| Mushrooms have been known for their nutritional and culinary values as well as viewed as tonics.They have been used as medicines by humans over decades up to now.In many Asian countries,they are considered as functional food which can provide health benefits beyond the traditional nutrients they contain.Phylum Basidiomycota,constitute of very diverse groups of mushrooms in which,most of them have macroscopic fruiting.Cancer is among the most dangerous diseases threatening humanity.Natural drugs have emerged as promising approaches for cancer due to their safety and absence of side effect compared with surgery and chemotherapy.Herein,we report an efficient natural anticancer glucan(CVG)extracted from Coriolus Versicolor(CV)Known as(Yunzhi)in China,is the second cultivated edible mushroom in the world and is one among the most widely used Traditional Chinese Medicine(TCM)mushroom in the global market.Its importance is attributed to both its nutritional value and medical application.Some bioactive compounds of CV including phenolic compounds,ergosterol,selenium,Berit adenine,vitamins,as well as calcium and minerals have been isolated and characterized.Glucans belong to a group of physiologically active compounds,known as carbohydrates,consisting of linked glucose molecules,and represent highly conserved structural components of seaweed,fungi and cell walls in yeast.The role of glucans as a biologically active compound has been well established.Glucans have been successfully used to treat high-risk neuroblastoma.Also,glucans have an immunomodulatory role by augmenting some natural killer cells and immunoglobulins.Not all,glucans have reported cholesterol-lowering ability,activation of bone marrow cell production,activation of macrophages and improving resistance to cancer cells.Recently,glucans extracted from fruiting bodies,mycelia and sclerotia of CV have been shown to have numerous activities including antitumor,immunomodulatory,antioxidant,anti-inflammatory,antiviral,hepatoprotective,hypocholesterolemia,hypoglycemic,etc.The present research study aim is an investigation of chemical structures,biological activity and structure-activity relationship of glucans,other than those reported,extracted from the fruiting bodies of CV.The fruiting bodies of CV were extracted successfully with hot water,precipitated with ethanol 80%(v/v)and deproteinized by using sevag method,to obtain a crude polysaccharide CVG-0,CVG-0 was 10.8%of the total weight of the dry materials used in the extraction.Upon submission of CVG-0 to the freeze-thawing process,a high polydispersed Jelly-like polysaccharide CVG-1 was obtained,after lyophilization,the yield of fraction CVG-1 recovered was 30.38%out of the total dry weight of the crude polysaccharide CVG-0 utilized.On solubilization of this glucan(with 2%aq.NaOH),neutralizing with 50%acetic acid,and submitting to the freeze-thawing process followed by centrifuging at 10,000 rpm for 20 min,a water soluble fraction CVG-S emerged,with a yield of 89.36%from the total dry weight of CVG-1 used.Also,chromatography techniques were used for further isolation and purification of fraction CVG-S in which,on applying to anion-exchange chromatography and Sephacryl S-500 preparative columns,two fractions(CVG-S 1,and CVG-S2)were collected.The two fractions were further purified on Sephacryl S-500 analytical gel column and showed single peak named(CVG).The homogeneity and molecular weight distribution of fraction CVG were estimated by HPGPC linked with GPC of TSK-gel G-3000PWXL,and it gives narrow and symmetric peak by HPGPC with the estimated Mw of 8.8 kDa.The HPLC analysis showed that;fraction CVG consisted of a glucose monosaccharide,and it was more dominant constituted of over 90%glucose(350.7 molar ratio)and a small amount of D-Fuc,D-Ara,D-Man,and D-Gal with a molar ratio of 1.0/1.1/3.0/3.9 respectively.However,structural analyses were done on fraction CVG,using NMR,FT-IT,and methylation analysis revealed that;CVG consisting of(1→6)-α-D-Glcp main chain.On a preliminary bioactivity test(cytotoxicity assay),of CVG at different concentrations(4,10,20 mg/mL)exhibited antitumor activity against Sarcoma S-180 in vitro with a dose-dependent manner.High concentration appeared to be more effective than those of low concentration.Also,this glucan presented selectively higher antitumor activities against suspended cell(Sarcoma-180).The growth inhibition of S-180 cells by CVG presented significantly high inhibition ratio of 95%at the concentration of 20 mg/mL,While the concentration of 4,and 10 mg/mL showed inhibition ratios of 31%,and 81%respectively.The results of the in vivo antitumor activity assay of CVG against Sarcoma-180 solid tumor grown in Kunming mice at the dose of(40,100,and 200 mg/kg)of CVG for 9 days showed that CVG,which is a glucan-type polysaccharide,exhibited a higher inhibition was found to be 64%,72%,and 79%at concentrations 40,100,and 200 mg/kg of CVG respectively.In comparison,the growth inhibition using 20 mg/kg of Cyclophosphamide is around 84%.Although the antitumor activity of CVG is lower than Cyclophosphamide,it is preferred due to its safety.In vivo bioassay test indicated that CVG could remarkably increase the splenocytes compared with the positive control(P<0.05)this is attributed to the high immunomodulatory activity of CVG,increased the thymus and spleen index in tumor-bearing mice,enhance T and B lymphocyte proliferations,augmenting the tumor weight regression,and the phagocytosis of macrophages was significantly decreased by CVG compared with the model control;but slightly higher compared with the normal and positive groups.Also,CVG enhances the immunity of white blood cells in the tumor-bearing mice leading to engulfment and growth suppression of S-180 cells.The present work shows that incubation of glucans together with tumor cells could change the expression of the signal within tumor cells.That could arrest the cell cycle and generate apoptosis,which can explain the inhibition of tumor growth.Going on,our study seems to suggest that CVG could be a promising therapeutic agent against tumors due to its immunomodulation activity.The effects of CVG on the production of IL-2,IL-4,IL-6,IL-10,IL-17A,IFN,and IFN-y were considered.With CVG stimulation,the production of all Cytokines mentioned above were significantly higher(at the dose of 200 mg/kg)than that obtained with Cyclophosphamide(positive group),and not significant compared with the dose of(40 mg/kg),and slightly higher when it compared with the dose of(100 mg/kg).Thus,the analysis and evaluation of CVG provide a unique opportunity for the discovery of novel therapeutic agents that exhibit beneficial antitumor and immunomodulatory properties.Our results suggest then that CVG should be explored as potential antitumor and immunomodulatory agents utilized as tumor cell growth inhibitors for food and pharmaceutical industries and could be potentially applied as a natural antitumor drug.This research contributed to a better understanding of CV compounds,especially glucans,and provided some essential data for successful interpretation of the bioactivities of its extracts. |
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