The Preliminary Study On Astaxanthin Liposomes Anti-photodamaged Induced By UVB In Mice Skin

Objective: Oxidative damage is considered to be the core of the formation of skin photodamage.UV irradiation can increase the level of reactive oxygen species(ROS).When more than skin antioxidant defensive capacity that the body can not adequately remove ROS,the accumulation of ROS can lead to oxidative damage intracellular macromolecules,icluding proteins and nucleic acids,which leads to a series of acute and chronic injuries.Topical antioxidants are proved to reduce oxidative damage mainly by scavenging ROS.Astaxanthin(Asx)is a carotenoid with strong antioxidant activity.We used topical astaxanthin liposomes(Asx-lipo)to intervent mice skin photodamage induced by UVB,compared with vitamin E liposomes(Vit E-lipo),to clarify the correlation between Asx-lipo with anti-photodamage and to explore possible mechanism.Methods: C57BL/6J mice were randomly divided into eight groups,including control group,model group,matrixⅠgroup,matrixⅡgroup,Vit E-lipoⅠgroup,Vit E-lipoⅡgroup,Asx-lipoⅠgroup,Asx-lipoⅡgroup.Each group was given the corresponding topical and light intervention.Two weeks later,we took the samples and detected the following indicators:(1)HE staining: the skin histological changes including epidermal and dermis were observed; (2)The skin expression of cell proliferation marker Ki-67 and DNA oxidative damage marker 8-OHd G were determined by using the immunohistochemistry;(3)Skin antioxidant enzymes SOD and CAT activities by respectively were measured using WST and visible methods;(4)Serum MMP-13 content was measured by ELISA.Statistical ananlysis was performed by one-way analysis(ANOVA)using SPSS 20.0 software.The results are taken to be statistically significant at a probability level of P<0.05.Results:(1)Compared with control group,model group had the following changes: the illuminated skin showed abvious scaling,relaxation,decreased flexibility,telangiectasia and so on;Pathological staining showed epidermal and dermis thickening,collagen fibers slender,fibers disorders loosely;Skin Ki-67 and 8-OHd G expressions increased abviously.The difference was statistically significant(P<0.01).(2)Compared with control group,Asx-lipoⅠgroup,Asx-lipoⅡgroup,Vit E-lipoⅠgroup and Vit E-lipoⅡgroup showed that the appearance and pathological changes were improved,increased the skin Ki-67 and 8-OHd G expressions,decreased SOD and CAT activity,and increased serum MMP-13 content.The difference was statistically significant(P<0.05).Compared with the model group,the four groups thinned epidermal and dermis,reduced Ki-67 and 8-OHd G expression,decreased SOD and CAT activity,and increased serum MMP-13 content.The difference was statistically significant(P<0.05);(3)Compared with Asx-lipoⅡgroup,Asx-lipoⅠgroup reduced the degree of thickening of the epidermis and dermis,increased CAT activity,and increased Ki-67 expression.The difference was statistically significan(P<0.05);Compared with Vit E-lipo Ⅱ group,Vit E-lipo Ⅰ group reduced the degree of thickening of the dermis,increased Ki-67 expression,and increased SOD and CAT activity.The difference was statistically significant(P <0.05);Asx-lipoⅠgroup is compared with Vit E-lipoⅠgroup,the difference was not statistically significant(P> 0.05).Conclusion:(1)C57BL/6J mice irradiated repeatedly by UVB were successfully made models.(2)The mice skin photodamage can be improved by topical Asx-lipo,which is similar to the positive control Vit E-lipo,and we recommend using Asx-lipo before exposure;(3)SOD and CAT activity increased and serum collagen-degrading enzyme MMP-13 content descended after topically using Asx-lipo,and this effect is similar to the positive control Vit E-lipo,which may be one of the anti-photodamage etipology.