양파외피추출물이 UVB에 손상된 피부에 미치는 영향

나윤영,송선영 한국생약학회 2013 생약학회지 Vol.44 No.4

In this study, we investigated the effects of onion(Allium cepa L.) peel extraction aplication on UVB-induced damage of mouse skin. The male C57BL/6 weeks mice were divided into three groups; the control group(Con), the UVB irradiated group(UVB) and the group treated with onion peel extract after UVB irradiation(UVB+Onion peel). Onion peel extraction were topically treated after UVB irradiation(800 mJ/cm 2) to dorsal skin. We were measured TEWL, melanin value, erythema index and histological of mouse skin. In the TEWL, melanin value and erythema index observation, UVB+onion peel group were decreased then in the UVB group and 120 and 168 hr groups were similar to the control group. In the histological observation,UVB+onion peel group were indicated hyperkeratosis then in the UVB. These results showed that onion peel extract as a topical application may have preventive effect against UVB-induced skin damage. Therefore onion peel extract might be good material for UVB-damage skin care.

자초(Lithospermum erythrorhizon) 추출물이 UVB로 조사된 생쥐 피부에 미치는 영향

송선영 韓國電子顯微鏡學會 2008 Applied microscopy Vol.38 No.3

본 연구는 UVB 조사로 인해 손상된 피부에 있어서 자초추출물의 유효성을 검증하기 위해 시도되었다. 생후 6주령된 제모한 C57BL/6 마우스를 대상으로 대조군, UVB 조사군 (UVB군), UVB 조사 후 자초추출물처치군(UVB+Le군)으로 구분하여 24시간, 48시간, 72시간, 120시간, 168시간의 시간대별로 관찰하였다. 경표피수분손실량을 측정한 결과, UVB+Le군이 UVB군 보다 시간이 경과함에 따라 TEWL이 감소하였다. 특히 168시간군에서 유의하게 낮게 나타났다(p<0.05). 멜라닌 양 측정 결과, UVB+Le군이 UVB군 보다 낮게 나타났으나 통계학적으로 유의성은 없게 나타났다(p>0.05). 홍반 지수 측정 결과, UVB+Le group 24시간, 48시간, 72시간군에서 UVB group 보다 유의하게 낮게 나타났다(p<0.05). 주사전자현미경적 관찰 결과, UVB group 24시간군에서는 UVB group보다 팽윤현상이 완화되었다. 48시간군에서는 가피형성, 72시간군에서는 규칙적인 판상구조, 120시간군에서 새로운 각질세포 생성, 168시간군에서는 얇은 섬유망으로 덮혀 있는 것이 관찰되었다. 투과전자현미경적 관찰 결과, UVB+Le group은 층판소체의 증가와 층판소체의 재형성이 UVB group 보다 모든 군에서 촉진되었다. 특히 168시간군에서는 지질이중막의 구조가 거의 회복되어졌다. 이상의 모든 실험결과를 통해 자초추출물이 UVB 조사로 손상된 생쥐 피부를 회복시키는 효과가 있는 것으로 사료된다. This study was intended to identify the effectiveness of Lithospermum erythrorhizon in the UVB-irradiated mouse skin. The C57BL mice were divided into three groups; the control group, the UVB irradiated group (UVB group), and the group treated with Lithospermum erythrorhizon extracts after UVB irradiation (UVB+Le group). 10 mouses were collected and sacrificed at 24 hrs, 48 hrs, 72 hrs, 120 hrs, and 168 hrs, respectively. In the result, the transepidermal water loss (TEWL) was decreased the UVB+Le group than UVB groups by time. At the 168 hrs group was significantly lower (p<0.05). In the result, the melanin value was decreased in the UVB+Le group than UVB group, but meaningless (p>0.05). In the result of erythema index, the UVB+Le group was meaningfully lower at 24 hrs, 48 hrs, and 72 hrs group than UVB group (p<0.05). In the result of scanning electron micrograph observation, the UVB+Le group was allevited swelling than UVB group at the 24 hrs, formation of the scab at the 48 hrs, regular plate shap at the 72 hrs, new keratin observated at the 120 hrs partially, and fine fiber covered epidermis surface at the 168 hrs. In the result of transmission electron micrograph observation, the UVB+Le group was facilitation of increased lamellar bodies and reformation lamellar bodies than UVB group at the all groups. Almost all the structures were recovered at the 168 hrs group. In conclusion, Lithospermum erythema extracts may recovery on the UVB-irradiated mouse skin.

배양된 정상 인체 각질형성세포에서 자외선 B 조사에 의한 아포프토시스와 p53의 발현

김명남(Myeung Nam Kim),서성준(Seong Jun Seo),홍창권(Chang Kwun Hong),노병인(Byung In Ro),노성욱(Sung Wook Ro),조성인(Sung In Cho) 대한피부과학회 2000 대한피부과학회지 Vol.38 No.4

N/A Cutaneous absorption of ultraviolet B(UVB) in the skin occurs primarily in keratinocyte, causing DNA and protein damage. p53 tumor suppressor gene appeared in the epidermis after UVB irradiation, and the wild type has been known to be responsible for apoptosis and plays an important role in excluding abnormal cells with significant DNA damage. While p53 has been implicated in both DNA repair and apoptosis, it is unclear whether the p53 protein is involved in both of these processes within the same cell. Therefore, UVB-induced apoptosis and changes in p53 expression were studied in cultured normal human keratinocyte to determine that the cellular response to UVB induced DNA damage(DNA repair or apoptosis) correlated with p53 expression. The cultured normal human keratinocytes were irradiated with the doses of UVB(25-150 mJ/cm2) and incubated for various times(3, 6, 12, 24 hour) after radiation. At UVB doses of 100 and 150 mJ/cm2, acridine orange/ethidium bromide(Ao/Eb) staining-positive cells and TUNEL (TdT mediated dUTP-biotin nick end labeling) staining-positive cells increased significantly after 3 hours and 6 hours postirradiation respectively. Twelve hour postirradiation, staining-positive cells increased at each level of UVB-radiation exposure. These results suggest that there were significant influences of UVB doses and time course after irradiation to the number of Ao/Eb and TUNEL staining-positive cells. To determine whether all Ao/Eb and TUNEL-positive cells were actually undergoing apoptosis, cellular DNA was extracted from keratinocytes at 12 hours after UVB irradiation and seperated by electrophoresis on an 2.5% agarose gel to detect the internucleosomal DNA fragmentation(DNA ladder). 'DNA ladder' occurred at every dose of UVB 12 hour after irradiation, but did not appear early after irradiation, suggesting that whether Ao/Eb and TUNEL-positive cells observed early after irradiation were not undergoing apoptosis. Activation of p53 and the response to DNA damage is not observed universally, but is dependent on tissue specificity, species specificity and type of genotoxic damage. To correlate p53 level with UVB-induced apoptosis at the dose of 100mJ/cm2 UVB, p53 levels were determined by western blot analysis. The accumulation of p53 protein was apparent after 6 hours postirradiation, and UVB irradiation caused a dramatic increase in p53 levels at 12 and 24 hours. These results demonstrate that p53 is required for UVB-induced apoptosis in cultured normal human keratinocyte and p53 has a time-dependent effect in the initiation of apoptosis. In this study, the results indicated that a low dose(25mJ/cm2) of UVB irradiation could induce apoptosis in human keratinocyte in vitro and UVB exerts a time-dependent effect on inducing apoptosis. And the results also give support to increasing evidence that p53 may play a role in UVB-induced DNA damage and the induction of apoptosis in cultured normal human keratinocyte and that p53 is involved in the decision process which determines the fate of keratinocyte after UVB -induced DNA damage. (Korean J Dermatol 2000;38(4):481~489)

Kojic acid와 Pentadecenoic acid가 자외선 B조사후 시험관 및 생체내의 색소계에 미치는 영향

엄상철,김상태 고신대학교 의학부 1993 高神大學校 醫學部 論文集 Vol.9 No.2

UVB를 조사하거나 조사치 않은 배양된 정상 인체 멜라닌 세포와 C57BL 마우스의 피부에 KA 혹은 PDA를 투여한 후 색소형성억제 효과를 관찰하여 다음과 같은 결과를 얻었다. 1. 배양된 정상 인체 멜라닌 세포에 UVB 조사 후 세포 수는 정상대조군에 비해 모두 유의하게 감소되었으며(P<0.05), 멜라닌 양은 UVB를 조사받은 모든 군에서 UVB 조사 3일 후에는 감소되었으나 5일 후에 유의하게 증가되었다(P<0.05). 2. 배양된 정상 인체 멜라닌 세포에서 세포수는 KA 군에서는 정상대조군에 비해 유의하게 감소되었으나(P<0.05) PDA군은 유의성이 없었으며(P>0.05), 멜라닌 양은 모두 실험군이 정상대조군에 비해 유의하게 감소되었다(P<0.05). 3. 배양된 정상 인체 멜라닌 세포에 UVB 조사 후 세포 수는 KA 10^(-3)M 군에서는 약물 투여 3일과 5일 후에, KA 10^(-5)M 군은 약물 투여 3일 후에, PDA 10^(-3)M군은 약물투여 5일 후에 UVB 대조군에 비해 유의하게 감소되었으며(P<0.05), 멜라닌 양은 모든 실험군에서 UVB 대조군에 비해 유의하게 감소되었다(P<0.05). 4. C57BL 생쥐에서 멜라인 세포 수는 모든 KA 군과 PDA 5% 군에서는 정상 대조군에 비해 유의한 감소를 보였으나(P<0.05), PDA 0.5% 군은 차이가 없었으며(P>0.05). UVB를 조사한 경우에도 PDA 0.5% 군을 제외한 모든 실험군에서 UVB 대조군에 비해 유의한 감소를 보였다(P<0.05). 이상의 결과로 KA와 PDA는 배양된 정상 인체 멜라닌 세포와 C57BL 생쥐의 멜라닌 세포에서 색소형성을 억제하는 작용이 있으며 UVB 조사에 의한 색소형성도 억제하는 것을 알 수 있었다. It has been well known that exposure to ultraviolet-B(UVB) light elicits increased pigmentation in the skin. The model has been widely adapted to assess the potential of chemicals a s compounds with skin-depigmenting effects. We observed the pigment inhibitory effect of kojic acid(KA) and pentadecenoic acid(PDA) on the cultured human melanocytes and C57BL mice skin after UVB irradiation. Cultured human melanocytes were irradiated with 30mJ/cm^(2) of of UVB once, than KA and PDA were administered for 3 or 5 days. C57BL black mice were irradiated with 100mJ/cm^(2) of UVB daily for 10 days. and then KA and PDA were topically applied daily for 1, 3, 5 or 7 weeks. For demonstration of the effect of both drugs. we observed numeric and morphologic changes and measured melanin contents of cultured normal human melanocytes. Also we examined the effect of the chemicals on split-DOPA stained epidermal melanocytes of C57BL mice. The results were a s follows : 1. After UVB-irradiation, cell number and melanin content decreased initially, but melanin content increased after 5 days in cultured human melanocytes. 2. In cultured human melanocytes, the KA 10^(-3)M group showed decreased number of melanocyte, but KA 10^(-5)M or PDA groups showed no change. In all experimental groups, melanin content decreased, compared to control group. 3. After UVB-irradiation, the number of cultured human melanocytes decreased in groups treated with KA 10^(-3)M for 3 and 5 days, KA 10^(-5)M for 3 days and PDA 10^(-3)M for 5 days compared to UVB control group. 4. In C57BL mice, the KA group showed decreased number of melanocytes compared to control group. The PDA group showed no change. After UVB- irradiation, both KA and PDA groups showed decreased number of melanocytes compared to UVB control group. In the present study, it was found that KA and PDA had suppressive effects on melanization of melanocytes in vitro and in vivo, suggesting KA and PDA might be candidates as compounds that control hyperpigmentary disorders.

자외선 조사간격이 브로일러 병아리의 중족골 광물질 함량에 미치는 영향

장윤환,조인호,여영수,이은택,배은경,김중달 한국가금학회 1993 韓國家禽學會誌 Vol.20 No.3

본 연구는 비타민 D$_{3}$(VD$_{3}$) 결핍 병아리에게 자외선을 상이한 간격으로 조사하여 경과시간에 따라 다리의 중족골을 채취하여 회분, Ca, P의 수준을 조사코자 실시되었다. 육용 Hubbard 계통 199수의 초생추(대조구 10수+3조사간격$\times$9조사 후 경과시간$\times$7반복)를 무창약등 육추사에 넣고 VD$_{3}$ 결핍사료로 3주간 사육한 후, 0.068 mJ/$\textrm{cm}^2$(10분간)의 선량으로 297nm의 UVB 광선을 3회 조사하되 조사간격을 0, 12 또는 24시간 간격으로 하였다. 조사 후 0, 6, 12, 18, 24, 48, 96, 144또는 240시간에 병아리의 중족골을 채취하였다. 중족골은 부착조직을 제거하고 탈지, 건조, 화화하여 회분, Ca, P 함량을 측정하였다. Ca은 원자흡수분광광도법으로, P은 ammonium metavanadate 법으로 비색정량하였다. UVB를 30분간 무간격으로 조사하였을 때 중족골의 Ca함량은 계속 증가되어 240시간에 16.75%에 도달하였다. P의 함량은 UVB 조사후 점점 증가되어 144시간에 최고치 9.75%를 나타내었으며, 회분함량은 UVB 조사후 점점 증가하여 240시간에 42.75%에 이르렀다. 12시간 간격으로 10분간씩 3회 조사하였을 때에는 중족골의 Ca 함량이 12시간에 작은 peak(13.31%), 144시간에 큰 peak (16.91%)를 보였다. P의 함량은 12시간에 작은 peak(7.18%), 240시간에 큰 수준(8.34%)을 보였다. 회분 함량은 UVB 조사후 계속 증가하여 240시간에 46.53%의 높은 값을 나타내었다. 도중의 Ca과 P의 작은 peak는 아마 12시간 및 24시간 전에 조사하였던 UVB의 영향인 것으로 생각된다. 24시간 간격으로 10분간씩 3회 조사했을 때 중족골의 Ca 함량은 점차 증가되어 96시간에 최고치 24.18%를 보였고 P함량은 역시 96시간에 최고치 7.29%를 나타내었으며, 회분 함량은 240시간까지 계속 증가되어 45.73%에 이르렀다. UVB조사 후 경과시간에 따라 살펴보면 중족골의 Ca와 P 함량은 UVB 조사후 96~144시간에 최고치에 도달했으나 회분함량은 240시간까지 계속 증가하는 모습을 보였다. 다음 UVB의 조사방법에 따라 종족골의 Ca함량을 봤을 때 무간격으로 조사시 240시간까지 계속 증가하였고, 12시간 간격으로 조사시 144시간에 최고치를, 24시간 간격으로 조사시에는 96시간에 최고치를 나타내었으며 회분 함량을 봤을 때 12시간 또는 24시간 간격으로 조사하였을 경우가 무간격으로 조사하였을 때보다 더 높은 수준을 보였으므로 24시간 간격으로 10분간씩 조사하는 것이 바람직한 것으로 생각되었다. A study was conducted to investigate the concentrations of Ca, P and ash in metatarsal bone of broiler chicks exposed to UV light in different Interval. Day-old Hubbard broiler chicks (199=10 control+3 irradiation interval $\times$ 9 elapsed time $\times$ 7 replicate) were fed vitamin D3 deficient diet for 3 wk in a windowless subdued-light room and exposed to 297 nm UVB light by 0.068 mJ/$\textrm{cm}^2$ three times In 0, 12 or 24 h interval. The metatarsal bones were taken at 0, 6, 12, 18, 24, 48, 96, 144 or 240 h after last irradiation, separated from adhering tissue, ether extracted, dried and ashed. The Ca concentration was measured by atomic absorption spectrophotometry and P by ammonium metavanadate colorimetry. When the birds were continuously exposed to UVB light for 30 min without interval, the Ca content in metatarsus increased gradually according to the time after irradiation and reached the highest value 16.75% at 240 h after exposure. The P content also increased gradually until 144 h, where it was 9.75%. The ash content in metatarsus increased continuously until 240 h, the final time in this research, where 42.75% was shown. As 10 min three times irradiation in 12 h interval was applied to the chicks, the metatarsal Ca presented a small peak(13.31%) at 12 h after irradiation and a large peak(16.91%) at 144 h. P content showed a small peak(7.18%) at 12 h and a large level(8.34%) at 240 h. Ash content increased continuously until 240 h, where it was 46.53%. The small peaks in Ca and P concentration were thought to be derived from preirradiation at 12 and 24 h before final irradiation for 10 min. When 24 h interval system was treated, the peak value of Ca content(24.18%) occurred earlier(96 h) than those in 0 and 12 h interval systems. P content also showed the maximum value at 96 h(7.29%). Ash content presented an increasing trend until 240 h, where 45.75% was appeared. In respecting the method of UVB irradiation, the peak value of Ca content in metatarsus appeared earlier in 24 h interval system than in other systems. Meanwhile the ash contents in metatarsus of birds exposed to UVB light in 12 and 24 h interval procedures were higher than those in 0 h interval one. Therefore, it was concluded that a daily 10 min irradiation of UVB light would be desirable for increasing the Ca and ash content in metatarsus of brolier chicks.

UVB를 조사한 HaCaT 세포의 세포사멸과 p53 및 GADD45 유전자 발현에 대한 파프리카 추출물 및 성분들의 효과

Se Eun Ha(하세은),Hyung-Do Kim(김형도),Jea Ran Kang(강제란),Jong Kun Park(박종군) 한국생명과학회 2011 생명과학회지 Vol.21 No.5

본 연구는 파프리카 추출물과 그 성분인 비타민 C, 라이코펜과 베타-카로틴이 UVB (ultraviolet-B)에 의한 유전독성의 감소에 효과를 보이는 지를 HaCaT 세포를 이용하여 분석하였다. 자외선을 조사하지 않은 정상 세포의 세포활성은 파프리카 추출물을 경우 처리하지 않은 대조군과 차이를 나타내지 않았지만 비타민 C의 경우 농도 의존적으로 증가시키는 것을 관찰하였다. 그러나 라이코펜과 베타-카로틴의 경우 농도 의존적으로 점차 세포활성이 감소하는 것으로 관찰되었다. UVB로 상해받은 세포를 추출물이나 그 성분으로 후 배양할 경우 정상 배양액으로 배양한 대조군에 비해 파프리카 추출물과 비타민C은 농도 의존적으로 세포 활성을 증가시켰으나 라이코펜과 베타-카로틴의 경우 농도 의존적으로 감소키는 것을 관찰할 수 있었다. 자외선을 조사하지 않은 정상세포의 핵 분절율은 파프리카 추출물과 비타민 C의 경우 대조군과 유의적인 차이를 나타내지 않았지만, 라이코펜, 베타-카로틴의 경우 농도 의존적으로 핵 분절율이 증가하는 것을 관찰하였다. UVB를 조사한 후 파프리카 추출물이나 비타민 C를 처리한 경우 정상 배양액으로 배양한 대조군에 비해 핵 분절율을 감소시켰지만 라이코펜과 베타-카로틴의 경우 농도 의존적으로 증가시켰다. 세포 상해에 반응하는 유전자인 p53과 GADD45의 단백질 수준을 Western blot으로 분석한 결과, 파프리카 추출물만 처리했을 경우 p53과 GADD45 단백질 수준은 처리하지 않은 대조군과 비교해서 유의미한 차이를 나타내지 않았으나 UVB를 조사한 후 파프리카 추출물을 처리한 경우 농도 의존적으로 p53 단백질 발현량이 감소하였다. 비타민 C를 단독 처리할 경우 대조군에 비해 p53과 GADD45 단백질 발현량은 감소하였으며, UVB를 조사한 후 비타민 C를 처리한 경우에도 농도 의존적으로 p53과 GADD45 단백질 발현량이 감소하는 것을 확인할 수 있었다. 그러나 라이코펜과 베타-카로틴만 단독 처리할 경우 p53과 GADD45 단백질 발현량이 처리하지 않은 대조군에 비해 농도 의존적으로 증가하였다. UVB를 조사한 후 베타-카로틴을 처리한 경우에도 상대적인 고농도에서 p53과 GADD45 단백질 발현량이 증가하는 것을 확인할 수 있었다. 위의 결과를 토대로 파프리카 추출물과 비타민 C는 UVB에 의해 손상된 세포의 세포 독성을 회복하는 효능이 있다고 생각된다. 라이코펜과 베타-카로틴의 경우에는 UVB에 의해 발현된 p53 단백질의 수준이 농도 의존적으로 더욱 증가하는 것으로 보아 UVB에 의한 세포고사가 라이코펜과 베타-카로틴에 의해 강화되는 것으로 생각된다. In the present study, the effects of paprika extract and its components including vitamin C, lycopene and beta-carotene on cell death in ultraviolet B (UVB)-exposed HaCaT cells were investigated. The cell viability upon treatment for 24 hr with either paprika extract or vitamin C alone was similar to or greater than that of the untreated control. However, the viability of the cells treated with lycopene or beta-carotene decreased to about 20% of that in the untreated control. When UVB-exposed cells were post-incubated for 24 hr in medium containing paprika extract or vitamin C, cell viability increased in a concentration dependent manner as compared to those post-incubated in a normal growth medium. In contrast, post-incubation of UVB-exposed cells with lycopene or beta-carotene decreased cell viability in a concentration dependent manner as compared to those post-incubated in a normal growth medium. The nuclear fragmentation analysis showed that paprika extract or vitamin C decreases UVB-induced apoptosis. The apoptotic nuclear fragmentation resulting from UVB exposure was also protected by the paprika extract or vitamin C post-incubation. However, the UVB-induced apoptotic nuclear fragmentation of the cells treated with lycopene or beta-carotene increased in a concentration dependent manner. Western blot analysis showed that either paprika extract or vitamin C treatment alone did not significantly change the level of p53 and GADD45 protein. Interestingly, post-incubation of UVB-exposed cells with paprika extract or vitamin C decreased the p53 and GADD45 protein level as compared to those post-incubated in a normal growth medium. In contrast, incubation of UVB-exposed or non-irradiated cells with lycopene or beta-carotene increased the p53 and GADD45 protein levels in a concentration dependent manner as compared to those incubated in a normal growth medium. All these results suggest that paprika extract and vitamin C help the survival of the UVB-exposed cells, while lycopene and beta-carotene potentiate the apoptotic death of UVB-exposed cells, in accordance with the respective changes in p53 and GADD45 protein levels.

HaCaT 각질형성세포에서 자외선 B에 대한 세포자멸사 및 자가포식현상 유도

윤상돈 ( Sang Don Yoon ),백원기 ( Won Ki Baek ),김상표 ( Sang Pyo Kim ),이규석 ( Kyu Suk Lee ),조재위 ( Jae We Cho ) 대한피부과학회 2013 대한피부과학회지 Vol.51 No.8

Background: UVB irradiation induces apoptosis or/and autophagy through several molecular pathways in keratinocytes. However, the precise molecular mechanism of UVB-induced autophagy is largely unknown in keratinocytes. Objective: The purpose of this study was to investigate the molecular mechanisms of UVB-induced apoptosis and autophagy in HaCaT cell lines. Methods: Cells were irradiated by UVB (Westinghouse FS-40 sunlamps) with various doses (0, 30, 60, 120, 240 mJ/cm2). The expression levels of caspase-3, Bax, Bcl2, Bcl-XL and LC3 were confirmed by Western blot analysis in UVB-irradiated HaCaT cell lines. Apoptotic cells were analyzed by PI staining, and autophagy cells were analyzed by immunofluorescent staining. Results: The expression of Bcl-XL decreased from UVB 60 mJ/cm2 and Bcl2 decreased from UVB 240 mJ/cm2. The expression of caspase-3 was increased from UVB 120 mJ/cm2. These data showed that UVB-induced apoptosis is mediated by up-regulation of caspase-3 and down-regulation of Bcl2 and Bcl-XL. Furthermore, the expression of LC3 increased from UVB 120 mJ/cm2. In addition, autophagy formation was observed in few fractions of apoptotic HaCaT cells in immunofluorescent staining; most apoptotic cells did not show autophagy formation. Moreover, autophagy formation inhibitor treatment induced a slight increment of apoptotic cell population under UVB irradiation. Conclusion: UVB irradiation induces not only apoptotic cell death but also autophagy formations; these events may create a defense mechanism for the prevention of apoptosis in UVB-treated HaCaT cells. (Korean J Dermatol 2013; 51(8):600∼607)

Protective Effects of EGCG on UVB-induced Damage in Living Skin Equivalents

So-Young Kim,김동석,Sun-Bang Kwon,Eun-Sang Park,Chang-Hun Huh,윤상웅,김석화,박경찬 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.7

In this study, we evaluate the effects of (-)-epigallocatechin-3-gallate (EGCG) on ultraviolet B (UVB)-irradiated living skin equivalents (LSEs). Histologically, UVB irradiation induced thinning of the LSE epidermis, whereas EGCG treatment led to thickening of the epidermis. Moreover, EGCG treatment protected LSEs against damage and breakdown caused by UVB exposure. Immunohistochemically, UVB-exposed LSEs expressed p53, Fas, and 8-hydroxy-deoxyguanosine (8-OHdG), all of which are associated with apoptosis. However, EGCG treatment reduced the levels of UVB-induced apoptotic markers in the LSEs. In order to determine the signaling pathways induced by UVB, Western blot analysis was performed for both c-Jun NH2- terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), which are associated with UVB-induced oxidative stress. UVB activated JNK in the epidermis and dermis of the LSEs, and EGCG treatment reduced the UVB-induced phosphorylation of JNK. In addition, p38 MAPK was also found to have increased in the UVB-exposed LSEs. Also, EGCG reduced levels of the phosphorylation of UVB-induced p38 MAPK. In conclusion, pretreatment with EGCG protects against UVB irradiation via the suppression of JNK and p38 MAPK activation. Our results suggest that EGCG may be useful in the prevention of UVB-induced human skin damage, and LSEs may constitute a potential substitute for animal and human studies.

Protective Effects of EGCG on UVB-Induced Damage in Living Skin Equivalents

Kim, So-Young,Kim, Dong-Seok,Kwon, Sun-Bang,Park, Eun-Sang,Huh, Chang-Hun,Youn, Sang-Woong,Kim, Suk-Wha,Park, Kyoung-Chan The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.7

In this study, we evaluate the effects of (-)-epigallocatechin-3-gallate (EGCG) on ultraviolet B(UVB)-irradiated living skin equivalents (LSEs). Histologically, UVB irradiation induced thinning of the LSE epidermis, whereas EGCG treatment led to thickening of the epidermis. Moreover, EGCG treatment protected LSEs against damage and breakdown caused by UVB exposure. Immunohistochemically, UVB-exposed LSEs expressed p53, Fas, and 8-hydroxy-deoxyguanosine (8-OHdG), all of which are associated with apoptosis. However, EGCG treatment reduced the levels of UVB-induced apoptotic markers in the LSEs. In order to determine the signaling pathways induced by UVB, Western blot analysis was performed for both c-Jun $NH_2$-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), which are associated with UVB-induced oxidative stress. UVB activated JNK in the epidermis and dermis of the LSEs, and EGCG treatment reduced the UVB-induced phosphorylation of JNK. In addition, p38 MAPK was also found to have increased in the UVB-exposed LSEs. Also, EGCG reduced levels of the phosphorylation of UVB-induced p38 MAPK. In conclusion, pretreatment with EGCG protects against UVB irradiation via the suppression of JNK and p38 MAPK activation. Our results suggest that EGCG may be useful in the prevention of UVB-induced human skin damage, and LSEs may constitute a potential substitute for animal and human studies.

Protective effect of the standardized green tea seed extract on UVB-induced skin photoaging in hairless mice

Jae-Youn Lim,Ok-Kyung Kim,Jeongmin Lee,Min-Jae Lee,Namgil Kang,Jae-Kwan Hwang 대한지역사회영양학회 2014 Nutrition Research and Practice Vol.8 No.4

BACKGROUND/OBJECTIVES: Ultraviolet B (UVB) irradiation on skin can induce production of reactive oxygen species (ROS), which cause expression of matrix metalloproteinases (MMPs) and collagen degradation. Thus, chronic exposure of skin to UVB irradiation leads to histological changes consistent with aging, such as wrinkling, abnormal pigmentation, and loss of elasticity. We investigated the protective effect of the standardized green tea seed extract (GSE) on UVB-induced skin photoaging in hairless mice. MATERIALS/METHODS: Skin photoaging was induced by UVB irradiation on the back of Skh-1 hairless mice three times per week and UVB irradiation was performed for 10 weeks. Mice were divided into six groups; normal control, UVB irradiated control group, positive control (UVB + dietary supplement of vitamin C 100 mg/kg), GSE 10 mg/kg (UVB + dietary supplement of GSE 10 mg/kg), GSE 100 mg/kg (UVB + dietary supplement of GSE 100 mg/kg), and GSE 200 mg/kg (UVB + dietary supplement of GSE 200 mg/kg). RESULTS: The dietary supplement GSE attenuated UVB irradiation-induced wrinkle formation and the decrease in density of dermal collagen fiber. In addition, results of the antioxidant analysis showed that GSE induced a significant increase in antioxidant enzyme activity compared with the UVB irradiation control group. Dietary supplementation with GSE 200 mg/kg resulted in a significant decrease in expression of MMP-1, MMP-3, and MMP-9 and an increase in expression of TIMP and type-1 collagen. CONCLUSIONS: Findings of this study suggest that dietary supplement GSE could be useful in attenuation of UVB irradiation-induced skin photoaging and wrinkle formation due to regulation of antioxidant defense systems and MMPs expression.