ABSTRACT
ObjectiveTo study the protective effect of total flavonoids of lavender on skin photoaging induced by ultraviolet B （UVB） in mice and to explore its mechanism from the perspective of nuclear factor E2-related factor 2 （Nrf2） antioxidant pathway. MethodEighty-four female KM mice were randomly divided into seven groups， namely blank group， model group， solvent group， vitamin E （0.013 g·kg-1） group， as well as low-， middle-， and high-dose （0.25， 1.25， 2.50 g·kg-1） groups of total flavonoids of lavender. The naked skin on the back of mice was irradiated with UVB for inducing optical damage. Thirty minutes before irradiation， the skin was coated with the total flavonoids of lavender. After continuous irradiation for one week， the skin moisture and elasticity on the back of mice were evaluated， and the effects of total flavonoids of lavender on histopathological changes in mouse skin were investigated by hematoxylin-eosin （HE） and Van Gieson （VG） staining. The levels of malondialdehyde （MDA）， superoxide dismutase （SOD）， total antioxidant capacity （T-AOC）， nitric oxide synthase （NOS）， and glutathione peroxidase （GSH-Px） after skin homogenization were detected by colorimetry， the inflammatory factors interleukin-1 （IL-1）， interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α） in skin tissue by enzyme-linked immunosorbent assay （ELISA）， and the mRNA expression levels of Nrf2， Kelch-like epichlorohydrin-associated protein 1 （Keap1）， BTB-CNC homology 1 （Bach1）， heme oxygenase-1 （HO-1）， quinone oxidoreductase 1 （NQO1）， and glutamate-cysteine ligase catalytic subunit （GCLC） by real-time polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the model group exhibited significantly increased appearance score （P<0.01）， reduced skin moisture and elasticity （P<0.01）， pronounced pathological changes in the skin tissue like epidermal thickening， scabbing， small abscess， and severe injury， elevated MDA， NOS， IL-1， IL-6 and TNF-α （P<0.05， P<0.01）， lowered SOD， T-AOC， Nrf2， Keap1， NQO1 and GCLC mRNA expression （P<0.05，P<0.01）， and up-regulated Bach1 mRNA expression （P<0.01）. Compared with the model group， the total flavonoids of lavender at the low， middle， and high doses all remarkably reduced the appearance score （P<0.01）， enhanced the skin moisture and elasticity （P<0.01）， diminished the MDA， NOS， IL-1， IL-6， and TNF-α （P<0.05， P<0.01）， increased SOD， T-AOC， Nrf2， Keap1， NQO1， HO-1 and GCLC mRNA expression （P<0.05， P<0.01）， and down-regulated the expression of Bach1 mRNA （P<0.01）. ConclusionThe protective effect of the total flavonoids of lavender against skin photoaging in mice is significant， which may be related to its activation of Keap1/Nrf2/ARE signaling pathway， regulation of oxidative stress， and improvement of inflammatory response.
ABSTRACT
Objective To prepare the sunscreen lipstick in order to prevent UVA and UVB.Methods The ratio of bees-wax,castor oil and liquid paraffin were optimized with the orthogonal test based on viscosity and heat resistance.The spread-able ability,stability and the anti-ultraviolet effect of the optimized lipstick were investigated.Results The best ratio of bees-wax,castor oil and liquid paraffin was 8:5:4(w/w/w).The viscosity of the sunscreen lipstick was appropriate,easy to spread and stable,which was demonstrated the good prevention effect from UVA and UVB.Conclusion The advantages of the prepared sunscreen lipstick included simple preparation,low cost and stable quality.It could be a new type of sunscreen lipstick protecting from UVA and UVB.
ABSTRACT
BACKGROUND: Ultraviolet irradiation causes various changes in cells or tissues including DNA damage, which results in changes of cell cycling, mutation and cell death such as apoptosis or necrosis. p53 has been studied widely to be as a regulator gene to modulate cell cycling. Previous report shows that RAD50 is a gene to be associated with p53 to repair damaged DNA. OBJECTIVE AND METHOD: In this study, we evaluated changes of RAD50 and p53 expression by ultraviolet B (UVB) irradiation in rat skin in vivo and in human fibroblasts (hF) in vitro. RESULTS: In rat skin irradiated with 400mJ/cm2 UVB, RAD50 protein and mRNA expression were decreased by from early stage after irradiation, and they were restored to its normal level after 12 h. In hF irradiated with 20mJ/cm2 UVB, change of RAD50 expression by UVB irradiation was similar to that of rat skin. On the contrary, p53 protein expression was increased by UVB irradiation from 6 h and 3 h after UVB irradiation in rat skin and hF, respectively, but p53 mRNA expression was not changed by UVB irradiation. CONCLUSION: RAD50 and p53 expression is modulated differently in UVB- irradiated skin. Further studies are warrented to evaluate functional relationship between the genes in repairing damaged DNA.