Schizophyllan, antitumor activity

The most famous example of non-specific polysaccharide immunoadjuvants is lentinan isolated from Lentinus edodes. Since 1985, lentinan has been used as an antitumor agent. Lentinan is a (1 3)-/3-glucop)ranan bearing (1 6)-/3-glucopyranoside branches (O Scheme 1). This neutral polysaccharide suppresses the proliferation of sarcoma 180 tumors implanted subcutaneously in mice. Its antitumor activity was due to a host-mediated reaction with participation of thymus or thymus-dependent cells [1]. The lymphokines induced by this polysaccharide enhance the activity of lymphocytes (e. g., macrophages, helper T cells, and/or natural killer cells) in a dramatic manner [2,3,4,5]. Lentinan-like (1 3)-/3-glucopyranan (schizophyllan) contained in the insoluble fraction of Schizophyllum commune has the stracture shown in O Scheme 2 and is known to possess antitumor activity [6]. 

Most fungal (3-glucans have been reported to have antitumor activity (Table 3.6). For example, schizophyllan has been used as immunotherapeutic agent in cancer treatment, in conjunction with chemo- and radiotherapy, in Asia for decades [106]. Lentinan has... 

---