A -galactosidase-expressing E-coli culture as an alternative test to identify skin sensitizers and non-sensitizers

作者：Nepal Mahesh Raj; Kang Youra; Kang Mi Jeong; Nam Doo Hyun; Jeong Tae Cheon^*

来源：Journal of Toxicology and Environmental Health Part A: Current Issues , 2018, 81(9): 288-301.

DOI：10.1080/15287394.2018.1440187

Although the Organization for Economic Cooperation and Development (OECD) has adopted several in vitro methods with reasonable predictive capacity, alternative methods for identifying skin sensitizers and non-sensitizers with reliability and simplicity are still required for more efficient and economic prediction. The present study was to design an in vitro system with the use of a -galactosidase-expressing E. coli culture for simpler but sufficiently accurate classification of skin sensitizers and non-sensitizers. A LacZ gene-containing E. coli strain that is capable of producing -galactosidase enzyme was induced by isopropyl -D-1-thiogalactopyranoside with concomitant treatment with test chemicals. After 6-hr incubation, cells were lysed and -galactosidase enzyme activity was monitored colorimetrically by using O-nitrophenyl-D-galactopyranoside as a substrate. Following optimization of several experimental conditions, 22 skin sensitizers and 11 non-sensitizers were examined to assess predictive capacity of this method. The results indicated that predictivity was as follows: 90.9% sensitivity, 81.8% specificity, and 87.9% accuracy, when 17.3% of control activity was used as the cut-off value to separate sensitizers from non-sensitizers. Data suggested that the current bacterial system expressing -galactosidase may serve as a useful alternative test for classifying skin sensitizers and non-sensitizers, without the utilization of animals or mammalian cell cultures.

• 出版日期2018