茶多糖对实验小鼠B16F10细胞瘤治疗效应的机制研究

Therapeutic effects and mechanisms of tea polysaccharides on B16F10 melanoma in experimental mice

目的:观察茶多糖(TPS)对实验小鼠黑色素B16F10细胞瘤治疗效应,探讨茶多糖抑制黑色素细胞瘤的免疫学机制。方法:将C57BL/6随机分组,建立小鼠黑色素细胞瘤模型,通过持续灌胃服用茶多糖28 d,观察并记录荷瘤小鼠一般情况、肿瘤体积变化,最终检测实验小鼠NK细胞活性以及IFN-γ和IL-4分泌水平。结果:1TPS治疗组延缓了小鼠体质量改变,差异均有统计学意义(P<0.05),以中剂量治疗组尤为明显(P<0.01);2TPS治疗组小鼠肿瘤直径与对照组比较差异均有统计学意义(P<0.05),以中剂量治疗组差异最为显著(P<0.01),中剂量抑瘤率最好;3TPS治疗组的NK细胞活性在效靶比为20∶1时,与对照组比较,差异均有统计学意义(P<0.05),中剂量治疗组的NK活性达39.06%,差异有显著统计学意义(P<0.01);4TPS治疗组IFN-γ分泌水平均显示升高,而IL-4分泌水平则呈现下降,与对照组比较差异均有统计学意义(P<0.05),以中剂量治疗组变化尤为显著(P<0.01)。结论:在本实验条件下,TPS对荷瘤小鼠显示出较为有效的治疗效应,以中剂量治疗组(400 mg/kg)效果最好,其机制可能与增强小鼠NK细胞活性、增加IFN-γ以及降低IL-4分泌水平等免疫调节有关。

Objective：To observe the therapeutic effects of tea polysaccharide （TPS） on B16F10 melanoma cells in experimental mice,and investigate the immunological mechanisms TPS in inhibiting such tumor cells .Methods：Female C57BL/6 mice,aged 6 weeks and weighed 12 to 14g ,were randomized into four groups（n=8 for each）.Melanoma models were developed,and administered with intragastric TPS for consecutive 28 days.The tumor-bearing mice were observed and recorded regarding the changes in general condition and tumor volume .Finally,the sera were obtained from the experimental mice to determine the NK cell activity as well as IFN-γand IL-4 levels.Results：① TPS was capable of delaying weight loss of mice,and the effect was obvious in animals treated with medium dose（P〈0.05,or P〈0.01）;②The tumor diameter was different,especially significant in medium dose treatment group, as compared with the controls（P〈0.05,or P〈0.01）,especially that of the middle dose group;③NK cell activity was significantly different in TPS treat-ment group from that of the controls when the optimal effector-target ratio was set at 20∶1（P〈0.05）,and the activity reached 39.06% in mice adminis-tered with medium dosage（P〈0.01）;④Although elevated IFN-γlevel and decreased IL-4 level were observed in animals treated with TPS,yet the chan-ges were significant in those managed with medium dose（P 〈0.05,or P〈0.01）.Conclusion：TPS may facilitate therapeutic effects on tumor-bearing mice under our established experimental conditions ,and the effects are optimal in dose of 400 mg/kg.The potential mechanisms may be involved in boosted NK cell activity,increased IFN-γsecretion,but decreased IL-4 level through immune regulation.