| Polysaccharide is a kind of natural polymeric compound, which is polymer composed through the aldose or ketose via glycosidic bond. As a class of important bio-active substance, polysaccharide has important biological activity, such as, the glycoprotein and lipopolysaccharide, which plays the significant roles in cell identification, secretion and proteins processing and transfering. Polysaccharide also affects cell division and differentiation. It could regulate cell growth and senescence, and has strong antioxidant activity. In recent years, the anti-tumor effects of fungus polysaccharides attracted people's attention worldwide. Except through enhancing the host's immune function to play an anti-tumor role, the polysaccharides can also kill tumor cells directly or induce apoptosis. However, the biological effect of single fungus polysaccharide is limited, the research on fungus polysaccharides gradually moves on to the combination use of multiple polysaccharides. Numerous studies showed that a number of fungus polysaccharides were used in varied combination. The combined-polysaccharides showed synergy action in immunoregulation, anti-tumor and antioxidant effects. In this study, based on the previous work, four polysaccharides were combined to study their antioxidation, anti-tumor and immunomodulatory activity in vitro and in vivo experiments. The four polysaccharides were Agaricus blazei, Grifola frondosa, Coriolus versicolor and mushrooms. Hopefully, the study result could provide some experimental evidences for the further research on the applications of combined-polysaccharides:Objectives1. To study the effects of antioxidant, immunomodulatory and anti-tumor activities of combined-polysaccharides and compare with the effect of single polysaccharide in vivo.2. To investigate the effects of anti-tumor and spleen lymphocyte proliferation of combined-polysaccharides and compare with the effect of single polysaccharide in vitro.Methods1. The antioxidant activity of combined-polysaccharides and single polysaccharide was detected using superoxide dismutase enzyme (SOD) kit and malondialdehyde (MDA) kit in adult mice.2. The tumor inhibitory effect of combined polysaccharides and single polysaccharide was studied through cell culture using SMMC-7721 human hepatoma cell as the target. The effects on isolated spleen lymphocyte proliferation of combined-polysaccharides and single polysaccharide were compared between normal and S-180 sarcoma bearing mice.3. The inhibitory effect on tumor growth and immunoregulation of combined-polysaccharides and single polysaccharide were studied in tumor-bearing mice.4. The experiment data were processed and analyzed using SPSS12.0 software. The data were expressdd as mean±SD. The overall difference among the groups was analyzed using ANOVA (analysis of variance). The comparison of two samples of multi-sampling was conducted using SNK method. The significant level was set at a =0.05.Results1. The T-SOD activity of combined and single polysaccharides was all higher than the blank control group (P<0.01) and MDA content was lower than the blank control group (P<0.01). The T-SOD activity of combined-polysaccharides was higher and MDA level was lower than all the individual polysaccharide (P<0.01).2. The cell culture showed that the inhibitory effect of combined-polysaccharides on tumor cell growth was dose dependent from the concentration of 125μg/ml to 500μg/ml. However, when the concentration was increased to 1000μg/ml, the inhibitory effect was decreased (P<0.05).3. The effect of polysaccharides on isolated splenic lymphocyte proliferation showed that the individual and combined-polysaccharide all significantly promoted the lymphocytes proliferation (P<0.01). The index of lymphocyte stimulation at the middle dosage combined-polysaccharides group was lower than the single polysaccharide (P<0.01).4. In carbon clearance experiments, the corrected phagocytic index of the combined-polysaccharides at middle dose was higher than the single polysaccharide of Agaricus blazei, Coriolus versicolor and mushrooms (P<0.05).5. In vivo study, the inhibition on the growth of tumor mass was weaker in polysaccharide groups than the cyclophosphamide group (P<0.01). The tumor inhibition rate of the combined-polysaccharides at the middle dosage was lower than that of Agaricus blazei, Coriolus versicolor and Grifola frondosa polysaccharide alone (P<0.05). The thymus index of the combined-polysaccharides at the middle dosage was higher than that the single polysaccharide (P<0.01).Conclusions1.Compared with the single polysaccharide, the combined four polysaccharides (Agaricus blazei, Grifola frondosa, Coriolus versicolor and mushrooms) were applied in combined form could significantly increase their antioxidant activity in vivo, prompt inhibitory effect on the SMMC-7721 human hepatocellular carcinoma cells in vitro and simulate the activation of mice monocyte-macrophage system more efficiently, as well as protect tumor-bearing mice's T lymphocytes and to prevent thymic atrophy.2. At the concentration of 250μg/ml, the stimulation of combined-polysaccharides on spleen lymphocyte proliferation was not as strong as the single polysaccharide in vitro. At the dosage of 0.250 g·kg-1·d-1, the inhibitory effect of combined-polysaccharides on tumor mass growth was also weaker than the single polysaccharide.3. The antioxidation and immunoregulation effects of combined-polysaccharides demonstrate the brilliant future on their utilization. Currently, they could not replace the medicines of chemotherapy in tumor treatment, but they are good sources of supplementation on tumor treatment along with the chemotherapy drugs. The selection of single or combined-polysaccharide should be careful, because the sensitivity of different tumor to the polysaccharide is varied. The dosage is also an important factor on its effectiveness of tumor treatment. |
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