The protein-bound polysaccharide preparation, PS-K, isolated from a mushroom, Coriolus versicolor, was found to stimulate human lymphocytes and induce them into blastogenesis in vitro. This stimulatory effect seemed to be nonspecific since lymphocytes from cord blood of newborn babies were also stimulated by PS-K. The highest lymphocyte blastogenesis by PS-K was observed after 5 days in culture.
Combined administration of a vaccine consisting of a small number (2 X 10(6)) of L1210 murine leukemic cells treated with glutaraldehyde and concanavalin A and a protein-bound polysaccharide preparation of Coriolus versicolor induced synergistic resistance to L1210 leukemia in BALB/c X DBA/2CrF1 mice. This effect was dependent on the dose and timing of the administration of the protein-bound polysaccharide preparation, being most effective at the time of or 1 day after the second vaccination. Induced resistance was not cross-reactive with P388 murine leukemia, indicating specificity of resistance. This immunopotentiation by the protein-bound polysaccharide did not occur when L1210 cells treated with glutaraldehyde, but not with concanavalin A, were used as a vaccine.
PMID: 922733 [PubMed – indexed for MEDLINE]Free Article
Formation of the mRNA specific for the inducible forms of laccase was evidenced in Coriolus versicolor, Pleurotus ostreatus and Pholiota mutabilis. The half-life time of these mRNAs in the fungi species studied were, respectively, 30, 37 and 24 min. Molecular weight of the newly synthesized mRNA in Pleurotus ostreatus was about 4.5X10(5), consistently with the size of the inducible laccase protein. The polysome obtained from the ferulic acid-treated mycelium, synthesized in vitro a polypeptide with the electrophoretic mobility similar to that of laccase.
The influence of PSK, a protein bound polysaccharide from Coriolus versicolor on various immunological parameters was studied, PSK was found to enhance B cell activity as measured by the spleen plaque-forming cell assay in mice, and to stimulate mouse macrophages as determined by an enhancement of carbon clearance and an increase in the phagocytosis of opsonized sheep red blood cells by peritoneal mouse macrophages in vitro. The activation of mouse macrophages by PSK appeared to correlate with the therapeutic effects of the compound. In mice made granulocytopenic with cyclophosphamide and subsequently infected with a variety of garm-negative pathogens or with Candida albicans, PSK prolonged the average survival time of the animals. The compound also led to a drastic increase in the number of animals surviving such experimental infections as compared to untreated controls. Possible mechanisms responsible for these protective effects by PSK are discussed.
A water-soluble polysaccharide, D-II with marked antitumor activity was isolated from the cultured mycelium of Coriolus versicolor by extraction with hot-water, fractional precipitation with ethanol and ion-exchange chromatography. D-II strongly inhibited the growth of Sarcoma-180 transplanted subcutaneously in mice by intraperitoneal, intravenous, subcutaneous or intra-muscular administration at a dose of 5 mg/kg. the molecular weight was estimated to be 2,000,000 by gel-filtration or 6,500,000 by light scattering analysis. The chemical structure of D-II was then investigated by periodate oxidation, methylation analysis, Smith degradation, and a combination of controlled Smith degradation and methylation analysis. These studies proposed that D-II is composed of a unit structure of four D-glucose residues, and is a glucan consisting of beta-D-1,3-linked main chain in which one for every three D-glucose residues is branched at C-6 with beta-D-1,6-linkage.
To investigate the mechanism of tumor growth enhancement induced by operative stress in rats, laparo-thoracotomy was performed on day 2 after tumor cell inoculation associated with administrations of various kinds of immunopotentiators. OK-432 (Streptococcal preparation), PS-K (extract from mycelium of Coriolus Versicolor), Lentinan (extract from Lentinus Edodus) and C. parvum were administered intravenously or intraperitoneally in the fractionated form prior to or after inoculation. In general, administration of each immunopotentiator, except for Lentinan, resulted in a recovery from the reduction in survival days after laparo-thoracotomy. In particular, OK-432 administration prior to inoculation showed a significant improvement.
Female C3H/He mice aged 10 weeks with transplanted MM46 tumor were used in an investigation of the timing of administration of immunomodulators, such as PSK (a protein-bound polysaccharide prepared from Coriolus versicolor), OK-432 (streptococcal preparation), bestatin (inhibitor of aminopeptidase B) combined with two fractionated local irradiation with the total dose of 3,000 rad. The daily dose of 250 mg/kg of PSK, 1.0 KE/mouse of OK-432, or 300 micrograms/mouse of bestatin were injected intraperitoneally for 4 consecutive days before or after irradiation. The antitumor effect was evaluated by the changes of tumor volume and survival curves. When PSK or OK-432 was administered after irradiation, tumor growth was decreased and 60-day survival rate and survival curve were significantly elongated compared with the control group and the group to which PSK or OK-432 were administered before irradiation (p less than 0.025, p less than 0.05, respectively). As for bestatin, no remarkable difference was observed irrespective of the timing of administration. These results suggested that some immunomodulators show different antitumor activity depending on the combined timing relative to radiotherapy.