Abstract: Objective: To determine the inhibition effect of lycium ruthenicum murr aqueous extract on the HaCaT cell apoptosis and the expression of p16 and p53 induced by UVB radiation. Methods: HaCaT cells cultured in vitro were divided into the blank control group, UVB group, UVB and lycium ruthenicum murr aqueous extract group. The dose of UVB and concentration of lycium ruthenicum murr aqueous extract were 30 mJ/cm2 and 2 mg/mL, respectively. The cell apoptosis rates in each group after UVB radiation 24h were detected by flow cytometer. The protein expression levels of p16 and p53 in HaCaT cells were detected by Western blot. Results: The cell apoptosis rates in the control group was (6.12±1.19)%, which in the UVB group, UVB and lycium ruthenicum murr aqueous extract group were (74.89±3.90)% and (57.52±2.93)%, with a significant difference（P<0.05）. The expression of p16 and p53 in the control group were 0.1±0.03 and 0.21±0.07,which in the UVB group and UVB and lycium ruthenicum murr aqueous extract group were were 0.28±0.06 and 0.5±0.04 , 0.15±0.025 and 0.25±0.01,with significant differences（Ps<0.05）. Conclusion: Lycium ruthenicum murr aqueous extract can inhibit the the cell apoptosis and the expression of p16 and p53 induced by UVB radiation.

Key words: lycium ruthenicum murr aqueous extraction, UVB, HaCaT cells, p16 and p53 protein