Construction Of Model Of Senile Plaque In Vitro And Study On The Scavening Effects Of Senile Plaque Of Several Natural Antioxidants

Senile plaques are formed by lipofuscin deposited on the surface of the skin.It is the special senile pigmented skin disease.Senile plaque is an important sign of aging,a marked feature of aging skin,Seriously affect the body’s facial beauty and body health.A rich variety of natural antioxidant substances can not only improve the body immunity and keep the health of the body,but also have the function of whitening skin.Through the construction of anti-age pigment model in vitro,screening of anti-age pigment strong substances.It provides new ideas and methods for the research and development of whitening and anti plaque products.It has important practical significance to promote the development of whitening and anti plaque industry.In this study,we constructed age pigment model in vitro and screened natural antioxidants,tyrosine,s’s activity inhibition test was used to compare,natural antioxidants which have good antioxidant effects on the two mechanisms were screened out,the main results are as follows:（1）Establishment of senile plaque model,It is based on the generation of fluorescent substances by the interaction between serum albumin and malondialdehyde.The optimum model was constructed in the incubation temperature was 37℃,the incubation time was 24 h,the concentration of MDA was about 24 nmol/mL,the concentration of serum albumin was400μg/mL,and the pH of phosphate buffer solution was 7.0,the concentration of phosphate buffer solution was 0.1mol/L.Methodological validation showed that reproducibility and accuracy of the established plaque model in vitro are good.（2）The effects of various natural antioxidants on clearance of senile plaques in vitro were studied.According to the established senile plaque model,Rutin,anthocyanin,proanthocyanidins and tea polyphenols have stronger ability to remove senile plaques in vitro.Their semi inhibitory concentration(IC₅₀)respectively was,28.93μg/mL,30.01μg/mL,32.02μg/mL,59.24μg/mL.Lycium barbarum polysaccharides,L-glutathione,resveratrol,curcumin,Vc,β-arbutin and so on,due to different mechanisms and do not clear age-related plaques in vitro.（3）The inhibition system of antioxidant activity on tyrosinase was optimized,The optimum process conditions were:100 U/mL tyrosinase,pH in 6.8 phosphate buffer solution system,the concentration of phosphate buffer solution was 0.1mol/L,water bath 10 min at 30℃.Methodological validation showed that reproducibility and accuracy of optimization of tyrosinase inhibitory system are good.（4）The inhibitory activity of various natural antioxidants on tyrosinase activity was studied.The result shows that the inhibitory capacity of tyrosinase was respectively,glabridin>curcumin resveratrol>V_C>kojic acid>L-GSH and so on.Their semi inhibitory concentration(IC₅₀)respectively was,6.8μg/mL,37.5μg/mL,39.1μg/mL,58.6μg/mL、88.5μg/mL,91.3μg/mL.Lycium barbarum polysaccharides and other polysaccharides have no inhibitory effect on tyrosinase activity because of their different mechanisms.（5）The compound effects of natural antioxidants.Proanthocyanidins and anthocyanins,which had good scavenging effect on absorbance and inhibited tyrosinase activity,The compound proportion of proanthocyanidins and anthocyanins was used for the clearance test of senile stains.The result showed that it was additive action.