract

Leucocalocybe mongolica (S. Imai) is a well-known edible medicinal mushroom. Polysaccharides extracted from L. mongolica show several pharmacological properties. Owing to increased predation and desertification, wild L. mongolica populations are declining and becoming increasingly rare. Microbial fermentation is emerging as a suitable alternative to obtain bioactive compounds from this mushroom. In this study, polysaccharides were isolated from the solid-state fermentation of L. mongolica (LMPs) and their anti-tumor activities were investigated. Treatment with LMPs significantly inhibited the growth of hepatoma H22 tumors after cell transplantation in mice. Notably, LMP treatment protected the spleen and the thymus against tumor-induced damage. Furthermore, LMP administration significantly increased the serum levels of the cytokines interferon gamma, tumor necrosis factor-α, interleukin (IL)-6 and IL-2, while simultaneously decreasing the serum level of vascular endothelial growth factor. Hematoxylin-eosin staining, the TUNEL assay, immunohistochemistry and western blotting indicated that the in vivo anti-tumor activity of LMP was achieved by promoting apoptosis and inhibiting angiogenesis. In summary, this study revealed that LMPs markedly suppressed the tumor growth of H22-transplanted tumors in vivo at least partly by enhancing the immune response, inducing apoptosis and inhibiting angiogenesis. These findings highlight LMP as a potential low-cost anti-tumor drug.

Keywords

• leucocalocybe mongolica
• polysaccharide
• antitumor activity