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Nutrients Jul 2022Vitamin A is a fat-soluble micronutrient necessary for the growth of healthy skin and hair. However, both too little and too much vitamin A has deleterious effects.... (Review)
Review
Vitamin A is a fat-soluble micronutrient necessary for the growth of healthy skin and hair. However, both too little and too much vitamin A has deleterious effects. Retinoic acid and retinal are the main active metabolites of vitamin A. Retinoic acid dose-dependently regulates hair follicle stem cells, influencing the functioning of the hair cycle, wound healing, and melanocyte stem cells. Retinoic acid also influences melanocyte differentiation and proliferation in a dose-dependent and temporal manner. Levels of retinoids decline when exposed to ultraviolet irradiation in the skin. Retinal is necessary for the phototransduction cascade that initiates melanogenesis but the source of that retinal is currently unknown. This review discusses new research on retinoids and their effects on the skin and hair.
Topics: Hair; Retinoids; Skin; Tretinoin; Vitamin A
PubMed: 35889909
DOI: 10.3390/nu14142952 -
Biomolecules Nov 2023The skin is the most-extensive and -abundant tissue in the human body. Like many organs, as we age, human skin experiences gradual atrophy in both the epidermis and... (Review)
Review
The skin is the most-extensive and -abundant tissue in the human body. Like many organs, as we age, human skin experiences gradual atrophy in both the epidermis and dermis. This can be primarily attributed to the diminishing population of epidermal stem cells and the reduction in collagen, which is the primary structural protein in the human body. The alterations occurring in the epidermis and dermis due to the aging process result in disruptions to the structure and functionality of the skin. This creates a microenvironment conducive to age-related skin conditions such as a compromised skin barrier, slowed wound healing, and the onset of skin cancer. This review emphasizes the recent molecular discoveries related to skin aging and evaluates preventive approaches, such as the use of topical retinoids. Topical retinoids have demonstrated promise in enhancing skin texture, diminishing fine lines, and augmenting the thickness of both the epidermal and dermal layers.
Topics: Humans; Vitamin A; Skin Aging; Skin; Retinoids; Aging
PubMed: 38002296
DOI: 10.3390/biom13111614 -
International Journal of Molecular... Jan 2022Vitamin A is an essential fat-soluble vitamin that occurs in various chemical forms. It is essential for several physiological processes. Either hyper- or... (Review)
Review
Vitamin A is an essential fat-soluble vitamin that occurs in various chemical forms. It is essential for several physiological processes. Either hyper- or hypovitaminosis can be harmful. One of the most important vitamin A functions is its involvement in visual phototransduction, where it serves as the crucial part of photopigment, the first molecule in the process of transforming photons of light into electrical signals. In this process, large quantities of vitamin A in the form of 11--retinal are being isomerized to all--retinal and then quickly recycled back to 11--retinal. Complex machinery of transporters and enzymes is involved in this process (i.e., the visual cycle). Any fault in the machinery may not only reduce the efficiency of visual detection but also cause the accumulation of toxic chemicals in the retina. This review provides a comprehensive overview of diseases that are directly or indirectly connected with vitamin A pathways in the retina. It includes the pathophysiological background and clinical presentation of each disease and summarizes the already existing therapeutic and prospective interventions.
Topics: Gene Expression Regulation; Humans; Light Signal Transduction; Retinal Diseases; Signal Transduction; Vitamin A
PubMed: 35162940
DOI: 10.3390/ijms23031014 -
Nature Communications Mar 2023Diabetic cardiomyopathy is a primary myocardial injury induced by diabetes with complex pathogenesis. In this study, we identify disordered cardiac retinol metabolism in...
Diabetic cardiomyopathy is a primary myocardial injury induced by diabetes with complex pathogenesis. In this study, we identify disordered cardiac retinol metabolism in type 2 diabetic male mice and patients characterized by retinol overload, all-trans retinoic acid deficiency. By supplementing type 2 diabetic male mice with retinol or all-trans retinoic acid, we demonstrate that both cardiac retinol overload and all-trans retinoic acid deficiency promote diabetic cardiomyopathy. Mechanistically, by constructing cardiomyocyte-specific conditional retinol dehydrogenase 10-knockout male mice and overexpressing retinol dehydrogenase 10 in male type 2 diabetic mice via adeno-associated virus, we verify that the reduction in cardiac retinol dehydrogenase 10 is the initiating factor for cardiac retinol metabolism disorder and results in diabetic cardiomyopathy through lipotoxicity and ferroptosis. Therefore, we suggest that the reduction of cardiac retinol dehydrogenase 10 and its mediated disorder of cardiac retinol metabolism is a new mechanism underlying diabetic cardiomyopathy.
Topics: Male; Animals; Mice; Diabetic Cardiomyopathies; Vitamin A; Diabetes Mellitus, Experimental; Metabolic Diseases; Tretinoin; Heart Diseases; Mice, Knockout; Myocytes, Cardiac; Diabetes Mellitus, Type 2
PubMed: 36864033
DOI: 10.1038/s41467-023-36837-x -
Nutrition in Clinical Practice :... Dec 2019Vitamin A is a general term for retinoids. Vitamin A deficiency leads to a variety of cutaneous manifestations. It also functions as a hormone through retinoic acid... (Review)
Review
Vitamin A is a general term for retinoids. Vitamin A deficiency leads to a variety of cutaneous manifestations. It also functions as a hormone through retinoic acid receptors altering the activity of multiple cell lines. Pancreatic vitamin A levels are critical for retinoid signaling and normal pancreatic control of glucose. Vitamin A deficiency is more common during infection, and supplementation reduces severe morbidity and mortality from infectious diseases. Vitamin A modulates activities at the cellular level and, via its interrelationship with hormones such as thyroid, insulin, and corticosteroids, has diffuse metabolic effects on the body. It plays an important role in all stages of wound healing. Vitamin A is known for its ability to stimulate epithelial growth, fibroblasts, granulation tissue, angiogenesis, collagen synthesis, epithelialization, and fibroplasia. Local (topical) and systemic supplementation with vitamin A has been proven to increase dermal collagen deposition. There are numerous animal studies and limited human studies regarding physiologic effect of vitamin A on acute or chronic wounds via systemic or topical administration. The most common use of vitamin A supplementation is to offset steroids' effect. When considering supplementation, the potential benefits must be weighed against the risk of harm. Vitamin A toxicity can be critical and even result in death. The evidence for supplementation with vitamin A is currently limited to expert opinion and is not backed up by rigorous trials. There is an acute need for therapeutic trials with vitamin A supplementations.
Topics: Administration, Oral; Administration, Topical; Animals; Dietary Supplements; Humans; Vitamin A; Vitamin A Deficiency; Vitamins; Wound Healing; Wounds and Injuries
PubMed: 31697447
DOI: 10.1002/ncp.10420 -
Journal of Cosmetic Dermatology Mar 2016All-trans retinol, a precursor of retinoic acid, is an effective anti-aging treatment widely used in skin care products. In comparison, topical retinoic acid is believed... (Comparative Study)
Comparative Study
BACKGROUND
All-trans retinol, a precursor of retinoic acid, is an effective anti-aging treatment widely used in skin care products. In comparison, topical retinoic acid is believed to provide even greater anti-aging effects; however, there is limited research directly comparing the effects of retinol and retinoic acid on skin.
OBJECTIVES
In this study, we compare the effects of retinol and retinoic acid on skin structure and expression of skin function-related genes and proteins. We also examine the effect of retinol treatment on skin appearance.
METHODS
Skin histology was examined by H&E staining and in vivo confocal microscopy. Expression levels of skin genes and proteins were analyzed using RT-PCR and immunohistochemistry. The efficacy of a retinol formulation in improving skin appearance was assessed using digital image-based wrinkle analysis.
RESULTS
Four weeks of retinoic acid and retinol treatments both increased epidermal thickness, and upregulated genes for collagen type 1 (COL1A1), and collagen type 3 (COL3A1) with corresponding increases in procollagen I and procollagen III protein expression. Facial image analysis showed a significant reduction in facial wrinkles following 12 weeks of retinol application.
CONCLUSIONS
The results of this study demonstrate that topical application of retinol significantly affects both cellular and molecular properties of the epidermis and dermis, as shown by skin biopsy and noninvasive imaging analyses. Although the magnitude tends to be smaller, retinol induces similar changes in skin histology, and gene and protein expression as compared to retinoic acid application. These results were confirmed by the significant facial anti-aging effect observed in the retinol efficacy clinical study.
Topics: Administration, Cutaneous; Adult; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type III; Female; Gene Expression; Humans; Male; Middle Aged; Skin; Skin Aging; Skin Physiological Phenomena; Tretinoin; Up-Regulation; Vitamin A
PubMed: 26578346
DOI: 10.1111/jocd.12193 -
Ciencia & Saude Coletiva Mar 2019To evaluate the effect of vitamin A supplementation in postpartum infants and women on serum retinol levels and breast milk. The databases Medline, PubMed, Lilacs and...
To evaluate the effect of vitamin A supplementation in postpartum infants and women on serum retinol levels and breast milk. The databases Medline, PubMed, Lilacs and SciELO were consulted. The descriptors used were vitamin A, dietary supplement, child, postpartum period, infant and nutrition programs policies. Search found 7432 articles. After elimination of duplicity and application of eligibility criteria, 8 studies remained. All evaluated the effect of vitamin A supplementation on immediate postpartum, five studies used retinyl palmitate supplementation, one with retinyl palmitate and two did not specify the form of supplementation. Six studies evaluated colostrum and two included supplementation of children. It was found that supplementation in the puerperium increases the concentrations of serum retinol and breast milk, however, this result was in the short term and was relevant when the previous concentrations of the mother were low. When maternal serum concentrations are adequate, the retinol content in milk does not change, with little relevance for children. Further studies should be performed to evaluate the effect of megadoses supplementation on serum concentrations of children.
Topics: Colostrum; Dietary Supplements; Diterpenes; Female; Humans; Infant, Newborn; Milk, Human; Postpartum Period; Pregnancy; Retinyl Esters; Time Factors; Vitamin A; Vitamin A Deficiency
PubMed: 30892504
DOI: 10.1590/1413-81232018243.07112017 -
International Journal of Environmental... Sep 2019Rubella is a systemic virus infection that is usually mild. It can, however, cause severe birth defects known as the congenital rubella syndrome (CRS) when infection... (Review)
Review
Rubella is a systemic virus infection that is usually mild. It can, however, cause severe birth defects known as the congenital rubella syndrome (CRS) when infection occurs early in pregnancy. As many as 8%-13% of children with CRS developed autism during the rubella epidemic of the 1960s compared to the background rate of about 1 new case per 5000 children. Rubella infection and CRS are now rare in the U.S. and in Europe due to widespread vaccination. However, autism rates have risen dramatically in recent decades to about 3% of children today, with many cases appearing after a period of normal development ('regressive autism'). Evidence is reviewed here suggesting that the signs and symptoms of rubella may be due to alterations in the hepatic metabolism of vitamin A (retinoids), precipitated by the acute phase of the infection. The infection causes mild liver dysfunction and the spillage of stored vitamin A compounds into the circulation, resulting in an endogenous form of hypervitaminosis A. Given that vitamin A is a known teratogen, it is suggested that rubella infection occurring in the early weeks of pregnancy causes CRS through maternal liver dysfunction and exposure of the developing fetus to excessive vitamin A. On this view, the multiple manifestations of CRS and associated autism represent endogenous forms of hypervitaminosis A. It is further proposed that regressive autism results primarily from post-natal influences of a liver-damaging nature and exposure to excess vitamin A, inducing CRS-like features as a function of vitamin A toxicity, but without the associated dysmorphogenesis. A number of environmental factors are discussed that may plausibly be candidates for this role, and suggestions are offered for testing the model. The model also suggests a number of measures that may be effective both in reducing the risk of fetal CRS in women who acquire rubella in their first trimester and in reversing or minimizing regressive autism among children in whom the diagnosis is suspected or confirmed.
Topics: Autistic Disorder; Humans; Hypervitaminosis A; Liver; Liver Diseases; Rubella; Rubella Syndrome, Congenital; Rubella virus; Vitamin A
PubMed: 31546693
DOI: 10.3390/ijerph16193543 -
Nutrients Jan 2021Vitamin A is a fat-soluble vitamin that plays an important role in skin immunity. Deficiencies in Vitamin A have been linked to impaired immune response and increased... (Review)
Review
Vitamin A is a fat-soluble vitamin that plays an important role in skin immunity. Deficiencies in Vitamin A have been linked to impaired immune response and increased susceptibility to skin infections and inflammatory skin disease. This narrative review summarizes recent primary evidence that elucidates the role of vitamin A and its derivatives on innate immune regulators through mechanisms that promote skin immunity and sustain the skin microbiome.
Topics: Animals; Dermatitis; Humans; Immunity, Innate; Microbiota; Skin; Staphylococcus aureus; Tretinoin; Vitamin A; Vitamin A Deficiency
PubMed: 33494277
DOI: 10.3390/nu13020302 -
Biomedicine & Pharmacotherapy =... Aug 2023Vitamin A (retinol) is a lipid-soluble vitamin that acts as a precursor for several bioactive compounds, such as retinaldehyde (retinal) and isomers of retinoic acid....
Vitamin A (retinol) is a lipid-soluble vitamin that acts as a precursor for several bioactive compounds, such as retinaldehyde (retinal) and isomers of retinoic acid. Retinol and all-trans-retinoic acid (atRA) penetrate the blood-brain barrier and are reported to be neuroprotective in several animal models. We characterised the impact of retinol and its metabolites, all-trans-retinal (atRAL) and atRA, on ferroptosis-a programmed cell death caused by iron-dependent phospholipid peroxidation. Ferroptosis was induced by erastin, buthionine sulfoximine or RSL3 in neuronal and non-neuronal cell lines. We found that retinol, atRAL and atRA inhibited ferroptosis with a potency superior to α-tocopherol, the canonical anti-ferroptotic vitamin. In contrast, we found that antagonism of endogenous retinol with anhydroretinol sensitises ferroptosis induced in neuronal and non-neuronal cell lines. Retinol and its metabolites atRAL and atRA directly interdict lipid radicals in ferroptosis since these compounds displayed radical trapping properties in a cell-free assay. Vitamin A, therefore, complements other anti-ferroptotic vitamins, E and K; metabolites of vitamin A, or agents that alter their levels, may be potential therapeutics for diseases where ferroptosis is implicated.
Topics: Animals; Vitamin A; Ferroptosis; Lipid Peroxidation; Tretinoin; Vitamins; Retinaldehyde; Lipids
PubMed: 37236031
DOI: 10.1016/j.biopha.2023.114930