Protective effect of Lycium barbanun glycopeptide on human keratinocytes against radiation-induced oxidative stress damage and its mechanism / 中国生物制品学杂志

ABSTRACT

@#Objective To investigate the protective effect of Lycium barbanun glycopeptide(LbGP)on human keratinocyte HaCaT cells against radiation-induced cytotoxicity and its mechanism. Methods HaCaT cells were exposed to radiation with linear accelerator(rate 6 Gy/min)at doses of 4,8,12,16,20,24 and 28 Gy respectively,and the cell activity was detected by CCK-8 assay. HaCaT cells were treated with LbGP(0,0. 05,0. 1,0. 5,0. 8,1. 0,1. 5 and 3 mg/mL)for 4 h,exposed to radiation of 12 Gy,and detected for the cell viability by CCK-8 assay. HaCaT cells were divided into control group(without LbGP and radiation),radiation group(radiation of 12 Gy)and LbGP + radiation group(0. 8 mg/mL LbGP for 24 h,radiation of 12 Gy). After irradiation for 1 h,the reactive oxygen species(ROS)production was measured by flow cytometry,the superoxide dismutase(SOD)activity was determined by WST-8 assay and the expression of nuclear factor-E2 related factor 2(Nrf2),p-Nrf2,NADPH quinone oxidoreductase 1(NQO1)and heme oxygenase-1(HO-1)were detected by Western blot;The mRNA transcription levels of Nrf2,HO-1 and NQO1 were detected by qRT-PCR at 1,3 and 5 h after irradiation. Results Radiation of12 Gy induced about 50% cell death,and 0. 8 mg/mL LbGP showed the best protective effect on the activity of irradiated cells. After irradiation for 1 h,compared with the control group,the content of ROS in HaCaT cells increased significantly in radiation group(F = 2. 55,P < 0. 001),the activity of SOD decreased significantly(F = 1. 23,P < 0. 01),the contents of NQO1 and Nrf2 protein had no significant difference(F = 1. 78 and 1. 00,respectively,P > 0. 05),the content of HO-1protein increased significantly(F = 1. 37,P < 0. 05),and the content of p-Nrf2 protein decreased significantly(F = 2. 75,P < 0. 01);Compared with the radiation group,the content of ROS in HaCaT cells of LbGP + radiation group decreased significantly(F = 3. 61,P < 0. 001),the activity of SOD increased significantly(F = 1. 23,P < 0. 05),and the contents of Nrf2,p-Nrf2,HO-1 and NQO1 protein increased significantly(F = 4. 00,2. 25,6. 25 and 1. 27,respectively,P < 0. 05). In addition,the mRNA levels of Nrf2,HO-1 and NQO1 genes in LbGP + radiation group were significantly higher than those in radiation group at 1,3 and 5 h after irradiation(F = 0. 20～36. 00,P < 0. 05). Conclusion LbGP can mitigate oxidative stress damage of HaCaT cells induced by radiation and protect cell activity,which may play a role by activating Nrf2 and increasing the levels of its downstream antioxidant enzymes SOD,HO-1 and NQO1.