Retinoids (vitamin A derivatives) have dual functions in physiology. 11-cisRetinal serves as the universal chromophore of the visual pigments in the eye, and the hormonal retinoids, mainly all-transand 9-cis-retinoic acid (RA),2 regulate the expression of target genes via activation of two classes of nuclear retinoid receptors, the retinoic acid receptors (RARs), and the retinoid X receptors (R...

The lining of the trachea consists of a pseudostratified, mucociliary epithelium that under a variety of conditions, such as vitamin A deficiency, toxic and mechanical injury, becomes a stratified squamous epithelium. Several in vitro cell culture models have been established to study the regulation of the mucosecretory phenotype. Such studies have indicated that the mucosecretory phenotype in ...

Retinoids and their naturally metabolized and synthetic products (e.g. all-trans retinoic acid, 13cis retinoic acid, bexarotene) induce differentiation in various cell types. Retinoids exert their actions mainly through binding to the nuclear retinoic acid receptors (α, β, γ), which are transcriptional and homeostatic regulators whose functions are often compromised early in neoplastic transfor...

BACKGROUND Retinoids, rexinoids and their biologically active derivatives are involved in a complex arrangement of physiological and developmental responses in many tissues of higher vertebrates. Both retinoids and rexinoids are either natural or synthetic compounds related to retinoic acids that act through interaction with two basic types of nuclear receptors belonging to the nuclear receptor...

Topical retinoids inhibit matrix metalloproteinases and accelerate collagen synthesis, thereby triggering antiaging effects in the skin. However, topical retinoids can cause severe skin reactions, including scaling, erythema, papules, and inflammation. The present study demonstrates that the ethanolic bark extract of Alstonia scholaris R. Br. can significantly inhibit all-trans retinoic acid-in...

BACKGROUND Nonmelanoma skin cancers are the most frequent malignancies in organ transplant patients. Patients who develop multiple new skin cancers may benefit from retinoid chemoprevention. OBJECTIVE The objective of this study was to advise on the use of retinoids in organ transplant recipients. METHODS A summary was performed of the existing literature regarding experience with retinoid ...

Retinoids are compounds with pleiotropic functions and a relatively selective targeting of certain skin structures. They are vitamins, because retinol (vitamin A) is not synthesized in the body and must be derived from diet, but also hormones with intracrine activity, because retinol is transformed into molecules that bind to nuclear receptors, exhibit their activity, and are subsequently inact...