Vitamin A5/X, a New Food to Lipid Hormone Concept for a Nutritional Ligand to Control RXR-Mediated Signaling

Vitamin A is a family of derivatives synthesized from carotenoids acquired the diet and can be converted in animals to bioactive forms essential for life. A1 (all-trans-retinol/ATROL) provitamin (all-trans-?,?-carotene/ATBC) are precursors all-trans-retinoic acid acting as ligand retinoic receptors. The contribution ATROL ATBC formation 9-cis-13,14-dihydroretinoic (9CDHRA), only endogenous retinoid X receptor (RXR) ligand, remains unknown. To address this point novel already known retinoids were stereoselectively administered vitro oligodendrocyte cell culture supplemented vivo (orally) mice with following high-performance liquid chromatography-mass spectrometry (HPLC-MS)/UV-Vis based metabolic profiling. In study, we show that at best weak non-selective 9CDHRA. Instead, identify 9-cis-13,14-dihydroretinol (9CDHROL) 9-cis-13,14-dihydro-?,?-carotene (9CDHBC) direct nutritional 9CDHRA, which present endogenously humans human food chain matrix. Furthermore, 9CDHROL displayed RXR-dependent promnemonic activity working memory test similar reported We also propose carotenoid 9-cis-?,?-carotene (9CBC) act weak, indirect precursor 9CDHRA via hydrogenation 9CDHBC further metabolism and/or summary, since classical vitamin not an efficient precursor, conclude group molecules constitutes new class or independent member family, named “Vitamin A5/X”.