Pharmacological evaluation of a nanodispersion system containing an slow release donor of H2S (GYY4137) in an experimental model of psoriasis.

Psoriasis is a chronic inflammatory disease, with high incidence worldwide and, characterized by skin lesions and intense itching. Previous findings of this group showed that systemic administration of the slow donor release of hydrogen sulfide (H2S), GYY4137, significantly inhibited skin inflammation and itching in mice with psoriasis. Thus, this study evaluated the therapeutic effect of a topical nanodispersion containing GYY4137 on the Imiquimod-induced psoriasis mice model and compared pharmacologically the effect of GYY4137 versus dexamethasone. Control or psoriasis animals were treated (1 and 2x/day) with nanodispersion (65 mg) containing GYY4137, dexamethasone, or just vehicle. Topical application of the nanodispersion with GYY4137 (4%) 2x/day was more effective and significantly reduced redness, thickness, total blood cells, MPO, and IL-6 and IL-1β levels. The pharmacological effects caused by H2S were similar to those of dexamethasone, however, the nanodispersion containing GYY4137 demonstrated less systemic effects when compared to glucocorticoid. (AU)