• Journal of Applied Biological Chemistry
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• v.66
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• pp.106-113
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• 2023

Plant extracts have been studied due to their potential as photoprotective agents against UV and blue light exposure. Previous studies have revealed that several plant extracts have photoprotection capacities and synergistic effects with synthetic products. However, such results for pu'er tea and Curcuma longa L. have not been reported yet for a cosmetic formulation. Thus, the objective of this study was to evaluate photoprotection capacities of pu'er tea and C. longa L. extracts for a sunscreen compound. The pu'er tea extract improved sun protection factor value of 2-ethyl-hexyl methoxycinnamate (a synthetic sunscreen compound) by 46% and showed a high antioxidant capability that could help skin recover from photo-induced damage. C. longa L. extract also showed a potential to protect skin from blue light-induced damage because it not only had a maximum absorption peak at the blue light range, but also protected human fibroblasts from blue light-induced damage. The addition of both extracts shifted the critical wavelength of 2-ethyl-hexyl methoxycinnamate from 350 nm to 386 nm, giving it a broad-spectrum feature. Thus, pu'er tea and C. longa L. extracts may enhance the photoprotection ability of synthetic sunscreen products.

• Journal of Pharmaceutical Investigation
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• v.38 no.5
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• pp.325-329
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• 2008

To enhance the skin delivery of genistein (GT), a soybean isoflavone having anti oxidative activity, comparative formulation studies including liposomes were carried out. GT-loaded conventional and elastic liposomal gel showed the enhanced skin deposition and photoprotection effect as well, in comparison to GT suspension. Elastic liposomes composed of soybean phosphatidylcholine and sodium deoxycholate (85:15, w/w%) were superior to conventional liposomes and were of characteristics as follows: about 130 nm in size; 85% encapsulation efficiency of GT; 5.8% skin deposition of applied dose; 40% inhibition effect on UVB-induced $H_2O_2$ production. Photoprotection effect was closely related to skin deposition of GT. In conclusion, it is possible to suggest that elastic liposomes could be a promising nanocarrier system for efficient skin delivery.

• Proceedings of the Korean Society of Potoscience Conference
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• spring
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• pp.36-36
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• 2000

• Journal of Photoscience
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• v.9 no.2
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• pp.63-65
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• 2002

This report concerns a putative role of mycosporine-like amino acids (MAA) as natural scavengers of singlet oxygen ($^1$O$_2$) in marine organisms. MAA prepared from the ascidian Lissoclinum patella were found to protect biological systems against detrimental effects of the type II photosensitization in vitro. L. patella MAA were resolved into five components, and the relative $^1$0$_2$ quenching efficiencies were measured for three major components in aqueous media. It turned out that they were all effective in scavenging $^1$0$_2$, to different degrees albeit. The results suggest that physiological relevance of MAA in marine organisms may be found in a 'built-in' defense against photooxidative effects of sunlight.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.6
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• pp.1014-1019
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• 2011

Curcumin is a natural phytochemical present in turmeric, the ground powder of the rhizomes of Curcuma longa. Curcumin has been described as having antioxidant, anti-inflammatory, and anti-carcinogenic properties. However, it is still largely unknown whether curcumin inhibits the UVB-induced inflammatory reaction in HaCaT keratinocyte cell lines. In this study, to confirm the photoprotection properties of curcumin, HaCaT keratinocyte cells were irradiated by UVB, and then treated with curcumin. UVB irradiation induced the increased expressions of IL-$1{\beta}$, TNF-${\alpha}$, IL-6, IL-8, and COX-2 in HaCaT cells. These increased expressions of cytokines (IL-$1{\beta}$, TNF-${\alpha}$, IL-6, IL-8, and COX-2) were down-regulated by curcumin treatment in UVB-irradiated HaCaT cells. In addition skin of hairless mice were damaged by UVB irradiation, which were evidenced by atrophy of epidermis and decrease of collagen in dermis. However, these damages were protected partially by co-treatment of curcumin. Taken together, this data indicate that curcumin may be a promising photoprotection agent, when used in massage pack or sunscreen product, to reduce cell death in UV-damaged skin.

• Korean Journal of Environmental Agriculture
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• v.25 no.2
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• pp.109-117
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• 2006

Photoinhibition and photoprotection of PSII in the leaves of hot pepper (Capsicum annuum L.) grown in Hoagland solution and Tap water were compared. Though changes in the rates of $O_2$ evolution as a function of photon fluence rate (PFR) were comparable, the rates of respiration in the dark was 3 times higher in the Hoagland solution grown leaves than in the Tap-water grown ones. Compared to Hoagland solution grown plane, PSIIs of Tap water grown pepper leaves were more susceptible to photoinhibitory light treatment. In order to inactivate functional PSII to the same extents, Hoagland solution grown plants required almost 2-fold high light $(1600{\mu}molm^{-2}s^-)$ treatment than those of Tap water $(900{\mu}molm^{-2}s^-)$. Interestingly, the remaining fraction of PSII in Hoagland grown pepper was able to survive under prolonged illumination in the presence of lincomycin, which probably means that the growth condition of plant seemed to have an effect on the recovery of PSII from light stress. When PSII was severly photoinactivated at a chilling temperature, recovery was observed only if the residual functional PSII were not inhibited with DCMU, Nigericin and MV during recovery. In conclusion, PSIIs grown in the Hoagland solution was more resistant to excess light than in the Tap water grown one and the recovery of PSII from photodamage was more efficient in Hoagland grown pepper leaves than Tap water grown one, which means that the increased dark respiration may play a important role in the protection of PSII from photoinhibition by helping repair photosynthetic proteins (in particular, the D1 protein of PSII) degraded by photoinhibition.

• Journal of Ocean Engineering and Technology
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• v.17 no.3 s.52
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• pp.52-56
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• 2003

This study investigates the photoelectrochemical behavior of STS304 steel with TiO2 thin films coating, applied by sol-gel mehod, for the purpose of cathodic photoprotection of the steel corrosion. One time TiO2-coated STS304 steel, adapted with two kinds of TiO2 sol solution, has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40 W fluorescent lamp, respectively. That had yielded more negative values than the corrosion potential of the bare metal(-130mv vs.SCE). The bleaching of TCE was confirmed on TiO2-coated STS304 steel under UV-illumination with 20W Black-light. This Study concluded that Ti02-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and a photocatalytic self-cleaning effect.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.307-311
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• 2002

This study was investigated the photoelectrochemical behavior of STS304 steel with $TiO_2$ thin films coating, applied by sol-gel method, for the purpose of cathodic photoprotection of the steel corrosion. One time $TiO_2$-coated STS304 steel adopted two kinds of $TiO_2$ sol solution has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40W fluorescent lamp, respectively. That was more negative than the corrosion potential of the bare metal(-150 mV). The bleaching of TCE was confirmed on $TiO_2$-coated STS304 under UV-illumination with 20 W Black-light. This Study was concluded that $TiO_2$-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and photocatalytic self-cleaning effect.

• Journal of Photoscience
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• v.12 no.1
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• pp.33-39
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• 2005

Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.

• Safety and Health at Work
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• v.12 no.2
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• pp.244-248
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• 2021

Background: Sunburn is the main avoidable cause of skin cancer. Beach lifeguards spend many hours exposed to the effects of solar radiation during their work day, precisely at times of the year when levels of solar irradiation are highest. The aim of this study is to quantify the risk to beach lifeguards of sun exposure. Methods: A descriptive cross-sectional study was carried out in the Western Costa del Sol, southern Spain, during the summer of 2018. The research subjects were recruited during a skin cancer prevention course for beach lifeguards. All participants were invited to complete a questionnaire on their habits, attitudes, and knowledge related to sun exposure. In addition, ten were specially monitored using personal dosimeters for three consecutive days, and the results were recorded in a photoprotection diary. A descriptive analysis (mean and standard deviation for the quantitative variables) was performed, and inter-group differences were evaluated using the Mann-Whitney U test. Results: Two hundred fifteen lifeguards completed the questionnaire, and 109 met the criteria for inclusion in this analysis. The mean age was 23.8 years (SD: 5.1), 78.0% were male, 71.5% were phototype III or IV (Fitzpatrick's phototype), and 77.1% had experienced at least one painful sunburn during the previous summer. The mean daily personal ultraviolet exposure per day, the minimal erythema dose, and the standard erythema dose, in J/m², were 634.7 [standard deviation (SD): 356.2], 2.5 (SD: 1.4) and 6.35 (SD: 3.6), respectively. Conclusion: Beach lifeguards receive very high doses of solar radiation during the work day and experience correspondingly high rates of sunburn. Intervention strategies to modify their sun exposure behavior and working environment are necessary to reduce the risk of skin cancer for these workers and to promote early diagnosis of the disease.