Molecular Biology Laboratory, Kotasato University School of Medicine, Kanagawa, Japan.
Abstract
The protein-bound polysaccharide of Coriolus versicolor QUEL (PS-K) expresses the mimicking activity of superoxide dismutase (SOD). Examination was made of the suppressive effects of PS-K on cancer cell lines cultured in vitro. The SOD activity of LLC-WRC-256 (Walker 256 fibrosarcoma) cell lines was less than that of NRK-49F (rat normal kidney fibroblast), H4-II-E (rat hepatoma) and H4-II-E-C3 (rat hepatoma) cell lines. This activity in Walker 256 fibrosarcoma cells increased by 3.6 times and H2O2 concentration, by 2.56 times by PS-K 500 micrograms/ml. Cell proliferation was consequently suppressed and living cells decreased to less than 50% of the cells cultured without PS-K. Catalase and glutathione peroxidase activity changed little by PS-K. The sensitivity of cancer cells to PS-K can be predetermined based on SOD activity in tumor tissue.
Molecular Biology Laboratory, Kitasato University School of Medicine, Kanagawa, Japan.
Abstract
The protein-bound polysaccharide of Coriolus versicolor QUEL (PS-K) expresses superoxide dismutase (SOD) mimicking activity. Examination was made of the suppressive effects of PS-K on cancer cell lines cultured in vitro. SOD activity of incorporated PS-K was 5.88 u/mg in LLC-WRC-256 (Walker 256 fibrosarcoma) cells and 4.73 u/mg in NRK-49F (rat normal kidney fibroblast) cells. SOD activity in both cell types was enhanced about 7-8 times that of the original PS-K. PS-K was not incorporated into H4-11-E or H4-11-E-C3 (rat hepatoma) cells. SOD activity of 1 mg/ml PS-K incubated with cell homogenates of LLC-WRC-256 cells for 6 hours increased from 0.68 u/mg to 1.35 u/mg. SOD activity of PS-K 1 mg/ml in 0.05 M phosphate buffer incubated with 50 microM NADPH increased from 0.68 u/mg. The consumption of NADPH at the same concentration was confirmed spectrophotometically by incubation with PS-K. The mechanism for the enhancement of SOD activity associated with PS-K is considered to be collaboration with NADPH as an electron donor in the cytoplasm of cancer cells whose SOD and coupling enzyme activities are significantly lower than in normal cells.
Kureha Chemical Ind. Co., Ltd., Biomedical Research Laboratories, Tokyo, Japan.
Abstract
The anti-angiogenic effects of an antitumor protein-bound polysaccharide, PSK, obtained from cultured mycelia of Coriolus versicolor in basidiomycetes were examined by the mouse dorsal air sac assay. PSK suppressed the mouse hepatoma MH134-induced angiogenesis when assessed by morphological and biochemical examinations. This finding suggested that the anti-metastatic effect of PSK is attributed to the suppression of tumor-induced angiogenesis.
Kureha Chemical Ind. Co., Ltd., Biomedical Research Laboratories, Tokyo, Japan.
Abstract
The antitumor effects of a monoclonal antibody against a human cancer cell line and a protein-bound polysaccharide, PSK, obtained from cultured mycelia of Coriolus versicolor in basidiomycetes were examined. The IgG2a monoclonal antibody against the human colon cancer cell line colo 205 induced in vitro antibody-dependent macrophage-mediated cytotoxicity against the cancer cells, but only slightly suppressed the in vivo growth of the cancer cells. Concurrent use of PSK with the antibody enhanced the in vitro antibody-dependent macrophage-mediated cytotoxicity as well as the in vivo antitumor activity. These findings suggest that the combined use of a monoclonal antibody and PSK, which have different modes of action, may be useful in the treatment of cancer.
Department of Forest Products, Faculty of Agriculture, Kyushu University, Fukuoka 812, Japan.
Abstract
To clarify the role of excreted extracellular enzymes during long-term incubation in a pulp biobleaching system with white rot fungi, we developed a cultivation system in which a membrane filter is used; this membrane filter can prevent direct contact between hyphae and kraft pulp, but allows extracellular enzymes to attack the kraft pulp. Phanerochaete sordida YK-624 brightened the pulp 21.4 points to 54.0% brightness after a 5-day in vitro treatment; this value was significantly higher than the values obtained with Phanerochaete chrysosporium and Coriolus versicolor after a 7-day treatment. Our results indicate that cell-free, membrane-filtered components from the in vitro bleaching system are capable of delignifying unbleached kraft pulp. Obvious candidates for filterable reagents capable of delignifying and bleaching kraft pulp are peroxidase and phenoloxidase proteins. The level of secreted manganese peroxidase activity in the filterable components was substantial during strain YK-624 in vitro bleaching. A positive correlation between the level of manganese peroxidase and brightening of the pulp was observed.
Pulp and Paper Research Institute of Canada, Pointe Claire, Quebec, Canada H9R 3J9.
Abstract
The white rot fungus Trametes (Coriolus) versicolor can delignify and brighten unbleached hardwood kraft pulp within a few days, but softwood kraft pulps require longer treatment. To determine the contributions of higher residual lignin contents (kappa numbers) and structural differences in lignins to the recalcitrance of softwood kraft pulps to biobleaching, we tested softwood and hardwood pulps cooked to the same kappa numbers, 26 and 12. A low-lignin-content (overcooked) softwood pulp resisted delignification by T. versicolor, but a high-lignin-content (lightly cooked) hardwood pulp was delignified at the same rate as a normal softwood pulp. Thus, the longer time taken by T. versicolor to brighten softwood kraft pulp than hardwood pulp results from the higher residual lignin content of the softwood pulp; possible differences in the structures of the residual lignins are important only when the lignin becomes highly condensed. Under the conditions used in this study, when an improved fungal inoculum was used, six different softwood pulps were all substantially brightened by T. versicolor. Softwood pulps whose lignin contents were decreased by extended modified continuous cooking or oxygen delignification to kappa numbers as low as 15 were delignified by T. versicolor at the same rate as normal softwood pulp. More intensive O(2) delignification, like overcooking, decreased the susceptibility of the residual lignin in the pulps to degradation by T. versicolor.
Department of Pharmacology, Faculty of Medicine, Chinese University of Hong Kong.
Abstract
The protective effects of polysaccharide peptide (PSP), isolated from Coriolus versicolor COV-1, on paracetamol-induced hepatotoxicity was investigated in this study. The effect of PSP on hepatic glutathione status was also studied. PSP (300 mg/kg, i.p.) caused a 40% depletion of hepatic reduced glutathione (GSH) with a concomitant 50% increase in oxidized glutathione (GSSG), thus producing a 3-fold increase in the GSSG/GSH ratio. The PSP-induced GSH depletion itself had no hepatotoxic effects. PSP protected against paracetamol-induced hepatotoxicity by decreasing the paracetamol-induced elevation of serum glutamic-pyruvic transaminase (SGPT) activity from 511 +/- 71 U/ml to 187 +/- 58 U/ml (controls without paracetamol 105 +/- 4 U/ml) and serum glutamic-oxaloacetic transaminase (SGOT) activity from 462 +/- 63 to 152 +/- 48 U/ml (controls without paracetamol 54 +/- 6 U/ml). PSP did not reverse the depletion of total glutathione (GSH+GSSG) by the toxic dose of paracetamol. The GSSG/GSH ratio, which is a measure of oxidative stress, was significantly (p < 0.05) decreased when PSP was coadministered with paracetamol. PSP dose-dependently decreased the covalent binding of [14C]-paracetamol to microsomal proteins in vitro. When PSP was given to rats subchronically for 7 days (300 mg/kg/day, i.p.), the subsequent microsomes obtained also showed a 25% decrease in covalent binding to [14C]-paracetamol, suggesting that PSP interacted with the microsomal proteins rather than the chemically reactive metabolite of paracetamol. The changes in the binding affinity and capacity of the microsomal proteins by PSP may be related to its ability to alter the redox potential as indicated by the effects of PSP on the GSSG/GSH status.
Department of Biology, Chinese University of Hong Kong, Shatin.
Abstract
A polysaccharide-peptide complex (PSPC) with immunomodulatory and antitumor activities was obtained from a submerged mycelial culture of Tricholoma sp., a local edible mushroom. The polysaccharide-peptide complex exhibited a molecular weight of 17 K in gel filtration and a single band after SDS-polyacrylamide gel electrophoresis. It was characterized by non-adsorption on both DEAE-Sepharose CL-6B and CM-cellulose. It could activate the macrophages, stimulate the proliferation of T-cells, and inhibit the growth of sarcoma 180 in mice. It possessed more potent immunomodulatory and antitumor activities than Coriolus versicolor polysaccharopeptide (PSP) and deserves to be studied as a potential agent for immunomodulation and cancer therapy.
Kureha Chemical Ind. Co., Ltd., Biomedical Research Laboratories, Tokyo, Japan.
Abstract
The antitumor effects of a protein-bound polysaccharide (PSK) obtained from cultured mycelia of Coriolus versicolor in basidiomycetes on mammary gland tumors produced in Sprague-Dawley rats by the intravenous injection of N-methyl-N-nitrosourea were investigated. PSK prolonged the survival period of tumor-bearing rats significantly, when given at the dose of 250 mg/kg twice a week for 3 weeks after the tumor reached 100 mm2 in size (p = 0.011 by log rank test and p = 0.023 by generalized Wilcoxon test). These findings suggest that PSK is effective in the prolongation of the survival period in the rat autochthonous tumor model, acting at the growth stage of the tumor during carcinogenesis.
Biotechnology Research Group, School of Applied Biological & Chemical Sciences, University of Ulster, Coleraine, Northern Ireland, UK.
Abstract
The biological treatment of spent wash from molasses distilleries was investigated. Analysis of raw spent wash showed it to be a recalcitrant waste, with a high COD of 85,170 mg/l and containing inhibitory phenolic compounds. Reverse phase thin layer chromatography identified gallic and vanillic acid present in spent wash. The fungi Geotrichum candidum, Coriolus versicolor, Phanerochaete chrysosporium and Mycelia sterilia were screened for their ability to decolourize spent wash and to reduce the COD level. A 10 day pretreatment with Geotrichum candidum at 30 degrees C resulted in reducing the COD by 53.17% and total phenols by 47.82%, enabling other bioremediating organisms to grow. Coriolus versicolor immobilized in a packed-bed reactor reduced the COD of spent wash by a further 50.3%, giving an overall reduction in COD of 77% to 15,780 mg/l. A small amount of decolourization was achieved (4.2%), although the spent wash was still coloured. Present studies are encouraging and indicate that it is possible to bioremediate spent wash using a multi-stage treatment process involving an initial pretreatment step with Geotrichum candidum.