Beneficial Effects of Two Hydrogen Sulfide (HS)-Releasing Derivatives of Dexamethasone with Antioxidant Activity on Atopic Dermatitis in Mice.

Hydrogen sulfide (HS) is particularly produced in the skin, where it participates in the regulation of inflammation, pruritus, cytoprotection, scarring, and angiogenesis. In this study, we compared the effects of dexamethasone (Dex) with two HS-releasing Dex derivatives in a murine model of atopic dermatitis (AD) induced by topical application of 2,4-dinitrochlorobenzene (DNCB). After sensitization with DNCB, the animals were topically treated for five consecutive days with either the HS-releasing compounds 4-hydroxy-thiobenzamide (TBZ) and 5-(p-hydroxyphenyl)-1,2-dithione-3-thione (ADT-OH), Dex, or the derivatives Dex-TBZ or Dex-ADT.

salivary gland extract alleviates acute itching by blocking TRPA1 channels.

() saliva induces a variety of anti-inflammatory and immunomodulatory activities. Interestingly, although it is known that mosquito bites cause allergic reactions in sensitised hosts, the primary exposure of humans to does not evoke significant itching. Whether active components in the saliva of can counteract the normal itch reaction to injury produced by a histaminergic or non-histaminergic pathway in vertebrate hosts is unknown.

Role of Gasotransmitters in Inflammatory Edema.

Nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (HS) are, to date, the identified members of the gasotransmitter family, which consists of gaseous signaling molecules that play central roles in the regulation of a wide variety of physiological and pathophysiological processes, including inflammatory edema. Recent studies show the potential anti-inflammatory and antiedematogenic effects of NO-, CO-, and HS-donors . In general, it has been observed that the therapeutical effects of NO-donors are more relevant when administered at low doses at the onset of the inflammatory process.

Hydrogen sulfide and dermatological diseases.

Skin diseases constitute a major health problem affecting a high proportion of the population every day and have different aetiologies that include inflammation, infections, and tumours. Hydrogen sulfide (H S) is a gaseous signalling molecule recognized as a gasotransmitter together with NO and carbon monoxide. Under physiological conditions, H S is produced in the skin by enzymic pathways and plays a physiological role in a variety of functions, such as vasodilatation, cell proliferation, apoptosis, and inflammation.