目的 探究土茯苓解重金属铅毒性的活性物质。方法 以“总提取物-有效萃取部位-有效部位及有效成分”顺序逐一追踪解毒活性成分的研究思路，以急/慢性铅致小鼠毒性为动物模型，以铅含量、生化指标及组织形态学检测结果为指标，确认土茯苓解铅毒的活性部位。依据文献及前期化学研究基础，采用高效液相色谱（HPLC）法对活性部位进行主要成分分析。结果 急性铅中毒实验结果显示，与模型组相比，土茯苓总提物组和醋酸乙酯组小鼠血液、肝和肾脏中铅含量显著降低（P＜0.05）；血清丙二醛（malondialdehyde，MDA）含量有所降低（P＜0.05），谷胱甘肽过氧化物酶（glutathione peroxidase，GSH-Px）和超氧化物歧化酶（superoxide dismutase，SOD）活性有不同程度提高（P＜0.05）；小鼠肝和肾损伤程度均有改善。慢性铅中毒实验结果显示，与模型组相比，土茯苓总黄酮低、中、高剂量组小鼠血液、肝和肾脏铅含量均有下降（P＜0.05），且呈剂量相关性；小鼠血清中丙氨酸氨基转移酶（alanine aminotransferase，ALT）、天门冬氨酸氨基转移酶（aspartate aminotransferase，AST）活性和肌酐（creatinine，Cr）、尿素氮（blood urea nitrogen，BUN）水平均有不同程度地降低（P＜0.05），并以土茯苓总黄酮高剂量组最为显著；小鼠肝和肾损伤程度均有所改善，且土茯苓总黄酮高剂量组组织结构趋近正常。新落新妇苷、落新妇苷、花旗松素、新异落新妇苷、异落新妇苷和黄杞苷6个黄酮类化合物为总黄酮部位的主要成分，占总黄酮的58.89%。结论 土茯苓醋酸乙酯部位对铅致小鼠急性毒性有显著解毒作用，且醋酸乙酯部位优于总提物，提示醋酸乙酯部位为土茯苓解铅毒的有效萃取部位；土茯苓总黄酮具有较好的排铅作用，对铅诱导的肝、肾功能损伤具有一定的保护作用，且呈剂量相关性，提示总黄酮为土茯苓解重金属铅毒的活性部位。土茯苓总黄酮主要由新落新妇苷、落新妇苷、花旗松素、新异落新妇苷、异落新妇苷和黄杞苷6个黄酮类化合物组成，提示上述化合物可能为土茯苓解铅毒的活性成分。

Objective To investigate the active components for relieving the toxicity of heavy metal Pb from Tufuling (Smilacis Glabrae Rhizoma). Methods The research order from identifying total extract, effective extraction parts to effective parts and effective components was used. The acute and chronic toxicity induced by Pb mice models were established. The detoxification effects were evaluated by Pb content, biochemical indexes and morphological detection. According to the literature and previous chemical research, HPLC was used to analyze the principal components of the active parts. Results The results of acute toxicity test showed that compared with model group, Pb contents in blood, liver and kidney of mice in total extract from Smilacis Glabrae Rhizoma group and ethyl acetate fraction group were significantly lower than that of model group (P < 0.05); The content of malondialdehyde (MDA) in serum was decreased (P < 0.05), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities were increased (P < 0.05); Liver and kidney damages were ameliorated. The results of slow toxicity test showed that compared with model group, Pb contents in blood, liver and kidney of mice in total flavonoids of Smilacis Glabrae Rhizoma group were significantly reduced with dose-dependent manner (P < 0.05); Alanine aminotransferase (ALT), aspartate aminotransferase (AST) activities and creatinine (Cr), blood urea nitrogen (BUN) levels in serum were reduced (P < 0.05), and high-dose total flavonoids of Smilacis Glabrae Rhizoma group was most significant; Liver and kidney damages in mice were relieved, and tissue structure of high-dose total flavonoids of Smilacis Glabrae Rhizoma group showed almost like normal. The main components of total flavonoids were neoastilbin, astilbin, taxifolin, neoIsoastilbin, isoastilbin and engelitin, which account for 58.89% of total flavonoids. Conclusion Ethyl acetate extraction parts from Smilacis Glabrae Rhizoma shows significant detoxification effect on Pb-induced toxicity in mice, and ethyl acetate extraction part was better than total extract in general, suggesting that ethyl acetate extraction part is the effective extraction part of Smilacis Glabrae Rhizoma to detoxify Pb; Total flavonoids of Smilacis Glabrae Rhizoma shows good lead excretion effect, and shows protective effect on liver and kidney damage induced by Pb with dose-dependent relationship. Besides, total flavonoids of Smilacis Glabrae Rhizoma are mainly composed of six flavonoids including neoastilbin, astilbin, taxifolin, neoisoastilbin, isoastilbin and engelitin, which suggests that these compounds may be the active components of Smilacis Glabrae Rhizoma in relieving Pb toxicity.

R285.5

国家自然科学基金资助项目（81760721）；国家自然科学基金资助项目（81760703）；江西省自然科学基金资助项目（20161BAB205219，20181BAB205077）