Retinyl Palmitate Research Articles

Comparative histological assessment of the effect of retinol palmitate preparations on aging skin

Background: Most often, the natural form of vitamin A (retinol palmitate) is used to prevent skin aging. There are two topical drugs on the Russian market that contain a high concentration of retinоl palmitate. This is the ointment "Videstim", which contains 0.5% retinol palmitate and ointment "RadevitАctive", which in addition to 1% retinol palmitate also includes cholecalciferol (0.005%) and tocopherol acetate (0.5%). The specific effects of these drugs on the structure of aging skin have not yet been fully studied. Aims: Comparative histological assessment of the effects of "Videstim" ointment and "RadevitАctive" ointmenton the epidermis and dermis of woman aged 40-55 years old. Materials and methods: The clinical study included 18 women aged 40 to 55 years old. Group I included 6 women who used "Videstim" ointment 2 times a day on the skin of the face. Group II consisted of 6 women who used "RadevitАctive" ointment 2 times a day on the skin of the face. Group III consisted of 6 women and was an intact comparison group. The observation period is 90 days. Patients underwent a punch biopsy with with histological examination of the skin before and after 90 days of using of the aforementioned drugs. Results: According to the results of the study, it was revealed that "Videstim" and "RadevitАctive" ointments they have a stimulating effect on the proliferation of keratinocytes of the epidermis, which manifested itself in an in increasing the number of rows of cells of the prickly layer. In addition, under the action of these drugs, the synthetic activity of keratinocytes of the granular layer increases, which contributes to the proper formation of the stratum corneum of the epidermis.. The use of ointments leads to a significant increase in the thickness of both the granular and prickly layers of the epidermis and the dermis. Conclusions: Ointments with a high concentration of retinol palmitate improve the structure of aging skin.

8290 Hypervitaminosis A Induced Severe Hypercalcemia In A Patient With Cirrhosis

Abstract Disclosure: N. Vennelaganti: None. S. Vennelaganti: None. R.L. Fitzgerald: None. K.C. McCowen: None. Introduction The liver stores vitamin A in hepatic stellate cells and regulates its absorption through bile production and distribution via retinol-binding protein 4 and transthyretin synthesis. Cirrhosis compromises these functions, resulting in vitamin A deficiency, which is inversely linked to the severity of nonalcoholic steatohepatitis. Addressing this deficiency in chronic liver diseases, particularly cirrhosis, is challenging due to the risk of vitamin A toxicity. This case describes a cirrhotic patient who developed hypervitaminosis A, leading to severe hypercalcemia. Clinical Case A 54-year-old male with alcoholic cirrhosis was diagnosed with hypovitaminosis A. He was prescribed 10,000 IU of vitamin A due to a low serum retinol level of less than 0.06 mg/L (reference range: 0.3-1.2 mg/L ). Two months later, he presented to the hospital with an erythematous patchy, scaling facial rash. His serum calcium corrected for albumin was high at 15.6 mg/dL. The rash and hypercalcemia, alongside vitamin A supplementation, raised suspicion of vitamin A toxicity. The patient, however, exhibited no hypercalcemia symptoms. He also had an acute kidney injury. His lab results revealed a PTH level of 10 pg/mL (normal range 15-65 pg/ml) and a normal myeloma screen, as well as normal vitamin D and TSH levels. An elevated PTHrP level of 5.2 pmol/l (normal range 0-2.3) was noted, which was attributed to the kidney injury(Cr 2.55 mg/l, eGFR 23 ml/min). Malignancy was excluded after a pan scan. Hypervitaminosis A is a clinical diagnosis, as serum vitamin A levels correlate poorly with toxicity. His serum retinol was normal at 0.83 mg/l, but his retinyl palmitate was high at 0.38 mg/L(reference range 0-0.10 mg/l), which supported our diagnosis. He received continuous IV 0.9% saline and subcutaneous calcitonin at 4 units/kg twice, and had a reduction in corrected calcium to 11 mg/dL over a week. The vitamin A-induced contact dermatitis improved with topical steroids. He was discharged; two months later, he remained asymptomatic with a corrected calcium of 11.1 mg/dL. He was not interested in further management as he was asymptomatic and serum calcium levels were improving. Labs were, however, notable for worsening renal function of unclear etiology. We will be trending his labs for improvement in serum calcium as the Vitamin A clears from his system. Clinical Lesson Vitamin A supplementation in cirrhotic patients is necessary in those with deficiency but carries a risk of toxicity. There are no definitive hepatology guidelines on the replacement of Vitamin A in patients with cirrhosis. This case emphasizes the importance of awareness of hypervitaminosis A-induced hypercalcemia in this population. Clinicians must carefully monitor and manage Vitamin A levels to avoid toxicity. Further research is essential for the management of this condition in cirrhotic patients. Presentation: 6/2/2024

Determination of retinol palmitate and tocopherol acetate in lipid microcapsules by HPLC/UV

Determination of retinol palmitate and tocopherol acetate in lipid microcapsules by HPLC/UV

Early activation of hepatic stellate cells induces rapid initiation of retinyl ester breakdown while maintaining lecithin:retinol acyltransferase (LRAT) activity

Lecithin:retinol acyltransferase (LRAT) is the main enzyme producing retinyl esters (REs) in quiescent hepatic stellate cells (HSCs). When cultured on stiff plastic culture plates, quiescent HSCs activate and lose their RE stores in a process similar to that in the liver following tissue damage, leading to fibrosis. Here we validated HSC cultures in soft gels to study RE metabolism in stable quiescent HSCs and investigated RE synthesis and breakdown in activating HSCs.HSCs cultured in a soft gel maintained characteristics of quiescent HSCs, including the size, amount and composition of their characteristic large lipid droplets. Quiescent gel-cultured HSCs maintained high expression levels of Lrat and a RE storing phenotype with low levels of RE breakdown. Newly formed REs are highly enriched in retinyl palmitate (RP), similar to freshly isolated quiescent HSCs, which is associated with high LRAT activity. Comparison of these quiescent gel-cultured HSCs with activated plastic-cultured HSCs showed that although during early activation the total RE levels and RP-enrichment are reduced, levels of RE formation are maintained and mediated by LRAT. Loss of REs was caused by enhanced RE breakdown in activating HSCs. Upon prolonged culturing, activated HSCs have lost their LRAT activity and produce small amounts of REs by DGAT1. This study reveals unexpected dynamics in RE metabolism during early HSC activation, which might be important in liver disease as early stages are reversible. Soft gel cultures provide a promising model to study RE metabolism in quiescent HSCs, allowing detailed molecular investigations on the mechanisms for storage and release.

Antioxidant efficacy of amino acids on vitamin A palmitate encapsulated in OSA-starch electrosprayed core-shell microcapsules

The encapsulation and the oxidative stability of vitamin retinyl palmitate (AP), a vitamin A derivative, within coaxial electrosprayed (AP) core – octenyl succinic anhydride (OSA-modified starch) shell microcapsules were investigated. The antioxidant efficiency of amino acids (AAs) (namely histidine, leucine, valine, tryptophan, tyrosine, cysteine and lysine) added to the core, on the oxidative stability of AP was evaluated using differential scanning calorimetry at the isothermal temperature of 140 °C. Confocal microscopy confirmed the location of the AP within the core with AAs microcapsules, surrounded by the shell layer of OSA starch. Scanning electron microscopy revealed that the microcapsules are uniform in size with an average diameter ranging from 2.06 ± 1.05 to 2.41 ± 1.42 μm. The AAs contributed substantially to enhance the oxidative stability of AP, with histidine being the most efficient with an improvement in oxidative stability of about 214 times, while lysine showed the lowest protection (about 3.9 times), compared to non-encapsulated AP. For the encapsulated AP, the presence of histidine or lysine enhanced the oxidative stability of the vitamin by about 70.6 or 1.3 times, respectively. The enhancement of the oxidative stability was mainly due to both the hydrophobic interactions formed between AP and AAs, and the adsorption of AP on the surface of AAs crystals (except lysine), assisted by the suspension of the AAs in ethanol antisolvent, as confirmed with attenuated total reflection–Fourier transform infrared (ATR–FTIR) and X-ray diffraction (XRD) analyses.

The Effects of a Multi-Ingredient Dietary Supplement on Recovery from Delayed-Onset Muscle Soreness

Introduction: The purpose of this investigation was to determine the effects of multi-ingredient dietary supplement on indices of muscle recovery on delayed-onset muscle soreness (DOMS). Methods: In a randomized, placebo-controlled trial, healthy exercise-trained subjects (n=24) consumed the treatment (i.e., Caraflame®: Retinyl Palmitate (Vit. A) 3.3 mg, Sodium Butyrate 175 mg, and Beta-Caryophyllene 30 mg or placebo (i.e., Maltodextrin 1000mg) daily over a 14-day period. Subjects completed the DOMS protocol and were assessed for changes in pain (visual analog scale (VAS) and a pressure algometer), strength (1-RM), and inflammatory markers (Interleukin-1b, Interleukin-6 and C-reactive protein). A dependent samples t-test was used to determine differences between groups with regard to the delta score. A p-value of P<0.05 was used to determine significance. Results: All subjects were physically active, healthy adults (Mean±SD – Age 23.5±7, Height 170±12.7 cm, Body Mass 71.0±19.57 kg, % body fat 24.3±10.6). A statistically significant difference was found for the assessment of pain threshold via VAS. Subjects in the treatment group exhibited a higher pain threshold two days post-DOMS (i.e., delta score data). No significant differences between groups for arm circumference, 1-RM, pain assessed by algometer, or arm circumference between the groups. Furthermore, there were no significant differences between groups for inflammatory markers (CRP, IL-6, and IL-1b). Conclusions: Based on this preliminary investigation, two weeks of a multi-ingredient dietary supplement may decrease the subjective perception of delayed-onset muscle soreness in exercise-trained adults.

Ultrasound-assisted intensification of Pickering interfacial biocatalysis preparation of vitamin A aliphatic esters

A novel approach to ultrasound-assisted Pickering interfacial biocatalysis (PIB) has been proposed and implemented for the efficient enzymatic transesterification production of vitamin A fatty acid esters. This is the first instance of exploiting the synergistic effect of ultrasound and the bifunctional modification of enzyme supports to accelerate biocatalytic performance in PIB systems. The optimal conditions were determined to be ultrasound power of 70 W, on/off time of 5 s/5 s, substrate molar ratio of 1:1, enzyme addition of 2 %, and a volume ratio of n-hexane to PBS of 3:1, a temperature of 40 °C, and a time of 30 min. The application of ultrasound technology not only improved lipase activity but also allowed for a reduction in emulsion droplet size to enhance interfacial mass transfer.Bifunctional modification of silica-based supports enhanced stability of immobilized enzymes by increasing hydrogen bonding while maintaining the active interface microenvironment. Compared with a non-ultrasound-assisted PIB system stabilized by mono-modified immobilized enzyme particles, the catalytic efficacy (CE) of the novel system reached 8.18 mmol g−1 min−1, which was enhanced by 3.33-fold, while the interfacial area was found to have increased by 17.5-fold. The results facilitated the conversion of vitamin A palmitate (VAP), vitamin A oleate (VAO), vitamin A linoleate (VAL), and vitamin A linolenate (VALn), with conversion rates of approximately 98.2 %, 97.4 %, 96.1 %, and 94.7 %, respectively. This represents the most efficient example that has been reported to our knowledge. Furthermore, the system demonstrated improved reusability, with a conversion rate of 62.1 % maintained even after 10 cycles. The findings presented in this paper provide valuable insights into an efficient and conveniently promising protocol for the development of PIB systems.

Spectral and mass characterization of kinetic conversion from retinoids to retinoic acid in an in vitro 3-D human skin equivalent model

To investigate the effect of retinoids, such as retinol (ROL), retinal (RAL), and retinyl palmitate (RP), on epidermal integrity, skin deposition, and bioconversion to retinoic acid (RA). 3-D human skin equivalent model (EpiDermFT™) was used. Epidermal cellular integrity measured by TEER values was significantly higher for a topical treatment of ROL and RAL than RP (p < 0.05). The skin deposition (μM) of ROL and RAL was approximately 269.54 ± 73.94 and 211.35 ± 20.96, respectively, greater than that of RP (63.70 ± 37.97) over 2 h incubation. Spectral changes were revealed that the CO maximum absorbance occurred between 1600∼1800 cm−1 and was greater from ROL than that from RAL and RP, indicating conjugation of R–OH to R-CHO or R-COOH could strongly occur after ROL treatment. Subsequently, a metabolite from the bioconversion of ROL and RAL was identified as RA, which has a product ion of m/z 283.06, by using liquid a chromatography-mass spectrometry (LC-MS) - total ion chromatogram (TIC). The amount of bioconversion from ROL and RAL to RA in artificial skin was 0.68 ± 0.13 and 0.70 ± 0.10 μM at 2 h and 0.60 ± 0.04 and 0.57 ± 0.06 μM at 24 h, respectively. RA was not detected in the skin and the receiver compartment after RP treatment. ROL could be a useful dermatological ingredient to maintain epidermal integrity more effectively, more stably deposit on the skin, and more steadily metabolize to RA than other retinoids such as RAL and RP.

Controlled release of vitamin A palmitate from crosslinked cyclodextrin organic framework for dry eye disease therapy

Controlled release drug delivery systems of eye drops are a promising ophthalmic therapy with advantages of good patient compliance and low irritation. However, the lack of a suitable drug carrier for ophthalmic use limits the development of the aforementioned system. Herein, the crosslinked cyclodextrin organic framework (COF) with a cubic porous structure and a uniform particle size was synthesized and applied to solidify vitamin A palmitate (VAP) by using the solvent-free method. The VAP@COF suspension eye drops were formulated by screening co-solvents, suspending agents, and stabilizing agents to achieve a homogeneous state and improve stability. According to the in vitro release study, the VAP@COF suspension exhibited a controlled release of VAP within 12 h. Both the ex vivo corneal contact angle and in vivo fluorescence tracking indicated that the VAP@COF suspension prolonged the VAP residence time on the ocular surface. This suspension accelerated the recovery of the dry eye disease (DED) model in New Zealand rabbits. Furthermore, the suspension was non-cytotoxic to human corneal epithelial cells and non-irritation to rabbit eyes. In summary, the particulate COF is an eye-acceptable novel carrier that sustains release and prolongs the VAP residence time on the ocular surface for DED treatment.

Quantification of Vitamin A in Edible Oils: Comparison of Portable Device iCheck Chroma3 to High-Performance Liquid Chromatography.

Fortification of edible oil with vitamin A is a widely adopted intervention to minimize the effects of vitamin A deficiency in vulnerable groups and mitigate some of its deleterious consequences. Regulatory monitoring is an important prerequisite to ensure that the fortification program is implemented effectively. Standard laboratory analysis methods for vitamin A in oils to assess adequate addition levels remain expensive and time-consuming. Portable testing devices are relatively less expensive in terms of capital investment and cost per test. However, the reliability of results needs to be assured to ensure acceptability and confidence. This study compared a portable device to high-performance liquid chromatography (HPLC) in terms of quantification of vitamin A in both spiked and commercially fortified oils. Nine oils (soybean, palm, cottonseed, rapeseed, corn, peanut, coconut, sunflower, and rice bran oils) were selected and spiked with retinyl palmitate at six different concentrations, and 112 commercially fortified oils were quantified for their vitamin A content using both methods. A good indicator of intra-day and inter-day repeatability (< 10% CV) was obtained for the measurement of vitamin A in the spiked oils for both methods, which denotes a high agreement between them. Vitamin A recoveries were 97-132% for HPLC and 74-127% for the portable device. A strong positive correlation, r = 0.88, is observed between the two methods for the quantification of vitamin A in the commercially fortified oils. The portable device provides a relatively low-cost, quick, and user-friendly alternative to HPLC.

In vivo retinoid metabolic and visual cycle pathways assessment of carotenoid-rich refined red palm-pressed mesocarp olein

The Palm-pressed mesocarp is a by-product from the palm oil mill and is comprised of 5–7 % of residual oil, which could be further refined into red palm-pressed mesocarp olein (PPMO). This study aimed to obtain the chemical profile of PPMO and assess its eye health effects through retinoid metabolic and visual cycle pathways regulation. PPMO contains exceptionally high vitamin E (1819.0 ppm) and carotenoid (1113.8 ppm) contents with a similar fatty acid composition to palm olein. The rats fed with 2 g/kg PPMO daily for 84 days through oral gavage up-regulated the retinol and retinyl palmitate levels, as well as the mRNA and protein expression levels of RBP4 in blood, CRBP1 and LRAT in the liver, RPE65 and RDH5 in the eye. The outcomes showed that PPMO showed comparable regulation effects with β-carotene in the retinoid metabolic and visual cycle pathways, revealing it as a phytonutrient-rich edible oil with beneficial eye health effects.

LX-2 Stellate Cells Are a Model System for Investigating the Regulation of Hepatic Vitamin A Metabolism and Respond to Tumor Necrosis Factor α and Interleukin 1β.

Hepatic stellate cells (HSCs) are the major site of vitamin A (retinol) esterification and subsequent storage as retinyl esters within lipid droplets. However, retinyl esters become depleted in many pathophysiological states, including acute and chronic liver injuries. Recently, using a liver slice culture system as a model of acute liver injury and fibrogenesis, a time-dependent increase and decrease in the apparent formation of the bioactive retinoid all-trans-retinoic acid (atRA) and retinyl palmitate was measured, respectively. This coincided with temporal changes in the gene expression of retinoid-metabolizing enzymes and binding proteins, that preceded HSC activation. However, the underlying mechanisms that promote early changes in retinoid metabolism remain unresolved. We hypothesized that LX-2 cells could be applied to investigate differences in quiescent and activated HSC retinoid metabolism. We demonstrate that the hypermetabolic state of activated stellate cells relative to quiescent stellate cells may be attributed to induction of STRA6, RBP4, and CYP26A1, thereby reducing intracellular concentrations of atRA. We further hypothesized that paracrine and autocrine cytokine signaling regulates HSC vitamin A metabolism in both quiescent and activated cells. In quiescent cells, tumor necrosis factor α dose-dependently downregulated LRAT and CRBP1 mRNA, with EC50 values of 30-50 pg/mL. Likewise, interleukin-1β decreased LRAT and CRBP1 gene expression but with less potency. In activated stellate cells, multiple enzymes were downregulated, suggesting that the full effects of altered hepatic vitamin A metabolism in chronic conditions require both paracrine and autocrine signaling events. Further, this study suggests the potential for cell type-specific autocrine effects in hepatic retinoid signaling. SIGNIFICANCE STATEMENT: HSCs are the major site of vitamin A storage and important determinants of retinol metabolism during liver fibrogenesis. Here, two LX-2 culture methods were applied as models of hepatic retinoid metabolism to demonstrate the effects of activation status and dose-dependent cytokine exposure on the expression of genes involved in retinoid metabolism. This study suggests that compared to quiescent cells, activated HSCs are hypermetabolic and have reduced apparent formation of retinoic acid, which may alter downstream retinoic acid signaling.

Novel Therapeutic Hybrid Systems Using Hydrogels and Nanotechnology: A Focus on Nanoemulgels for the Treatment of Skin Diseases.

Topical and transdermal drug delivery are advantageous administration routes, especially when treating diseases and conditions with a skin etiology. Nevertheless, conventional dosage forms often lead to low therapeutic efficacy, safety issues, and patient noncompliance. To tackle these issues, novel topical and transdermal platforms involving nanotechnology have been developed. This review focuses on the latest advances regarding the development of nanoemulgels for skin application, encapsulating a wide variety of molecules, including already marketed drugs (miconazole, ketoconazole, fusidic acid, imiquimod, meloxicam), repurposed marketed drugs (atorvastatin, omeprazole, leflunomide), natural-derived compounds (eucalyptol, naringenin, thymoquinone, curcumin, chrysin, brucine, capsaicin), and other synthetic molecules (ebselen, tocotrienols, retinyl palmitate), for wound healing, skin and skin appendage infections, skin inflammatory diseases, skin cancer, neuropathy, or anti-aging purposes. Developed formulations revealed adequate droplet size, PDI, viscosity, spreadability, pH, stability, drug release, and drug permeation and/or retention capacity, having more advantageous characteristics than current marketed formulations. In vitro and/or in vivo studies established the safety and efficacy of the developed formulations, confirming their therapeutic potential, and making them promising platforms for the replacement of current therapies, or as possible adjuvant treatments, which might someday effectively reach the market to help fight highly incident skin or systemic diseases and conditions.

Oxidative stress and antioxidant parameters in dogs with lymphoma during chemotherapy

Purpose: Oxidative stress is a contributor in the development of neoplasms. OS is involved in multidrug resistance, adverse events, and outcome. Methods: Forty- two dogs with lymphoma have been included in the study, 30 of which were treated by Cyclophosphamide - Hydroxyldaunorubicin® (doxorubicin) - Oncovin® (vincristine) - Prednisolone (CHOP)-based protocol. Tumor samples were excised for histopatholgy, immunophenotyping, Ki67%, and biochemical analyses. Thiobarbituric acid reactive substances (TBARS), reduced and oxidized glutathione (GSH, GSSG), glutathione peroxidase (GSH-Px), Cu-Zn-superoxide dismutase (SOD), ferric reducing ability (FRAP), vitamin-C, -E, retinyl palmitate and trans-retinol in red blood cell hemolysates, lymph node homogenates, and blood plasma have been measured. The results were correlated with the outcome of the chemotherapy. Results: Median overall survival time (OST), relapse-free period (RFP) were 862 and 280 days, respectively, with adverse effects in 18 cases. Plasma GSH levels increased with age (dogs from 1 to 6 years vs 9 to 13 years, p = 0.0385). Lymph node FRAP levels were higher in samples with higher Ki67%, and plasma GSH/GSSG ratio was lower in dogs with increased OST and RFP. Plasma retinyl palmitate levels were lower in dogs with increased RFP. Overall survival time was increased with lower lymph node TBARS (cut off: 53 nmol/mg protein), GHS-Px (cut off: 16 U/mg protein), and higher plasma all-trans-retinol (cut off: 4 mg/ml). Relapse-free period was increased with lower lymph node TBARS (cut off: 53 nmol/mg protein), lower FRAP (cut off: 6 µmol/mg) and higher SOD (cut off: 70 U/mg protein). During chemotherapy a gradual increase in plasma vitamin E and C concentrations was detected, while GSH and GSSG showed a decrease before adverse events. Conclusion: Although oxidative stress parameters varied, some parameters, i.e. TBARS, GSH-Px, SOD, FRAP measured in lymph node samples, and plasma all-trans retinol might be used as prognostic indices.

Oat protein isolate-Pleurotus ostreatus β-glucan conjugate nanoparticles bound to β-carotene effectively alleviate immunosuppression by regulating gut microbiota.

Individuals with immune disorders cannot establish an adequate defense to pathogens, leading to gut microbiota dysbiosis. β-Carotene can regulate immune response, but its bioavailability in vivo is very low. Herein, we developed a glycosylated oat protein-based nanoparticle to improve the application of β-carotene for mitigating cyclophosphamide-induced immunosuppression and gut microbiota imbalance in mice. The results showed that the nanoparticles facilitated a conversion of β-carotene to retinol or retinyl palmitate into the systemic circulation, leading to an increased bioavailability of β-carotene. The encapsulated β-carotene bolstered humoral immunity by elevating immunoglobulin levels, augmenting splenic T lymphocyte subpopulations, and increasing splenic cytokine concentrations in immunosuppressed mice. This effect was accompanied by the alleviation of pathological features observed in the spleen. In addition, the encapsulated β-carotene restored the abnormal gut microbiota associated with immunosuppression, including Erysipelotrichaceae, Akkermansia, Bifidobacterium and Roseburia. This study suggested that nanoparticles loaded with β-carotene have great potential for therapeutic intervention in human immune disorders by specifically targeting the gut microbiota.

Influence of chronic immobilization stress on vitamin status in rats fed different diets

The influence of a stress factor, widespread in modern conditions, on the vitamin status has not been studied enough. At the same time, the negative stress impact can be aggravated against the background of unhealthy nutrition, which in turn affects the vitamin status of the organism. In this regard, the goal of the research was to evaluate the effect of chronic restrict stress on the vitamin supply in rats fed a diet with adequate and increased content of fat, sugar and cholesterol. Material and methods. The experiment was carried out on 37 growing male Wistar rats (initial body weight of 45±5 g) divided into 4 groups. Animals of the 1st (control) and the 2nd groups received a complete semi-synthetic diet (CSSD) (20% protein, 10% fat, 58% carbohydrates in the form of starch, 384 kcal/100 g) for 92 days. The levels of all vitamins and mineral elements in the rats' diets were adequate for growing rats. Rats of the 3rd and the 4th groups were fed a high-calorie, high-fat high-carbohydrate diet (HFHCD) (20% protein, 28% fat, 2% cholesterol, 18% carbohydrates in the form of starch, 20% sucrose, 511 kcal/100 g). Animals of groups 2 and 4 were subjected to daily 90-minute immobilization. The concentration of vitamins A (retinol and retinol palmitate) and E (α-tocopherol) in the blood serum and liver were determined by high-performance liquid chromatography, vitamins B1 and B2 in the liver and urine, as well as riboflavin in the blood serum and 4-pyridoxic acid (4-PA) in urine were determined by fluorimetric methods. Biochemical parameters of blood serum were determined on a biochemical analyzer; the total content of fat, triglycerides (TG) and cholesterol (CH) was determined in the liver. Results. Replacing CSSD with HFHCD, both under restraint stress and without, was accompanied by an increase in liver weight by 1.8-2.0 fold, in its fat content by 2.6-3.3 fold, cholesterol by 32.6-35.3 fold and TG - by 33.0-57.6 fold (p=<0.001). An increase in alanine aminotransferase (ALT) activity by 1.7-2.0 fold (p=<0.01), in low-density lipoprotein (LDL) cholesterol level by 5.4 fold (p=<0.05) and the atherogenic coefficient by 2.5 fold (p<0.01) as well as a decrease in creatinine and urea level (p=<0.05) in blood serum were revealed. Immobilization was accompanied by a decrease in body weight, liver and liver fat in rats fed both CSSD and HFHCD (p<0.05), but didn't affect the blood serum biochemical parameters, with the exception of an increase in ALT activity. If the activity of alkaline phosphatase (ALP) did not change during immobilization of rats fed the CSSD, then in animals fed the high-calorie diet it decreased by 37.5% (p=<0.05 from the control) under its increase against the background of restrict stress by 78.7% (p=<0.01) compared to the indicator of rats of the 3rd group. Immobilization of rats treated with CSSD was accompanied by an increase in both absolute serum α-tocopherol level and concentration correlated with the level of cholesterol and triglycerides by 26.0-57.5% (p<0.05), with a simultaneous decrease in its content in the liver per 1 g of wet tissue by 22.1% (p=0.041) relative to the indicators of intact animals. Immobilization reduced the level of retinol palmitate in the liver by 2.3 times (p<0.01), but did not affect retinol level in the blood serum. At the same time, indicators of B vitamin status (the content of vitamins B1 and B2 in the liver per 1 g of wet tissue and per organ, blood serum riboflavin level, urinary excretion of riboflavin and 4-PA) did not change, with the exception of thiamine urinary excretion, which reduced compared to the control by 38.8%. In rats fed HFHCD, immobilization had no additional effect on the supply with vitamins A and E. The content of vitamins B1 and B2 in the liver in terms of the whole organ was reduced by 14.0-26.7% relative to the indicator in animals of the 3rd group, not subjected to chronic stress, only due to differences in liver weight in animals of these groups. Conclusion. The data obtained indicate that chronic stress has a negative effect on the vitamin status of the body, worsening the supply with vitamins A, E and B1, and substantiate the feasibility of studying the mechanisms of this effect in order to develop effective vitamin complexes for the treatment and prevention of diseases caused by long-term stress.

Effects of Hair Essence Containing Vitamin E, Vitamin A, and Phytantriol on Hair Quality

Purpose: This study examined the effect of a hair essence containing α-tocopheryl acetate, retinyl palmitate, and phytantriol (TRP-hair essence) on damaged hair and hair quality characteristics such as hair volume and gloss.Methods: The TRP-hair essence containing 0.01% (w/w) each of α-tocopheryl acetate (vitamin E), retinyl palmitate (vitamin A), and phytantriol was prepared. The effect of the TRP-hair essence on damaged hair was analyzed using a scanning electron microscope; its impact on hair volume and gloss was confirmed using a high-resolution digital camera. Furthermore, a sensory evaluation was used to determine satisfaction after using the TRP-hair essence.Results: The cuticle of the hair that had been damaged because of chemical treatment improved by 19.8% (&lt;i&gt;p&lt;/i&gt;&lt;0.05) following only a single round of the TRP-hair essence treatment. Hair volume and gloss significantly increased immediately and 24 hours after using the TRP-hair essence (&lt;i&gt;p&lt;/i&gt;&lt;0.05). There was substantial satisfaction in terms of the sensory evaluation of directly using the TRP-hair essence on human hair.Conclusion: Using the TRP-hair essence effectively recovered the damaged hair and improved its quality characteristics such as hair volume and gloss, resulting in high satisfaction with use.

Scavenging of Cation Radicals of the Visual Cycle Retinoids by Lutein, Zeaxanthin, Taurine, and Melanin.

In the retina, retinoids involved in vision are under constant threat of oxidation, and their oxidation products exhibit deleterious properties. Using pulse radiolysis, this study determined that the bimolecular rate constants of scavenging cation radicals of retinoids by taurine are smaller than 2 × 107 M-1s-1 whereas lutein scavenges cation radicals of all three retinoids with the bimolecular rate constants approach the diffusion-controlled limits, while zeaxanthin is only 1.4-1.6-fold less effective. Despite that lutein exhibits greater scavenging rate constants of retinoid cation radicals than other antioxidants, the greater concentrations of ascorbate in the retina suggest that ascorbate may be the main protectant of all visual cycle retinoids from oxidative degradation, while α-tocopherol may play a substantial role in the protection of retinaldehyde but is relatively inefficient in the protection of retinol or retinyl palmitate. While the protection of retinoids by lutein and zeaxanthin appears inefficient in the retinal periphery, it can be quite substantial in the macula. Although the determined rate constants of scavenging the cation radicals of retinol and retinaldehyde by dopa-melanin are relatively small, the high concentration of melanin in the RPE melanosomes suggests they can be scavenged if they are in proximity to melanin-containing pigment granules.

Conversion of Retinyl Palmitate to Retinol by Wheat Bran Endogenous Lipase Reduces Vitamin A Stability.

Wheat bran can be used as a cost-effective food ingredient to stabilise vitamin A. However, wheat bran endogenous enzymes have been shown to reduce vitamin A stability. In this study, we elucidated the mechanism for this negative effect in an accelerated storage experiment with model systems consisting of native or toasted wheat bran, soy oil and retinyl palmitate (RP). Both native and toasted wheat bran substantially stabilised RP. While RP was entirely degraded after ten days of storage in the absence of wheat bran, the RP retention after ten days was 22 ± 2% and 75 ± 5% in the presence of native and toasted bran, respectively. The significantly stronger stabilising effect of toasted bran was attributed to the absence of bran endogenous enzymes. In contrast to toasted bran systems, noticeable free fatty acid production was observed for native bran systems. However, this did not result in a pronounced lipid oxidation. Next to lipid hydrolysis, wheat bran lipase was shown to hydrolyse retinyl esters to the less stable retinol and fatty acids. This reaction could explain the major part, about 66 ± 5%, of the difference in RP stabilisation between native and toasted wheat bran.

A SYSTEMATIC REVIEW: MECHANISM OF ACTION ORAL AND TOPICAL RETINOL (Retinyl palmitate) AS A THERAPY OF ACNE SKIN IN BEAUTY PRODUCTS

Acne is one of the dermatological diseases that often appears in adolescence to adulthood. Retinol (retinyl palmitate) is a first-generation vitamin A derivative used for acne therapy by reducing sebum production which can cause acne bacteria to grow. This study aims to determine the effectiveness and safety of oral and topical retinol preparations. The method used in the study is systematic review using the PubMed search engine and google scholar according to keywords using the PICO method. Articles that can be downloaded with a period of 2013-2023 for the next article are downloaded in selection according to the criteria, namely inclusion and exclusion. The results of the selection of inclusion criteria there are 12 journals to discuss the effectiveness and safety related to topical preparations and peroral retinol as anti-products acne. The mechanism of action of topical retinol is to reduce the production of micro-comedones caused by the bacteria Propionibacterium acnes (P. acne) for oral retinol has the mechanism of action works by inhibiting the production of sebum by androgen hormones in the 3-alpha-hydroxysteroid oxidation pathway using the enzyme retinol dehydrogenase to retinaldehyde to be able to dissolve and be delivered at the destination. Oral or topical retinol preparations provide different side effects. Topical retinol has a lower rate of side effects compared to oral retinol. The level of safety and effectiveness of topical retinol preparations is better than oral retinol.