Study on the anti-photoaging effect of Paulownia fortunei leaf extract
The study aimed to investigate the effect of Paulownia fortunei leaf extract(PFLE)on ultraviolet B(UVB)-induced skin photoaging in mice.The mice were divided into 5 groups:normal control group(NC),model group(M),low-dose PFLE group(L-PFLE),medium-dose PFLE group(M-PFLE),and high-dose PFLE group(H-PFLE).Mice in NC group were not irradiated.Mice in the other groups were irradiated with UVB using ultraviolet photo-therapy equipment.On the day of UVB irradiation,mice in NC group and M group were smeared with cream on their backs,and mice in L-PFLE,M-PFLE and H-PFLE groups were smeared with 50,100 and 200 mg/kg PFLE cream,respectively.The UVB irradiation and administration cycles were both 6 weeks.The body weight,skin moisture content,skin oxidative stress indicators(SOD,CAT,GSH-Px and MDA),HYP and HA levels of the mice were detected.HE staining was used to observe skin morphology.The protein expression levels of Nrf2(nucleus),Keap1 and HO-1 in the skin were detected by Western blotting.The transcript levels of MMP-1 and MMP-3 in the skin were detected by RT-qPCR.The results show that compared with M group,the skin moisture content of the mice in L-PFLE group,M-PFLE group and H-PFLE group increases,the skin morphological changes are significantly improved,the levels of SOD,CAT and GSH-Px increase,the MDA level decreases,the relative expressions of Nrf2(nucleus)and HO-1 protein increase,the relative expression of Keap1 protein decreases,the levels of HYP and HA increase,and the relative expressions of MMP-1 and MMP-3 mRNA decrease(P<0.05).This study shows that transdermal administration of PELE has a good anti-skin photoaging effect.