Antitumor activity lentinan

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]. 

Table 5. Some antitumor activities of lentinan (after Chihara etaL 120 )...

Antitumoral activity of lentinan against sarcoma 180 cells. Lentinan (1 mg/kg) was intraperi-toneally injected once a day for ten days in ICR mice 24 h after subcutaneous transplantation of 6 X10 tumor cells. 

Table 3. Antitumor activity of lentinan and its suppressive effect on carcinogenesis ... 

Chihara G, Hamuro J, Maeda YY, Arai Y, Fukuoka F (1970) Fractionation and purification of the polysaccharides with marked antitumor activity, especially lentinan, from Lentinus edodes (Berk.) Sing, (an edible mushroom). Cancer Res 30 1776-17SI... 

Suga T, Shiio T, Maeda YY, Chihara G (1984) Antitumor activity of lentinan in murine syngeneic and autochthonous hosts and its suppressive effect on 3-methylcholanthrene-induced carcinogenesis. Cancer Res 44 5132-5137... 

Takatsuki F, Namiki R, Kikuchi T, Suzuki M, Hamuro J (1995) Lentinan augments skin reaction induced by bradykinin Its correlation with vascular dilatation and hemorrhage responses and antitumor activities. Int J Immunopharmac 17 465-474... 

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... 

Mushrooms have been consumed as flavorful and medicinal foods for millenniums. Mushroom polysaccharides possess antitumor activity through the stimulation of cytokine productions from immunocytes. On the other hand, lipopolysaccharide suppresses the expression of various hepatic cytochrome P450s (CYPs) through the production of cytokines such as tumor necrosis factor (TNF)-a. In this study, lentinan prepared from Lentinus edodes and polysaccharides from Agaricus blazei (ABPS) were intraperitoneally injected to female BALB/c mice, and the effects of these polysaccharides on the expression of CYPs were investigated in the liver. Both polysaccharides down-regulated the activity and level of constitutive and 3-methylcholanthrene-inducible CYPIA accompanied by the TNF-a production. When... 

Lentinan and ABPS stimulate the release of tumor necrosis factor (TNF)-a and nitric oxide (NO) from macrophages 9-10), NO is known as a bioregulatory agent in a wide variety of biological functions such as control of blood pressure, platelet aggregation, cytotoxicity of macrophages, and carcinogenesis 11-13), Thus, NO is likely to be associated with the antitumor activity of the mushroom polysaccharides. 

This Asian fungus is the second most commonly cultivated edible Tricholomataceae] mushroom also used for medicinal purposes (II). It contains immunostimuiating polysaccharides, including linear (l->3)-p-D-glucans. Lentinan, a polysaccharide (P-D-glucan) fraction from L edodes has been studied more extensively and displays greater antitumor activity than other similar substances (12). Lentinan appears active in certain animals against various tumors (13). 

Zhang, L Li, X Xu, X Zeng, F. Correlation between antitumor activity, molecular weight, and conformation of Lentinan. Carbohydrate Research, 2005, 340,1515-1521. 

Maeda, YY Chihara, G. The effects of neonatal thymectomy on the antitumor activity of Lentinan, carboxymethylpachymaran and zymosan, and their effects on various immune responses. International Journal of Cancer, 1973, 11, 153-161. 

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