杂质5-羟甲基糠醛及其二聚体和代谢产物遗传毒性研究

Genotoxicity of 5-hydroxymethylfurfural and its dipolymer and metabolite

目的 评价杂质单体5-羟甲基糠醛(5-hydroxymethylfurfural,5-HMF)、其二聚体5,5’-二甲酰基呋喃二甲醚[5,5’-oxydimethylenebis(2-furfural),OMBF]及单体代谢产物5-磺基氧甲基糠醛(5-sulfooxymethylfurfural,5-SMF)的潜在遗传毒性。方法 采用定量构效关系计算机模型(Q)SAR技术(包括Derek和Sarah模型)预测杂质5-HMF、OMBF和5-SMF的遗传毒性,进一步采用细菌回复突变试验(Ames试验)进行验证。在Ames试验中,用6种组氨酸营养缺陷型(his-)鼠伤寒沙门氏菌分别与不同浓度的5-HMF、OMBF和5-SMF在有/无代谢活化系统混合液(小鼠、大鼠和人S9 mix)条件下孵育48 h,通过比较不同菌株实验组与溶媒对照组相比回复菌落数的倍数关系,来判定结果。结果 Derek预测5-HMF和5-SMF致突变风险为可疑阳性,OMBF为阴性;Sarah预测5-HMF和5-SMF致突变风险均为阳性,OMBF为可疑阳性。Ames试验结果表明,5-HMF和OMBF仅在大鼠肝S9代谢活化后,导致回复突变菌落数呈弱阳性。5-SMF在非代谢活化及在小鼠、大鼠和人肝S9代谢活化后回复突变菌落数呈阳性。结论 5-HMF和OMBF仅在大鼠肝酶代谢活化系统条件下,具有潜在致突变性;5-SMF在有/无代谢活化系统条件下,均具有潜在致突变性。因此,杂质单体5-HMF、二聚体OMBF及单体代谢产物5-SMF均具有潜在遗传毒性,为2类遗传毒性杂质,对于可能长期暴露的人群,为保障用药安全,建议对3种杂质进行限量。

Objective To evaluate the potential genotoxicity of impurities-5-hydroxymethylfurfural(5-HMF),its polymer 5,5’-oxydimethylenebis(2-furfural)(OMBF),and its metabolite 5-sulfooxymethylfurfural(5-SMF).Methods The genotoxicity of 5-HMF,OMBF and 5-SMF was predicted by means of Derek and Sarah with the quantitative structureactivity relationship(QSAR) technology.The bacterial reverse-mutation(Ames) test and single cell gel electrophoresis assay(SCGE,also called the comet assay) were performed to verify the above results.In Ames tests,the potential mutagenicity was evaluated using six strains of S.typhimurium(TA97、TA98、TA100、TA102、TA1535 and TA1537)treated with five different concentrations of 5-HMF,OMBF and 5-SMF with or without S9 mix from liver microsomes of mice,rats or humans and incubated for 48 h.DMSO 20 μg/well served as the vehicle control.In the absence of S9 mix,AF-2,NaN3 and 9-AA served as the positive control,otherwise 2-AA served as the positive control.When TA1535 and TA1537 had three times as many colonies as the vehicle control and when the number of colonies of TA97,TA98,TA100and TA102 was twice that of the vehicle control,the test compound was considered mutagenic.Results In silico evaluation by Derek software showed that 5-HMF and 5-SMF were equivocally positive mutagenic and OMBF was inactive,while Sarah software predicted that 5-HMF and 5-SMF were positive mutagenic and OMBF was equivocally positive mutagenic.Ames test results demonstrated that 5-HMF and OMBF at a dose greater than 750 μg/well increased the number of TA100 revertant colonies only with rat-liver S9 mix.5-SMF was positive mutagenic with mouse-,rat-or human-liver S9 mix on TA97,TA100,TA102 and TA1535 at a dose above 20~40 μg·well-1,or without S9 mix on TA97,TA98,TA100 and TA102 at a dose over 50 μg·well-1.Conclusion 5-HMF and OMBF show potential mutagenicity with a rat-liver S9 mix,while 5-SMF shows mutagenicity with/without S9 mix in vitro.Therefore,5-HMF,OMBF and 5-SMF are class 2 genotoxic impurities,thus the limit of the three impurities should be enforced to ensure the safety of drugs,especially for people who may be chronically exposed to any of them.