No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Antiwrinkle Effects of Mugwort (Artemisia vulgaris) Extracts on UVB-Irradiated Hairless Mouse Skin
Abstract
This study was to investigate antiwrinkle effect of mugwort (Artemisia vulgaris) methanol extract in hairless mouse skin induced by UVB-irradiation. Hairless mouse were topically treated with the basic lotion alone (control), ascorbic acid (AA-0.5%, AA-1.0%, AA-2.0%, and AA-5.0%) and mugwort extract (ME-0.5%, ME-1.0%, ME-2.0%, and ME-5.0%) dissolved in a basic lotion. After topical treatment of 30 minutes, the animals were irradiated with increasing doses of UVB radiation (60-100 mJ/cm2) for 4 weeks. In our experimental condition, skin thickness of hairless mouse was significantly decreased (12.5-21.4%) in all ME groups compared with control group. Ra value, that is surface roughness parameter induced by skin wrinkling, was significantly decreased (23.7-31.1%) in ME-1.0%, 2.0% and 5.0% group compared with control group. Furthermore, Rq, Rz and Rt value were significantly decreased to 11.2-21.2%, 19.8%-24.5%, and 14.2%-22.7%, respectively. Wrinkle formation of ascorbic acid treatment group as reference group was inhibited, but its effect was less than ME treatment. Matrix metalloproteinase-1 activity was significantly inhibited (19.7-22.6%) compared with control group and collagen content was significantly increased (about 10%) when compared with control group. These results indicate that ME could protect skin aging and wrinkle formation in hairless mouse from photo-irradiation.
... A UV test was performed using the method suggested by Park et al. (2008). At a certain time everyday, 50 L of the μ coating solution was coated on the back of hairless mice, and UVB was irradiated after 30 minutes. ...
... Recently, there has been an increasing number of studies that have focused on the UV protective effects of food on skin to maintain healthy skin through diet. The food items that have been researched include green tea (6), red ginseng (7), mug-wort (8), and sesame oil (9). ...
Lotus (Nelumbo nucifera Gaertn.) seed is widely used as a traditional medicine in countries of Asia. Among many functions of the lotus seed, one interesting activity is its skin protection from the sunlight and scar. In this study, we focused on the skin protective property of lotus seed tea against ultraviolet B (UVB) irradiation. Two groups of a hairless mouse model, water as control (water group) and lotus seed tea (LST group), were administrated a fluid drink water for six months. After 6 month of administration, UVB exposure was carried out to both groups for another 3 months. During and after the administration, the skin moisture content and the morphological and histopathological analyses through biopsy were carried out. Prior to UVB irradiation, no significant difference was discovered in the skin moisture content for the water group and LST group (P<0.05). However, drastic changes were observed after the UVB treatment. The LST group showed a clear evidence of skin protection compared to the control group (P<0.05). The moisture content, epidermal and horny layer thickness, and protein carbonyl values all revealed that the intake of the lotus seed tea enhanced protection against UVB exposure. As a result, the long-term intake of the lotus seed tea showed the effect of preventing loss of skin moisture, mitigating the formation of abnormal keratinocytes, and contributing to protein oxidation inhibition.
We investigated the effects of bonito fish (Katsuwonus pelamis) elastin HC (KE) on skin dryness, wrinkles, and pigmentation in vitro and in vivo. In vitro, we evaluated the expression of mRNA genes and proteins related to skin dryness, wrinkles, and pigmentation. HaCaT and HS27 cells were exposed to ultraviolet B radiation (UVB) (50 mJ/cm2), and B16F10 cells were stimulated with 3-isobutyl-1-methylxanthine (IBMX, 250 μg/mL) for 72 h to induce melanin synthesis. All cells were treated with KE (50-400 μg/mL) for 24 h. We found that KE increased the expression of long-chain base 1, dihydroceramide desaturase 1, elastin, hyaluronan synthase 2, and ceramide synthase 4 mRNA or protein as well as hyaluronic acid and sphingomyelin levels in UVB-irradiated HaCaT cells. Moreover, KE regulated factors related to collagen production, wrinkles, and melanin production in UVB-irradiated HS27 cells and IBMX-stimulated B16F10 cells. In vivo, we evaluated skin hydration and the expression of mRNA genes and proteins in the skin, and conducted morphological observations in SKH-I hairless mice (5-week-old male). The mice were exposed stepwise to UVB and given KE (10, 20, and 30 mg/kg b.w.) for 8 weeks. We found that skin hydration and protein or mRNA expression related to skin moisturization were increased in the KE group. Moreover, KE intake increased factors related to collagen production, wrinkles, and melanin production in UVB-irradiated SKH-I hairless mice. These results suggest that KE may have efficacy for the development of treatments for improving skin health.
To develop a new functional agent for cosmetics, we investigated the anti-aging activities in fibroblasts of casuarictin. The anti-aging effect of casuarictin in CCD-986sk cell was as follows: it inhibited ROS expression increased by Ultraviolet B and suppressed pro-collagen expression. Also, casuarictin had inhibited Matrix metalloproteinase-1 expression. Therefore, the results suggested that casuarictin has considerable potential as a cosmetics ingredient with a anti-aging effect.
We investigated the anti-wrinkle efficacy of hydrolysate from oyster protein by Protamex and Neutrase for the purpose of finding materials to assist skin health originating from marine organisms. There were about 7.9% free amino acids in the oyster hydrolysate, and contents of urea, taurine, alanine, and glycine were high. Oyster hydrolysate also showed collagenase inhibitory activity and was not toxic to CCD986sk human fibroblast cells. Yield of the fractions according to the molecular weight of oyster hydrolysate was 40% for less than 1,000 Da and 60.4% for less than 5,000 Da, respectively. Antioxidative effect, procollagen production, and matrix metalloproteinase-1 inhibitory activity were highest in 1,000~3,000 Da fractions. We observed that oyster hydrolysate and its less than 5,000 Da fraction are potential functional compounds for skin health and for improving wrinkles. © 2015, Korean Society of Food Science and Nutrition. All rights reserved.
Objective : UV irradiatiion causes skin-aging involving coarse wrinkles, thickning, dyspigmentation, and rough skin surface. This study was aimed to elucidate the anti-winkle activity of complex diet of Korean red ginseng (RG) and fish oil (FO) on UV-induced Photoaging. Methods : To investigated photo-protective effects of Korean red ginseng and fish oil on UV-induced damaged skins, SKH hairless female mice were randomly divided into six groups [control, UV, UV/RG, UV/FO, UV/RG/FO(low), UV/RG/FO(high)]and orally administered three times a week respectively. UV radiation was applied to the backs of the mice three times a week for 8 weeks. Expressions of matrix metalloproteinase (MMP)-3, MMP-13 and tissue inhibitor matrix metalloproteinase (TIMP)-1 in skin were measured by immunohistochemical staining. Results : In this study, UVB-induced epidermal hypertropy was diminished by RG group or FO group or complex group of RG and FO. Expression levels of MMP-3 and MMP-13 were reduced and expression level of TIMP-1 was increased by RG group or FO group or complex group of RG and FO. Especially MMP-3 and MMP-13 were markedly reduced by diet of FO and complex diet of RG and FO compared with untreated group. Conclusions : This results suggest that complex diet of RG and FO have a anti-wrinkle activity on UV-induced photo-aging and intrinsic aging.
Panax ginseng C.A. Meyer, Korean herb medicine, has been widely used in China and Japan for fatigue and enhancement of resistance to many diseases. In this study, we investigated the synergistic effect of Korean red ginseng and Fagopyrum esculentum extracts (RGFE) on dermal bioactive properties. RGFE treatment significantly increased electron donating ability, nitrite scavenging activity and collagenase inhibitory activity compared to red ginseng-treated group. Superoxide dismutase (SOD) activity in RGFE-treated group was similar to that of red ginseng. However, tyrosinase activity as indicator of melanin synthesis was not affected by RGFE or red ginseng. The results indicate that RGFE has anti-oxidative property and inhibitory effect of collagenase, and it may serve as a effective ingredient for beauty food.
We investigated the protective effect of UVB inducing photodamage from mulberry extract (ME) and Lithospermum erythrorhizon extract (LE). The contents of total anthocyanin and shikonin as a color compound of ME and LE were 4.92 mg/g and 9.58 mg/g, respectively. The electron donating ability and superoxide radical scavenging activity of ME were 84.32% and 76.34%, respectively. The oxygen radical absorbance capacity of the ME ( TE/g) was higher than LE ( TE/g). MMP-1 production in the HS68 cells were exposed to UVB suppressed by treatment with of ME (68.6%) and LE (32.7%). ME and LE were applied to a skin aging mouse model, which was induced by the irradiation of UVB to the backs of hairless mice. The value of skin erythema index, wrinkle depth and thickness, epidermis thickness, and collagenous fiber damage in the experiment groups (MEL: ME 3%, MEM: ME 5%, MEH: ME 7%, LEL: LE 3%, LEM: LE 5%, LEH: LE 7%) were remarkably reduced than in the control group (only UVB exposure group), while water capacity increased. The level of total wrinkles depth in the skin was decreased to be 30% of the control group by MEH and LEM. These results suggest that ME and LE are useful cosmetic materials for skin protection against UVB-inducing.
Skin wrinkles typically appear as a result of aging processes. One of causes may be the nonenzymatic glycation followed formation of browning products called advanced glycation endproducts (AGEs), an irreversible cross-linked protein. The accumulation of glycated collagen cross-linked in skin inhibits the formation and function of skin tightening agents such as collagen and elastin. To development for anti-wrinkle ingredients from edible plants, MeOH and hot-water extracts were prepared and evaluated for their inhibitory effects of AGEs formation. The activities of both extracts from bay laurel (Laurus nobilis), cinnamon (Cinnamomum loureirii), clove (Eugenia caryophyllate), oregano (Origanum vulgare), rosemary (Rosemarinus officinalis), savory (Satureja hortensis) and star anis (Illicium verum) of western spices, and blackberry (Rubus coreanus), dayflower (Commelina communis), Epimedium koreamun (whole), termunalia frutus (Terminalia chebula) and turkestan rose (Rosa rugosa) of medicinal plants were higher than the others. Of Korean vegetables, however, MeOH and hot-water extract from only Asters caber and green tea showed higher activities, and no activity in Korean marine plants (seaweeds).
Phenolics in dry Artemisia princeps Pampanini, an herbal plant traditionally consumed as food ingredients in Korea was extracted, fractionated, and quantified as well as evaluated for its neuroprotection for PC-12 cells. Whole extract had 5,852 mg gallic acid equivalents/100 g of total phenolics and 6,274 mg and 9,698 mg vitamin C equivalents/100 g of antioxidant capacities assayed by DPPH and ABTS radicals, respectively. The fraction extracted with n-butanol had the highest levels of total phenolics and antioxidant capacity than the other fractions (n-hexane, chloroform, ethyl acetate, and water). Using a reversed-phase HPLC system, caffeoylquinic acid (CQA) and its derivatives such as 3-CQA, 4-CQA, 5-CQA, 1,5-diCQA, 3,4-diCQA, 3,5-diCQA, and 4,5-diCQA were isolated and quantified. The whole extract and its n-butanol fraction yielded 3,5-diCQA with the highest amount, which consisted of approximately 36.8% and 33.5%, respectively. The whole extract, the n-butanol fraction, and 3,5-diCQA showed neuroprotective effect on PC-12 cells under the insult of amyloid ß peptide in a dose-dependent manner. Treatments of the whole extract and the n-butanol fraction for PC-12 cells under oxidative stress increased approximately 1.6 and 2.4 times higher cell viability, compared with the control without treatments. For PC-12 cells treated with 3,5-diCQA, intracellular oxidative stress decreased by 51.3% and cell viability increased up to 2.8 times compared to the control with oxidative insult of amyloid ß peptide only. These results indicate that phenolics from A. princeps Pampanini alleviated the oxidative stress and enhanced the viability of PC-12 cells, suggesting that it may be applied as a dietary antineurodegenerative agent in functional foods.
Although glutamine (Gln) is known as an important stimulator of collagen biosynthesis in collagen-producing cells, the mechanism and endpoints by which it regulate the process remain largely unknown. Intermediates of Gln interconversion: glutamate (Glu) and pyrroline-5-carboxylate (P5C) stimulate collagen biosynthesis in cultured cells but evoke different maxima of collagen biosynthesis stimulating activity at different times of incubation. P5C was found to be the most potent stimulator of collagen biosynthesis after 6 h of incubation (approx. three-fold increase); after 12 h, it induced increase in collagen biosynthesis to 260%, while at 24 h, the process was decreased to approximately 80% of control values. Glu induced increase in collagen biosynthesis to approximately 180%, 400% and 120% of control values, after 6, 12 and 24 h, respectively, suggesting that after 12 h of incubation, Glu was the most potent stimulator of collagen biosynthesis. Glu was also the most potent stimulator of type I procollagen expression at this time. After 6, 12 and 24 h incubation, Gln induced collagen biosynthesis to approximately 112, 115 and 230% of control values, respectively. Since prolidase is known to be involved in collagen metabolism, the enzyme activity assay was performed in fibroblasts cultured in the presence of Gln, Glu and P5C. While Gln and Glu required 24 h for maximal stimulation of prolidase activity, P5C induced it after 6-12 h. The data suggest that P5C induced collagen biosynthesis and prolidase activity in a shorter time than Gln and Glu. We considered that P5C directly stimulates the processes, while Gln acts through its intermediate-P5C. Reduction of P5C to proline is coupled to the conversion of glucose-6-phosphate (G6P) to 6-phospho-gluconate, catalyzed by G6P dehydrogenase. We have found that dehydroepiandrosterone (DHEA), a potent inhibitor of G6P dehydrogenase, inhibited a stimulatory effect of P5C on collagen synthesis, expression of type I collagen and prolidase activity. Our results postulate a potential mechanism of glutamine-induced collagen biosynthesis through its intermediate - P5C. P5C-dependent activation of nucleotide biosynthesis, prolidase activity and P5C conversion into proline may contribute to the stimulation of collagen biosynthesis.
Dehydroepiandrosterone (DHEA) and its sulfate conjugate (DHEA-S) are the most abundantly produced human adrenal steroids to be reduced with age. DHEA may be related to the process of skin aging through the regulation and degradation of extracelluar matrix protein. In this study, we demonstrate that DHEA can increase procollagen synthesis and inhibit collagen degradation by decreasing matrix metalloproteinases (MMP)-1 synthesis and increasing tisuue inhibitor of matrix metalloprotease (TIMP-1) production in cultured dermal fibroblasts. DHEA was found to inhibit ultraviolet (UV)-induced MMP-1 production and the UV-induced decrease of procollagen synthesis. probably due to the inhibition of UV-induced AP-1 activity. DHEA (5%) in ethanol:olive oil (1:2) was topically applied to buttock skin of volunteers 12 times over 4 weeks, and was found to significantly increase the expression of procollagen alpha1(l) mRNA and protein in both aged and young skin. On the other hand, topical DHEA significantly decreased the basal expression of MMP-1 mRNA and protein, but increased the expression of TIMP-1 protein in aged skin. We also found that DHEA induced the expressions of transforming growth factor-PI and connective tissue growth factor mRNA in cultured fibroblasts and aged skin, which may play a role in the DHEA-induced changes of procollagen and MMP-1 expression. Our results suggest the possibility of using DHEA as an anti-skin aging agent.
This study investigated the antioxidative effect of mugwort (Artemisia vulgaris L.) extracts in hairless mouse skin from oxidative stress induced by UV-irradiation. After topical application on hairless mouse back with basic skin lotion group (control), ascorbic acid group (AA-0.5%, AA-1.0%, AA-2.0%, and AA-5.0%), and mugwort extract group (ME-0.5%, ME-1.0%, ME-2.0%, and ME-5.0%), the animals were irradiated to increasing doses of UVB (60 mJ∼100 mJ) for 4 weeks. Hydrogen peroxide of hairless mouse skin homogenate significantly decreased in 2% (p<0.05) and 5% (p<0.05) of ME and AA groups. Hydroxyl radicals were decreased significantly in both of 2% and 5% ME groups as compared to AA groups (p<0.05). Oxidative stress levels deduced by oxidized protein contents were greatly decreased (14.6∼18.5%) in all ME treatment groups, while only at 2% of AA treatment group. Lipid peroxide contents were greatly inhibited in all ME and AA treatment groups (p<0.01). Application of ME significantly increased catalase activity, over 25% in all mugwort and AA groups. Glutathione peroxidase activities were increased up to 20.5%∼32.8% in 2.0% and 5% ME groups, whereas it increased in all AA groups. These results suggested that mugwort extract was more effective than that of ascorbic acid in protecting hairless mouse skin from photo-irradiation, and can be used as an potential anti-aging cosmetic ingredients.
Damage to human skin due to ultraviolet light from the sun (photoaging) and damage occurring as a consequence of the passage of time (chronologic or natural aging) are considered to be distinct entities. Photoaging is caused in part by damage to skin connective tissue by increased elaboration of collagen-degrading matrix metalloproteinases, and by reduced collagen synthesis. As matrix metalloproteinase levels are known to rise in fibroblasts as a function of age, and as oxidant stress is believed to underlie changes associated with both photoaging and natural aging, we determined whether natural skin aging, like photoaging, gives rise to increased matrix metalloproteinases and reduced collagen synthesis. In addition, we determined whether topical vitamin A (retinol) could stimulate new collagen deposition in sun-protected aged skin, as it does in photoaged skin. Sun-protected skin samples were obtained from 72 individuals in four age groups: 18-29 y, 30-59 y, 60-79 y, and 80+ y. Histologic and cellular markers of connective tissue abnormalities were significantly elevated in the 60-79 y and 80+ y groups, compared with the two younger age groups. Increased matrix metalloproteinase levels and decreased collagen synthesis/expression were associated with this connective tissue damage. In a separate group of 53 individuals (80+ y of age), topical application of 1% vitamin A for 7 d increased fibroblast growth and collagen synthesis, and concomitantly reduced the levels of matrix-degrading matrix metalloproteinases. Our findings indicate that naturally aged, sun-protected skin and photoaged skin share important molecular features including connective tissue damage, elevated matrix metalloproteinase levels, and reduced collagen production. In addition, vitamin A treatment reduces matrix metalloproteinase expression and stimulates collagen synthesis in naturally aged, sun-protected skin, as it does in photoaged skin.
Objective The degree of reproducibility and precision of the mechanical direct profilometry and the intra- and interindividual fluctuations of 7 surface parameters were investigated.
Material and methods Negative replicas were sampled from defined areas of the skin of 31 volunteers an evaluated with the profile-tracking device TKC 300 Hommeltester in order to derive data about the inter- and intraindividual fluctuations. To determine the precision of this method 6 roughness parameters and J of waviness of each replica were repetitively evaluated. The practicability was tested introducing minimal changes in the experimental set-up. Further, the effect of urea-containing creme on the skins topography was investigated in a double-blind clinical setting on a collective of 11 patients.
Results The precision of this method is shown by nearly unchanged topographic parameters. Moreover, our data show smaller intra- than interindividual fluctuations of roughness (Ra) and waviness (Wt), being an important demand for clinical investigations.
Conclusion In this paper we demonstrate that the parameters of both roughness as well as the recently introduced waviness can be conveniently evaluated with a high degree of precision with the direct profilometry.
Flavonoids, a group of phenolic compounds widely occurring in the plant kingdom, have been reported to possess strong antioxidant activity. This preliminary study was designed to estimate the potential utility of topically applied flavonoids to prevent photooxidative stress in the skin. With this aim we have evaluated the protective effect of three flavonoids (quercetin, hesperetin and naringenin), chosen according to their structural characteristics, against UV radiation-induced peroxidation on phosphatidylcholine (PC) vesicles as a model membrane. Furthermore ‘in vitro’ human skin permeation of these flavonoids was measured, given that a suitable percutaneous absorption is an essential requirement for satisfactory topically applied photoprotective agents. The flavonoids tested in our study proved to protect efficiently PC liposomes from UV radiation-induced peroxidation, probably by scavenging oxygen free radicals generated by UV irradiations; their antilipoperoxidative activity can be classified as follows: quercetin > hesperetin > naringenin. In addition, naringenin, hesperetin and, at a very lower degree, quercetin were able to permeate through the stratum corneum (which is the main barrier against the penetration of exogenous substances through the skin) and, so, to penetrate into deeper skin layers. Taken together, these findings suggest that topically applied flavonoids could be excellent candidates for successful employment as protective agents in certain skin diseases caused, initiated or exacerbated by sunlight irradiation.
A principal mechanism by which ultraviolet (UV) B radiation exerts its selective and antigen-specific suppressive influence on immune responses is through its effects on the capacity of antigen-presenting cells (APC) in skin, primarily Langerhans cells (LC), to differentially activate T-cell subsets. Recent evidence has indicated that LC, following UVB radiation, lose the capacity to stimulate proliferation of CD4+ Th1, but not of Th2, clones. Additional work has shown this acquired unresponsiveness of Th1 cells to represent a long-lasting form of clonal anergy that results from a block in their ability to produce IL-2. Although not completely delineated, these defects appear to be the result of preserved delivery of the primary signal transduced by interaction of the MHC/antigen complex on APC with the T-cell receptor complex, in the absence of a viable second signal normally delivered by interaction of a co-stimulatory factor from APC with its appropriate ligand on the T cells. These findings support the notion that the outcome of certain immune responses depends greatly upon conditions that are brought to bear on APC and T cells during the time of antigen presentation.
The effects of all-trans retinoic acid (t-RA) on photodamaged and normal non-irradiated skin were examined in hairless mice (Skh:HR-1). After being exposed to increasing doses of UVB for 10 weeks (total dose = 1.4 J/cm2), the animals were then treated with 0.1% t-RA in ethanol (50 microliters, five times per week) for another 10 weeks. Several animals (the follow-up group) were further observed after the termination of the t-RA treatment to investigate if the t-RA effect was reversible. Wrinkle effacement induced by t-RA was compared with three other parameters: a) de novo collagen synthesis, b) width of the dermal repair zone, and c) epidermal thickening. Interestingly, t-RA did not stimulate collagen synthesis in animals not exposed to UVB. In the irradiated animals, the time course of wrinkle reduction correlated with the stimulation of collagen synthesis. After a synchronous initial lag phase of 4-6 weeks, the wrinkling decreased from the maximum grade of 4 to a mean grade of 1.3, whereas collagen synthesis was enhanced to 245% of the control at week 10 of t-RA treatment. In contrast, a similar lag phase was not observed for either the appearance of the dermal repair zone or epidermal thickening. In the follow-up group, upon termination of t-RA treatment, collagen synthesis returned to the control level. Wrinkle effacement and thickening of the dermal repair zone, however, did not regress, suggesting the anti-photoaging effect of t-RA was not reversible over this time frame. The correlation between the length of the lag phases for collagen synthesis and wrinkle reduction points to the possibility that collagen plays an important role in tRA-induced wrinkle effacement. Both parameters are thus important endpoints for investigating the mechanism of RA-induced repair of photodamaged skin.
Histochemical and ultrastructural studies demonstrate that topical all-trans retinoic acid (RA) stimulates the deposition of a subepidermal band of collagen in photoaged hairless mice. The aim of this study was to examine the effect of RA treatment on collagen synthesis using biochemical and immunochemical techniques. Albino hairless mice were irradiated three times a week for 10 weeks with four minimal erythema doses of UVB from Westinghouse FS-40 bulbs. In the post-UV period, mice were either nontreated or treated with 0.05% RA or the ethanol-propylene glycol vehicle for up to 10 weeks. Antibodies against the aminopropeptide (AP) of type III procollagen were used in immunofluorescence microscopy and radioimmunoassay techniques. The AP of type III collagen is normally present throughout the dermis and in areas of active collagen synthesis (i.e., the dermal-epidermal junction). In this study, a similar distribution was seen in all untreated and vehicle-treated mice, and in mice treated with RA for 2, 4, and 6 weeks. However, increased staining, in a subepidermal band, was detected in the 8-week RA-treated skin. This region became intensely fluorescent to a depth of 100 mu in the 10-week RA-treated skins. As determined by radioimmunoassay, the content of the AP of type III procollagen increased twofold with 10-week RA treatment. Because the ratio of type I to type III collagens remained constant in treated and untreated skins, it is reasonable to assume that the content of type I collagen increased in proportion to type III collagen in RA-treated skins.
Aging of the skin is a composite of actinic damage, chronologic aging, and hormonal influences. The majority of changes associated with aging, such as wrinkles and solar lentigines ("liver spots"), are due to photoaging and reflect cumulative sun exposure as well as skin pigmentation. Classically, chronologic aging includes those cutaneous changes that occur in non-sun-exposed areas, such as the buttocks, and are observed in both men and women. A clinical example would be soft tissue sagging due to elastic fiber degeneration. In women, investigations into the effect of hormones on aging of the skin have concentrated on estrogens; in men, there have been a limited number of studies on the influence of testosterone. The latter have shown an age-dependent decrease in tissue androgens in pubic skin, but not scrotal or thigh skin. To date, age has not been shown to have an effect on androgen receptor binding, although a decrease in foreskin 5 alpha-reductase activity with increasing age has been described. In fibroblast cultures from foreskins, there have been conflicting results as to whether 5 alpha-reductase activity decreases in an age-dependent manner. Some of the skin changes that have been categorized as secondary to chronologic aging, such as decreased sebaceous gland activity and decreased hair growth, may actually represent a decline in the concentration of tissue androgens with increasing age. The influence of androgens on age-related changes in keratinocyte and fibroblast function remains speculative.
Humans express three distinct collagenases, MMP-1, MMP-8, and MMP-13, that initiate degradation of fibrillar type I collagen. We have previously reported that ultraviolet irradiation causes increased expression of MMP-1, but not MMP-13, in keratinocytes and fibroblasts in human skin in vivo. We report here that ultraviolet irradiation increases expression of MMP-8 in human skin in vivo. Western analysis revealed that levels of the full-length, 85 kDa proenzyme form of MMP-8 increased significantly within 8 h post ultraviolet irradiation (2 minimal erythema doses). Increased full-length MMP-8 protein was associated with infiltration into the skin of neutrophils, which are the major cell type that expresses MMP-8. Immunofluorescence revealed coexpression of MMP-8 and neutrophil elastase, a marker for neutrophils. Immunohistology demonstrated MMP-8 expression in neutrophils in the papillary dermis between 4 and 8 h post ultraviolet irradiation, and in the epidermis at 24 h post radiation. MMP-8 mRNA expression was not detected in nonirradiated or ultraviolet-irradiated human skin, indicating that increased MMP-8 following ultraviolet irradiation resulted from preexisting MMP-8 protein in infiltrating neutrophils. Pretreatment of skin with the glucocorticoid clobetasol, but not all-trans retinoic acid, significantly blocked ultraviolet-induced increases in MMP-8 protein levels, and neutrophil infiltration. In contrast, all-trans retinoic acid and clobetasol were equally effective in blocking ultraviolet induction of MMP-1 and degradation of collagen in human skin in vivo. Taken together, these data demonstrate that ultraviolet irradiation increases MMP-8 protein, which exists predominantly in a latent form within neutrophils, in human skin in vivo. Although ultraviolet irradiation induces both MMP-1 and MMP-8, ultraviolet-induced collagen degradation is initiated primarily by MMP-1, with little, if any, contribution by MMP-8.
To the best of our knowledge, no study has been conducted to date to directly compare the collagen metabolism of photoaged and naturally aged human skin. In this study, we compared collagen synthesis, matrix metalloproteinase-1 levels, and gelatinase activity of sun-exposed and sun-protected skin of both young and old subjects. Using northern blot analysis, immunohistochemical stain, and Western blot analysis, we demonstrated that the levels of procollagen type I mRNA and protein in photoaged and naturally aged human skin in vivo are significantly lower than those of young skin. Furthermore, we demonstrated, by northern blot analysis, that the procollagen alpha1(I) mRNA expression of photoaged skin is much greater than that of sun-protected skin in the same individual. In situ hybridization and immunohistochemical stain were used to show that the expression of type I procollagen mRNA and protein in the fibroblasts of photoaged skin is greater than for naturally aged skin. In addition, it was found, by Western blot analysis using protein extracted from the dermal tissues, that the level of procollagen type I protein in photoaged skin is lower than that of naturally aged skin. The level of matrix metalloproteinase-1 protein and the activity of matrix metalloproteinase-2 were higher in the dermis of photoaged skin than in naturally aged skin. Our results suggest that the natural aging process decreases collagen synthesis and increases the expression of matrix metalloproteinases, whereas photoaging results in an increase of collagen synthesis and greater matrix metalloproteinase expression in human skin in vivo. Thus, the balance between collagen synthesis and degradation leading to collagen deficiency is different in photoaged and naturally aged skin.
Cutaneous ageing is a complex biological phenomenon consisting of two components; intrinsic ageing, which is largely genetically determined and extrinsic ageing caused by environmental exposure, primarily UV light. In sun-exposed areas, these two processes are superimposed. The process of intrinsic skin ageing resembles that seen in most internal organs and is thought to involve decreased proliferative capacity leading to cellular senescence, and altered biosynthetic activity of skin derived cells. Extrinsic ageing, more commonly termed photoageing, also involves changes in cellular biosynthetic activity but leads to gross disorganisation of the dermal matrix. The molecular mechanisms underlying some of these changes are now beginning to be unravelled and are discussed. As these mechanisms are identified, further insights into the underlying processes of skin ageing should emerge and better strategies to prevent the undesirable effects of age on skin appearance should follow.
Three-dimensional lattices of reconstituted, polymerized type I collagen were subjected to partial hydrolysis by organ culture fluid from human skin or by various matrix metalloproteinases, including matrix metalloproteinase-1 (interstitial collagenase), -2 (72 kDa gelatinase A), -8 (neutrophil collagenase), -9 (92 kDa gelatinase B), or -13 (collagenase 3). Following partial digestion, human dermal fibroblasts were incubated on the enzyme-treated or control lattices and examined for ability to contract the collagen lattice and synthesize type I procollagen. Collagen lattices partially degraded by organ culture fluid were contracted by fibroblasts under conditions in which control collagen lattices were not. On the partially degraded collagen, fibroblasts synthesized reduced amounts of type I procollagen (approximately 70% reduction). Purified matrix metalloproteinases with collagenolytic activity duplicated the effects of the human skin organ culture fluid, although matrix metalloproteinases 8 and 13 were less efficient than matrix metalloproteinase-1 (65% vs 40% and 18% reduction in type I procollagen production for matrix metalloproteinases 1, 8, and 13, respectively). Matrix metalloproteinases 2 and 9 were without effect on intact collagen; however, when collagen lattices were subjected to digestion by a combination of matrix metalloproteinases 1 and 9, fragments produced by matrix metalloproteinase-1 were further degraded by the gelatinase. Collagen contraction and inhibition of procollagen synthesis were both reduced. Matrix metalloproteinase-2 was less effective than matrix metalloproteinase-9 in clearing matrix metalloproteinase-1-generated fragments. Matrix metalloproteinase-2 was also less effective in preventing contraction and inhibiting the downregulation of type I procollagen synthesis. These observations suggest that in the presence of high molecular weight fragments of type I collagen, type I procollagen synthesis is inhibited. As these fragments are processed further, there is less inhibition of type I procollagen production.
UV irradiation acts as a broad activator of cell surface growth factor and cytokine receptors. This ligand-independent receptor activation induces multiple downstream signaling pathways that regulate expression of multiple genes. These signaling pathways converge to stimulate transcription factor AP-1. Among genes whose expression is regulated by AP-1 are several matrix-metalloproteinase (MMP) family members and type I procollagen. UV-enhanced matrix degradation is accompanied with decreased collagen production mediated not only by activation of AP-1, but also by inhibition of transforming growth factor (TGF)-beta signaling. Several alterations to skin connective tissue that occur during aging are mediated by mechanisms that are similar to those that occur in response to UV irradiation. Thus, skin aging is associated with increased AP-1 activity, increased MMP expression, impaired TGF-beta signaling, enhanced collagen degradation, and decreased collagen synthesis. Knowledge gained from examining molecular responses of human skin to UV irradiation provides not only a framework for understanding mechanisms involved in skin aging, but also may help in development of new clinical strategies to impede chronological and UV-induced skin aging.
Biochemical and ultrastructural approaches were used to assess collagen changes in photodamaged skin. Extensive collagen fragmentation, clumping of the fragmented collagen, and interaction of fibroblasts with the damaged matrix were observed. Similar, though less extensive, collagen damage was also observed in sun-protected skin-individuals aged 80 y or older (naturally aged skin). In comparison, sun-protected skin from young individuals (18-29 y of age) demonstrated little damage. A uniform distribution of collagen fibrils was seen. Interstitial fibroblasts were embedded in the collagen matrix and in close apposition with intact collagen fibrils. In additional studies, three-dimensional lattices of type I collagen were exposed in vitro to matrix metalloproteinase-1 (interstitial collagenase), and examined for biochemical and ultrastructural alterations. Under conditions in which enzyme treatment produced fragmentation in 30-40% of the collagen molecules, the lattices demonstrated collagen fragmentation and clumping of the damaged matrix. Recent studies have demonstrated a loss of procollagen production by fibroblasts in contact with collagen fragments in vitro. This study demonstrates similar changes in collagen structure in vivo in aged and photodamaged skin. We suggest that collagen fragmentation in vivo could underlie the loss of collagen synthesis in photodamaged skin and, to a lesser extent perhaps, in aged skin.
Dehydroepiandrosterone (DHEA) and its sulfate conjugate (DHEA-S) are the most abundantly produced human adrenal steroids to be reduced with age. DHEA may be related to the process of skin aging through the regulation and degradation of extracelluar matrix protein. In this study, we demonstrate that DHEA can increase procollagen synthesis and inhibit collagen degradation by decreasing matrix metalloproteinases (MMP)-1 synthesis and increasing tisuue inhibitor of matrix metalloprotease (TIMP-1) production in cultured dermal fibroblasts. DHEA was found to inhibit ultraviolet (UV)-induced MMP-1 production and the UV-induced decrease of procollagen synthesis, probably due to the inhibition of UV-induced AP-1 activity. DHEA (5%) in ethanol:olive oil (1:2) was topically applied to buttock skin of volunteers 12 times over 4 weeks, and was found to significantly increase the expression of procollagen alpha1(I) mRNA and protein in both aged and young skin. On the other hand, topical DHEA significantly decreased the basal expression of MMP-1 mRNA and protein, but increased the expression of TIMP-1 protein in aged skin. We also found that DHEA induced the expressions of transforming growth factor-beta1 and connective tissue growth factor mRNA in cultured fibroblasts and aged skin, which may play a role in the DHEA-induced changes of procollagen and MMP-1 expression. Our results suggest the possibility of using DHEA as an anti-skin aging agent.
Skin photoaging in reconstituted skin culture models
- S J Kang
Kang SJ. 1999. Skin photoaging in reconstituted skin culture models. J Soc Cosmet Scientists Korea 25: 59-74.
Anti-wrinkle effect by ginsenoside Rg3 derived from ginseng
- S W Kim
- J H Jeong
- Jo Bk
Kim SW, Jeong JH, Jo BK. 2004. Anti-wrinkle effect by
ginsenoside Rg3 derived from ginseng. J Soc Cosmet
Scientists Korea 30: 221-225.
Studies on the amino acid, sugar analysis and antioxidative effect of extracts from Artemisia sp
- B B Choi
- H J Lee
- S K Bang
Choi BB, Lee HJ, Bang SK. 2004. Studies on the amino acid,
sugar analysis and antioxidative effect of extracts from
Artemisia sp. Korean J Food Nutr 17: 86-91.
Anti-wrinkle effect of Morinda citrifolia (Noni) extracts
- Jn Lee
- Sw Kim
- Yk Yoo
- Gt Lee
- Kk Lee
Evaluation of age-dependent crow's feet in Korean women
- M Y Lee
- E J Kim
- H K Lee
- Y K Seu
- M S Lee
- J S Koh
Lee MY, Kim EJ, Lee HK, Seu YK, Lee MS, Koh JS. 2004.
Evaluation of age-dependent crow's feet in Korean women.
J Soc Cosmet Scientists Korea 30: 85-91.
Evaluation of skin furrows in the ageing process using an image analysis system
- H C Choi
- C H Oh
Choi HC, Oh CH. 1997. Evaluation of skin furrows in the
ageing process using an image analysis system. Korean
J Dermatol 35: 292-302.
Research and application for natural extract that contain ultraviolet rays absorbent ingredient
- K D Kim
Kim KD. 2004. Research and application for natural extract
that contain ultraviolet rays absorbent ingredient. J Soc
Cosmet Scientists Korea 30: 117-122.
Superoxide dismutase activites in the human skin. The biological role of reactive oxygen species in skin
- Y P Kim
- S C Lee
Kim YP, Lee SC. 1987. Superoxide dismutase activites in
the human skin. The biological role of reactive oxygen species in skin. University of Tokyo Press, Tokyo. p 225-320.
UV-light-induced signal cascades and skin aging
- R G Laure
- J Fisher
Laure RG, Fisher J. 2002. UV-light-induced signal cascades and skin aging. Ageing Res Rev 1: 705-720.
Molecular mechanism of skin ageing
- J Gail
Gail J. 2002. Molecular mechanism of skin ageing. Mech
Ageing Dev 123: 801-810.