4种典型个人护理品有效成分对嗜热四膜虫的生长抑制及联合毒性

Growth inhibition effects and joint toxicity of four typical personal care products to Tetrahymena thermophila

目的研究4种典型个人护理品有效成分对嗜热四膜虫的生长抑制及联合毒性作用。方法将嗜热四膜虫分别暴露于不同浓度3-(4-甲基苯亚甲基)-樟脑(4-MBC)、二苯甲酮-3(BP-3)、三氯卡班(TCC)和三氯生(TCS),其中,4-MBC、BP-3的终浓度均为0.001、0.01、0.1、1.0、5.0、10.0、15.00 mg/L,TCC的终浓度为0.001、0.01、0.1、0.25、0.50、0.75、1.0 mg/L,TCS的终浓度为0.001、0.01、0.1、1.0、1.5、2.0、4.0 mg/L,并设置对照组(0.1%DMSO),30℃暴露24 h,测定细胞浓度并计算半数抑制效应浓度(EC50)。根据毒性单位(TU)法将4种化合物两两组合形成6组混合体系,即4-MBC+BP-3、4-MBC+TCC、4-MBC+TCS、BP-3+TCC、BP-3+TCS和TCC+TCS。并按照等毒性设置6个暴露浓度,即总TU依次为0.1、0.2、0.4、0.8、1.6和3.2,同时设对照组(0.1%DMSO)。联合毒性分别采用浓度相加(CA)模型和独立作用(IA)模型进行评价。结果4-MBC、BP-3、TCC和TCS对嗜热四膜虫的生长均存在浓度依赖性抑制作用,24 h-EC50值分别为5.125、7.544、0.295、1.063 mg/L。二元混合体系中,4-MBC+BP-3、4-MBC+TCC、4-MBC+TCS和TCC+TCS组符合CA模型,联合毒性表现为相加作用;4-MBC+BP-3、BP-3+TCC和BP-3+TCS组符合IA模型,联合毒性判别为独立作用;其中,4-MBC+BP-3的联合毒性既符合CA模型,又符合IA模型。结论4种典型个人护理品有效成分对嗜热四膜虫均存在生长抑制作用,CA模型更加适用于预测这类新兴污染物的联合毒性。

Objective To understand the growth inhibition effects of four typical personal care products and the joint toxicity to Tetrahymena thermophila.Methods T.thermophila were exposed respectively to 4-methyl-benzylidene camphor(4-MBC),benzophenone-3(BP-3),triclocarban(TCC)and triclosan(TCS)at different concentrations.The final concentrations were0.001,0.01,0.1,1.0,5.0,10.0 and 15.00 mg/L for 4-MBC and BP-3,0.001,0.01,0.1,0.25,0.50,0.75 and 1.0 mg/L for TCC,0.001,0.01,0.1,1.0,1.5,2.0 and 4.0 mg/L for TCS respectively.The control was set with 0.1%DMSO.After 24 h-culture at30℃,the densities of cell population were measured,and EC50 values were calculated.According to the toxic unit(TU)approach,the four compounds were combined into six mixed systems,i.e.,4-MBC+BP-3,4-MBC+TCC,4-MBC+TCS,BP-3+TCC,BP-3+TCS and TCC+TCS.Mixture experiment was conducted following an equal toxicity ratio with six concentrations,i.e.,sum TU of 0.1,0.2,0.4,0.8,1.6 and 3.2,respectively,and the control group was set(0.1%DMSO).Mixture toxicity was evaluated by the concentration addition(CA)model and independent action(IA)model,respectively.Results 4-MBC,BP-3,TCC and TCS could dose-dependently inhibit the growth of T.thermophila,24 h-EC50 values were 5.125,7.544,0.295 and1.063 mg/L,respectively.In the binary mixtures,the toxicity of four groups including 4-MBC+BP-3,4-MBC+TCC,4-MBC+TCS and TCC+TCS conformed to the CA model,suggesting concentration additive.While the toxicity of three groups of 4-MBC+BP-3,BP-3+TCC and BP-3+TCS conformed to the IA model,considering independent action.However,among these combined groups,the toxicity of 4-MBC+BP-3 conformed to both the CA model and the IA model.Conclusion All the four typical personal care products have growth inhibition effect on T.thermophila,and the CA model is more suitable for predicting the joint toxicity of these emerging contaminants.