PM 10 Exposure Induced IL-1β and IL-6 Expression in Hairless Mouse Skin

More recently, air pollution is acknowledged as an immense risk factor for developing serious health issues, and particulate matter (PM10) are a common air pollutant. To evaluate the biological mechanisms of PM10 on skin damage. PM10 was applied to mouse skin at 10 µg/mL for 7 days. In this study, we analyzed that PM10-induced inflammation on hairless mouse skin by immunohistochemistry and western blot. As a result, immunohistochemical staining demonstrated that the IL-1β and IL-6 expression levels were increased after PM10 treatment. Moreover, the analysis of western blot suggested that PM10 treatment increased the expression levels of proinflammatory cytokines IL-1β (**<i>P</i><0.01) and IL-6 (**<i>P</i><0.05). In conclusion, our findings contribute to the understanding of the pathophysiological mechanisms of PM10 to the skin and can be used as a therapeutic strategy to control inflammatory skin diseases caused by PM10.

Anti-Melanogenic Effects of Korean Red Ginseng Oil in an Ultraviolet B-Induced Hairless Mouse Model

A ‘remedy for all’ natural product widely known in the Korean Peninsula is called Panax Ginseng Meyer. Globalization represents a persistent risk to the ozone layer, leading to bountiful amounts of Ultra-Violet B beams (UVB). The variety in human skin hues is ascribed to the characteristic color called Melanin. However, Melanin overproduction due to UVB beams promotes skin staining and tumorigenesis, a process called photo aging, which damages skin quality. To assess the effects of Korean Red Ginseng Oil (KGO) on photo aging, the murine melanoma cell lines B16/F10 were used in vitro and HRM-2 hairless mice exposed to UVB were studied in vivo. Our results revealed that KGO reduced tyrosinase activity and melanin production in B16/F10 cells along with the suppression of upstream factors involved in the melanin production pathway, both transcriptionally and transitionally. In the in vivo studies, KGO suppressed the expression of Matrix Metalloproteinase (MMP) and Interleukins along with a reduction of depth in wrinkle formation and reduced collagen degradation. Moreover, the feed intake and feed efficiency ratio that decreased as a result of UVB exposure was also improved by KGO treatment. In light of our results, we conclude that KGO can have considerable benefits due to its various properties of natural skin enhancement.

Are FDA-Approved Sunscreen Components Effective in Preventing Solar UV-Induced Skin Cancer?

Solar ultraviolet (SUV) exposure is a major risk factor in the etiology of cutaneous squamous cell carcinoma (cSCC). People commonly use sunscreens to prevent SUV-induced skin damage and cancer. Nonetheless, the prevalence of cSCC continues to increase every year, suggesting that commercially available sunscreens might not be used appropriately or are not completely effective. In the current study, a solar simulated light (SSL)-induced cSCC mouse model was used to investigate the efficacy of eight commonly used FDA-approved sunscreen components against skin carcinogenesis. First, we tested FDA-approved sunscreen components for their ability to block UVA or UVB irradiation by using VITRO-SKIN (a model that mimics human skin properties), and then the efficacy of FDA-approved sunscreen components was investigated in an SSL-induced cSCC mouse model. Our results identified which FDA-approved sunscreen components or combinations are effective in preventing cSCC development. Not surprisingly, the results indicated that sunscreen combinations that block both UVA and UVB significantly suppressed the formation of cutaneous papillomas and cSCC development and decreased the activation of oncoproteins and the expression of COX-2, keratin 17, and EGFR in SSL-exposed SKH-1 (Crl:SKH1-Hrhr) hairless mouse skin. Notably, several sunscreen components that were individually purported to block both UVA and UVB were ineffective alone. At least one component had toxic effects that led to a high mortality rate in mice exposed to SSL. Our findings provide new insights into the development of the best sunscreen to prevent chronic SUV-induced cSCC development.

Topical Pioglitazone Nanoformulation for the Treatment of Atopic Dermatitis: Design, Characterization and Efficacy in Hairless Mouse Model

Pioglitazone (PGZ) is a drug used to treat type 2 diabetes mellitus that has been reported to show additional therapeutic activities on diverse inflammatory parameters. The aim of this study was to optimize a topical PGZ-loaded nanoemulsion (PGZ-NE) in order to evaluate its effectiveness for treating atopic dermatitis (AD). The composition of the nanoformulation was established by pseudo-ternary diagram. Parameters such as physical properties, stability, in vitro release profile, and ex vivo permeation were determined. The efficacy study was carried out using oxazolone-induced AD model in hairless mice. PGZ-NE released the drug following a hyperbolic kinetic. Additionally, its properties provided high retention potential of drug inside the skin. Therapeutic benefits of PGZ-NE were confirmed on diverse events of the inflammatory process, such as reduction of lesions, enhancement of skin barrier function, diminished infiltration of inflammatory cells, and expression of pro-inflammatory cytokines. These results were reinforced by atomic force microscope (AFM), which demonstrated the ability of the formulation to revert the rigidification caused by oxazolone and consequently improve the elasticity of the skin. These results suggest that PGZ-NE may be a promising treatment for inflammatory dermatological conditions such as AD.

Optimization of psoriasis – like mouse models: A comparative study

Psoriasis, a common chronic, autoimmune, inflammatory, relapsing disease should benefit from reliable and human relevant animal models in order to pre-clinically test drugs and approach their mechanism of action. Due to ease of use, convenience and low cost, imiquimod (IMQ) induced psoriasis-like model is widely utilized; however, are all mouse strains equivalent, is the hairless mouse utilizable and can the imiquimod model be further optimized? Under similar experimental conditions, common mouse strains (BALB/c, C57BL/6J, ApoE) and a new hairless strain (ApoE/SKH-hr2) as well as several inducers (IMQ, IMQ + Acetic Acid (AcOH) topical and IMQ +AcOH systemic) were compared by clinical, histopathological, biophysical and locomotor activity assessment. Results showed that BALB/c mice yielded optimal psoriasis-like phenotype with IMQ+AcOH topical treatment, C57BL/6J moderate, ApoE mild, while the ApoE/SKH-hr2 mice due to Munro abscess absence in histopathology analysis left doubts about the psoriasis-like acquisition. The locomotor activity of BALB/c mice treated with IMQ, IMQ+AcOH topically and IMQ+AcOH systemically, showed with all treatments, a decreased covered distance and rearing and an increased immobility. In conclusion, BALB/c appears an optimal psoriasis-like model when utilizing IMQ+AcOH topical application.