oxazolone and Erythema

Atopic dermatitis (AD) is a chronic inflammatory disease of the skin, characterized by dryness and more or less severe itching. The etiology of AD is complex and has not been fully clarified, involving genetic susceptibility, immunological abnormalities, epidermal barrier dysfunction, and environmental factors. Xyloglucan (XG) and pea protein (PP) are two compounds of natural origin characterized by the ability to create a physical barrier that protects mucosae membranes, reducing inflammation. The aim of the present study was to evaluate the potential beneficial effects of XG + PP in both a mouse model of AD and

Topics: Animals; Cell Degranulation; Cytokines; Dermatitis, Atopic; Disease Models, Animal; Erythema; Female; Filaggrin Proteins; Glucans; Inflammation; Intermediate Filament Proteins; Mast Cells; Mice; Nitric Oxide Synthase Type II; Occludin; Oxazolone; Pea Proteins; Skin; Staphylococcal Infections; Staphylococcus aureus; Tight Junctions; Xylans

Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disease characterized by hyperproliferation and abnormal differentiation of the epidermis, and dermal infiltration of inflammatory cells. Appropriate animal models that recapitulate human AD and allow the analysis of disease processes in a reliable manner are essential to the study of AD. In this study, we established two AD models in rabbits by applying an allergen, Dermatophagoides farinae (Der f), or a hapten, oxazolone (OXZ). Application of the allergen or hapten induced a rapid onset and a chronically sustained AD-like skin lesion. The clinical symptoms, which include skin erythema, scaling, papula and edema, of AD-like rabbit skin were similar to those in human AD. Histological analysis showed that allergen- or hapten-treated rabbit skin showed increased epidermal thickening and inflammatory cell infiltration. Furthermore, PCNA and keratin 10 (K10) staining revealed excessive proliferation and insufficient differentiation of the epidermis in the rabbit AD-like skin. Western blot analysis showed decreased expression of thymic stromal lymphopoietin (TSLP), an AD cytokine, in the rabbit AD-like skin. Our results suggest that the allergen- or hapten-induced rabbit AD models have pathological features of human AD-like symptoms and will be useful for evaluating both pathogenic mechanisms and potential therapeutic agents for human AD.

Topics: Allergens; Animals; Cell Proliferation; Cytokines; Dermatitis, Atopic; Dermatophagoides farinae; Disease Models, Animal; Edema; Epidermis; Erythema; Female; Oxazolone; Rabbits; Thymic Stromal Lymphopoietin

Solar radiation contains ultraviolet B (280-315 nm) and ultraviolet A (ultraviolet AII, 315-340 nm; ultraviolet AI, 340-400 nm) wavebands. Ultraviolet B is known to suppress certain aspects of cell mediated immunity. Using three ultraviolet lamps (the broad-band ultraviolet B TL-12, the narrow-band ultraviolet B TL-01 and an ultraviolet AI source), we investigated the dose and waveband dependencies for the suppression of contact hypersensitivity to oxazolone and delayed-type hypersensitivity to herpes simplex virus, plus the formation of cis-urocanic acid in C3H/HeN mice. A single exposure of 1500 J/m2 TL-12 or 10,000 J/m2 TL-01 or 500,000 J/m2 ultraviolet AI corresponded to 1 minimum erythema dose in this mouse strain. The percentage of cis-urocanic acid of the total urocanic acid rose from a background level of 1.7% to 40% with 1000 J/m2 TL-12 or 10,000 J/m2 TL-01, but only 17% cis-urocanic acid was obtained with 500,000 J/m2 ultraviolet AI. The contact hypersensitivity response was significantly suppressed after a minimum dose of 5000 J/m2 TL-12 or 50,000 J/m2 TL-01 or 500,000 J/m2 ultraviolet AI. The delayed-type hypersensitivity response was suppressed by a minimum dose of 100 J/m2 TL-12 or 10,000 J/m2 TL-01 or 1000 J/m2 ultraviolet AI. So, whereas a low dose of ultraviolet AI reduced the delayed-type hypersensitivity response, a 500-fold higher dose was required to suppress contact hypersensitivity. There was no correlation between the suppression of these responses and the concentration of cis-urocanic acid in the skin. Thus different mediators may modulate the various immune responses affected by ultraviolet exposure, depending on the wavelength of the radiation.

Topics: Animals; Dermatitis, Contact; Dose-Response Relationship, Radiation; Erythema; Female; Hypersensitivity, Delayed; Mice; Mice, Inbred C3H; Oxazolone; Simplexvirus; Skin; Ultraviolet Rays; Urocanic Acid

11 beta-Hydroxy-16 alpha, 17 alpha, 21-trimethyl-pregna-1,4-diene-3,20-dione(ORG 6216) is a novel type of anti-inflammatory steroid which displays a dissociation of local from systemic effects in a range of animal models. Moreover, ORG 6216 is exceptional in that it has not shown any significant atrophogenic activity in the skin when administered either topically or intracutaneously in animal models.

Topics: Administration, Topical; Animals; Anti-Inflammatory Agents; Collagen; Edema; Erythema; Glucocorticoids; Injections, Subcutaneous; Liver Glycogen; Male; Mice; Oxazolone; Pregnadienes

The topical effects of N0164 (a phenyl phosphonate derivative which is a partially selective antagonist of prostagladin E2), indomethacin and triamcinolone acetonide have been shown to reduce the erythema and ear weight gain from inflammation induced by experimental contact allergic eczema. Oxazolone sensitized Swiss Webster mice were used, ear erythema and ear weights being used as a measure of the anti-inflammatory response to the drugs. N0164 was also shown to have systemic anti-inflammatory activity after intraperitoneal injection.

Topics: Administration, Topical; Animals; Anti-Inflammatory Agents; Dermatitis, Contact; Erythema; Indomethacin; Inflammation; Injections, Intraperitoneal; Mice; Organophosphonates; Oxazolone; Prostaglandin Antagonists; Triamcinolone Acetonide