Abstract: OBJECTIVE: To determine efficiency in using two assays,the human cell line activation test (h-CLAT) and the occluded patch test of Buchler (BT),in detecting skin sensitization of two preservatives commonly used in cosmetics. METHODS: BT was carried out according to "cosmetics safety technical specification (The 2015 Edition)". Skin sensitizations to ethylparaben,butylparaben andglycerin were used as negative controls and to 2,4-dinitrochlorobenzene (DNCB) as positive control. In test animals,skin sensitization was evaluated by score. The h-CLAT was set up,according to the OECD No 442 (E) toxicology test method,to evaluate the ethylparaben,butylparaben,glycerin and the DNCB groups. The CCK-8 (cell counting kit-8) method was used to test evaluate cytotoxicity and to calculate the CV₇₅ value. The RFI values of CD86 and CD54 were detected by flow cytometry. RESULTS: The results from the BT test show that glycerin was a non-sensitizer while DNCB was strong sensitizer,ethylparaben was a nonsensitizer and butylparaben was a moderate sensitizer. The results from h-CLAT show that the CV₇₅ value of ethylparaben was 126 μg/mL,RFI_CD86 was 110%-140%,RFI CD54 was 140%-260%;the CV₇₅ value of butylparaben was 18 μg/mL,RFI_CD86 was 75%-200%,RFI_CD54 was 90%-210%,the CV₇₅ value of glycerol as more than 5 000 μg/mL,RFI_CD86 was 75%-100%,RFI_CD54 was 60%-140%,the CV₇₅ value of DNCB was 2.5 μg/mL,RFI_CD86 was 185%-640% and RFIcd54 was 100%-460%. The test results indicate that ethylparaben and butylparaben were weak and strong sensitizers,respectively,DNCB was a very strong sensitizer and glycerol was a non-sensitizer. CONCLUSION: In this comparative test,the sensitivity of h-CLAT was higher than BT. In addition,this cell culture method can be used as a screening method for some allergenicity evaluations.

Key words: human cell line activation test, occluded patch test of Buchler, skin sensitization, ethylparaben, butylparaben