Protective effect of aucubinon on the eucommia ulmoides on skin photoaging induced by UVB

Abstract

Objective To explore the protective effect of aucubin on the photoageing of the skin that induced by ultraviolet (UVB) radiation. Methods Human skin fibroblasts were divided into normal group, model group and high, medium and low dose groups of apocynin by random method. Except the normal group, the other groups of cells were subjected to UVB radiation with a radiation wavelength of 311 nm, irradiation intensity of 9.00 mw/cm2, radiation time of 2.8 s, radiation dose of 25 mJ/cm2. The cells in the high, medium and low doses of aglycone were cultured for 24 h at an equal volume of 400, 200, 100 μg/ml, and then subjected to UVB irradiation, and then cultured for 24 h. The normal group and the model group were cultured for 48 h in a common medium. The apoptosis rate of each group was detected by flow cytometry. The levels of IL-1, IL-6 and TNF-α in each group were detected by ELISA. The expressions of Bax and Bcl-2 mRNA in each group were detected by RT-PCR. Results Compared with the model group, the apoptosis rate (4.84% ± 0.24%, 12.32% ± 0.67% vs. 35.63% ± 2.77%) in the medium and high dose group significantly decreased (P<0.05), the content of IL-1 (21.14 ± 1.94 ng/ml, 16.17 ± 0.74 ng/ml vs. 22.55 ± 1.02 ng/ml), IL-6 (17.46 ± 0.93 ng/ml, 14.51 ± 0.79 ng/ml vs. 18.39 ± 2.05 ng/ml), TNF-α (44.21 ± 1.16 ng/ml, 35.94 ± 3.08 ng/ml vs. 45.67 ± 2.28 ng/ml) significantly increased (P<0.05). Compared with the model group, the expression of Bax mRNA (0.29 ± 0.05, 0.42 ± 0.05, 0.51 ± 0.04 vs. 0.59 ± 0.05) significantly decreased, and the expression of Bcl-2 mRNA (0.52 ± 0.04, 0.44 ± 0.03, 0.35 ± 0.03 vs. 0.26 ± 0.04) significantly increased (P<0.05). Conclusions The aucubin has protective function to the damage of skin fibroblasts which is induced by UVB radiation, indicating the protective function of decreasing Bax mRNA expression, increasing Bcl-2 mRNA expression, reducing the expression of inflammatory factor IL-1, IL-6, TNF-α, holding-up the cell apoptosis which is induced by UVB radiation, and inhibiting apoptosis of cell that caused by UVB radiation, playing an role of protective fibroblasts for delay of the photoageing. Key words: Eucommiae cortex; Aucubin; Ultraviolet rays; Apoptosis; Skin care; Fibroblasts