ABSTRACT
Objective To explore the effect of tert?butylhydroquinone(tBHQ)on ultraviolet B(UVB)?induced oxidative damages in human im?mortalized keratinocytes(HaCaT),and discuss its mechanism. Methods The cultured HaCaT cells were randomly divided into 4 groups:control group(G1),ultraviolet irradiation group(G2),25μmol/L tBHQ pretreatment before ultraviolet irradiation group(G3),and 50μmol/L tBHQ pre?treatment before ultraviolet irradiation group(G4). The content of reactive oxygen species was detected by DCFH?DA method,and the cell prolifera?tion was evaluated by MTT. Western blot was used to measure the protein expression of nuclear factor E2?related factor 2(Nrf2)in both nuclear fac?tions and whole?cell of HaCaT. The mRNA expressions of CAT and SRX were determined by real?time RT?PCR. Results The content of reactive oxygen species in HaCaT cells was increased,and the cell proliferation rate was decreased significantly after ultraviolet irradiation. The pretreatment of 25 and 50μmol/L tBHQ can inhibit the UVB?induced oxidative damage in a dose?dependent manner in HaCaT cells. Compared with G2 group, tBHQ pretreatment could dose?dependently increase the level of Nrf2 protein in nuclear factions and whole?cell of HaCaT,and also the mRNA ex?pressions of CAT and SRX. Conclusion UVB irradiation can induce oxidative stress damages of HaCaT cells. tBHQ may inhibit the UVB?induced oxidative damages through enhancing Nrf2 expressions and nuclear translocation,then activating the transcription of the downstream antioxidant en?zymes CAT and SRX.