UVB Irradiation In Hairless Mice Research Articles

Enzyme-processed Korean Red Ginseng extracts protects against skin damage induced by UVB irradiation in hairless mice

UV irradiation is the main factor contributing to skin damages that are associated with an excessive production of matrix-degrading metalloproteinase (MMP)-1 and a deficient expression of collagens. To date, red ginseng has been revealed to possess many biomedical effects, such as anti-aging, anti-oxidation, and anti-inflammatory. In this study, we prepared the Korean Red Ginseng extracts treated with enzyme (KRGE) and investigated the effects of dietary KRGE on the formation of wrinkles generated by UVB irradiation in hairless mice. It was found that KRGE inhibited the UVB-induced formation of wrinkles, epidermal thickness, and skin dryness in hairless mice. Further results also showed that KRGE attenuated UVB-induced MMP-1 level, while accelerated procollagen type I, transforming growth factor-β1 secretion. Interestingly, the expression of profilaggrin and filaggrin in both the epidermis and dermis were decreased due to UVB exposure and reversed by KRGE. The KRGE 0.06% was prior to KRGE 0.24%. In view of these results, which indicated that KRGE protected skin from UVB-induced photodamages, which may not only mediated by regulating of MMP-1 and procollagen type I, but also by increasing the production of profilaggrin and filaggrin. In conclusion, our results suggest that KRGE may be a promising agent for the treatment of skin photodamages. The challenge of KRGE will be expected as cosmeceuticals and nutraceuticals in order to intervene in aging-related degenerative skin changes.

Therapeutic and immune effects of 5‐aminolevulinic acid photodynamic therapy on UVB‐induced squamous cell carcinomas in hairless mice

The therapeutic effects of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) on cutaneous squamous cell carcinoma (SCC) are not fully understood, and the usefulness of topical PDT in the treatment of SCC is still debatable. The most interesting aspect in SCC PDT is perhaps its potential in inducing antitumor immune responses. In this study, cutaneous SCCs were established by UVB irradiation of hairless mice and treated with multiple ALA PDT. Immunohistochemistry assays showed that ALA PDT could induce quick apoptosis, overexpression of TNFα and marked increases in DCs, CD4(+) and CD8(+) cells in tumor interstitium and subcutaneous connective tissues. However, a complete response was only achieved for small SCCs. The clinical value of ALA PDT-induced specific antitumor immune responses in long-term control of SCCs deserves further study.

야관문 에탄올 추출물의 자외선 조사에 의한 피부 광노화 억제 효과

To investigate the inhibitory effects of Lespedeza cuneataextract (LC) on photo aging, skin aging was induced by UVB irradiation of hairless mice for 5 weeks. The skin erythema indices for the positive control (PC) and Lespedeza cuneata extract (LC-1%, 3%, and 5%) groups were lower than that of the control group. However, both lipid and water capacities of the PC and LC-3% groups were significantly higher than those of the control group. Skin wrinkles in the PC and LC-3% groups formed in a pattern of shallow furrows and thin crests. Skin TBARS contents and XO activity in the LC group were lower than those of the control group. The activities of GSH, SOD, and CAT in the LC-3% group were significant higher than those of the control group. Therefore, Lespedeza cuneata extract could be an effective natural herbal material for the inhibition of skin aging in hairless mice skin.

Improving Effects of White Tea Water Extract on Skin Wrinkle Induced by UVB Irradiation in Hairless Mice

Improving Effects of White Tea Water Extract on Skin Wrinkle Induced by UVB Irradiation in Hairless Mice

Olive Leaf Extract and Its Main Component Oleuropein Prevent Chronic Ultraviolet B Radiation-Induced Skin Damage and Carcinogenesis in Hairless Mice1–3

Chronic exposure to solar UV radiation damages skin, increasing its thickness and reducing its elasticity, and causes skin cancer. Our aim in this study was to examine the effects of an olive leaf extract and its component oleuropein on skin damage and the incidence of skin tumors caused by long-term UVB irradiation in hairless mice. Male hairless mice (5 wk old) were divided into 6 groups, including a non-UVB group, a vehicle-treated UVB group (control), 2 olive leaf extract-treated UVB groups, and 2 oleuropein-treated UVB groups. Five groups were UVB irradiated (36–180 mJ/cm2) 3 times each week for 30 wk and skin thickness and elasticity after UVB irradiation were measured every week. Olive leaf extract (300 and 1000 mg/kg) and oleuropein (10 and 25 mg/kg) were administered orally twice daily every day for 30 wk. The extract and oleuropein significantly inhibited increases in skin thickness and reductions in skin elasticity, and skin carcinogenesis and tumor growth. Furthermore, they prevented increases in the expression of matrix metalloproteinase (MMP)-2, MMP-9, and MMP-13 as well as in levels of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in the skin. Based on histological evaluation, they prevented increases in the expression of Ki-67 and CD31-positive cells induced by the irradiation. These results suggest that the preventative effects of the olive leaf extract and oleuropein on chronic UVB-induced skin damage and carcinogenesis and tumor growth may be due to inhibition of the expression of VEGF, MMP-2, MMP-9, and MMP-13 through a reduction in COX-2 levels.

Anthocyanins from Black Soybean Seed Coats Inhibit UVB-Induced Inflammatory Cylooxygenase-2 Gene Expression and PGE2 Production through Regulation of the Nuclear Factor-κB and Phosphatidylinositol 3-Kinase/Akt Pathway

Ultraviolet (UV) radiation can cause inflammatory changes and may further contribute to skin carcinogenesis. Anthocyanins are known to be powerful antioxidants that help protect plants from UV damage. Recently, we isolated anthocyanins from black soybean [Glycine max (L.) Merr] seed coats. Thus, we investigated the protective effect of anthocyanins from black soybean seed coats on UVB radiation-induced inflammatory responses and the molecular mechanism responsible for regulation of apoptosis and inflammatory responses. Anthocyanins inhibited UVB-induced cylooxygenase-2 (COX-2) and PGE 2 production through a nuclear factor-kappaB-dependent pathway and regulation of the PI3 kinase/Akt pathway activated by UVB in a human keratinocyte cell line, HaCaT. Topical application of anthocyanins prior to UVB irradiation of hairless mice also inhibited induction of COX-2 and PGE 2. In conclusion, it is suggested that anthocyanins from the seed coat of black soybeans can be used as a useful drug to modulate oxidative disorders including UVB-induced inflammation.

Dietary Tocotrienol Reduces UVB-induced Skin Damage and Sesamin Enhances Tocotrienol Effects in Hairless Mice

We have previously reported that substantial amounts of tocotrienols were present in the skin of animals fed a diet containing a tocopherols and tocotrienols rich fraction (T-mix) extracted from palm oil, and further, that sesame lignans enhanced tocotrienol levels in the skin. The present studies were undertaken to determine whether dietary tocotrienols and those with sesamin could protect the skin from damage induced by UVB irradiation in hairless mice fed four diets: a vitamin E-free diet, a 50 mg/kg alpha-tocopherol diet, a 229 mg/kg T-mix (with 50 mg alpha-tocopherol) diet and a 229 mg/kg T-mix with 2 g/kg sesamin diet. In Experiment 1, mice were fed the diets for 6 wk, and half of the mice were exposed to 180 mJ/cm(2 )of UVB light once daily for 7 d. After the intensity of sunburn was scored, vitamin E and thiobarbituric acid reactive substances (TBARS) concentrations in the skin and liver were determined. In Experiment 2, hairless mice were initiated with a single application of 7, 12-dimethylbenz[a]anthracene (DMBA), then 1 wk later mice were fed the experimental diets and subjected to 180 mJ/cm(2) UVB irradiation twice weekly for 20 wk. Tumor incidences were counted once a week. Tocotrienols were detected in the skin of mice fed T-mix, but their concentrations were significantly lower than for alpha-tocopherol. Sesamin elevated tocotrienol contents in the skin. In spite of the high alpha-tocopherol contents, the effects of alpha-tocopherol on sunburn and incidence of tumor were slight. T-mix fed groups reduced the extent of sunburn and incidence of tumor, and further reduction of sunburn and incidence of tumor were observed in the T-mix with sesamin group. These results suggest that dietary tocotrienols protect the skin more strongly than alpha-tocopherol against damage induced by UVB and sesamin enhances tocotrienol effects.

Skin damage and mitochondrial dysfunction after acute ultraviolet B irradiation: relationship with nitric oxide production

Ultraviolet (UV) radiation is the main environmental carcinogen. It is able to induce injury in the keratinocytes, which triggers mechanisms in order to protect the skin against molecular alterations that may lead to the development of skin cancer. UVB is capable of producing genotoxic damage, directly or indirectly through reactive oxygen species, inducing DNA alterations and mutations. UVB radiation has also been associated with the generation of nitric oxide (NO), which is able to induce many physiological and physiopathological processes. The aim of the current study was to investigate the effect of UVB irradiation in hairless mice skin. We evaluated the effect of an acute dose (200 mJ/cm(2)) of UVB irradiation correlating with histological alterations, nitric oxide synthase expression and activity, mitochondrial respiratory function, superoxide anion production and lipid peroxidation, 0, 6, 17 and 24 h post-irradiation treatment. Morphological analysis showed disruption of the epidermal stratum corneum and basale after UVB irradiation. The results indicated that skin UVB irradiation was associated with an increased cytosolic inducible nitric oxide synthase (iNOS) expression, inversely related to lipid peroxidation processes. An increase in mitochondrial superoxide anion (O(2) (*-)) and NO production 17 h post-irradiation was correlated with a mitochondrial dysfunction, all of them integrating the skin response to acute UVB irradiation. UVB irradiation of the skin produces morphological alterations as a consequence of the induction of molecular mechanisms associated with mitochondrial respiratory dysfunction and O(2) (*-) production, probably mediated by the increased mitochondrial NO production. On the other hand lipid peroxidation decrease inversely correlates with cytosolic iNOS expression, suggesting a protective role for the inflammatory response.