BACKGROUND: Stratum corneum lipids serve as a water retainer as well as permeability barrier by forming a multi-lamellae structure in the stratum corneum. The major constituent of these lipids, ceramides, have been shown to be predominantly associated with both functions. OBJECTIVE: Exposure of human epidermis to ultraviolet(UV) irradiation leads to changes in the physiologic and biochemical features of the skin. In order to investigate the effect of UVB irradiation on the skin barrier function in hairless mice, transepidermal water loss (TEWL) and lipid composition of stratum corneum were evaluated in hairless mice. METHODS: Hairless mice were irradiated 3 times weekly for 3 weeks with suberythemal dose (0.6MED, Group I) and minimal erythemal dose(MED), Group II) of UB. The mice of Group III received high dose of UVB(3MED) on the back in a single exposure. The control was Group IV. TEWL measured by evaporimeter and lipid composition of stratum corneum appraised by high performance thin layer chromatography(HPTLC) were evaluated weekly for 3 weeks. RESULTS: 1. Each time it was measured, the values of TEWL in group I were lower than group IV, but the difference was not significant. The peak value of TEWL in group II was 8.2+/-1.56 g/cm/h on the 7th day. The increase in TEWL was markedly significant at this point(P<0.001). Although the values of TEWL on the 14th and 21th day in group E increased compared with those of the control group, the significance of the values decreased (P<0.05). 2. The peak value of TEWL in group III was 9.88+/-1.13 g/cm/h on the 2nd day, showed a markedly significant increase compared with that of the control group(P<0.001). The values of TEWL decreased to the level of the control group on the 14th day. 3. The lipid(cholesterol sulfate, ceramide and neutral lipid) and total lipid mass in group 1 were insignificantly larger than that of the group IV measured each time. On the 7th and 14th day, the amount of each three lipid and total lipid mass significantly increased (P<0.05). On the 21th day, the amount of ceramide and neutral lipid showed a significant increase(P<0.05), furthermore the total lipid mass increased pronouncedly(P<0.01) in group II. 4. The amount of the 3 kinds of lipid and total lipid mass in group III significantly increased compared with those of the control group on the 2nd day(P<0.05). After the 7th day, no significant difference of the lipid mass except neutral lipid compared with that of the control group was seen. Comparing the 2nd and 14th day, there was a significant decrease in the amount of ceramide and total lipid mass(P<0.05) CONCLUSION: These results results suggest that considerable amount of UVB irradiation given in single or repeated exposure causes the disruption of skin barrier function, but a compensatory increase of skin lipid, especially ceramide, protests it from further damage and also improves skin barrier function.
Animals ; Ceramides ; Epidermis ; Humans ; Mice ; Mice, Hairless* ; Permeability ; Skin*

Chinese herbal medicine ultrafine powder has become a research hotspot for the addition of cosmetic raw materials. Dendrobium candidum is a traditional Chinese herbal medicine. Its extract and stem extract are already cosmetic raw materials and its water extract has the effect of preventing photoaging,but D. candidum ultrafine powder has not been accepted as a raw material for cosmetics,and no relevant research on photoaging prevention has been reported. In this experiment,the ultra-fine powder and fine powder of D. candidum to prevent photoaging were observed and compared,and its mechanism of action was discussed to provide a basis for the prevention of skin photoaging products. Seventy-two female ICR mice were randomly divided into normal group,model group,solvent group,titanium dioxide(Ti O2) group,isooctyl salicylate(2-ES) group,D. candidum ultrafine powder 1(DP1),ultrafine powder 2(DP2) and fine powder(DP3) groups. The photoaging model was established by ultraviolet irradiation for 8 weeks,and the model was intervened while modeling. The skin wrinkle grade,elastic parameters,skin microcirculation blood flow,skin structure and pathological changes(skin thickness,skin collagen fiber,elastic fiber) were observed,the skin transforming growth factor-β1(TGF-β1),Smad3 levels were determined,and the type Ⅰ and type Ⅲ collagen,matrix metalloproteinase-1(MMP-1),activated protein-1(AP-1),VEGF expression were detected. The results showed that ultrafine powder(DP1,DP2) significantly reduced the wrinkle level and skin blood flow of the model mice(P<0. 05,P<0. 01); DP1,DP2 and DP3 could significantly reduce the thickness of the epidermis(P<0. 001),improve collagen fiber,elastic fiber hyperplasia,and distortion and decrease VEGF expression,and DP1 is better than DP2 and DP3; each group could up-regulate type Ⅰ collagen,down-regulate type Ⅲ collagen,AP-1,MMP-1 protein expression,and DP1 improvement optimal. However,it has no obvious effect on TGF-β1 and Smad3. The ultrafine powder and fine powder of D. candidum have certain preventive effect on photoaging,and the effect of ultrafine powder is better than that of fine powder. Ultrafine powder may down-regulate the expression of type Ⅲ collagen,AP-1 and MMP-1 by up-regulating type Ⅰ collagen. Inhibition of collagen degradation plays a role in preventing photoaging.
Animals ; Dendrobium ; Female ; Mice ; Mice, Hairless ; Mice, Inbred ICR ; Skin ; Skin Aging ; Ultraviolet Rays

PURPOSE: Ultraviolet (UV) irradiation decreases epidermal hydration, which is maintained by reduction of natural moisturizing factors (NMFs). Among various NMFs, free amino acids (AA) are major constituents generated by filaggrin degradation. This experiment was conducted to determine whether or not dietary supplementation of green tea extract (GTE) in UV-irradiated mice can improve epidermal levels of hydration, filaggrin, free AAs, and peptidylarginine deiminase-3 (PAD3) expression (an enzyme involved in filaggrin degradation). METHODS: Hairless mice were fed a diet of 1% GTE for 10 weeks in parallel with UV irradiation (group UV+1%GTE). As controls, hairless mice were fed a control diet in parallel with (group UV+) or without (group UV-) UV irradiation. RESULTS: In group UV+, epidermal levels of hydration and filaggrin were lower than those in group UV-; these levels increased in group UV+1% GTE to levels similar to group UV-. Epidermal levels of PAD3 and major AAs of NMF, alanine, glycine and serine were similar in groups UV- and UV+, whereas these levels highly increased in group UV+1% GTE. CONCLUSION: Dietary GTE improves epidermal hydration by filaggrin generation and degradation into AAs.
Alanine ; Amino Acids ; Animals ; Diet ; Dietary Supplements ; Epidermis* ; Glycine ; Metabolism* ; Mice ; Mice, Hairless* ; Serine ; Tea*

BACKGROUND: Chronic exposure to ultraviolet radiation(UVE) nduces photoaging characterized by dry, deeply wrinkled, inelastic, leathery, and irregulaity pigmented skin. UVR also induces solar keratosis and carcinoma, and is a contributing factor in melanoma. Sunscreens are used to prevent solar damage to skin and, if used on a daily lass should significantly reduce the incidence of the chronie photodamaging events. OBJECTIVE: We tried to evaulate the photoaging effects of UVR in the skin and the photoprotective effect of sunscreens. METHOD: We examined the gross and microscopic changes skin of albino hairless Skh : HR-1 mice exposed chronically to ultraviolet B(UVB) and suncreen-treated mice. RESULTS: The skin of the UVB-irradiated mouse shows chear, cteristic signs of photoaging, such as deep wrinkles across the back, and thickened and a hery skin. Histologically, the photoaged skin shows increased epidermal thickness, numeross fibroblasts and inflammatory cell infiltration in the upper dermis, and many enlarged keratering cysts in the lower dermis. By the 20th week, seven of the total of 9 mice(78%) in UVB irradiated mice developed at least one tumor. Histologically, the tumor is a papilloma, but the he are many dyskeratotic cells and loss of polarity in epidermis. Octyl methoxycinnamate or TiO ZnO Talc-treated mic show a significantly decreased wrinkling score, mimmal epidermal hyperplasia, slightly increased dermal cellularity, and lack of proliferation of cysts. The octyl dimethyl PABA-treatd mice shows significantly increased wrinkling score and marked inflammatory infiltration dermis. By the 20th week, only one mouse had developed a tumor in the octyl methoxy irmamate-treated group and no evidence of tumor was seen in the TiO ZnO Talc-treated group. In the octyl dimethyl PABA-treated group, five of 7 mice(71%) developed at least one tumor. CONCLUSION: The skin which is chronically exposed to UVB is subject to photoaging and photocarcinogenesis and regular use of an adequate sunscreen would prevent these photodamaging effects of UVB.
Animals ; Dermis ; Epidermis ; Fibroblasts ; Hyperplasia ; Incidence ; Keratosis ; Melanoma ; Mice ; Mice, Hairless ; Papilloma ; Skin* ; Sunscreening Agents*

BACKGROUND: The epidermal permeability barrier necessary for terrestrial life resides in the intercellular spaces of the stratum corneum and is composed of lipids. OBJECTIVE: Since strrtum corneum lipid may be important for the permeability barrier, we studied the differences and effects of experimentally altered barrier function using acetone and tape-stripping technique. METHODS: The permeability barrier of hairless mouse was disrupted by tape-stripping and acetone treatment and the recovery rate was assessed by histochemical staining, electron microscopic examination and lipid analysis. RESULTS: Although the transepidermal water loss recovered completely by 48 hours in both of the acute models, acetone treated samples seem to have on over-all better recovery rate than tape-stripped samples. The return of barrier function to normal in both tape-stripped and acetone-treated skin was accompanied by a comparable return of normal nile red and ruthenium tetroxide staining. The amount of lipid in stratum corneum paralleled both the return of barrier function towards normal and the extent of prior damage to the barrier in acetone treated skin, yet, the lipid synthesis in tape-stripped skin showed a slower return of lipid content. CONCLUSION: The difference in the recovery rate of the two acute models may be due to the fact that acetone mainly extracts intercellular lipids, whereas, tape-stripping has a prolonged effect by removal of comeocyte in addition to the intercellular lipids. This shows the importance of comeocytes as well as the intercellular lipid bilayer in the recovery of normal barrier function.
Acetone* ; Animals ; Extracellular Space ; Lipid Bilayers ; Mice ; Mice, Hairless ; Permeability ; Ruthenium ; Skin ; Water

Collagen pentapeptide (Lys-Thr-Thr-Lys-Ser, KTTKS) and its palmitoylated derivative (pal-KTTKS) have received a great deal of attention as cosmeceutical ingredients for their anti-wrinkle effects. The objective of this study was to evaluate stability and permeability of KTTKS and pal-KTTKS in hairless mouse skin. In this study, a liquid chromatography-tandem mass spectrometric method was developed for the quantification of pal-KTTKS, and used for stability and permeability studies. Stability studies were performed using skin extracts and homogenates. Both KTTKS and pal-KTTKS were rapidly degraded, but pal-KTTKS was more stable than KTTKS. When protease inhibitors were added, the stability of both compounds (KTTKS and pal-KTTKS) improved significantly. In the skin permeation study, neither KTTKS nor pal-KTTKS was detected in the receptor solution, which indicates that neither compound could permeate through the full-thickness hairless mouse skin in the experimental conditions of this study. While KTTKS was not detected in any of the skin layers (the stratum corneum, epidermis, and dermis), pal-KTTKS was observed in all skin layers: 4.2 +/- 0.7 microg/cm2 in the stratum corneum, 2.8 +/- 0.5 microg/cm2 in the epidermis, and 0.3 +/- 0.1 microg/cm2 in the dermis. In conclusion, this study indicated that pal-KTTKS had greater stability and permeability than that of un-modified KTTKS, and may be a useful anti-wrinkle and anti-aging cosmeceutical agent.
Animals ; Collagen* ; Dermis ; Epidermis ; Mice ; Mice, Hairless ; Permeability ; Protease Inhibitors ; Skin*

Ultraviolet (UV) irradiation is an environmental factor that causes skin aging, and is also a major factor leading to cumulative alterations of skin structure, function and appearance. To investigate the effects of Selenium (Sel) on UV-induced skin aging, hairless mice were treated for 4 weeks with UV irradiation and topical application of Sel. Then, the effects of Sel were measured in the skin of these mice via histological analysis and Western blotting. According to the results of wrinkle formation analysis, the topical application of Sel induced a reduction in wrinkling formation in the damaged skin of the UV-irradiated mice. Additionally, our histological analysis demonstrated that the skin thickness in the Sel-treated group was less than in the UV-irradiated group. Furthermore, in an effort to investigate the mechanisms underlying the effects of Sel, the expression levels of matrix-metalloproteinase (MMP) and MAPK protein were assessed in both groups. The application of Sel induced a reduction in MMP-1 expression levels to the levels observed in the non-irradiated group. However, the expression level of MMP-9 was increased slightly in the Sel application group as compared with the vehicle application group. Additionally, the levels of ERK phosphorylation were increased by the application of Sel, but the levels of JNK and p38 were not altered by Sel treatment. These results suggest the possibility that Sel should be considered as a skin aging-protective and therapeutic drug candidate, which functions via the regulation of MMP expression levels.
Animals ; Blotting, Western ; Mice ; Mice, Hairless ; Phosphorylation ; Selenium ; Skin ; Skin Aging

BACKGROUND: Acetone disrupts the cutaneous permeability barrier through the removal of stratum corneum lipids. This pertubation of barrier integrity stimulates a variety of homeostatic repair that ultimately results in the normalization of barrier function. OBJECT: To measure the effect of steroid on the barrier recovery of acetone applied skin. MATERIAL AND METHODS: The flank skin of 8~10 week old hairless mice was treated with acetone and then topical and systemic steroids were applied. Transepidermal water loss(TEWL) was checked after 0, 3, 6, 12 and 24 hours. Electron and light microscopic examination and ion capture cytochemistry were performed after 3, 6, 12 and 24 hours after systemic and topical steroids had been applied. RESULTS: The results were as follows ; 1) During 3~6 hours after experiment, the recovery rate of TEWL was most prominent in the group of acetone applied animal than other groups. 2) After 12 hours after acetone applied, formation of new stratum corneum was found in the groups of acetone applied or acetone applied skin with topical steroid application. But loss of stratum corneum was observed in the groups of high or low dose steroid injection. 3) Ruthenium tetroxide staining of acetone alone or topical steroid treated specimens after 12 hours experiment revealed that the lipid bilayer was partly impaired and fragmented. Intercellular spaces were widening and the lipid bilayer disappeared or was damaged in the groups of high or low dose steroid injection. 4) Six hours after acetone application, pattern of calcium distribution had been partially reestabilished in the group of acetone alone or topical steroid treated animals. But calcium content was still sparse and decreased from the stratum granulosum to basale in the groups of high or low dose steroid injection. CONCLUSION: In summary the present study demonstrates that steroid treatment acutely delays recovery rate of TEWL, inhibits normalization of calcium gradient or epidermal lipid synthesis that leads to abnormalities in permeability barrier homeostasis.
Acetone ; Animals ; Calcium ; Extracellular Space ; Histocytochemistry ; Homeostasis ; Lipid Bilayers ; Mice ; Mice, Hairless* ; Permeability ; Ruthenium ; Skin ; Steroids

BACKGROUND: Topical irritants disrupt the cutaneous permeability barrier through the removal of stratum comeum lipids. This perturbation of barrier integrity stimulates a variety of homeostatic repair responses that ultimately result in the normalization of bamer function. Object To measure the effect of desoxymethasone ointment, vaseline and hydrobase on the barrier recovery of benzalkonium chloride (BKC) imtated skin. MATERIALS AND METHODS: The left flank skin of 2-3 monthold hairless mice was treated with BKC and then desoxymethasone ointment, vaseline and hydrobase were applied. Transepidermal water loss (TEWL) was checked after 0, 3, 6, 9, 12, 15, 18, 21 and 24 hours. Electron microscopic examination was performed after 3 and 24 hours after desoxymethasone, vaseline and hydrobase had been applied. RESULTS: The recovery of TEWL was most prominantly observed in the desoxymethasone ointment treated group followed by vaseline and hydrobase. Electron microscopic examination using ruthenium tetroxide fixation revealed that secretion and numbers of lamellar bodies and complete formatice of lipid bilayers were most prominent at desoxymethasone ointment and vaseline treated group. CONCLUSION: Desoxymethasone ointment, vaseline and hydrobase can be good agents in improving bamer recovery after exposure to irritant material.
Animals ; Benzalkonium Compounds* ; Desoximetasone* ; Irritants ; Lipid Bilayers ; Mice ; Mice, Hairless* ; Permeability ; Petrolatum* ; Ruthenium ; Skin*

BACKGROUND: Moisturizers induce skin hydration and then increase flexibility and elasticity, making the skin soft and smooth, and protecting it against environmental stimuli. OBJECTIVE: The aim of this work was to study the role of intercorneocyte lipid layers and desmosomes in the mechanism of moisturization. METHODS: Transepidermal water loss (TEWL) and capacitance were measured and the morphologic changes of the intercorneocyte lipid layers and desmosomes with electron microscopy, using ruthenium tetroxide (RuO4) postfixation, following the application of glycerin, propylene glycol, and a mixture of glycerin and propylene glycol for a 2 hour period to the epidermis of hairless mice were measured. RESULTS: 1. The TEWL was significantly increased in all three groups; glycerin, propylene glycol, and mixture of glycerin and propylene glycol. The increase of TEWL after the application of glycerin was maintained from the second to the forth hour after application which was statistically significant, after the application of propylene glycol it was maintained for 5 hours, and after the application of a mixture of glycerin and propylene glycol, for 6 hours. 2. The capacitance also was increased in all three experimental groups, compared to the control group. However there was no statistical significance. 3. Light microscopic findings showed no specific changes in all three groups, compared to the control group. 4. Ultrastructural observation by electron microscope, using RuO4 postfixation, showed widening of the intercorneocyte lipid layers in all three groups. In contrast to glycerin in which the results showed detachment of the desmosomes without changes in the intercorneocyte lipid layers, propylene glycol showed interruption and undulation of the intercorneocyte lipid layers and expansion of the lacunae spaces. A mixture of glycerin and propylene glycol showed interruption and undulation of the intercorneocyte lipid layers, detachment of the desmosomes, and, partial, formation of lacunae. CONCLUSION: These results suggest that the moisturizing effects of glycerin result from an increased detachment of the desmosomes and widening of the intercorneocyte lipid layers and then an increase in the water holding capacity of the stratum corneum. Propylene glycol, a chemical penetration enhancer, induce widening, interruption, and undulation of the lipid layers and expansion of the lacunae space. In the mixture of glycerin and propylene glycol, propylene glycol potentiate and continue the moisturizing effects of the glycerin.
Animals ; Desmosomes* ; Elasticity ; Epidermis ; Glycerol* ; Mice ; Mice, Hairless ; Microscopy, Electron ; Pliability ; Propylene Glycol* ; Ruthenium ; Skin