铁皮石斛对镉胁迫牛蛙红细胞诱变的缓解作用

摘要

An acute toxicity assay of cadmium were performed using bullfrog as the material.The concentrations of Cd2+ are 0.0,0.5,1.0,2.0,4.0 mg / L respectively either with distilled water (exposure agent I)or Dendrobium officinale extracts (exposure agent II).The mutagenic effect to the bullfrog erythrocytes under the stress of the exposure agent I or exposure agent II were determined.The results showed that with the concentration of Cd2+ increase in exposure agent I,ratios of micronuclei,apoptosis and abnormal nuclei of the bullfrog erythrocytes firstly increase and then decrease as a parabolic curve.Peaks of these ratios were reached at concentration of Cd2+ 2.0,2.0 and 1.0 mg/L respectively.Exposure agent II showed similar trend while ratios mentioned above reached maximal all at concentration of Cd2+ 2.0 mg/L.Dose effect between the Cd2+ concentration and the ratio of apoptotic cells or micronuclei was observed.In addition,exposure agent II revealed less toxicity compared with exposure agent I in terms of micronuclei,apoptosis and abnormal nuclei ratios of the bullfrog erythrocytes.Therefore,Dendrobium officinale has protection effect over heavy metal stress such as Cd2+ on bullfrog erythrocytes.%以牛蛙为材料,采用急性毒性实验方法,以蒸馏水配制成 Cd2+浓度为0.0,0.5,1.0,2.0,4.0 mg/L 的染毒剂Ⅰ和铁皮石斛提取液配制成 Cd2+浓度为0.0,0.5,1.0,2.0,4.0 mg/L 的染毒剂Ⅱ,研究了在染毒剂Ⅰ和染毒剂Ⅱ的胁迫下对牛蛙血红细胞的诱变效应.结果表明：染毒剂Ⅰ胁迫诱导牛蛙红细胞所得到的微核千分率,凋亡率,异形核率,呈先上升后下降的“抛物线”型,且分别在 Cd2+浓度为2.0,2.0,1.0 mg/L 时有最大值,染毒剂Ⅱ胁迫牛蛙红细胞所产生的异形核率呈先上升后下降的“抛物线”型,且在 Cd2+浓度为2.0 mg/L 时有最大值.凋亡率和微核千分率与 Cd2+浓度呈剂量效应.染毒剂Ⅱ胁迫的红细胞的微核千分率,凋亡率,异形核率随 Cd2+浓度的上升趋势较 Cd2+单独胁迫牛蛙红细胞小.结论：铁皮石斛对重金属 Cd2+胁迫的牛蛙红细胞有保护作用.