Liquiritin Carbomer Gel Cold Paste Promotes Healing of Solar Dermatitis in Mice.

Ultraviolet radiation (UVR) has various effects on human cells and tissues, which can lead to a variety of skin diseases and cause inconvenience to people's lives. Among them, solar dermatitis is one of the important risk factors for malignant melanoma, so prevention and treatment of solar dermatitis is very necessary. Additionally, liquiritin (LQ) has anti-inflammatory effects. In this study, we aimed to evaluate the anti-inflammatory and pro-wound healing effects of liquiritin carbomer gel cold paste (LQ-CG-CP) in vitro and in vivo. The results of MTT experiments showed no cytotoxicity of LQ at concentrations of 40 µg/mL and below and cell damage at UVB irradiation doses above 60 mJ/cm2. Moreover, LQ can promote cell migration. ELISA results also showed that LQ inhibited the elevation of the inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) after UVB irradiation. In the mouse model of solar dermatitis, 2% LQ-CG-CP showed the best therapeutic efficacy for wound healing and relief of itching compared to MEIBAO moist burn moisturizer (MEBO). What is more, the results of skin histopathological examination show that LQ-CG-CP promotes re-epithelialization, shrinks wounds, and promotes collagen production, thus promoting wound healing. Simultaneously, LQ-CG-CP reduced TNF-α, IL-1ß, and IL-6 expression. In addition, LQ-CG-CP was not observed to cause histopathological changes and blood biochemical abnormalities in mice. Overall, LQ-CG-CP has great potential for the treatment of solar dermatitis.

Conjugated Network Supporting Highly Surface-Exposed Ru Site-Based Artificial Antioxidase for Efficiently Modulating Microenvironment and Alleviating Solar Dermatitis.

Solar dermatitis, a form of acute radiation burn that affects the skin, results from overexposure to ultraviolet B (UVB) radiation in strong sunlight. Cell damage caused by the accumulation of reactive oxygen species (ROS) produced by UVB radiation plays an important role in UVB-induced inflammation in the skin. Here, for efficiently scavenging excess ROS, modulating the microenvironment, and alleviating solar dermatitis, a π-conjugated network polyphthalocyanine supporting a highly surface-exposed Ru active site-based artificial antioxidase (HSE-PPcRu) is designed and fabricated with excellent ROS-scavenging, antioxidant, and anti-inflammatory capabilities. In photodamaged human keratinocyte cells, HSE-PPcRu could modulate mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B signaling pathways, prevent DNA damage, suppress apoptosis, inhibit pro-inflammatory cytokine secretion, and alleviate cell damage. In vivo animal experiments reveal the higher antioxidant and anti-inflammatory efficacies of HSE-PPcRu by reversing the activation of p38 and c-Jun N-terminal kinase, inhibiting expression of cyclooxygenase-2, interleukin-6, interleukin-8, and tumor necrosis factor-α. This work not only provides an idea for alleviating solar dermatitis via catalytically scavenging ROS and modulating the microenvironment but also offers a strategy to design an intelligent conjugated network-based artificial antioxidase with a highly surface-exposed active site.

Pyruvate and lactate based hydrogel film inhibits UV radiation-induced skin inflammation and oxidative stress.

Solar skin damage is one of the most common diseases among outdoor workers. An important cause for the damage is the ultraviolet and infrared rays in sunlight, which are absorbed by the skin in large amounts, leading to severe skin inflammation and oxidative stress. Therefore, physical prevention by shielding the light from harmful wavelengths can be an effective method of skin protection from radiation. However, for existing skin lesions, prompt treatment is essential to avoid the aggravation of the injury and promote repair. Therefore, to improve the therapeutic effect on sun-damaged skin, we attempted to design a system with a dual purpose of eliminating toxic free radicals and modulating tissue inflammatory response. Here, we designed and synthesized a poly-acryloyl lysine (P-Ac-Lys) and polyvinyl alcohol-dihydroxyphenylalanine (PVA-DOPA) composite hydrogel (PAL@PVA-DOPA Hydrogel) loaded with lactate and pyruvate, that exhibites a good free radical scavenging activity and an excellent ability to modulate the inflammatory response. Experimental results showe that this hydrogel film could effectively reduce the UV-induced skin inflammation response, alleviate pathological damage and promote the recovery of the damaged skin.

Topical Imiquimod Therapy for Localized Solar Dermatitis in a Dog.

Chronic sun exposure in dogs can result in clinical changes in the skin referred to as solar or actinic dermatitis. A 5-year-old, neutered male, American Bulldog presented with localized unilateral erythematous macules, plaques, alopecia, comedones and hemorrhagic bullae involving the non-pigmented skin on left lateral ventral flank area. The presence of hyperplastic epidermis with keratinocyte dysplasia, superficial dermal elastosis, and multiple follicular cysts with occasional rupture (furunculosis) on histology, together with history and characteristic skin lesions was consistent solar dermatitis/actinic keratosis. Skin scrapings were negative and treatment for secondary pyoderma was initiated with oral clindamycin for 8 weeks. After 2 months of antibiotic therapy, the hemorrhagic bullae resolved; however, erythematous solar/actinic skin lesions with induration and comedones persisted. Topical application of imiquimod 5% cream 3 times weekly for 8 weeks resulted in the resolution of erythema, but some of the non-inflamed comedones remained. Staining for elastin and Ki67 revealed keratinocyte hyperplasia in hair follicle infundibulums and alterations in the elastic fibers around follicles, which may lead to closure and formation of follicular cysts. Imiquimod has been long suggested as a treatment option for solar dermatitis, but this is the first known case report detailing its efficacy in dogs.

The acute effects of ultraviolet radiation exposure on solar dermatitis in Shanghai, China.

Ultraviolet radiation (UVR) has long been considered associated with solar dermatitis, but the associations have not been well quantified. To depict the full-range exposure-response association between daily UVR exposures and daily outpatient visits of solar dermatitis. We collected the daily number of outpatient visits of solar dermatitis and monitored hourly ground data of UVR (the sum of A- and B-band) from 1 January 2013 to 31 December 2017 in Shanghai, China. The data were analyzed using the time-series approach, in which overdispersed generalized additive model was used and time trends and weather conditions were controlled for. During the study period, we recorded a total of 15,051 outpatient visits of solar dermatitis. There was a consistently increasing risk of solar dermatitis associated with stronger UVR without a discernible threshold. The effects occurred on the present day, increased to the largest at lag 1 or 2 days, and attenuated to the null at lag 5 days or more. A unit (w/m2) increase in daily maximum-hour UVR was associated with 1.70% (95%CI: 1.19%, 2.20%) increase of outpatient visits of solar dermatitis. Stronger effects occurred among the young people, females, and in the warm season. The risks of solar dermatitis due to UVR exposure would be overestimated if ambient temperature was not adjusted. This study provides quantitative epidemiological estimates for the positive associations between short-term exposure to UVR and increased risks of solar dermatitis. The associations were more prominent among young people, females, and in warm seasons.

Protective Effect of Yinhuangshen Essential Oil on Skin Damage in Mice with Solar Dermatitis / 中国实验方剂学杂志

Objective: To study the effect of Yinhuangshen essential oil in mice of solar dermatitis model by ultraviolet (UVB). Method: Sixty SPF BALB/c female mice were randomly divided into blank group, model group, Minlixiao group, and large and small-dose Yinhuangshen essential oil groups. Except for blank group, model group was given 0.25 mL·cm-2 normal saline on the back every day. The Minlixiao group was given Min Lixiao every day. Low-dose Yinhuangshen essential oil group was given 0.125 mL·cm-2, and large-dose group was given 0.25 mL·cm-2, once a day, and the corresponding drugs were given continuously for 8 days. Except for blank group, all of the other groups were irradiated for 1.5 hours at 15 cm away from 308 nm UVB lamp on the 6th day. One hour and 24 hours after irradiation, mice were given corresponding drug once, and skin was observed 48 hours later. Contents of nitric oxide (NO), nitric oxide synthase (NOS) and tumor necrosis factor-alpha (TNF-α) in some local skin homogenates were measured. The histopathological changes were observed by htoxylin eosin(HE) staining. Result: Compared with blank group, skin of model group was reddish, swollen and ulcerated, epithelium and adnexal were absent, a large number of inflammatory cells and necrosis were adhered to the surface, the local histopathological changes significantly (Pα were significantly increased (Pα in the skin tissue of Minlixiao group and Yinhuangshen essential oil group were significantly decreased, and it could remarkable reduce the pathological changes in local tissue morphology (PConclusion: Yinhuangshen essential oil has a good effect in preventing and treating solar dermatitis.

Impact of transtheoretical model on sun protection behaviors of soldiers in plateau area / 中华护理杂志

Objective To explore the impact of transtheoretical model on sun protection behaviors of soldiers in plateau area.Methods A total of 208 male soldiers trained in 4 200 meters altitude and medically supported by our hospital were randomly divided into the experimental group(n=104) and the control group(n=104).The experimental group received health education based on the transtheoretical model,and the control group received routine health education.Score of sun protection behaviors questionnaire,sunscreen using behavior and score of the Dermatology Life Quality Index (DLQI) before and after the intervention between two groups were compared.Results Score of sun protection behaviors questionnaire in the experimental group was higher than that in the control group (P＜0.05),sunscreen using behavior in the experimental group was better than the control group(P＜0.05),score of the Dermatology Life Quality Index in the experimental group was lower than the control group(P＜0.05).Conclusion Health education guided by the transtheoretical model can improve the plateau soldiers' sun protection behaviors,and it is an effective method of health education.