Experimental Study On Antitumor Effect Of Phellinus Linteus

Mglignant tumor is one of the major diseases affecting person's health and the invasion and metastasis of malignancy will threaten patiens'lives at last.Traditional therapenutic tools and drugs are not efficient to certain malignancy. So, we must develop and utilize effective drugs against tumors. The development of tumor cytobiology and molecular biology provide new methods for Chinese herbal medicine against tumor. Phellinus linteus is a basidiomycete belonging to the family Polyporaceae. In some folk recipes, it is used as a treatment for stomachaches and arthritis.Polysaccharides extracted from Phellinus linteus were known to potentiate the immunostimulating activities and prevent tumor growth without direct cytotoxicity to tumor cells. The antitumor activity of the polysaccharides from the fruit body of this mushroom was first reported in 1968.In this experiment, the antitumor effect, decreasing toxicity and enhancing effect of PL were studied. We also studied on its mechanism through tumor immunity.1.Antitumor experiment in vivoAntitumor activity of PL was determined using solid tumor models. MFC,H22 and S180 were xenografted into ICR mice and 0.5,1.0 and 2.0 g/kg PL were administered for 10 days. The result showed 0.5,1.0 and 2.0 g/kg PL groups could evidently reduce the tumor weight of MFC,H22 and S180 Average inhibition rate(IR) in MFC is 30.46%,35.08%,42.84% respectively ; Average IR in H22 is 36.30%,37.62%, 44.71% respectively; Average IR in S180 is 28.98%,36.60%,46.36% respectively.Throughout the experimental period, no severe weight loss was observed. 2. Increase in life span experimentThe animals were injected intraperitonially (i.p.) with 3×106 viable EAC cells in saline. After 24h of tumor inoculation PL was administered intragastricly at a dose of 0.5,1.0 and 2.0g/kg body weight and continued for 10 consecutive days. The percent increase in life span (ILS) was calculated using the formula ILS=( T/C－1)×/100 where T is mean survival time of treated group and C that of control group.The result showed PL could prolong survival time of mice modeled with EAC. Average increase of life span in EAC is 31.69%,41.34%,51.87% respectively.3.Decreasing toxicity and improving effect experiments3.1Improving effect experimentPL was administered i.g. to MFC bearing mice combining with CTX.14 days later,for MFC mice, the tumor was peeled off and weighed. The result showed PL could improve the antitumor effects of CTX.3.2 Decreasing toxicity experimentPL was administered i.g. to MFC bearing mice combining with CTX.14 days later,for MFC mice, leucocyte were counted. The result showed PL could lessen the chemotherapy side-effects.4. Antitumor experiment in vitro Direct cytotoxicity of PL against MFC and S180 was evaluated by MTT assay.Optical density(OD) was measured with a microplatereader at 570nm. The result showed PL was not toxic to MFC and S180.The results indicate that PL is a biological response modifier showing antitumor activity by potentiating the host immunity.5. Effect of PL on immune system 5.1 Lymphocyte proliferation experimentLymphocytes proliferation induced by ConA was measured by MTT assay.The result showed the lymphocyte proliferations were significantly improved when cultured with 1mg/L ConA. When the concentration of PL were at 250μg/mL, 25μg/mL, 2.5μg/mL and 0.25μg/mL, lymphocyte proliferations were significantly promoted.5.2 Effect on IL-2 and TNF-α activity of bearing mouse The animals were injected subcutaneously (s.c.) with 3×106 viable MFC cells in saline. After 24h of tumor inoculation PL was administered intragastricly at doses of 0.5,1.0 and 2.0 g/kg body weight and continued for 10 consecutive days.10 days later,for MFC bearing mice, the IL-2 and TNF-α content in serum was tested by enzyme-linked immunosorbent assay.The result showed that PL could improve the level of IL-2 and reasonably decrease the level of TNF-α in the serum of mice bearing MFC.To sum up, PL has showed the efficient antitumor effect, enhancing the antitumor acti...