Studies on Metabolism and Disposition of Sizofiran (SPG), an Anti-tumor Polysaccharide. III. Degradation and Excretion of SPG in Rats

Kupffer cells play important roles in the metabolic degradation of a soluble anti-tumor (1 → 3)-β-d-glucan, SSG, in mice

“…It is known that the molecular weight of (1 + 3) (3-D-glucans is one of the important factors with respect to anti-tumor a.ctivity [25]. In the case of SPG (schizophyllan), it has been reported that its molecular weight is reduced in the liver, but does not change in spleen [26]. The data shown in this paper also supported the report on SPG.…”

Immunomodulator polysaccharides: Chemistry, disposition and metabolism

“…This material also seems to have a similar antitumour activity as the parent substance.63 However, later studies have suggested that degradation of both glucans, schizophyllan and grifolan certainly take place but at a very slow rate.60,74 One of these studies also showed that schizophyllan in the spleen and lymph nodes was metabolized at a slower rate than that in the liver. 74 The complex polysaccharide, biostim, is partially degraded crossing the duodenal villi, nevertheless it appears to retain at least some of its antigenic ability after oral a b~o r p t i o n .~~ PS-K is broken down and rapidly excreted in the expired air as carbon dioxide in mice31 while schizophyllan is, as we have already seen, eliminated very slowly in the urine in rats. 63,65 In rats over a 6-month period, 41 per cent of administered activity is recovered in the urine and 8 per cent in the faeces at a dose level of 0.2 mg kg-l while at a dose of 2 mg kg-' the figures are 26 and 2 per cent respectively.…”

High plasma concentration of beta-D-glucan after administration of sizofiran for cervical cancer

“…Furthermore, SPG in the spleen and mesenteric lymph nodes is metabolized at a much slower rate than in the liver. Finally, SPG is excreted in the urine, mainly in the form of metabolites with a molecular weight < 10000 16. Hase et al studied the clearance of SPG in humans, and found that 30 days after a single intramuscular injection of 20 or 40 mg SPG, the blood SPG concentration was in the order of tens of nanograms per milliliter 17.…”