The Anti-photodamage Effect And Mechanism Of Gypenosides In Mouse Skin

Objective To establish photo-damaged model of Balb/C mice with ultraviolet B (UVB) irradiation. To observe the anti-photodamage effect and the change of oxidative stress enzymatic activity with cream gypenosides (GP), and to explore the mechanism of anti-photodamage effect of gypenosides by studying the effects of gypenosides(GP) on signaling pathway of associated with UVB irritation.Methods 1. To establish photo-damaged model of Balb/C mice with ultraviolet B (UVB) irradiation and to treat photo-damaged skin by topical treated with 1.5% GP cream.2. The expression levels of proliferating cell nuclear antigen (PCNA), tumor suppressor P53 protein and P21 protein in the eight groups were observed by immunohistochemistry (IHC). 3. To measured the eight groups levels of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) in the epidermis of mice with visible spectrophotometry and ultraviolet spectrophotometric methods.4. The nuclear NF-κB Inhibitor (IκB) protein, inhibitionκB of protein kinase (IKK), P53 protein and P21 protein expression were detected by western blotting of the eight groups. Grouping: the sham control group, UVB model group, Gypenosides groupⅠ(GPⅠ), Gypenosides groupⅡ(GPⅡ), Vitamine E groupⅠ(VitEⅠ), Vitamine E groupⅡ(VitEⅡ), Matrix groupⅠ, and Matrix groupⅡ.Results 1.The epidermic of mouse was acanthosis and mild intarcellular edema of photo-damaged model group (UVB group).2. The expression of PCNA in Ba1b/C mouse epidermic of the sham control group was lower than that of UVB group. The expression of PCNA in gypenosides groupⅠand groupⅡwere lower than that of UVB group(p<0.05), the expression of PCNA in VitE groups were similar to gypenosides groups.3.The levels of SOD, CAT,GSH-Px and GR in Balb/C mice's epidermal tissue of UVB group were lower than those of the control group (P<0.05).4.The levels of SOD, CAT,GSH-Px and GR of gypenosides group were higher than those of the UVB group (P<0.05). The significant difference of the level of SOD, CAT, GSH-Px, GR was not observed between gypenosides group and the vitamin E group.5. There were not expression IκB and IKK in the normal control group. The IκB expression of UVB group was significantly decreased compared to other groups, and IKK protein expression higher than other groups.6. The IκB expression of gypenosides groups was significantly higher than that of UVB group, whereas IKK protein expression was significantly lower than that of UVB group, similar with the vitamin E group.7. The P53 and P21 protein of Balb/C mouse skin in the sham control group were lower than that of UVB group.8. The expression P53 and P21 protein in gypenosides group I and groupⅡwere higher than that of the normal control group and UVB group. The expression of p53 and P21 protein in VitE groupⅠandⅡwere similar to gypenosides groups.Conclusion 1. The 1.5% cream gypenosides have the anti-hyperplasia of mouse epidermic effect; 2. The levels of SOD, CAT, GSH-Px and GR in UVB mediated photo-damage mice epidermal tissue were increased after topical used with 1.5% cream gypenosides. The 1.5% cream gypenosides can inhibit the oxidative damages caused by UVB.3. The mechanisms of resistance UVB-induced damages of cream GP 1.5% are possibly related with increasing the anti-oxidative stress enzymatic activity, inhibiting the activity of NF-κB, inhibiting epidermic hyperplasia, increasing the expression of P53, P21 proteins and decreasing the expression of PCNA in mouse epidermis.