Commercial sunscreen lotions prevent ultraviolet radiation-induced depletion of epidermal Langerhans cells in Skh-1 and C3H mice

Characteristics of choice and satisfaction regarding the use of ultraviolet blockers in the golf population in Republic of Korea: A quantitative study

Background and Aims

Korea's golf population surpassed 5 million (5.15 million) as of 2020 according to data analyzed by Shinhan Financial Investment in 2021. Due to the continuous increase in the golf population, it is necessary to study the use of specific sunscreens. Men and women are using sunscreen selective attributes based on the actual use and perception of sunscreens for life. A questionnaire survey was conducted for an analysis of the effect of product satisfaction.

Methods

Statistical processing of materials collected by the data analysis method is analyzed using the Statistical Package for Social Science WIN 25.0 statistical package program through the process of data coding and data cleaning.

Results

This exercise was done under 3-4 h of strong ultraviolet (UV) rays, so products that have ensured the durability of UV protection are needed. Among the demographic characteristics of the golf population, gender, age, academic background, occupation, marriage status, and monthly income were investigated, and it was confirmed that the information path of a particular product was affected by the choice of purchase, increasing satisfaction and repurchase.

Conclusion

An analysis of the paper's survey showed that men's awareness and interest in sunscreens increased. It is expected that differentiated strategies will be needed for products that match the actual conditions and aptitudes of the effective golf population.

Photoprotection

Many agents affect the transmission of ultraviolet light to human skin. These include naturally occurring photoprotective agents (ozone, pollutants, clouds, and fog), naturally occurring biologic agents (epidermal chromophores), physical photoprotective agents (clothing, hats, make-ups, sunglasses, and window glass), and ultraviolet light filters (sunscreen ingredients and sunless tanning agents). In addition, there are agents that can modulate the effects of ultraviolet light on the skin (antioxidants and others). All of the above are reviewed in this article.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be able to provide an overview of all aspects of photoprotection.

Decrease in Langerhans Cells and Increase in Lymph Node Dendritic Cells Following Chronic Exposure of Mice to Suberythemal Doses of Solar Simulated Radiation

Exposure of certain strains of mice to ultraviolet radiation (UVR) causes suppression of some innate and adaptive immune responses. One such consequence of acute UVB exposure is a reduction in the number of Langerhans cells (LC) in the epidermis and an increase in dendritic cells (DC) in lymph nodes draining the irradiated skin sites. Exposure to chronic UVB irradiation also has effects on the immune system, but it is unknown what effects are caused by repeated doses of solar simulated radiation (SSR). Consequently, the main aims of the present study were to determine whether repeated exposure to low doses of SSR would lead to similar changes in these cell populations and whether chronic doses of SSR activate a protective photoadaptation mechanism. Groups of C3H/HeN mice were irradiated daily with 3.7 J/cm(2) SSR from Cleo Natural lamps for 2, 10, 20, 30 or 60 days. Further groups of mice received an additional dose of 7.4 J/cm(2) SSR on days 2, 10, 30 or 60 to test for photoadaptation. The numbers of LC in the epidermis and DC in the lymph nodes draining irradiated skin sites were counted 24 h after the final irradiation. With the exception of mice irradiated for only 2 days, LC were significantly reduced throughout the chronic irradiation protocol, and no recovery occurred. DC numbers were significantly increased in the draining lymph nodes of mice irradiated for 20 days and 60 days.

The role of calcitonin gene-related peptide in cutaneous immunosuppression induced by repeated subinflammatory ultraviolet irradiation exposure

Ultraviolet (UV) light is an effective treatment for skin disorders like psoriasis in which the cutaneous neurosensory system may have a pathogenic role. In this study, we examined the possibility that UV modulation of the cutaneous neurosensory system and calcitonin gene-related peptide (CGRP) may contribute to local immunosuppression mediated by repeated subinflammatory UV irradiation. Our results indicated that exposure of hairless mice to subinflammatory UV three times weekly for 4 weeks significantly increased the number of epidermal nerve fibers (ENFs) immunoreactive for CGRP without altering the total number of ENFs. The skin content of CGRP as measured by enzyme-linked immunosorbent assay was also significantly increased after exposure to this dose of UV. These effects were most apparent 1 day after the last UV exposure and declined 1 week after UV. The role of CGRP in UV-induced immunosuppression of contact hypersensitivity was then examined. Our results indicated that UV suppression of epicutaneous 2,4-dinitro-1-fluorobenzene (DNFB) sensitization could be significantly inhibited by a systemically administered CGRP receptor antagonist. A broad-spectrum sunscreen applied before UV exposure inhibited increased cutaneous CGRP and blocked immunosuppression. These findings support a role for CGRP in the local immunosuppression caused by chronic, repeated subinflammatory UV exposure.

Protection against pyrimidine dimers, p53, and 8-hydroxy-2'-deoxyguanosine expression in ultraviolet-irradiated human skin by sunscreens: difference between UVB + UVA and UVB alone sunscreens

As DNA damage induced by ultraviolet radiation plays an essential role in skin cancer induction, we pursued the measure of several DNA lesions induced by ultraviolet radiation in human skin for determining the efficacy of different topical photoprotectors. Non-exposed skin (buttocks from 20 individuals) was exposed to 10 doses of ultraviolet, which corresponded to three to four minimal erythema doses of solar-simulating radiation, and biopsies were taken at 24 h within the half and one minimal erythema dose sites and a nonirradiated, adjacent control area. We report that even suberythemal doses of ultraviolet radiation are capable of inducing substantial DNA damage, namely pyrimidine dimers, p53 induction, and the DNA base-modified product generated by oxidative stress, 8-hydroxy-2'-deoxyguanosine. All three lesions are induced in a dose-dependent manner. An additional eight individuals were treated with either ultraviolet B or ultraviolet B + ultraviolet A sunblock (sun protection factor 15) and exposed to 71/2 and 15 times the minimal erythema dose on each individual, with biopsies taken at 24 h post-ultraviolet. Pyrimidine dimer and p53 expression were rarely seen in nonirradiated skin but occasional staining was seen in all normal skin for 8-hydroxy-2'-deoxyguanosine. Applications of sunscreens to human skin before irradiation were shown to attenuate erythema but did not completely eliminate all three types of cellular damage when tested up to their sun protection factor 15. Furthermore, ultraviolet B + ultraviolet A sunscreens were less efficient than the ultraviolet B alone formulation for protection against all three lesions. These results suggest that DNA damage assessed in vivo by immunohistochemistry provides a very sensitive endpoint for determining the efficacy or photosensitivity of possible different protective measures in human skin.

Effects of low-dose ultraviolet radiation on in vivo human cutaneous recall responses

Relatively few studies have examined the effects of low-dose ultraviolet (UV) radiation on in vivo human cutaneous immunity, or the ability of sunscreens to prevent UV-induced immunosuppression. We have studied the effects of solar-simulated UV radiation on nickel contact hypersensitivity (CHS) in nickel-allergic volunteers, and on delayed type hypersensitivity responses in Mantoux-positive volunteers. Nickel CHS and Mantoux responses were significantly suppressed by acute, suberythemal UV exposures equivalent to less than 8 min summer sunlight. Both UVA and UVB wavebands were immunosuppressive, but UVA-induced immunosuppression was transient, whereas UVB had a more sustained effect. Dose-responses for UV immunosuppression were determined using the nickel method, enabling calculation of in vivo sunscreen immune protection factors in a manner analogous with sun protection factor measurement. Sunscreens were found to confer significantly less protection against UV-induced immunosuppression than against UV-induced erythema.