霍山石斛类原球茎免疫调节活性的有效部位及其毒理安全性评价

目的研究霍山石斛类原球茎对小鼠免疫调节活性的有效部位及其毒理安全性。方法制备霍山石斛类原球茎冷冻干燥物、醇提物、水提物、醇溶物、醇沉物、多糖等不同提取部位;检测不同提取部位对ConA诱导的小鼠脾淋巴细胞增殖反应及免疫器官指数的影响;采用急性毒性试验、Ames试验、大鼠30d喂养实验考察多糖的毒性及致突变作用。结果水提物、醇沉物和多糖各剂量组均可以促进ConA诱导的小鼠脾淋巴细胞增殖反应和免疫器官指数的增加,且具有浓度依赖性,其中,多糖的促进作用最强;多糖对小鼠ig给药的最大耐受量大于15.6g/kg,属基本无毒物质;无论有无S9活化系统,霍山石斛类原球茎多糖各剂量组对鼠伤寒沙门菌株TA97、TA 98、TA 100、TA102无致突变作用;30d喂养期间,霍山石斛类原球茎多糖各剂量组对大鼠生长发育无不良影响。结论霍山石斛类原球茎对小鼠免疫调节活性的有效部位是多糖,其无毒,无致突变作用。

Immunomodulatory active fraction of protocorm-like bodies in Dendrobium huoshanense and its toxicological safety

Objective To demonstrate immunomodulatory active fraction of protocorm-like bodies of Dendrobium huoshanense(PLBDH) and to evaluate its toxicological safety.Methods The different extract fractions of PLBDH were prepared,including lyophilizate,alcoholic extract,water boiled extract,alcohol soluble extract,ethanol sediments,and polysaccharide.The effects of different extract fractions on ConA-induced splenocyte proliferation and immune organ index were determined.The toxicity and mutagenicity of polysaccharide were studied by cute toxicity test,Ames test,and 30-d feeding test in rats.Results Each dose group of water boiled extract,ethanol sediments,and polysaccharide enhanced splenocyte proliferation induced by ConA and increased immune organ index with concentration-dependent manner.The group of polysaccharide had the strongest activity.The maximal tolerant dose(MTD) of polysaccharide to mice was more than 15.6 g/kg,which means polysaccharide was basically nontoxic.Each dose group of polysaccharide from PLBDH had no significant mutagenicity to strains of Salmonella typhimurium TA97,TA98,TA100,and TA102 with or without S9 mixture.Each dose group of polysaccharide had no significant adverse effects on the growth and development of rats during the period of 30-d feeding.Conclusion The effective immunomodulatory extract fraction of PLBDH is polysaccharide,which has no significant toxicity and mutagenicity.