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Vitamin E: Critical Review of Its Current Use in Cosmetic and Clinical Dermatology
Abstract
The lipophilic antioxidant vitamin E has been used for more than 50 years in clinical and experimental dermatology. However, although a large number of case reports were published, there is still a lack of controlled clinical studies providing a rationale for clinical indications and dosage. In contrast, advances in basic research on the physiology, mechanism of action, penetration, bioconversion, and photoprotection of vitamin E in human skin have led to the development of numerous new formulations for use in cosmetics and skin care products.
This article reviews the basic mechanisms and possible cosmetical and clinical implications of the recent advances in cutaneous vitamin E research. Experimental evidence suggests that topical and oral vitamin E has anticarcinogenic, photoprotective, and skin barrier-stabilizing properties.
Although its current use is largely limited to cosmetics, controlled clinical studies for indications such as atopic dermatitis or prevention of photocarcinogenesis are needed to evaluate the clinical benefit of vitamin E.
... VEs have been used as nutrients, antioxidants, moisturizers, and anti-inflammatory agents in human skin, eyes and hair, respectively 83 . In particular, Tocs are reported to function in cosmetics as antioxidants or skin-conditioning agents, and tocotrienols are reported as light stabilizers, oral care agents and skin-conditioning agents. ...
... In particular, Tocs are reported to function in cosmetics as antioxidants or skin-conditioning agents, and tocotrienols are reported as light stabilizers, oral care agents and skin-conditioning agents. VEs are also expected to provide benefits as cosmeceuticals that surpass the purpose of cosmetics 83,84 ; Topical products that contain VEs are classified as cosmetics or medicines, depending on their purpose. ...
... Numerous studies have demonstrated that various VEs have been reported to provide photoprotective effects of human skin owing to the antioxidant effect 83 87 . In vivo and/ or clinical study have demonstrated the effectiveness 83,87 . VE and the derivatives have been most frequently used in the sunscreen formulations 66.3 in 2021 85 . ...
Vitamin E (VE) is a lipophilic vitamin, and Evans and Bishop demonstrated the existence of a hitherto unrecognized dietary factor essential for normal reproduction in rat. During 100 years after the discovery, α-tocopherol (α-Toc) has been the representative species in VE homologues, and both naturally occurring and synthetically prepared α-Toc have been widely used and studied. Although it is indicated by a single-word VE, research on VE involves various chemical species. It is important to understand the fine structure and accurate characteristics of individual VE species when using VE. Each VE sample has compositional and/or isomer issues, and furthermore, the usability greatly varies depending on the modified species of esterification. The VE industry involves many interdisciplinary fields. Improvements in formulation technology and confirmation of the novel biological activity of VE greatly owns its utility and opens up new applications. As the interim period between the start and end of the agenda for Sustainable Development Goals (SDGs), in this minireview, the recent trends and future guidelines of VE, especially α- Toc, in relation to the SDGs have been demonstrated.
graphical abstract Fullsize Image
... 32,33 In vivo, tocopherol's antioxidant capacity is regenerated via hydrophilic co-antioxidants such as vitamin C and glutathione, thus topical products often contain a combination of antioxidants. 35 Combination formulations often demonstrate better efficacy compared to single antioxidant formulations. Tocopherol concentration in topical formulations is generally between 1% and 5%, which is well-tolerated. ...
... Tocopherol concentration in topical formulations is generally between 1% and 5%, which is well-tolerated. 35 Adverse effects of these products are rare, with only few cases of mild skin irritation reported. 35 ...
... 35 Adverse effects of these products are rare, with only few cases of mild skin irritation reported. 35 ...
The eternal pursuit to prevent ageing and maintain a youthful appearance has resulted in a rapidly expanding cosmeceutical industry. Cosmeceutical products, particularly of natural origin, are in high demand due to claims of efficacy for signs of ageing and other skin conditions. Consumers often include cosmeceutical products in their skin care regime as they are readily available, and a more affordable option compared to prescription products. However, many cosmeceutical ingredients lack clinical evidence regarding their efficacy and safety as these products are not regulated by the U.S. Food and Drug Administration. This review provides a brief overview of several popular cosmeceutical ingredients with regards to their potential indications, targets and mechanisms of action.
... Tocopherol, or vitamin E, is a natural lipophilic vitamin found in fruits, vegetables, and seeds, well-known for its strong antioxidant, peroxyl radical scavenging, and cytoprotective properties [30]. It also inhibits the activity of protein kinase C, which is beneficial in various diseases like cancer, diabetes, and cardiovascular diseases, being involved in a variety of signal transduction pathways; however, tocopherol has poor chemical-and photo-stability and it is easily susceptible to oxidation by alkoxyl radicals, which has led to the development of acetylated and glucoside derivatives [28,30,31] ( Fig. 4). ...
... Tocopherol, or vitamin E, is a natural lipophilic vitamin found in fruits, vegetables, and seeds, well-known for its strong antioxidant, peroxyl radical scavenging, and cytoprotective properties [30]. It also inhibits the activity of protein kinase C, which is beneficial in various diseases like cancer, diabetes, and cardiovascular diseases, being involved in a variety of signal transduction pathways; however, tocopherol has poor chemical-and photo-stability and it is easily susceptible to oxidation by alkoxyl radicals, which has led to the development of acetylated and glucoside derivatives [28,30,31] ( Fig. 4). These pro-vitamins require bioactivation and can potentially overcome the poor topical formulation and instability of tocopherol [28]. ...
Excessive exposure to sunlight can contribute for skin photo-damage, such as sunburn, dryness, wrinkles, hyperpigmentation, immunosuppressive events and skin sensitization reactions. The use of aftersun products is an effective strategy to reduce the visible signs and symptoms of acute photodamage in the skin. Aiming to unveil the active ingredients able to offset acute sun damage, this work focuses on the characterization of the aftersun products market. A total of 84 after-sun formulations from 41 international brands currently marketed in Portugal were analyzed concerning the composition described on the product label, identifying natural and synthetic/semi-synthetic ingredients with the ability to mitigate solar-induced effects. The majority of aftersun formulations contained ingredients derived from terrestrial and marine sources (> 80%). An in-depth examination of these compounds is also offered, revealing the top of the most used natural and synthetic/semi-synthetic ingredients present in aftersun products, as well as their mechanism of action. A critical appraisal of the scientific data was made aiming to highlight the scientific evidence of ingredients able to mitigate skin photodamage. Amino acids and peptides, and A. barbadensis extract were tested for their in vivo efficacy. Nevertheless, all the ingredients were analyzed with in vitro studies as preliminary screening before in vivo, ex vivo and/or clinical studies. In summary, this study provides an overview of the use of active ingredients in commercial aftersun products to understand better the benefits associated with their use in cosmetic formulations and identify opportunities for innovation.
Graphical abstract
... Using a topical application, the antioxidant properties of vitamin E have been well evidenced [182][183][184]. Besides antioxidant activity, vitamin E in topical application may also exert skin protective effects through anti-inflammatory properties [185][186][187] and its ability to inhibit the action of metalloproteinases [188]. Vitamin E may also interfere with global DNA methylation [189]. ...
... Of all the antioxidants, vitamin E is certainly the one that has been most studied for its skin protective effects. The direct topical application of vitamin E seems to be the classical and safety route for skin protection via its capacity to eliminate lipid peroxides [185,191,264]. Oral use of vitamin E exhibits photo protection at supra nutritional doses (Table S2). ...
The relationship between oxidative stress and skin aging/disorders is well established. Many topical and oral antioxidants (vitamins C and E, carotenoids, polyphenols) have been proposed to protect the skin against the deleterious effect induced by increased reactive oxygen species production, particularly in the context of sun exposure. In this review, we focused on the combination of vitamin E and selenium taken in supplements since both molecules act in synergy either by non-enzymatic and enzymatic pathways to eliminate skin lipids peroxides, which are strongly implicated in skin and hair disorders.
... Tocopherols are crucial in inhibiting the oxidation of lipids in almonds, which can extend the storage time of the kernels. In recent times, the beauty industry and clinical dermatology have shown increased interest in tocols because of their photoprotection and antioxidant characteristics [17]. An antioxidant is classified as having very strong activity when its IC50 value is less than 50 µg/mL (IC50 <50 µg/mL), strong activity when the IC50 value is between 50 and 100 µg/mL (50 µg/mL <IC50 <100 µg/mL), moderate activity when the IC50 value is between 100 and 150 µg/mL (100 µg/mL <IC50 <150 µg/mL), weak activity when the IC50 value is between 150 and 200 µg/mL (150 µg/mL <IC50 <200 µg/mL), and very weak activity when the IC50 value is greater than 200 µg/mL (IC50 >200 µg/mL) [18]. ...
Corn is a well-cultivated food crop that is grown extensively worldwide. The used portion of corn is its seeds, which are rich in oil. The objective of this study is to separate and characterize tocopherol from corn oil in Dompu, Sumbawa by employing spectroscopic techniques such as ultraviolet (UV) spectrophotometry, ultra-performance liquid chromatography (UPLC), nuclear magnetic resonance (NMR), and liquid chromatography-mass spectrometry (LC-MS). Subsequently, the in-vitro antioxidant activity of the tocopherol was assessed. 1 kilogram of dry maize kernels subjected to 70% ethanol extraction yielded 30 grams (35 ml) of corn oil. The purified isolate obtained from the fractionated extract, using radial chromatography, demonstrated the presence of tocopherol. The isolated sample exhibited the presence of beta-tocopherol. Beta-tocopherol's anti-aging properties were assessed by conducting an in-vitro antioxidant activity test utilizing the tyrosinase enzyme. The IC50 value obtained was 83.954±2.849 ppm. The IC50 value indicates that beta-tocopherol possesses significant antioxidant activity, making it suitable for usage as a primary ingredient in cosmetics and pharmaceutical products.
... Taking into account that the five active ingredients work synergistically, meaning that their therapeutic, healing, and regenerative properties are either complementary or additive, it is recommended to combine them in cosmetic formulations in order to achieve the optimal result. Their suggested percentage composition in cosmetics is for ferulic acid 0.5-1% [20], for resveratrol up to 5%, for quercetin 0.1-3, up to 0.3% for retinol [21], and up to 5% [22] for vitamin E. Therefore, in the context of the present work, a new formulation was prepared and then evaluated, incorporating the five active ingredients. The formulation belongs to the cold cream category, i.e., it is a water-in-oil (w/o) emulsion with a greasy texture that ensures prolonged contact at the application surface, compared to other semi-solid forms. ...
Due to the rapid increase in the use of anti-aging cosmetic products, there is a need to develop valid analytical methods to control their quality. The present work deals with the development and validation of a new chromatographic method for the quantitative determination of five lipophilic components (resveratrol, ferulic acid, quercetin, retinol, and α-tocopherol), with anti-aging properties, in a cold cream (w/o). For the HPLC-UV separation of the active ingredients, an HS, Discovery® Supelco (Supelco Inc., Bellefonte, PA, USA), C18 column (25 cm × 4.6 mm), 5 μm (at 40 °C) was used as a stationary phase while a binary system of A: Acetonitrile with formic acid 0.2% and B: H2O with formic acid 0.2%, in gradient elution (flow 1.5 mL·min−1), was used as mobile. The analytical method was validated according to ICH guidelines Q2(R2), where linearity (r2 ≥ 0.998), selectivity, precision (% recovery 97.1–101.9), and accuracy (%RSD < 2) were evaluated. The processing of the samples for the recovery of the five analytes from the cream was investigated by experimental design methodology and the cross D-optimal technique (% recovery 98.5–102.9, %RSD < 2%, n = 5). Finally, the same analysis was applied to study the transdermal penetration of the active ingredients incorporated in cold cream (over a period of 8 h). Their behavior was compared with the corresponding one in suspension using Franz cells in a vertical arrangement. The new method is considered reliable for the analysis of the anti-aging product.
... In addition, products with a concentration of less than 0.001% have been reported. 46 Vitamin E plays an essential role in defense against lipid peroxidation. 45 It is considered to be the most important lipophilic antioxidant, protecting the membrane from oxidation by scavenging lipid radicals. ...
Skin aging can be divided into intrinsic and extrinsic aging. Even though it is inevitable, symptoms of skin aging are a common concern for patients. As a result, there is a surge in the making of anti-aging cosmeceuticals. However, there is a lack of evidence-based data to support the usage of topical preparations as anti-aging treatments. Therefore, further studies are needed to explore topical treatment options for skin aging. This literature review discusses the mechanism of commonly used topical anti-aging agents and their adverse reactions.
... Green leafy vegetables, vegetable oils, nuts, and seeds are good vitamin E sources. 38 The possible mechanism of action of vitamin E on scar management involves the anti-inflammation effect and the inhibitory effects on fibroblast proliferation and collagen synthesis. 37,[39][40][41] Additionally, the antioxidant effect may prevent scar formation by decreasing cell damage from free oxygen radicals available during the inflammatory phase and preventing lipid peroxidation in membranes. ...
Hypertrophic scarring is an aberrant wound-healing response to reestablish dermal integrity after an injury and can cause significant abnormalities in physical, aesthetic, functional, and psychological symptoms, impacting the patient's quality of life. There is currently no gold standard for preventing and treating hypertrophic scars. Therefore, many researchers have attempted to search for antihypertrophic scar agents with greater efficacy and fewer side effects. Natural therapeutics are becoming attractive as potential alternative anti-scarring agents because of their high efficacy, safety, biocompatibility, low cost, and easy accessibility. This review demonstrates various kinds of natural product-based therapeutics, including onion, vitamin E, Gotu kola, green tea, resveratrol, emodin, curcumin, and others, in terms of their mechanisms of action, evidence of efficacy and safety, advantages, and disadvantages when used as anti-scarring agents. We reviewed the literature based on data from in vitro, in vivo, and clinical trials. A total of 23 clinical trials were identified in this review; most clinical trials were ranked as having uncertain results (level of evidence 2b; n = 16). Although these natural products showed beneficial effects in both in vitro and in vivo studies of potential anti-scarring agents, there was limited clinical evidence to support their efficacy due to the limited quality of the studies, with individual flaws including small sample sizes, poor randomization, and blinding, and short follow-up durations. More robust and well-designed clinical trials with large-scale and prolonged follow-up durations are required to clarify the benefits and risks of these agents.
... Vitamin E is one such substance, which is a potent antioxidant, promotes collagen and elastin synthesis, protects the skin lipid membrane, and has skin-barrier stabilizing properties. 10,11 Vitamin C participates in keratinocyte differentiation, collagen synthesis, prevents melanin synthesis, and protects the skin from photoaging. 10 Hyaluronic acid is also one of the most commonly used ingredients in the cosmetics industry, as it acts as a skin conditioning agent and primarily maintains the skin's hydration. It holds moisture and increases the firmness and radiance of the skin. ...
Background: The skin plays different functions during the day and night to adapt to the changing environments. Various specialized creams are available to meet these skincare needs. The present study was conducted to explore the perspective of Indian dermatologists and cosmetologists on skin’s circadian rhythm and assess the effectiveness of a particular day and night cream formulation. Methods: A non-interventional, questionnaire-based study was conducted as part of a survey series on multiple dermatology products across India. Every month, a product-specific survey link was released to these registered doctors, and each doctor could take up to 10 surveys for a maximum of two products. A total of 379 healthcare professionals (HCPs) took the survey on the day and night cream and reported experiences of 2085 patients regarding the use of these products. Results: The doctors believed that for majority of the patients (1997, 97%), required day and night cream to maintain their skin’s circadian rhythm. Most patients (1440, 70%) were compliant with day and night care cream regimens. Most patients (966, 47%) were highly satisfied with the use of day and night cream, with majority of the patients (1028, 49.4%) experiencing considerable reduction in dark spots and uneven skin tone. Most patients (971, 47%) felt that the application of day and night cream left their skin moisturized and rejuvenated. Conclusions: The use of day and night cream improved skin condition and hydration, addressing circadian rhythm imbalance. Indian HCPs understand the impact of skin circadian rhythm imbalance and promote a comprehensive skincare regimen to patients.
... However, the nature of commercially availablesynthetic AVE being its high viscousity; light-sensitivity; a skin irritant and difficult incorporation into cosmetic formulations still present limitations in AVE's potential applications [6]. These obstacles have led to the innovation of various novel formulations for dermatological use during the last decade [7]. The work of Trombino's research team focusing on stearyl ferulate-based solid lipid nanoparticles as a vehicle for both beta-carotene and alpha-tocopherol suggested a novel formulation to prevent skin damage [8]. ...
Recently, fabrication of nanoemulsion has drawn substantial interest in the field of pharmaceutical chemistry, particularly the development of nanosystems for the delivery of bioactive compounds. The idea of this material is to encapsulate and carry water-insoluble active agents to the targeted site. Our work focuses on the ideal delivery system for alpha-tocopheryl acetate (AVE), which currently covers a broad range of medications, supplementation and cosmetics. To put it in detail, we investigated different kinds of pluronic emulsifiers (pluronic F127, pluronic P123 and their mixture) to fabricate the AVE-loaded nanoemulsion particles. The structure, physicochemical properties, stability and biocompatibility of various formulations were compared using Fourier-transform infrared spectroscopy (FT-IR) spectra; Dynamic light scattering (DLS); macroscopic and microscopic images; Transmision electron microscopy (TEM) and in vitro cytotoxicity test. The obtained results exhibited a high stability of AVE-loaded pluronic mixture as compared to that of the free-AVE sample. Moreover, the dual pluronic formulation also showed a great cytocompatibility which could be utilized in topical and transdermal delivery.
... The study showed that α-tocotrienol has antioxidant activity 40-60 times stronger than α-tocopherol in liver microsomes [6] and has unique anti-carcinogenic properties [7]. Interest in tocotrienols is also increasing in the food, cosmetic and clinical dermatology industries because of their light-protective effects and strong antioxidants [8]. When compared to synthetic products, natural vitamin E has greater market interest and acceptance. ...
Objective: Tocotrienols have now stepped into the limelight of vitamin E research and have proven to have some exceptional benefits that are not shared by their “older” tocopherol siblings. Unlike tocopherols, tocotrienols are able to inhibit cholesterol biosynthesis, have specific neuroprotective activities stronger antioxidant effects, antihypertensive and anti-cancer. The purpose of this study was to carry out selective separation of tocotrienols homologues from Palm Fatty Acid Distillate (PFAD) by liquid-liquid extraction, using Ionic liquids (ILs) as extractants in the presence of diluent. Methods: Four kinds of imidazolium-based ILs that used are 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), 1-Butyl-3-methylimidazolium acetate ([Bmim]Ac), 1-Hexyl-3-methylimidazolium chloride ([Hmim]Cl) and 1-Ethyl-3-methylimidazolium chloride ([Emim]C]). The extraction is carried out by creating a two-phase system between ILs and PFAD in n-hexane. Quantification of extracted tocotrienols was performed using High-Performance liquid Chromatography (HPLC) with a C18 column, mobile phase methanol: water (97.5:2.5), flow rate 1 ml/min and Ultraviolet (UV) detector at 295 nm. Results: The results showed that the concentration (extraction efficiency) of tocotrienols extracted using ILs in order were [Bmim] Ac 1611.09 mg/Kg (75.41%) and [Hmim][Cl] 1603.39 mg/Kg (75.05%), [Bmim]Cl 1523.60 mg/Kg (71.32%) and [Emim]Cl 1174.24 mg/Kg (54.96%). Conclusion: [Bmim]Ac yielded the highest tocotrienols concentration and extraction efficiency.
... Considering the release of vitamins from the analyzed creams with microspheres formed from hydrogel blends (containing modified chitosan), a continuous release process is observed, without the sharp flattening of the curve observed above. The vitamin doses, measured every 15 min (Figures 7-9), were very similar to each other for the first 1 h of the release process, and during the following hours were gradually decreasing, but for up to 6 h, they were still therapeutically significant [52][53][54]. Therefore, the expected distributed dosage of these substances through the membrane imitating the epidermis was achieved over a longer period. ...
Chitosan (CS) has a natural origin and is a biodegradable and biocompatible polymer with many skin-beneficial properties successfully used in the cosmetics and pharmaceutical industry. CS derivatives, especially those synthesized via a Schiff base reaction, are very important due to their unique antimicrobial activity. This study demonstrates research results on the use of hydrogel microspheres made of [chitosan-graft-poly(ε-caprolactone)]-blend-(ĸ-carrageenan)], [chitosan-2-pyridinecarboxaldehyde-graft-poly(ε-caprolactone)]-blend-(ĸ-carrageenan), and chitosan-sodium-4-formylbenzene-1,3-disulfonate-graft-poly(ε-caprolactone)]-blend-(ĸ-carrageenan) as innovative vitamin carriers for cosmetic formulation. A permeation study of retinol (vitamin A), L-ascorbic acid (vitamin C), and α-tocopherol (vitamin E) from the cream through a human skin model by the Franz Cell measurement system was presented. The quantitative analysis of the release of the vitamins added to the cream base, through the membrane, imitating human skin, showed a promising profile of its release/penetration, which is promising for the development of a cream with anti-aging properties. Additionally, the antibacterial activity of the polymers from which the microspheres are made allows for the elimination of preservatives and parabens as cosmetic formulation ingredients.
... Squalene, the main component of skin surface polyunsaturated lipids, nurtures the skin as an emollient and antioxidant, and has hydrating and antitumor properties [12]. Tocopherols are the most prevalent antioxidants in cosmetics [13] and have been shown to be helpful in reducing erythema generated by acute UV radiation exposure edema, sunburn, photoaging, immunosuppression caused by solar radiation, and even skin cancer [14,15]. ...
Camellia oleifera oil (CO oil) extracted from C. oleifera seeds has a 2300-year consumption history in China. However, there is relatively little research regarding its non-edible uses. This study determined the physicochemical properties of CO oil extracted via direct pressing, identified its main components using GC-MS, and evaluated its antioxidant, moisturizing, and anti-inflammatory activities. The results revealed that CO oil’s acid, peroxide, iodine, and saponification values were 1.06 ± 0.031 mg/g, 0.24 ± 0.01 g/100 g, 65.14 ± 8.22 g/100 g, and 180.41 ± 5.60 mg/g, respectively. CO oil’s tocopherol, polyphenol, and squalene contents were 82.21 ± 9.07 mg/kg, 181.37 ± 3.76 mg/kg, and 53.39 ± 6.58 mg/kg, respectively; its unsaturated fatty acid (UFA) content was 87.44%, and its saturated fatty acid (SFA) content was 12.56%. CO oil also demonstrated excellent moisture retention properties, anti-inflammatory effects, and certain free radical scavenging. A highly stable CO oil emulsion with competent microbiological detection was developed using formulation optimization. Using CO oil in the emulsion significantly improved the formulation’s antioxidant and moisturizing properties compared with those of the emulsion formulation that did not include CO oil. The prepared emulsion was not cytotoxic to cells and could reduce cells’ NO content; therefore, it may have potential nutritional value in medicine and cosmetics.
... Vitamin C acts by interacting and reducing various oxidative steps involved in melanin formation thus inhibit melanogenesis. Furthermore, vitamin E would be acts by obstructing and interfering with lipid peroxidation of the membrane of melanocyte, furthur it would act by raise in cellular glutathione content as well as tyrosinase inhibition [35][36][37][38][39]. ...
Natural bleaching agents are the natural metabolites mostly obtained from plants as well as from other natural sources implied to reduce or alter melanin production in the human body. Many natural compounds exert their efficiency as skin lightening agent, i.e., vitamin C, E and niacinamide flavonoids, phenolic compounds, arbutin, kojic acid, azelaic acid, Mulberroside F, Aloin, aloesin, Glabridin, liqriritin, N-acetyl glucosamine has found as a substantial compound obtained from a natural source and could be used reduce skin condition that causes hyperpigmetation. Natural bleaching agents could be better alternatives to synthetic bleaching agents due to their biocompatatibily to the human skin.
... No study yet performed to give pleasant feel to the wearers by managing the moisture of the fabric along with maintaining fabric hand feel and strength. Vitamin E is classified as a water-insoluble vitamin and is known chemically as alpha-tocopherol which is frequently employed as an ingredient in functional cosmetics due to its ability to protect the skin from harmful oxidative stress, a leading cause of skin aging, and its excellent moisturizing properties [45]. In this regard, this study is conducted by application of Vitamin E to the flame retardant finishing system without hampering flame retarding property of the fabric along with improving moisture management capacity of the flame retardant fabric which gives pleasant feeling to the consumers. ...
The aim of this study is to analyze the use of vitamin E to enhance fabric's hand feel, moisture management and fabric strength which are affected due to flame retardant finish. Flame retardant treated fabrics typically become stiff, but the addition of Vitamin E along with emulsifier and binding agent through a vertical padding mangle by two times dipping and nipping results a soft fabric without impairing the flammability properties as determined by 45-degree flammability test. The samples were characterized by FTIR spectra, SEM images, and water contact angle. A new characteristics band is appeared at 1455 cm − 1 for skeletal vibration of phenyl ring system of alpha tocopherol for Vitamin E measured by Fourier transform infrared spectroscopy (FTIR) that proves the effective attachment of vitamin E with fabric. Hydrophilicity of vitamin E containing sample is discovered after showing 37.629 • as a water contact angle at optical tensiometer (Attension theta lite). Additionally, fabric comfort properties, moisture management properties, and mechanical properties were measured by fabric touch tester (FTT), moisture management tester (MMT) machine and tensile strength tester respectively that demonstrate significant affirmative change in almost all indexes of FTT, 43.5 % increase of overall moisture management capacity by MMT and 23 % increase of tear strength by tensile strength tester due to use of vitamin E that effectively compensate lower strength, poor fabric comfort, and low moisture management capability of flame retardant treated fabric.
... Vitamin C acts by interacting and reducing various oxidative steps involved in melanin formation thus inhibit melanogenesis. Furthermore, vitamin E would be acts by obstructing and interfering with lipid peroxidation of the membrane of melanocyte, furthur it would act by raise in cellular glutathione content as well as tyrosinase inhibition [35][36][37][38][39]. ...
Natural bleaching agents are the natural metabolites mostly obtained from plants as well as from other natural sources implied to reduce or alter melanin production in the human body. Many natural compounds exert their efficiency as skin lightening agent, i.e., vitamin C, E and niacinamide flavonoids, phenolic compounds, arbutin, kojic acid, azelaic acid, Mulberroside F, Aloin, aloesin, Glabridin, liqriritin, N-acetyl glucosamine has found as a substantial compound obtained from a natural source and could be used reduce skin condition that causes hyperpigmetation. Natural bleaching agents could be better alternatives to synthetic bleaching agents due to their biocompatatibily to the human skin.
... Vitamin E (Vit. E) is a lipophilic antioxidant which has been in use for more than 50 years in dermatology (Thiele, Hsieh, Ekanayake-Mudiyanselage, 2005). It has a primary role in protecting cell membranes against oxidative stress and maintaining the collagen network of the skin. ...
... Vitamin E (Vit E) can be found in high concentrations in the deepest layers of the stratum corneum (SC), forming the primary defense of the skin to the oxidative stress induced by UV exposure. Topical delivery of Vitamin E protects the skin against UV-caused cutaneous harm, and carcinogenic and mutagenic activity of chemical agents [21,22]. ...
In the current work, Oil in Water (O/W) and Water in Oil (W/O) emulsions containing Vitamins A, C and E in 0.5, 1 and 2% wt concentrations were prepared. The pH and viscosity stability over storage, as well as the sunscreen and antioxidant properties of the obtained emulsions, were investigated. The results obtained showed that vitamins slightly increased the pH of the blank emulsions; however, their pH values were within the acceptable values (pH = 4–6). Nevertheless, all emulsions presented excellent pH stability during storage for up to 90 days. Similar results were observed by rheological measurements as the prepared emulsions did not exhibit viscosity instabilities deriving during storage. Moreover, emulsions containing Vitamin A exhibited higher UV protection than the other emulsions, as the W/O emulsion containing 2% wt Vitamin A presented the highest SPF value at 22.6.
... The antioxidant Vitamin E (principally α-tocopherol) is a constituent of sebum secretions and it has been suggested that sebum may serve to deliver α-tocopherol to the skin surface where it functions as the main skin antioxidant [43]. However, Vitamin E acetate (α-tocopheryl acetate) is an ingredient in skin care products as an anti-aging product [49], con- This study only included adults with an age above 20 years, as this is when puberty is considered to have ceased [50,51] and thus there should be less fluctuation in hormone levels which have proven to be evident from fingermark residue [28,52]. Individuals receiving hormone or steroid treatment for illness, ailments, or for the purpose of gender affirmation [53][54][55] were also excluded as it was uncertain how this might influence fingermark residue. ...
While fingerprints are a highly used means of identification, not every fingerprint left behind on a potential crime scene can be used for identification purposes. In some cases, the fingerprint may be smudged, partially preserved or overlapping with other prints hence distorting the ridge pattern and may therefore be not appropriate for identification. Further, fingermark residue yields a very low abundance of genetic material for DNA analysis. In such cases, the fingermark may be used to retrieve basic donor information such as sex. The focus of this paper was to assess the possibility of differentiating between the sexes of the donor of latent fingermarks. Analytical method was GC-MS analysis of the chemical compounds of latent fingermarks using 22 male and 22 female donors. Results showed 44 identified compounds. Two alcohols, octadecanol C18 and eicosanol C20 , were found to show a difference that was statistically significant between male and female donors. There is also some evidence for the possibility of distinguishing sex of the fingermark donor based on the distribution of branched chain fatty acids, as free compounds or esterified in wax esters.
... Vitamin E is the major lipophilic compound, commonly found in fruits, vegetables, and seeds, present in plasma, membranes, and tissues and with strong antioxidant activity [116,117]. Vitamin E is the major lipid-soluble antioxidant in the skin, being rapidly absorbed and integrated within the lipidic skin layer, supporting the extracellular lipid matrix of the stratum corneum and contributing to enhancing its antioxidant defenses [118]. It is widely used in cosmetics due to its ability to scavenge free radicals, namely hydroxyl radical, singlet oxygen, and superoxide anion [119,120]. ...
Skin repair encompasses epidermal barrier repair and wound healing which involves multiple cellular and molecular stages. Therefore, many skin repair strategies have been proposed. In order to characterize the usage frequency of skin repair ingredients in cosmetics, medicines, and medical devices, commercialized in Portuguese pharmacies and parapharmacies, a comprehensive analysis of the products’ composition was performed. A total of 120 cosmetic products, collected from national pharmacies online platforms, 21 topical medicines, and 46 medical devices, collected from INFARMED database, were included in the study, revealing the top 10 most used skin repair ingredients in these categories. A critical review regarding the effectiveness of the top ingredients was performed and an in-depth analysis focused on the top three skin repair ingredients pursued. Results demonstrated that top three most used cosmetic ingredients were metal salts and oxides (78.3%), vitamin E and its derivatives (54.2%), and Centella asiatica (L.) Urb. extract and actives (35.8%). Regarding medicines, metal salts and oxides were also the most used (47.4%) followed by vitamin B5 and derivatives (23.8%), and vitamin A and derivatives (26.3%). Silicones and derivatives were the most common skin repair ingredients in medical devices (33%), followed by petrolatum and derivatives (22%) and alginate (15%). This work provides an overview of the most used skin repair ingredients, highlighting their different mechanisms of action, aiming to provide an up-to-date tool to support health professionals’ decisions.
... Tocopherols are potent antioxidants [8,9], prevent rancidity [10], have the capability to reduce the risk of cancer [11], and reduce inflammatory angiogenesis [12]. Vitamin E has also led to the development of numerous new formulations in cosmetics and skin care products [13]. The principal dietary sources of tocopherols are vegetable oils such as corn, soybean, sesame, and cottonseed. ...
Optimization and validation of reversed-phase high-performance liquid chromatography with fluorescence detection (RP-HPLC/FLD) for the determination of tocopherols (d, β+g, and α) were studied. In a simple sample preparation, oils were diluted in ethanol without saponification and injected directly onto Zorbax Eclipse plus C18. Acetonitrile and methanol (70:30) mixture was used as a mobile phase with a flow rate of 1 mL/min. Fluorescence detection was operated at 296 nm of excitation wavelength and 330 nm of emission wavelength. Tocopherols were separated at 30 °C in less than 15 min after injection. The method showed to be good linear (r 2 > 0.999). Mean recoveries were 97.6-100.7%, with intra-and inter-day RSD less than 3.79 and 4.11%, respectively. The detection limits and quantification limits of the method were 0.08-0.21 and 0.23-0.71 µg/mL. The technique had been applied to analyze tocopherols in thirteen cold-pressed vegetable oils extracted using a mini screw press, which were virgin oils. The results showed statistically significant differences (P < 0.5) between the kinds of oil sample. The total tocopherols content ranges from 3.62 mg/kg in Japanese pumpkin oil to 1890.71 mg/kg in sacha inchi oil.
... Proteins rich in aromatic amino acids exhibited photoscreening activities, while eumelanin, porphyrins, flavins, and hemoglobin behaved as photosensitizers molecules [87]. The efficacy of the human barrier against UV rays can be related to photoprotector/photosensitizer balance, which is susceptible to gradual deterioration through the aging progress [88]. In dermatological fields, sunscreen lotions and creams are the most popular skincare products that are recommended as primary preventive measures for UV-induced skin disorders [89]. ...
Photoaging is the premature aging of the skin caused by repeated exposure to ultraviolet (UV) rays. The harmful effects of UV rays—from the sun or from artificial sources—alter normal skin structures and cause visible damage, especially in the most exposed areas. Fighting premature aging is one of the most important challenges of the medical landscape. Additionally, consumers are looking for care products that offer multiple benefits with reduced environmental and economic impact. The growing requests for bioactive compounds from aromatic plants for pharmaceutical and cosmetic applications have to find new sustainable methods to increase the effectiveness of new active formulations derived from eco-compatible technologies. The principle of sustainable practices and the circular economy favor the use of bioactive components derived from recycled biomass. The guidelines of the European Commission support the reuse of various types of organic biomass and organic waste, thus transforming waste management problems into economic opportunities. This review aims to elucidate the main mechanisms of photoaging and how these can be managed using natural renewable sources and specific bioactive derivatives, such as humic extracts from recycled organic biomass, as potential new actors in modern medicine.
... For instance, in beverages, it was used as a fortification agent by Raikos (2017). Vitamin E nutraceuticals are suggested in the prevention and therapy of different health conditions, such as yellow-nail syndrome, claudication, cancer, collagen synthesis, cutaneous ulcers, vibration disease, wounds, and epidermolysis bullosa (Thiele et al. 2005). Moreover, some researchers also found successful results on murine nasal allergy (Zheng et al. 1999) and allergic rhinitis (Shahar et al. 2004) after the oral supplementation of vitamin E. A decrease in side effects of some schizophrenia treatments (Sivrioglu et al. 2007) and inflammation problems that occur in hemodialysis patients (Pirhadi-Tavandashti et al. 2020) have also been reported as the result of vitamin E supplementation. ...
... Tocopherol also enhances collagen synthesis while preventing collagen degradation by lowering MMP levels and maintaining tissue inhibitors of MMP expression, thus preserving the dermis' integrity [55,56]. Moreover, acute and chronic UV-mediated skin reactions such as erythema and edema, sunburn-cell formation, DNA photo-adduct creation, immunosuppression, and photocarcinogenesis have been shown to be effectively reduced by topical application of vitamin E [57,58]. ...
Ultraviolet (UV) radiation promotes the generation of reactive oxygen species (ROS) and nitrogen species (RNS), resulting in skin damage. Cosmetic industries have adopted a strategy to incorporate antioxidants in sunscreen formulations to prevent or minimize UV-induced oxidative damage, boost photoprotection effectiveness, and mitigate skin photoaging. Many antioxidants are naturally derived, mainly from terrestrial plants; however, marine organisms have been increasingly explored as a source of new potent antioxidant molecules. This work aims to characterize the frequency of the use of antioxidants in commercial sunscreens. Photoprotective formulations currently marketed in parapharmacies and pharmacies were analyzed with respect to the composition described on the label. As a result, pure compounds with antioxidant activity were found. The majority of sunscreen formulations contained antioxidants, with vitamin E and its derivatives the most frequent. A more thorough analysis of these antioxidants is also provided, unveiling the top antioxidant ingredients found in sunscreens. A critical appraisal of the scientific evidence regarding their effectiveness is also performed. In conclusion, this work provides an up-to-date overview of the use of antioxidants in commercial sunscreens for a better understanding of the advantages associated with their use in photoprotective formulations.
... In response to ultraviolet light, it can decrease the risk of carcinogenesis, rhytide formation, and erythema of the skin. It reduces skin ultrastructural oxidative damage by scavenging lipid peroxyl radicals [23]. ...
... It has also shown its potential to impede tumor development in experimentally-induced colon cancer models [85]. Simultaneously, the role of tocotrienol has also been projected in the treatment of neural diseases [86], inflammatory disorders [87,88], osteoporosis [89], respiratory disorders [90], cancer [81,91], etc. Exploration of tocotrienols has also been made for topical application, dermatologically and cosmetologically [92,93]. Furthermore, a positive response of tocotrienols has also been reported while applied to surgical wound repair [94]. ...
Healing wounds is an important attempt to keep the internal higher organs safe. Complications in topical wound healing may lead to the formation of scars, which can affect the patient’s quality of life. Although several approaches are ongoing in parallel in the exploration of natural compounds via advanced delivery, in this article, an attempt has been made to highlight tocotrienol. Tocotrienol is a natural form of vitamin E and has shown its potential in certain pharmacological activities better than tocopherol. Its antioxidant, anti-inflammatory, cell signal-mediating effects, angiogenic properties, management of scar, and promotion of wound environment with essential factors have shown potential in the management of topical wound healing. Therefore, this review has aimed to focus on recent advances in topical wound healing through the application of tocotrienols. Challenges in delivering tocotrienols to the topical wound due to its large molecular weight and higher logP have also been explored using nanotechnological-based carriers, which has made tocotrienol a potential tool to facilitate the closure of wounds. Exploration of tocotrienol has also been made in human volunteers for biopsy wounds; however, the results are yet to be reported. Overall, based on the current findings in the literature, it could be inferred that tocotrienol would be a viable alternative to the existing wound dressing components for the management of topical wounds.
... Chemically, α-tocopherol is known as a powerful antioxidant due to the presence of hydroxyl group attached to the aromatic ring, which can easily react with peroxyl radicals and thus protect the skin from the larger breakdown of skin collagen. Antioxidant supplementation of vitamin E together with synergistically active antioxidants, such as vitamin C may lead to an increase in the photoprotective effects of vitamin E (Baumann & Spencer, 1999;Thiele, Hsieh, & Ekanayake-Mudiyanselage, 2005;Nimse & Pal, 2015;Cassano, 2012). ...
The study investigates the use of fiber carriers, based on biopolymeric gums as potential candidates for cosmetic and dermatological applications, in particular for skin regeneration. Gum arabic (GA), xanthan gum (XA), and gum karaya (GK) were used as the main gum materials for the fibers, which were prepared by centrifugal spinning from an aqueous solution. These solutions of different mass gum ratios were blended with poly (ethylene oxide) (PEO) for better spinnability. Finally, vitamins E and C were added to selected solutions of gums. The resulting fibers were extensively investigated. The morphology and structure of all fibers were investigated by scanning electron microscopy and Fourier transformed infrared spectroscopy. Most importantly, they were characterized by the release of vitamin E loaded in the fibers using UV-VIS spectroscopy. The presentation will show that the newly prepared fibers from GA and PEO represent a very promising material for cosmetic and dermatologic applications.
... 7,8 Vitamin E is a group of eight natural compounds that include four tocopherols (α-, β-, γ-, and δ) and four tocotrienols (α-, β-, γ-, and δ) which contribute to its activities. 9 Vitamin E inhibits lipid peroxidation 10 and also has antioxidant and anti-inflammatory properties. 11 Omega-3 supplements are polyunsaturated fatty acids (PUFAs) that include long-chain ethyl eicosapentaenoic acid (E-EPA) and docosahexaenoic acid (DHA) as well as linoleic acid. ...
This systematic review was conducted to investigate the effects of vitamin E and omega-3 used alone and in combination on the frequency and intensity of hot flushes (primary outcomes) and adverse effects (secondary outcome) in menopausal women. English and Persian databases were searched until March 18, 2021. The quality of the published papers was evaluated using Cochrane Handbook and the meta-analysis was conducted in RevMan 5.3. Heterogeneity was assessed using I2. In cases with substantial heterogeneity, a random effects model was used instead of a fixed effects model. A total of 387 papers were obtained from the databases. Finally, 10 papers with a sample size of 1100 participants entered the systematic review and a meta-analysis was conducted on nine of them. The results of the meta-analysis of two studies indicated that using vitamin E and omega-3 in combination significantly reduced the intensity of hot flushes compared to the placebo (mean difference (MD): -0.35; 95% CI: -0.48 to -0.21). The mean frequency (MD: -0.50; 95% CI: -1.58 to 0.58) and intensity (SMD: -0.61; 95% CI: -1.50 to 0.29) of hot flushes in the omega-3 group and the frequency of hot flushes (SMD: -0.21; 95% CI: -0.47 to 0.04) in the vitamin E group showed no significant differences with the placebo. No serious adverse effects were reported in the studies. Given the low number of RCTs, more clinical trials with larger sample size are required.
... These beneficial effects include prevention of arteriosclerosis (and cardiovascular diseases) along with anti-inflammatory, immune-supporting, and anti-angiogenic effects of these micronutrients [10][11][12][13]. Also, in cosmetics (creams, make-up) vitamin E is considered an important ingredient for skin protection [14]. The National Health and Nutrition Examination Survey (NHANES, 2017-2018) indicated mean vitamin E intakes of 10.5 mg/day and 8.6 mg/ day, respectively, for adult males and females (> 19 y) from the U.S. [15]. ...
A variety of vitamin E dietary supplement capsules (DSC) based on different natural oils or synthesis products are currently found on the market whose vitamin contents need to be controlled before and after marketing. Here, we present an instrumental thin-layer chromatography (TLC) method which allows a direct determination of all tocopherols (T) and tocotrienols (T3) as well as α -tocopherol acetate simultaneously in one run with short analysis time. For this purpose, contents of the DSC were extracted, applied on silica gel 60 plates, and developed with n -hexane/ethyl acetate/acetic acid, 90:10:2 ( v/v/v ) as mobile phase. The UV scan of the plate at 293 nm was used for quantification based on the peak height. Following the scan, the plate was treated with 10% sulphuric acid in methanol which led to characteristic yellow-to-brown colouring of the tocochromanol spots which allowed to distinguish tocochromanols from matrix components with similar R f values. In most cases, determined vitamin E contents matched well with the information listed on the label of the investigated DSC samples. The method is fast, easy to perform and gently treats the analytes as it requires no thermal treatment prior to quantification, which makes it suitable as a screening method.
... The antioxidant vitamin E has also photoprotective and skin barrier-stabilizing properties [91], being indicated to atopic dermatitis, psoriasis, skin cancer prevention, wound healing, and melasma [92]. ...
... Previous studies have demonstrated that physiological lipids are sufficient to enhance lipid lamellae structure 25 The test cream also contains a significant percentage of glycerol, which has contradictory effects, appearing to promote SB repair while also acting as a penetration enhancer 26 We found a weak correlation between SC glycerol levels and lipid structure or SB integrity, suggesting a limited role. Another candidate ingredient of the test cream, tocopherol, is an antioxidant reported to protect against chemical irritation 27,28 Tocopherol scavenges free radicals, including those responsible for lipid peroxidation, which damage the structures of the SB 29 Overall, after 4 weeks of treatment, the test cream increased skin hydration on the legs by approximately 50%, whereas the reference increased hydration by <10%. The level of increased hydration imparted by the test cream was significant, taking the skin from a dry or very dry state to a sufficiently hydrated state 30 In contrast, the effect of the reference was limited, with skin dryness persisting for longer. ...
Background
The skin of atopic dermatitis (AD) patients is characterised by abnormal stratum corneum (SC) lipid levels. Consequently, the lamellar matrices are disrupted and skin barrier function is diminished, increasing skin sensitivity to irritants and allergens.
Objective
To determine whether a cream containing ceramides, triglycerides and cholesterol in a multi-vesicular emulsion can reinforce the skin barrier, and protect against skin irritation.
Methods
A randomized observer-blind intrasubject-controlled study in 34 adults with dry, eczema-prone, skin was conducted. Each participant underwent 4 weeks treatment with the test cream on one forearm and lower leg and a reference emollient cream on the other. Skin properties were determined before and after treatment. Lipid structure was assessed by FTIR spectroscopy using a novel interface.
Results
Skin barrier integrity was greater at sites treated with the Test cream (effect size -161.9 area-under-the-TEWL-curve, 95% CI -205.5, -118.3), and skin sensitivity to sodium lauryl sulfate reduced (-0.5 points [97.57% CI -1.00, -0.25] visual redness and -15.34 g/m²/h [95% CI -20.28, -10.40] TEWL) compared to the reference. Sites treated with the test cream displayed enhanced lipid chain ordering, which was significantly associated with skin barrier integrity (r0.606). Compared to the reference, treatment with the Test cream increased hydration (8.61 capacitance units, 95% CI 6.61 to 10.60) and decreased signs of dryness.
Conclusion
The Test cream facilitates skin barrier restoration and protects the skin from dryness and irritation. Compared to a commonly prescribed emollient in the UK, the Test cream is highly suited to the management of dry, sensitive, skin.
... Vitamin E is known to have a key role in the prevention of many pathogens thanks to its anti-inflammatory effects (Konieczka et al., 2019). It is therefore a pivotal nutrient in dermatological application (Thiele et al., 2005) because it seems to affect collagen turnover to improve wound healing (Hobson, 2016). ...
DEVELOPING BIOACTIVE MATERIALS FOR DENTAL APPLICATIONS
The rise in the use of cosmeceuticals among children and adolescents has created a new challenge for dermatologists, who are confronted with the task of advising young patients on the risks that these products can carry and the often questionable efficacy of these products. While some cosmeceuticals can be beneficial for this population when used correctly, such as broad‐spectrum sunscreen or specific anti‐acne agents, other products may not carry benefits for young skin and could even cause complications, particularly in young consumers who have skin conditions such as acne or atopic dermatitis. Many of the common ingredients in cosmeceutical products have had very limited (if any) studies conducted in pediatric populations, and much of the data regarding the efficacy claims and risks of these products must be inferred from studies in adult patients.
Hyperpigmentation is a common dermatological condition characterized by the darkening of patches of skin compared to the surrounding areas. It can occur in individuals of all skin types and ethnicities, and is caused by an overproduction or accumulation of melanin, the pigment responsible for the color of our skin, hair, and eyes. This comprehensive overview aims to delve into the various types, causes, risk factors, clinical manifestations, diagnosis, and treatment options for hyperpigmentation. Additionally, it explores the global and national prevalence of hyperpigmentation, its etiology, pathophysiology and diagnosis and treatment strategies. Furthermore, examines the formulations and dosage forms used to treat hyperpigmentation, including their side effects. It also discusses combination drugs and their associated side effects, as well as novel drug delivery systems and nanocarriers employed in the treatment of hyperpigmentation, providing insight into future prospects in this field.
This manuscript introduces a novel, green, paper-based format for directly quantifying antioxidant capacity in emulsions using the DPPH assay. This method eliminates the need for extraction or any other pre-treatment steps. Quantification relies on analyzing the color intensity captured by a digital camera. The optimization of assay parameters is described in terms of reagent concentration, reaction time and color channel for monitoring. The assay demonstrates a linear relationship between antioxidant concentration and camera-captured color intensity, for both water soluble and non-soluble antioxidants: a correlation coefficient of at least 0.965 was calculated upon fitting the antioxidant concentration versus color intensity data to the linear model, which is an indicator of their strong linear correlation. Half-maximal effective concentrations were calculated and aligned with literature reports. The ability to incorporate higher concentrations of non-polar compounds in emulsions allowed for studying antioxidants like α-tocopheryl acetate, which are typically limited by solubility in solution-based assays. Acceptable technical parameters were obtained for vitamin C in an oil-in-water emulsion: the coefficient of variation was ≤18.4 %, while the relative error was ≤±11.9 %, across quality control levels. Analysis of commercial samples showed a relative error of ≤±7.7 %. The pros of the proposed format are being discussed in terms of its green character and simplicity and the possibility to provide a more realistic assessment of antioxidant effectiveness in emulsions. An additional advantage is the possibility to study the radical quenching capacity of highly insoluble compounds, which is a limitation of conventional solution-based assays. Cons are also considered mainly with regards to the inability of the assay to follow the kinetics of the radical scavenging reaction, making it suitable for measuring antioxidant capacity rather than activity.
There is overwhelming evidence from in vitro and in vivo investigations as well as animal and human studies that incorporation of some vitamins in skincare products and cosmeceuticals promote healthy skin and re-engineer the skin to a healthy state. This comprehensive review illustrates the protective roles of vitamins A, B3, C, D, and E in skin- care products and cosmeceuticals. We have evaluated the impact of vitamin-based skincare products on the skin microbiomes and reviewed the popular vitamin-based cosmeceuticals. Our review also identifies the gaps in our knowledge for future research and describe the potential mechanisms of vitamins to promote skin health and reduce wrinkle formation in the ageing skin. The challenges and future opportunities in the area of cosmeceuticals and skincare products also are discussed, along with consumer perceptions, safety implications, and the comparison of dietary vitamin intake as opposed to topical applications. Overall, the aims of this review are to enhance our understanding regarding the physiological role of vitamins in skincare products and cosmeceuticals and to rejuvenate the skin towards healthy state. Such information would provide a valuable resource for consumers, dermatologists, and stakeholders in this important and evolving field of environmental skin protection and anti-aging research in elderly population.
The aim of this study is to analyze the use of vitamin E to enhance fabric's hand feel, moisture management and fabric strength which are affected due to flame retardant finish. Flame retardant treated fabrics typically become stiff, but the addition of Vitamin E along with emulsifier and binding agent through a vertical padding mangle by two times dipping and nipping results a soft fabric without impairing the flammability properties as determined by 45-degree flammability test. The samples were characterized by FTIR spectra, SEM images, and water contact angle. A new characteristics band is appeared at 1455 cm⁻¹ for skeletal vibration of phenyl ring system of alpha tocopherol for Vitamin E measured by Fourier transform infrared spectroscopy (FTIR) that proves the effective attachment of vitamin E with fabric. Hydrophilicity of vitamin E containing sample is discovered after showing 37.629° as a water contact angle at optical tensiometer (Attension theta lite). Additionally, fabric comfort properties, moisture management properties, and mechanical properties were measured by fabric touch tester (FTT), moisture management tester (MMT) machine and tensile strength tester respectively that demonstrate significant affirmative change in almost all indexes of FTT, 43.5 % increase of overall moisture management capacity by MMT and 23 % increase of tear strength by tensile strength tester due to use of vitamin E that effectively compensate lower strength, poor fabric comfort, and low moisture management capability of flame retardant treated fabric.
The term cosmeceutical refers to a category of skincare products that are purported to have active ingredients whose physiological or pharmacological actions are capable of inducing cosmetic enhancements to the skin. Given a demand for brighter, healthier, younger‐appearing skin, and relatively limited regulatory control, thousands of different cosmeceutical formulations have found their way onto store shelves and onto the skin of hopeful consumers, despite a lack of scientific evidence. This chapter summarizes new and old, common and rare cosmeceutical ingredients; their uses and side effects; and the science, where available, behind the claims.
Background:
Skin aging is regulated by multiple physiological processes, such as oxidative stress. Natural products have been considered as a promising source of antioxidant compounds. As a result, few innovative products on the market based on natural products tackle additional underlying mechanisms of skin aging.
Aims:
The present work reports the nonclinical evaluation of a novel extract from the skin of V. vinifera fruits (codified as ACH37 extract), with the aim of supporting its use as an antiaging cosmetic ingredient candidate in clinical trials.
Methods:
We employed enzymatic, phenotypic, and gene expression assays, both in vitro and ex vivo, to investigate the action of the ACH37 extract in different biological processes that could be related to skin aging mechanisms.
Results:
The ACH37 extract was able to scavenge reactive oxygen species (DPPH, O2 - ), prevent inflammation (LPS- and UV-induced COX-2, IL-1β, and IL-8 expression), modulate extracellular matrix remodeling (inhibiting elastase, MMP-1, MMP-3, and MMP-12, as well as associated expression), increase telomere length, telomerase activity, and reverse the UV-induced suppression of genes involved in skin protection. In addition, the ACH37 extract permeated human skin explants and presented antioxidant efficacy ex vivo.
Conclusion:
The results indicated that the ACH37 extract acts on multiple targets commonly related to skin aging, being a promising antiaging active ingredient candidate to be further investigated in clinical trials.
During the last decades, there has been a huge consumer concern about animal proteins that has led to their replacement with plant proteins. Most of those proteins exhibit emulsifying properties; thus, the food industry begins their extensive use in various food matrices. In the present study, pea and soy protein isolates (PPI and SPI) were tested as potential candidates for stabilizing food emulsions to encapsulate α-tocopherol and squalene. More specifically, PPI and SPI particles were formulated using the pH modification method. Following, emulsions were prepared using high-shear homogenization and were observed at both a microscopic and macroscopic level. Furthermore, the adsorption of the proteins was measured using the bicinchoninic acid protein assay. The emulsions’ droplet size as well as their antioxidant capacity were also evaluated. It was found that the droplet diameter of the SPI-based emulsions was 60.0 μm, while the PPI ones had a relatively smaller diameter of approximately 57.9 μm. In the presence of the bioactives, both emulsions showed scavenging activity of the 2,20-Azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cation (ABTS·+) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, with the ones loaded with α-tocopherol having the greatest antioxidant capacity. Overall, the proposed systems are very good candidates in different food matrices, with applications ranging from vegan milks and soups to meat alternative products.
The novel discoveries of biologically active compounds from medicinal plants have driven various research fields toward establishing essential sources of natural drug candidates. Tabernaemontana ventricosa Hochst. ex A. DC. (Apocynaceae) is a medicinal plant often used to palliate fever, treat wounds, and reduce blood pressure. The present study aimed to examine the organoleptic characters, elemental composition, phytochemical compounds and evaluate the antibacterial activity of the crude leaf, stem, and latex extracts of T. ventricosa. The microscopic analyses of the organoleptic characters, fluorescence analysis, and elemental composition revealed no harmful compounds. Qualitative phytochemical screening of the extracts detected alkaloids, flavonoids, saponins, sterols, steroids, phenols, fats, fixed oils, carbohydrates, and amino acids. These results correspond to the significant chemical classes observed within Tabernaemontana. The chemical composition of the crude leaf and stem, and latex extracts determined by Gas Chromatography-Mass Spectrometry (GC–MS) analysis showed alkaloids, terpenes, phytosterols, and fatty alcohols. Major identified compounds (>1%) in all extracts were α-linolenic acid, pentadecanoic acid, α-d-mannofuranoside, methyl, 13-docosenamide, (Z)-, 9,12-octadecadienoic acid (Z, Z)-, lup-20(29)-en-3-ol, acetate, (3β), 9,19-cyclolanost-24-en-3-ol, (3β) and β-amyrin. These compounds possess pharmacological effects such as antibacterial, anti-inflammatory, and anticancer properties. The antibacterial activity was evaluated using various extracts, with different concentrations against gram-positive and gram-negative bacterial strains. Substantial antibacterial activity of the methanolic extracts of the leaf and stem and latex extracts were observed against Bacillus subtilis (ATCC 6653), Escherichia coli (ATCC 25922), Methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), Staphylococcus aureus (ATCC 29213), and Pseudomonas aeruginosa (ATCC 27853) respectively. Leaf and stem hexane extracts showed considerable activity against B. subtilis and MRSA. Conversely, E. coli, MRSA, S. aureus, and P. aeruginosa displayed resistance or minimal activity at relatively low concentrations. These results suggest that the extracts of T. ventricosa have a substantial antibacterial activity that justifies their use in traditional medicine. Further studies should be considered to establish the full pharmacological potential of this species.
Background
Melasma is a common disorder of hyperpigmentation that affects populations globally and can adversely affect quality of life. Topical therapies—including hydroquinone and nonhydroquinone‐containing formulations—play a central role in the management of melasma.
Methods
A literature review was conducted using PubMed and Google Scholar. Search keywords included a combination of the following: “melasma,” “chloasma,” and “topical treatment.” We identified and included seminal and high‐quality peer‐reviewed publications, systematic reviews, randomized controlled trials, case series, case reports, consensus statements, and expert opinions.
Results
Topical therapies are widely used for the treatment of melasma. Triple combination cream containing hydroquinone, fluocinolone, and tretinoin is the most studied formulation with the strongest evidence among treatment options. Numerous other prescription‐based and nonprescription topical agents, including a growing list of cosmeceuticals, have been used in the treatment of melasma, albeit in smaller studies.
Conclusion
A growing range of topical agents is available for the treatment of melasma. While larger, more robust studies are warranted, nonhydroquinone cosmeceuticals may be useful adjuncts or alternatives to the gold standard of triple‐combination hydroquinone cream.
Melasma is a common malady affecting all races with a higher incidence in Hispanics, Middle Eastern, Asians and African origin females (Fitzpatrick skin phototypes III‐V). Women are affected much more often than men. Melasma remains a significant cause of cosmetic morbidity and psychosocial embarrassment affecting quality of life necessitating effective and reliable treatment. Unfortunately, treatment remains unsatisfactory due to limited efficacy, adverse effects and relapses after stopping treatment. Although chemical peels, laser and light therapies and dermabrasion may have utility, the evidence available for their efficacy is limited and they often cause post inflammatory hyperpigmentation particularly in individuals with darker skin types. Medical therapies remain mainstay in the management of melasma. The triple combination, hydroquinone 4%, tretinoin 0.05% and fluocinolone acetonide 0.01% (Triluma, Galderma, Ft. Worth Texas, often modified incorporating different corticosteroids) remains the only US FDA approved treatment for melasma and is the gold standard due its demonstrated efficacy across ethnicities. Oral tranexamic acid alone or in combination with other modalities has also shown significant efficacy. Several cosmeceuticals and botanical extracts used as skin lightening agents have been demonstrated to be useful. Physical sunscreens containing zinc oxide, iron oxide, titanium dioxide, and silicones provide photoprotective and camouflage effect. We propose that a multimodality approach to the treatment of melasma is the most effective treatment approach. This review is focused on the medical therapies for melasma.
Conventional treatments for atopic dermatitis include topical corticosteroids, emollients, and topical and/or systemic immunomodulators (e.g., dupilumab). However, there is an increasing interest and demand from patients for alternative therapies. In this chapter, we discuss CAM approaches with clinical evidence in atopic dermatitis. Topics discussed include topical and oral oils, topical and oral micronutrients, bathing additives, fabrics, and topical endocannabinoids. Evidence-based CAM therapies can be strategically integrated with conventional therapies to augment response in appropriate cases.
Many people in developing countries rely primarily on medicinal plants as their main source of healthcare, particularly for the treatment of skin infections. Despite the widespread use of medicinal plants, there is a lack of literature describing the relevance and risks of exposure of the phytochemicals present. Galenia africana has been used traditionally in the form of pastes, decoctions, and lotions to treat wounds and other skin-related ailments. This is a report on the phytochemical composition of G. africana and a review on the pharmacological importance and relevance of these phytochemicals. The major groups of phytochemicals identified in G. africana extracts were aliphatics, aliphatic triterpenoids, fatty acids, flavonoids, and phenolic and tocopherol compounds. These have been found to exhibit medicinal properties, thus highlighting the need to assess the safety of G. africana for topical application. The information related to the safety of the various compounds could indicate the potential risks related to accidental intake of the extract upon topical product applications. This report concludes that the quantities of the phytochemicals present in G. africana should not cause undue risk to human health, which provides comfort to pursue future work on using and developing G. africana as a therapeutic agent.
Pulmonary alveolar proteinosis (PAP) can be due to primary autoimmune and secondary causes, including e‐cigarette, or vaping, product use‐associated lung injury. We present a 33‐year‐old male presenting with PAP and a history of vaping. Serum anti‐granulocyte‐macrophage colony‐stimulating factor antibodies were present. Vitamin E (VE), but not VE acetate, was detected in bronchoalveolar lavage. This is the first report of potential association between vaping and autoimmune PAP. We present a 33‐year‐old male presenting with pulmonary alveolar proteinosis (PAP) and a history of vaping. Serum anti‐granulocyte‐macrophage colony‐stimulating factor antibodies were present. Vitamin E (VE), but not VE acetate, was detected in bronchoalveolar lavage. This is the first report of potential association between vaping and autoimmune PAP.
The skin of the skh-1 mouse after ultraviolet B (280-320 nm, UVB) irradiation shows the pathological changes typical of sunburn damage: spongiosis (edematous spaces) around some cells, necrosis of keratinocytes, giving rise to sunburn cells, inflammatory infiltration of polymorphonuclear leucocytes, etc. In our previous study, these were accompanied by erythema, increased skin sensitivity, and edematous swelling. The topical application of tocopherol acetate (TA) immediately after the UVB exposure decreased these changes. In this paper, multiple measurements of the skin thickness were made at different locations along the magnetic resonance imaging (MRI) cross-sectional image of the skin. This permits effects to be quantified with (if desired) the contralateral half of the back serving as an internal control, either exposed (positive control) or unexposed (negative control). Topical application of TA resulted in an increase in the concentration of free tocopherol in the skin. No qualitative differences in ultrastructural appearance of the UVB-irradiated, TA-treated skin could be discerned by careful examination. In vivo high resolution video microscopy of blood flow in venules of the irradiated mouse ear revealed a large (tenfold) but not statistically significant decrease in stationary lymphocytes adhering to the venule walls. The delaying of the application of TA up to 8 hours after the termination of UVB irradiation still offered statistically significant protection as did immediate application of 5% TA in diluent Myritol 318 (Delios S, Henkel).
Radioactive tocopherol acetate was diluted with either (1) unlabelled tocopherol acetate or (2) Delios S (Henkel, a medium chain triglyceride prepared from fractionated coconut oil), a cosmetic base. These preparations were applied topically to a 2 cm diameter circle of skin. After 24 hours the percent of label which was still removable by swabbing the skin surface was 1.7% for (1) and 11.5% for (2). The central circles contained 2.86% of the label applied in 259 mg skin for (1) and 24.2% of the label applied in 226 mg skin for Delios S for (2). Surprisingly, combined samples of approximately one third of the side skin contained 0.7% of the label applied in 460 mg for (1) and 13.2% of the applied label in one third of the side skin in 523 mg for (2). The percent conversion to tocopherol in the skin central areas was 4.52% by HPLC and 4.13% by TLC for (1) and 5.97% for (2). In the side skin the percent conversion to tocopherol was 5.0% for (1) and 6.01% for (2).
Ultraviolet B (UVB, 290-320 nm) exposure results in a variety of cellular insults including induction of cyclobutane pyrimidine dimers in DNA. Accumulation of these lesions can lead to mutations in critical genes and contribute to the development of nonmelanoma skin cancer. Topically applied alpha-tocopherol (vitamin E) has previously been shown to prevent the induction of skin tumors in UVB irradiated female C3H/HeNTac mice. We hypothesized that alpha-tocopherol, which absorbs strongly in the UVB, may act as a sunscreen to prevent photodamage. To explore possible mechanisms of photoprotection, we topically applied alpha-tocopherol dispersed in a neutral cream vehicle to the dorsal epidermis of female C3H/HeNTac mice and exposed them to 2.5 J/m2/s of UVB for 60 min. Immediately after exposure, we analyzed thymine dimer levels in DNA by capillary gas chromatography with electron capture detection. Epidermal DNA from mice receiving this UVB dose contained 247 +/- 42 pmol thymine dimers/micromol thymine. Topical application of alpha-tocopherol inhibited dimer formation in a dose-dependent manner. A 1% alpha-tocopherol dispersion inhibited the formation of thymine dimers to 43% of levels in vehicle controls. Several vitamin E compounds, including alpha-tocopherol acetate, alpha-tocopherol methyl ether, gamma-tocopherol, and delta-tocopherol also inhibited thymine dimer formation, but were five- to ten-fold less potent than alpha-tocopherol. A variety of commercially available sunscreens were also less potent than alpha-tocopherol in their ability to reduce dimer formation. These results suggest that DNA photoprotection is an important mechanism by which topically applied alpha-tocopherol can inhibit UVB induced skin cancer. Alpha-Tocopherol acetate, the most common form of vitamin E in commercial skin care products, conferred less protection, perhaps due to its lower absorptivity in the UVB. Our results further underscore the importance of determining which forms of vitamin E can inhibit specific lesions involved in photocarcinogenesis.
Tocopherol, the major biologically active form of vitamin E, represents a frequently added lipophilic compound of skin care products. Despite its emerging use in rinse-off formulations, little is known on its efficacy with respect to its deposition or its antioxidant potential in human skin. The objective of this study was to investigate whether the single use of an ·-tocopherol-enriched rinse-off product provides effective deposition of ·-toco-pherol on human stratum corneum. To test this, forearm skin of 13 volunteers was washed either with an ·-toco-pherol-enriched rinse-off product (test product, TP) or with an ·-tocopherol-free vehicle control (control product , CP) (contralateral arm) using a standardized wash protocol. Thereafter, skin surface lipids were extracted with pure ethanol after the wash procedure as well as after 24 h. Additionally, one group of volunteers was subjected to irradiation of their forearms with low-dose UVA (8 J/cm 2) prior to lipid extraction. Skin lipid extracts were analyzed by high performance liquid chromatography using electrochemical detection for vitamin E and UV detection for squalene (SQ) and squalene monohy-droperoxide. The results of this in vivo study demonstrated that (1) while CP treatment lowers, TP treatment strongly increases ·-tocopherol levels of skin barrier lip-ids; (2) increased vitamin E deposition levels were maintained for a period of at least 24 h, and (3) TP treatment significantly inhibited photooxidation of SQ. In conclusion , the use of ·-tocopherol-enriched rinse-off products may help to maintain the integrity of the skin barrier by providing protection against photooxidative stress at the level of skin surface lipids.
The objective of this research was to investigate the permeation and metabolism of alpha-tocopheryl acetate (alpha-TAc) and alpha-tocopherol (alpha-T) from solution and emulsion formulations and to delineate the kinetics of such metabolism. Simple formulations containing alpha-TAc and alpha-T were applied to fresh, viable micro-Yucatan skin dermatomed to a thickness of 250-300 mum, as a finite dose in a flow-through diffusion system. The experiments were stopped at time intervals of 2, 6, 12, and 24 hours. At the end of each time interval, the amounts removed by washing, retained in the stratum corneum (SC), and penetrated into the viable skin and receptor were determined by a validated HPLC method. Receptor concentrations were below the limit of detection. alpha-TAc underwent metabolism in pig skin to the active antioxidant alpha-T. The metabolite appeared as early as two hours after application. The extent of metabolism was highest at 6-12 hours after application, No metabolism was detected in the stratum corneum. Delivery of alpha-T from isopropyl myristate (IPM) solution was more efficient than utilization of alpha-TAc from the same solution. Approximately 1.5% of alpha-T yielded the same viable skin concentration as 5% alpha-TAc. Topical application of alpha-tocopherol or its prodrug acetate was capable of enhancing the overall antioxidant capacity of pig skin. The hydrolytic pathway of alpha-TAc leading to the active antioxidant alpha-T could possibly be saturable.
A search of the literature has not revealed any reports of allergic eczematous contact dermatitis due to the topical application of vitamin E. A case of contact allergy to synthetically produced α-tocopherol is herein reported. It is felt that this is a rare event in view of the fact that this vitamin is widely used topically in this country and abroad.
Es wird eine Literaturübersicht über neuere Forschungsergebnisse auf dem Gebiet der topischen Anwendung von Vitamin E gegeben. In diesem Zusammenhang werden auch einige bisher unveröffentlichte Wirkungen von Vitamin E auf die Haut beschrieben und Angaben zu möglichen Wirkungsmechanismen gemacht. Vitamin E übt im gesamten Organismus eine außerordentlich wichtige Schutzfunktion aus. Für die breite biologische Wirksamkeit von Vitamin E sind im wesentlichen zwei Eigenschaften verantwortlich: 1) Es ist ein sehr effizientes lipophiles Antioxidans, das die Lipidperoxidation hemmt. 2) Durch die verzweigte Seitenkette in der natürlichen Konfiguration besitzt es eine hohe Affinität zu biologischen Membranen und stabilisiert sie durch physikalische Wechselwirkungen. Sowohl für kosmetische als auch für dermatologische Zwecke ist eine lokal erhöhte Vitamin-E-Versorgung von großem Nutzen, wie anhand zahlreicher Beispiele belegt werden kann. Wegen des guten Penetrationsvermögens durch die Haut ist oft die topische Applikation vorteilhaft. Als Beispiele für seine Wirkung im kosmetischen Bereich werden angeführt: Vitamin E verbessert die Mikrozirkulation in der Haut, fördert das Haar-wachstum, schützt vor UV-Lichteinwirkung, verzögert den Hautalterungsprozeß und beeinflußt die Hautfeuchtigkeit günstig. Beim dermatologischen Einsatz kann hervorgehoben werden: Entzündungen werden gehemmt, Gingivitis wird zurückgedrängt, Juckreiz wird gelinder, Wundheilung und Vernarbung werden verbessert, Aknebehandlung wird unterstützt und Pilzerkrankungen werden bekämpft. Die dermatologischen und kosmetischen Befunde bedürfen vielfach noch genauerer mechanistischer Erklärungen. Es ist zu erwarten, daß spezielle biochemische, insbesondere zellbiologische Untersuchungen zur Aufklärung von Wirkprinzpien auf diesem Gebiet beitragen.
Currently available kwowledge on 1)the presence and physiological distribution of natural antioxidants in skin 2)their response to oxidative environmental stressors 3)the photoprotective potential of topically applied antioxidants.
— The photoprotective effect of topically applied α-tocopheryl acetate (vitamin E acetate), a stable derivative of α-tocopherol (vitamin E), and its possible bioconversion to the active antioxidant species (α-tocopherol) was examined in skin tissue of female hairless mice (HRS/J) exposed to UV-B irradiation. Our results indicate that topically applied α-tocopheryl acetate is absorbed into and retained by skin tissue. Furthermore, skin tissue from UV-B-irradiated animals that received daily topical α-tocopheryl acetate treatments contained significantly higher levels (P < 0.001) of α-tocopheryl acetate than non-UV-B-irradiated mice that received identical daily topical α-tocopheryl acetate treatments. Finally, free α-tocopherol levels in skin also were significantly increased (P < 0.00 1) by topical applications of α-tocopheryl acetate and skin levels of free α-tocopherol were significantly greater (P < 0.001) in UV-B-irradiated animals that received daily topical α-tocopheryl acetate treatments than in non-UV-Birradiated animals. These results suggest that UV-B irradiation enhances both the absorption of α-tocopheryl acetate and its bioconversion to free α-tocopherol.
Background: In Spring 1992, an epidemic outbreak of papular and follicular rashes caused by a new line of cosmetics occurred throughout Switzerland. Objective: Epidemiological and clinical data were collected in order to identify the offending agent and to specify the pathophysiological mechanisms. Methods: The data concerning 263 patients seen by dermatologists plus 642 additional cases directly reported by consumers to the manufacturer were analyzed. Seventy-seven patients were patch-tested, 26 extensively, and 15 performed a repeated open application test for a duration of 4 weeks. Control patch and use tests were performed in 73 and 25 patients, respectively. The results were analyzed statistically. In addition, 12 skin biopsies were performed for histological examination. Biochemical studies on the cosmetics (final products and offending ingredient) supplemented the clinical studies. Results: The lesions were mainly papular and follicular, widely distributed, with pronounced pruritus, which was aggravated by sweating or heat exposure, and were long lasting. In a few cases, the papules were located on intensely erythematous, well-defined plaques, suggesting irritation rather than allergy. Both immediate and delayed onsets of the lesions were observed. Skin biopsies showed signs of folliculitis and perifolliculitis with little alteration of the interfollicular epidermis. Patch and use testing disclosed vitamin E linoleate® (a mixture of tocopheryl esters, mainly tocopheryl linoleate) as the offending agent. An in vitro time-dependent formation of oxidative products under storage or oxidation-stimulating conditions was observed. Conclusion: Though vitamin E esters have been widely and safely used for decades in dermatological preparations and in cosmetics, vitamin E linoleate was the cause of about 1,000 cases of unusual papular mainly follicular contact dermatitis. Oxidized vitamin E derivatives could act in vivo as haptens and/or irritants, possibly with synergistic effects.
Background. Vitamin E is a generic term for a group of tocol and tocotrienol derivatives. Since the discovery that vitamin E is the major lipid soluble antioxidant in skin, this substance has been tried for the treatment of almost every type of skin lesion imaginable. Anecdotal reports claim that vitamin E speeds wound healing and improves the cosmetic outcome of burns and other wounds. Many lay people use vitamin E on a regular basis to improve the outcome of scars and several physicians recommend topical vitamin E after skin surgery or resurfacing.Objective. We attempted to determine whether topically applied vitamin E has any effect on the cosmetic appearance of scars as suggested by multiple anectodal reports.Methods. Fifteen patients who had undergone skin cancer removal surgery were enrolled in the study. All wounds were primarily closed in 2 layers. After the surgery, the patients were given two ointments each labeled A or B. A was Aquaphor, a regular emollient, and the B was Aquaphor mixed with vitamin E. The scars were randomly divided into parts A and B. Patients were asked to put the A ointment on part A and the B ointment on part B twice daily for 4 weeks. The study was double blinded. The physicians and the patients independently evaluated the scars for cosmetic appearance on Weeks 1, 4, and 12. The criteria was simply to recognize which side of the scar looked better if there was any difference. The patients’ and the physicians’ opinions were recorded. A third blinded investigator was shown photographs of the outcomes and their opinion was also noted.Results. The results of this study show that topically applied vitamin E does not help in improving the cosmetic appearance of scars and leads to a high incidence of contact dermatitis.Conclusions. This study shows that there is no benefit to the cosmetic outcome of scars by applying vitamin E after skin surgery and that the application of topical vitamin E may actually be detrimental to the cosmetic appearance of a scar. In 90% of the cases in this study, topical vitamin E either had no effect on, or actually worsened, the cosmetic appearance of scars. Of the patients studied, 33% developed a contact dermatitis to the vitamin E. Therefore we conclude that use of topical vitamin E on surgical wounds should be discouraged.
Skin plays an important part in the protection against oxidative stressors, such as ultraviolet radiation, ozone, and chemicals. This study was based on the observation that upper facial stratum corneum contained significantly higher levels of the antioxidant alpha-tocopherol than corresponding layers of arm stratum corneum. We hypothesized that the underlying mechanism involves sebaceous gland secretion of vitamin E. To test this, we examined in eight human volunteers: (i) stratum corneum levels and distribution profiles of vitamin E in sites with a different sebaceous gland density (arm versus cheek); (ii) whether vitamin E is a significant constituent of human sebum; and (iii) if there is a correlation between levels of vitamin E and squalene, a marker of sebum secretion, in skin surface lipids. Using standardized techniques for stratum corneum tape stripping and sebum collection, followed by high-performance liquid chromatography analysis of tocopherols and squalene, we found that: (i) the ratio of cheek versus upper arm alpha-tocopherol levels was 20 : 1 for the upper stratum corneum and decreased gradually with stratum corneum depth; (ii) vitamin E (alpha- and gamma-tocopherol forms) is a significant constituent of human sebum and is continuously secreted at cheek and forehead sites during a test period of 135 min; and (iii) vitamin E correlates well with levels of cosecreted squalene (r2 = 0.86, p < 0.001). In conclusion, sebaceous gland secretion is a relevant physiologic pathway for the delivery of vitamin E to upper layers of facial skin. This mechanism may serve to protect skin surface lipids and the upper stratum corneum from harmful oxidation.
Synopsis
This paper assesses the suitability of UVB induced skin erythema measured by reflectance spectrophotometry in humans as a model for differentiating topical efficacy of free radical scavengers. Two different formulations (aqueous gels and O/W emulsions) of each active compound (tocopherol, tocopherol acetate, superoxide dismutase (SOD), glutathione, ascorbyl palmitate) were tested on healthy human volunteers before and after skin exposure to UVB radiation. Skin erythema was monitored by calculating erythema index values from the skin spectral data obtained using a reflectance spectrophotometer. The free radical scavengers tested were not able to inhibit UVB induced skin erythema from both formulations when they were topically applied before UVB irradiation. Applying the free radical scavenger formulations after skin exposure to UVB radiation, glutathione and SOD showed the best ability in inhibiting the induced erythema (percentage inhibition 53.3 and 41.6%, respectively from gels). Tocopherol and tocopherol acetate inhibited UVB skin erythema by 27% while ascorbyl palmitate showed a poor efficacy. For all the active compounds tested, no significant difference was observed comparing the results obtained from gels to those from emulsions. Liposomal gel formulations containing the free radical scavengers which showed the best activity (SOD and glutathione) were prepared and topically applied after skin exposure to UVB radiation. SOD and glutathione liposomal formulations were more effective than the corresponding conventional gels. The proposed model, if validated by further studies, could be useful for differentiating the effectiveness of free radical scavengers in inhibiting photoaging due to long‐term sunlight skin exposure.
VITAMIN E (α-tocopherol) and vitamin C (ascorbic acid) react
rapidly with organic free radicals, and it is widely accepted that the
antioxidant properties of these compounds are responsible in part for
their biological activity1-5. Tissue vitamin C levels are
often considerably greater than those of vitamin E, for example in liver
the values are approximately 2 mM and 0.02 mM, respectively.
Nevertheless, vitamin E is considerably more lipophilic than vitamin C,
and in biomembranes has been found to be the more potent antioxidant,
particularly with respect to lipid peroxidation; penetration to a
precise site in the membrane may be an important feature of the
protection against highly reactive radicals6. Tappel has
suggested that the two vitamins act synergistically, vitamin E acting as
the primary antioxidant and the resulting vitamin E radical then
reacting with vitamin C to regenerate vitamin E7. We now
report direct observation of this interaction, which we feel may be an
important feature in the maintenance of vitamin E levels in tissues.
Exposure of the skin of the back of skh-1 hairless mice to UVB (310 nm peak) irradiation at doses of 0.115-0.23 J/cm2 results after 24-48 h in an erythema which can be quantified using an erythema meter, providing a useful model of sunburn. Application of pure d-alpha-tocopherol acetate, a thick oil, to the skin immediately following the exposure to UVB significantly reduces the increase in erythema index, by 40-55%. At the lower dose (0.115 J/cm2), skin thickness (associated with edematous swelling of the sunburned skin) was measured by a novel non-invasive technique not previously reported for this purpose--magnetic resonance imaging (MRI). In two experiments the UVB-induced increase in skin thickness was significantly reduced at 24 hr by 29 and 54%, and at 48 hr by 26 and 61%. After 8 days the untreated irradiated mouse skin still showed a significant increase in thickness (24%) compared to the untreated unirradiated control, while the treated irradiated control was not significantly thicker than the unexposed control. Skin sensitivity was tested using a modification of the technique of esthesiometry, by observing rapid avoidance responses of the mouse to a pressure of 0.96 g/cm2 exerted by applying to the skin the tip of a nylon esthesiometer fiber extended to 60 mm in length. The untreated irradiated mice were more sensitive (p less than 0.07, Wilcoxon test) than the treated irradiated mice, and also significantly different from the untreated unirradiated control mice (p less than 0.04, Wilcoxon test), but the treated irradiated mice were not significantly differently sensitive when compared to the unirradiated controls (p less than 0.32). Taken together these data indicate that the erythema, edema, and skin sensitivity commonly associated with UVB-induced sunburn are significantly reduced by topical application of tocopherol acetate even after the exposure has occurred. This observation suggests that treatment of sunburn may be possible even after the irradiation has stopped, by a derivative of d-alpha-tocopherol which is stable to autooxidation.
Hairless mice were fed diets containing different levels of vitamin E or received topical applications of the vitamin for three weeks before a single exposure equivalent to one minimal erythematous dose of ultraviolet light provided by an artificial sunlight source. Lipid peroxidation and suppression of incorporation of thymidine into DNA were used to estimate the degree of damage caused by the radiation. Restriction of dietary vitamin E had little effect on degree of epidermal lipid peroxidation or on thymidine incorporation into DNA. High dietary levels of the vitamin did not alter the degree of lipid peroxidation; however, the incorporation of thymidine was restored to levels comparable to those of unirradiated animals. Topical administration of a 1% solution of the vitamin in ethanol 1 or 24 hours before irradiation also restored thymidine incorporation and reduced the degree of lipid peroxidation. The results suggest that both dietary and topical vitamin E are effective in protecting the epidermis against some of the early damage induced by ultraviolet radiation.
4 cases of cosmetic allergy to tocopheryl acetate are reported. The literature on contact allergy to vitamin E and its derivatives is reviewed.
The possible formation of singlet oxygen via photoexcited psoralens has been associated with the occurrence of, amongst others, erythema. Therefore it has been suggested to combine PUVA with the topical or systemic administration of antioxidants. However, the effect of these antioxidants on the photobinding of psoralens to DNA, which is held responsible for the anti-proliferative effect, should be taken into account. In the present study the effect of two phenolic antioxidants, alpha-tocopherol (AT) and butylated hydroxytoluene (BHT), on the in vivo photobinding of 8-methoxypsoralen (8-MOP) to not only epidermal DNA, but also proteins and lipids was determined. After topical application of an ethanolic antioxidant solution onto the shaven skin of Wistar rats, labeled 8-MOP was applied using the same solvent. After this the rats were exposed to UV-A. By separating epidermal lipids, DNA/RNA and proteins by a selective extraction method, irreversible binding of 8-MOP to each of these biomacromolecules was determined. Both AT and BHT caused a decrease in the photobinding of 8-MOP to epidermal DNA and proteins. To investigate the underlying mechanism of this protection, the effect of AT was compared with that of AT-acetate. It also proved helpful to study the effects of the antioxidants on the photobinding of another photosensitizer, namely chlorpromazine. From these experiments it was concluded that AT and BHT affect 8-MOP photobinding by quenching reactive 8-MOP intermediates, involving the phenolic hydroxyl group of the antioxidants. BHT offered protection against lipid binding of 8-MOP but AT, especially at high concentrations, enhanced the UV-A-induced binding of 8-MOP to lipids.(ABSTRACT TRUNCATED AT 250 WORDS)
Ultraviolet (UV) irradiation of C3H/HeN mice induces skin cancer and an immunosuppression that prevents the host from rejecting antigenic UV-induced tumors. The capacity of topical vitamin E (dl-alpha-tocopherol) to prevent photocarcinogenesis or the immunosuppression induced by UV irradiation were assessed. Skin cancer incidence in UV-irradiated mice was 81% at 33 weeks after the first UV exposure; application to mice of 25 mg vitamin E three times per week for three weeks before UV irradiation, and throughout the experiment, reduced this incidence to 42% (p = 0.0065, log rank test). Immunoenhancement by vitamin E was assessed by comparing levels of immunosuppression by splenocytes from normal or UV-irradiated mice, with and without topical vitamin E treatment. Transfer of splenocytes from UV-irradiated mice to naive mice prevented the recipients from rejecting a UV-induced tumor challenge, whereas splenocytes from UV-irradiated mice treated with vitamin E did not prevent recipients from rejecting a similar tumor challenge. Phenotypic analysis of splenocytes used in the passive transfer assay, conducted with a biotin-avidin-immunoperoxidase technique, revealed that vitamin E treatment of mice undergoing UV irradiation prevented the UV-induced down regulation of Ia expression in splenocytes and increased the proportion of Lyt-2+ and L3T4+ splenocytes. Therefore, chronically applied vitamin E can effectively reduce cancer formation and immunosuppression induced by UV irradiation. Prevention of UV-induced down regulation of Ia expression may have contributed to this immunomodulation.
Albino hairless mice (Skh:HR-1) exposed chronically to suberythemal doses of ultraviolet (UV) radiation display visible and histological alterations in the skin. One alteration is an increase in dermal cellularity, including inflammatory cells. This suggested a role for inflammation in chronic photodamage. We evaluated the photoprotective effect of topical hydrocortisone, ibuprofen, and naproxen against photodamage. All 3 agents protected against UVB radiation-induced visible wrinkling, tumor formation, and histological alterations. Hydrocortisone and naproxen were also evaluated for protection against UVA radiation-induced visible skin sagging and histological alterations. Both were very effective. These data indicate that chronic topical application of anti-inflammatory agents provides broad solar UV spectrum photoprotection.
Albino hairless mice (Skh:HR-1) exposed chronically to suberythemal doses of ultraviolet radiation develop visible skin changes, histological alterations, and tumors. Topical treatment of mice with solutions of superoxide-scavenging antioxidants (such as alpha-tocopherol, ascorbic acid, propyl gallate and Trolox) prior to each UVB radiation exposure reduced significantly the severity of these events. Tocopherol esters and ascorbyl palmitate were not as effective as the parent compounds in providing protection. The data suggest a role for superoxide in UVB radiation-induced skin photoaging and the protective potential of superoxide scavengers. In contrast, the severity of UVA radiation-induced mouse skin damage was not reduced by topical application of the antioxidants tested here.
The purpose of this study was to confirm the photoprotective effect on skin of vitamins A and E, due to inhibition of polyamine synthesis and production of free radicals. These variables were measured in the lumbar epidermis of the female hairless mouse subjected to UVA + B irradiation. Polyamines were assayed in epidermal homogenate by HPLC, and production of oxygenated free radicals was determined by spectrofluorometric assay of malonyl dialdehyde. It was determined that butyl-hydroxy-toluene and vitamin E inhibited production of free radicals (56% and 60%, respectively) and caused a significant reduction in polyamine biosynthesis (P less than 0.01), whereas the inhibitory effect of malonyl dialdehyde induced by vitamin A (30%) had no associated effect on polyamine metabolism.
One hundred fifty-nine operative procedures for postburn contractures of interdigital webs (96), the axilla (46), or the neck (17) were prospectively randomized to be treated postoperatively for four months with a topical steroid (Aristocort A), topical vitamin E, or the base cream carrier for these drugs. The nature of the medication was blinded both to the patient and to the evaluator. Patients were followed for one year. Observations were made for range of motion, scar thickness, change in graft size, and ultimate cosmetic appearance. No beneficial effect of either vitamin E or topical steroid could be demonstrated. However, adverse reactions occurred in 16.4% of patients receiving active drug, compared to 5.9% treated only with base cream. Interestingly, the grafts initially contracted and subsequently grew to be a size larger (about 20%) than the original graft by one year. It is concluded that neither topical steroid nor topical vitamin E is effective in reducing scar formation after grafting procedures for reconstruction for postburn contractures.
By spraying 14C-labeled α-tocopheryl acetate on the surface of the skin, and by conducting microradiographic investigations on the condition of its absorption in seven cases and 14 samples, the following observation have been acquired, and at the same time, some discussion have been made.1. α-Tocopheryl acetate is absorbed well through the healthy hartless skin.2. There are two routes of absorption from the surface of the skin to the dermis. The first one leads through the horny layer, the epidermis and the borderline between the epidermis and the dermis. The second one goes through the pilo-sebaceous canal, the interior of hair follicles, inner and outer root sheaths and connective-tissue sheaths. No route through the sebaceous gland and sweat ducts has been detected.3. The material has proven to have a high affinity for small blood vessels everywhere.4. Hesitation in the absorption of the material has been observed in line with the lower part of the horny layer, the borderline between the epidermis and dermis, the borderline of inner and outer root sheaths, and the borderline between epidermal and connective-tissue hair follicles.5. Noticeable observations on the study of microdistribution are as follows:(a) In a comparatively short period of time, a large quantity of the material has appeared in hair papillae.(b) Although a large quantity of the material is seen in the sebaceous gland and excretory ducts, it is scarcely detected in the environment of those systems.(c) The material has not been seen in the sweat gland and sweat ducts. However, a large quantity of the agent has been witnessed in the environment of these systems and also in the blood vessels around them.(d) Although the agent has not been observed in the fatty cell, it was seen in the fatty intercellular septum in large quantities.
Influence of antioxidants on two phototoxic effects of 8-methoxypsoralen (8-MOP) was studied: erythema and changes in mechanoelectrical properties of skin. alpha-Tocopherol and its analogs with shortened lateral hydrocarbon chains at C2-atoms of chromane groups (chromanols) were used as antioxidants. alpha-Tocopherol and its analogs inhibited both phototoxic effects of 8-MOP. Inhibition was observed only if antioxidants were present in skin during irradiation. When applied after irradiation these antioxidants produce no inhibitory effect. The antioxidant antierythemal action depends greatly on their concentration. The protective effects is maximal at antioxidant concentrations 2.5 . 10(-10) - 5 . 10(-9) mol . cm-2 of skin, at concentrations higher than 5 . 10(-9) mol . cm-2 the protective action is decreased. The protective effect of antioxidants depends on the irradiation dose.
A multi-clinical double-blind study on therapeutic effect of combination preparation of vitamins E and C was undertaken in comparison with single preparation of vitamin E and vitamin C in the treatment of chloasma or pigmented contact dermatitis (PCD). Combination treatment resulted in significantly better clinical improvement than vitamin C alone in both diseases. Objective data compiled from color difference measurements and color photographs revealed significantly better results with combination treatment in chloasma than vitamin C alone and, in PCD, than vitamin E or C alone. Differences in skin luminosity between hyperpigmented and normal areas significantly decreased in all three groups, with the combination group producing the most significant change. The total serum lipoperoxide level and its ratio to total serum lipids tended to decline in the combination group, and decreased significantly in vitamin E group. The sebum lipoperoxide level decreased significantly only in the combination group (EC).
Vitamin E acetate is often used rather than vitamin E as an ingredient of skin care products and dermatological preparations, because it lacks the free phenolic OH group. However, because of this the acetate as such is biologically inactive. In spite of this intrinsic inactivity, the skin is protected against the harmful effects of sunlight after topical application of vitamin E acetate. Therefore it is supposed that hydrolysis takes place in the skin and that the reaction product, the radical scavenger vitamin E, is responsible for the protection observed. In this in vivo study with the rat, we have investigated the hydrolysis of RRR-alpha-tocopheryl acetate (vitamin E acetate) in the epidermis in relation to UV radiation protection. (As a measure of protection, we used the UV-induced binding of 8-methoxypsoralen to epidermal biomacromolecules.) After a period of 5 h from a single application of vitamin E acetate, hydrolysis into free vitamin E was not observed. No protection was found at this time point, corresponding with the absence of vitamin E. After treatment for 5 days, consisting of one topical application daily, the percentage of acetate present in the stratum corneum which was hydrolysed into free vitamin E was less than 1%, whereas the corresponding value for the viable layer of the epidermis was about 5%. The hydrolysis of vitamin E acetate in the epidermis proceeded very slowly. As a result, the absolute amount of free vitamin E, found in the total epidermis after treatment for 5 days with the acetate, was only a few times higher than the normal level. Yet, this very small amount of free vitamin E proved to be sufficient for maximal protection in this animal model. The results show that vitamin E acetate acts as a prodrug, which very slowly releases minute amounts of active vitamin E.
Superoxide-driven reduction of alpha-tocopheroxyl radical in the presence of ubiquinone-10 has been demonstrated in dimethylsulfoxide. Our HPLC measurements showed that ubiquinone-10 protected alpha-tocopherol against oxidation by KO2 in a concentration-dependent manner. alpha-Tocopherol was oxidized by KO2 to form ESR-detectable radicals of tocopherol ubisemiquinone. In the presence of ubiquinone-10, neither these radicals nor alpha-tocopheroxyl radicals (generated by uv light or PbO2) could be detected in ESR spectra. Instead, ESR signals of ubisemiquinone-10 radicals were observed. Formation of ubisemiquinone-10 radicals from ubiquinone-10 upon addition of KO2 was ascertained by their characteristic ESR and uv-vis spectra. alpha-Tocopherol caused a concentration-dependent decrease of the ubisemiquinone-10 radical steady-state concentration. We conclude that one-electron reduction of ubiquinone-10 by superoxide ion resulting in the formation of ubiquinone-10 radicals caused redox-cycling of alpha-tocopherol from its phenoxyl radical, thus preventing loss of alpha-tocopherol. This suggests that coenzyme Q may have another physiological function, i.e., protection of alpha-tocopherol against superoxide-driven oxidation.
Previously, we demonstrated by electron paramagnetic resonance (EPR) spectroscopy that ultraviolet radiation induces free-radical formation in Skh-1 hairless mouse skin. Because free-radical oxidative stress is thought to play a principal role in skin photoaging and cancer, oxidative stress and subsequent photodamage should be decreased by supplementation of skin with antioxidants. Using both the ascorbate free radical and an EPR spin-trapping system to detect short-lived radicals, we evaluated the effect of the topically applied antioxidants tocopherol sorbate, alpha-tocopherol, and tocopherol acetate on ultraviolet radiation-induced free-radical formation. We show that tocopherol sorbate significantly decreases the ultraviolet radiation-induced radical flux in skin. With our chronically exposed mouse model, tocopherol sorbate was also found to be significantly more protective against skin photoaging than alpha-tocopherol and tocopherol acetate. These results extend our previous observations of ultraviolet radiation-induced free-radical generation in skin and indicate the utility of tocopherol sorbate as an antioxidant in providing significant protection against ultraviolet radiation-induced oxidative damage.
In Spring 1992, an epidemic outbreak of papular and follicular rashes caused by a new line of cosmetics occurred throughout Switzerland.
Epidemiological and clinical data were collected in order to identify the offending agent and to specify the pathophysiological mechanisms.
The data concerning 263 patients seen by dermatologists plus 642 additional cases directly reported by consumers to the manufacturer were analyzed. Seventy-seven patients were patch-tested, 26 extensively, and 15 performed a repeated open application test for a duration of 4 weeks. Control patch and use tests were performed in 73 and 25 patients, respectively. The results were analyzed statistically. In addition, 12 skin biopsies were performed for histological examination. Biochemical studies on the cosmetics (final products and offending ingredient) supplemented the clinical studies.
The lesions were mainly papular and follicular, widely distributed, with pronounced pruritus, which was aggravated by sweating or heat exposure, and were long lasting. In a few cases, the papules were located on intensely erythematous, well-defined plaques, suggesting irritation rather than allergy. Both immediate and delayed onsets of the lesions were observed. Skin biopsies showed signs of folliculitis and perifolliculitis with little alteration of the interfollicular epidermis. Patch and use testing disclosed vitamin E linoleate (a mixture of tocopheryl esters, mainly tocopheryl linoleate) as the offending agent. An in vitro time-dependent formation of oxidative products under storage or oxidation-stimulating conditions was observed.
Though vitamin E esters have been widely and safely used for decades in dermatological preparations and in cosmetics, vitamin E linoleate was the cause of about 1,000 cases of unusual papular mainly follicular contact dermatitis. Oxidized vitamin E derivatives could act in vivo as haptens and/or irritants, possibly with synergistic effects.
To review the possible uses of topical and systemic tocopherols as therapy for skin conditions in light of the widespread use of vitamin E by patients.
Index Medicus was searched for articles published from 1922 (when vitamin E was discovered) to 1966 (the beginning of MEDLINE). MEDLINE was searched for articles in English and French on vitamin E or tocopherol in relation to dermatology. Additional original articles were identified from the reference lists of the review articles.
Only well-designed controlled studies were accepted; anecdotes and open studies are cited for completeness and as direction for future research.
There was some weak or conflicting evidence that vitamin E is of value in yellow nail syndrome, vibration disease, epidermolysis bullosa, cancer prevention, claudication, cutaneous ulcers, and collagen synthesis and wound healing. It was of no use in atopic dermatitis, dermatitis herpetiformis, psoriasis, subcorneal pustular dermatosis, porphyrias and skin damage induced by ultraviolet light.
After 44 years of research there is still scant proof of vitamin E's effectiveness in treating certain dermatologic conditions. Further research in well-designed controlled trials is needed to clarify vitamin E's role.
Fluconazole administered at 150 mg/week for 1-5 weeks is effective orally against dermatophytes and yeast in stratum corneum. Clinical and mycological cure rates approach 90%, but the precise distribution of the drug within various layers of skin is uncertain. We administered fluconazole at 150 mg/week for 2 weeks to 5 volunteers. Distribution of fluconazole in biopsies of skin was imaged by energy dispersive analysis of X-rays (EDX) and transmission electron microscopy, and in cells by electron energy-loss spectroscopy (EELS). Eight hours after a second dose, EDX showed fluconazole highest and homogeneously distributed in stratum corneum, lower in the rest of the epidermis, and lowest in dermis. The highest fluconazole levels detected by EELS were in cytoplasmic inclusions of sweat and sebaceous glands and less in keratinocytes and dermal collagen. We conclude that fluconazole delivered to stratum corneum by direct diffusion from capillaries and in sweat is also in all likelihood transported in sebum.
This article is a review of the fundamental chemistry of the tocopherols and tocotrienols relevant to their antioxidant action. Despite the general agreement that alpha-tocopherol is the most efficient antioxidant and vitamin E homologue in vivo, there was always a considerable discrepancy in its "absolute" and "relative" antioxidant effectiveness in vitro, especially when compared to gamma-tocopherol. Many chemical, physical, biochemical, physicochemical, and other factors seem responsible for the observed discrepancy between the relative antioxidant potencies of the tocopherols in vivo and in vitro. This paper aims at highlighting some possible reasons for the observed differences between the tocopherols (alpha-, beta-, gamma-, and delta-) in relation to their interactions with the important chemical species involved in lipid peroxidation, specifically trace metal ions, singlet oxygen, nitrogen oxides, and antioxidant synergists. Although literature reports related to the chemistry of the tocotrienols are quite meager, they also were included in the discussion in virtue of their structural and functional resemblance to the tocopherols.
How much vitamin E is enough? An established use of supplemental vitamin E in humans is in the prevention and therapy of deficiency symptoms. The cause of vitamin E deficiency, characterized by peripheral neuropathy and ataxia, is usually malabsorption-a result of fat malabsorption or genetic abnormalities in lipoprotein metabolism. Genetic abnormalities in the hepatic alpha-tocopherol transfer protein also cause vitamin E deficiency-defects in this protein cause an impairment in plasma vitamin E transport. Impaired delivery of vitamin E to tissues, thereby, results in deficiency symptoms. Also discussed is the use of supplemental vitamin E in chronic diseases such as ischemic heart disease, atherosclerosis, diabetes, cataracts, Parkinson's disease, Alzheimer's disease, and impared immune function, as well as in subjects receiving total parenterol nutrition. In healthy individuals, a daily intake of about 15-30 mg of alpha-tocopherol is recommended to obtain "optimal plasma alpha-tocopherol concentrations" (30 microM or greater).
Considerable interest has been recently generated concerning the use of natural compounds, anti-oxidants in particular, in photoprotection. Two of the best known anti-oxidants are vitamins C and E, both of which have been shown to be somewhat effective in different models of photodamage. Very little has been reported, however, on the effectiveness of a combination of the two (known to be biologically the more relevant situation); nor have there been detailed studies on the ability of these antioxidants to augment commercial sunscreen protection against UV damage. We report that (in swine skin) vitamin C is capable of additive protection against acute UVB damage (sunburn cell formation) when combined with a UVB sunscreen. A combination of both vitamins E and C provided very good protection from a UVB insult, the bulk of the protection attributable to vitamin E. However, vitamin C is significantly better than vitamin E at protecting against a UVA-mediated phototoxic insult in this animal model, while the combination is only slightly more effective than vitamin C alone. When vitamin C or a combination of vitamin C and E is formulated with a commercial UVA sunscreen (oxybenzone), an apparently greater than additive protection is noted against the phototoxic damage. These results confirm the utility of anti-oxidants as photoprotectants but suggest the importance of combining the compounds with known sunscreens to maximize photoprotection.
Skin cancers are a serious health problem in the United States. One common method of skin cancer primary prevention is use of sunscreens. Research has been conducted to ascertain the role of active ingredients of sunscreen products in photoprotection and possible carcinogenesis. In contrast, little is known about the "other ingredients", listed or unlisted, on sunscreen product labels. One such ingredient is vitamin E. usually in the form of alpha-tocopherol acetate. Results of recent studies of skin carcinogenesis in an ultraviolet (UV) B mouse carcinogenesis model suggest that topically applied alpha-tocopherol acetate does not prevent and, under some conditions, enhances skin cancer development and growth, whereas the free unesterified from of alpha-tocopherol significantly reduces experimental UVB carcinogenesis. We have performed a Phase II cancer prevention study to evaluate whether topically applied alpha-tocopherol acetate is absorbed in human skin and metabolizes to the free or other forms. In this double-blind study, 19 men and women > 30 years of age who had at least three actinic keratoses on their forearms were randomly assigned to apply alpha-tocopherol acetate (125 mg/g) or difluoromethylornithine cream to their arms twice daily for three months. Blood samples and photographs and punch biopsies of actinic keratoses were obtained before and at the end of the study (Month 4). Plasma and skin concentrations of free alpha-tocopherol, alpha-tocopherol acetate, and gamma-tocopherol were analyzed by high-performance liquid chromatography at Month 4. The results of this report focus only on data obtained from the 11 participants randomized to the alpha-tocopherol acetate arm of the study. Topically applied alpha-tocopherol acetate was substantially absorbed in skin, with no evidence of conversion within skin to its unesterified form (i.e., free alpha-tocopherol). There was no evidence of systemic availability or biotransformation of topically applied alpha-tocopherol acetate. In summary, we have determined that alpha-tocopherol acetate is not metabolized to the free form of alpha-tocopherol in plasma or skin.
With increasing solar ultraviolet (UV)-B radiation reaching the Earth's surface and the incidence of skin cancer rising steadily, there is an ever-increasing need to determine agents that modulate photocarcinogenesis and to understand the mechanisms underlying this modulation. Our laboratory has demonstrated that topical application of the dl-alpha-tocopherol form of vitamin E to mice prevents skin cancer and the immunosuppression induced by UVB irradiation. However, dl-alpha-tocopherol has limited stability at room temperature. The current study was designed to ask whether the thermostable esters of vitamin E, alpha-tocopheryl acetate, or alpha-tocopheryl succinate prevent skin cancer and immunosuppression induced in mice by UV radiation. In the alpha-tocopheryl acetate study, skin cancers developed in 70% of UVB-irradiated control mice and in 90%, 73%, and 90% of mice receiving topical applications of 12.5, 25, and 50 mg of dl-alpha-tocopheryl acetate, respectively. In the alpha-tocopheryl succinate study, skin cancer developed in 59.3% of control UVB-irradiated mice and in 82%, 100%, and 81.5% of mice treated with 2.5, 12.5, and 25 mg d-alpha-tocopheryl succinate, respectively. Thus neither alpha-tocopheryl acetate nor alpha-tocopheryl succinate prevented photocarcinogenesis. At 12.5 and 25 mg/treatment, alpha-tocopheryl acetate and alpha-tocopheryl succinate, respectively, enhanced photocarcinogenesis (p = 0.0114 and 0.0262, respectively, log rank test). On the basis of high-performance liquid chromatography analysis at 16-17 weeks after the first vitamin E treatment, the esterified forms of vitamin E applied epicutaneously accumulated in the skin, but the levels of free alpha-tocopherol remained low. Neither alpha-tocopheryl acetate nor alpha-tocopheryl succinate prevented the induction by UV radiation of immunosusceptibility to implanted syngeneic antigenic UV-induced tumor cells. Thus alpha-tocopheryl acetate or alpha-tocopheryl succinate not only failed to prevent photocarcinogenesis, but may have enhanced to process. Considering that alpha-tocopherol esters are included in many skin lotions, cosmetics, and sunscreens, further studies are needed to determine the conditions under which topical alpha-tocopheryl acetate and alpha-tocopheryl succinate enhance photocarcinogenesis.
We investigated the involvement of epidermal lipid peroxidation in the induction of ultraviolet radiation (UVR)-induced suppression of the skin immune system. The shaved dorsal skin of C3H/HeJ mice was irradiated with one of two subinflammatory solar-simulated UVR protocols 3 days per week for 4 weeks. Then half of 1 mg, 1, 2.5 or 5 mg alpha-tocopherol in a vehicle of acetone was topically applied to the shaved dorsal skin before UVR, A 5 mg dose of vitamin E gave complete protection against a UVR protocol that induced a 55% reduction in the contact hypersensitivity response to 2,4,6-trinitrochlorobenzene and a 23% reduction in epidermal Langerhans cell density. Lower doses were ineffective. alpha-Tocopherol was unable to protect against a higher UVR protocol. As 5 mg alpha-tocopherol did not prevent postirradiation inflammatory edema it is unlikely that the antioxidant acted as a sunscreen. However, 5 mg alpha-tocopherol inhibited UVR-induced epidermal lipid peroxidation, suggesting that this may be one mechanism by which alpha-tocopherol prevented UVR-induced local immunosuppression. Scavenging of UVR-generated lipid peroxides and reactive oxygen may have inhibited loss of cell membrane integrity preventing depletion of LC numbers, thus protecting from local immunosuppression.
Mouse skin was exposed to UVA radiation (320-400 nm). The in vivo chemiluminescence of the skin was measured after irradiation. Chemiluminescence showed a maximum 13-fold increase (control emission, 10 +/- 1 cps cm-2) after 45-60 min of exposure to UVA, with no further increase with 60 min additional exposure. Spectral analysis of the emitted chemiluminescence showed that the principal species emitted in the 400-500 nm range. Topical application with alpha-tocopherol (10% v/w) and beta-carotene (1 mM) greatly reduced the UVA-induced skin chemiluminescence. Thiobarbituric acid reactive substance (TBARS) levels were increased by 130% in skin homogenates after 2 h of exposure to UVA (control value, 77 +/- 14 nmol malonaldehyde equivalents (g tissue)-1). The activities of antioxidant enzymes in skin homogenates were decreased after 2 h of irradiation: the superoxide dismutase (SOD) activity (control value, 181 +/- 10 U SOD (g tissue)-1) was decreased by 40% and the catalase activity (control value, 1.34 +/- 0.14 pmol (g tissue)-1) was decreased by 45%. In vivo chemiluminescence appears to be a suitable method for following the kinetics of the oxidative stress processes and for testing the effect of topical application with antioxidant and photoprotective agents.
Oxygen free radicals have been shown to result from and mediate deleterious effects of ultraviolet radiation on the skin. The purpose of this study was to determine if topical DL-alpha-tocopherol (vitamin E) could reduce ultraviolet-induced damage to the epidermis. Twenty mice were treated with either ethanol or a 1:1 mixture of tocopherol and ethanol. Treatments consisted of once-daily 0.1-ml topical applications for 1 week, followed by irradiation with 0.30 mW/cm2 of ultraviolet B irradiation. A statistically significant decrease in Schiff base formation was noted between tocopherol-treated animals and their controls. Histologic study revealed a statistically significant increase in epidermal thickness in tocopherol-treated skin versus controls or vehicle alone. The thicker epidermis was accompanied by the presence of parakeratosis, implicating increased proliferation as the cause of the increasing thickness. The number of sunburn cells was decreased by tocopherol treatment. Tocopherol protection from ultraviolet irradiation may have been due to both direct protection from free radicals and indirect protection by means of increased epidermal thickness. The demonstration of beneficial effects of tocopherol administration suggests that further studies in clinically relevant models to define optimal dosage, frequency of administration, vehicle, and quantitation of the possible protective effects afforded to Langerhans cells may be useful.
Mutations or alterations in the p53 gene have been observed in 50-100% of ultraviolet light (UV)-induced squamous cell carcinoma in humans and animals. Most of the mutations occurred at dipyrimidine sequences, suggesting that pyrimidine dimers in the p53 gene play a role in the pathogenesis of cutaneous squamous cell carcinoma. We previously showed that topical alpha-tocopherol prevents UV-induced skin carcinogenesis in the mouse. In the present study we asked whether topical alpha-tocopherol reduces the level of UV-induced cyclobutane pyrimidine dimers in the murine epidermal p53 gene. Mice received six dorsal applications of 25 mg each of alpha-tocopherol, on alternate days, before exposure to 500 J/m2 of UV-B irradiation. Mice were killed at selected times after irradiation. The level of dimers in the epidermal p53 gene was measured using the T4 endonuclease V assay with quantitative Southern hybridization. Topical alpha-tocopherol caused a 55% reduction in the formation of cyclobutane pyrimidine dimers in the epidermal p53 gene. The rate of reduction of pyrimidine dimers between 1 and 10 hours after irradiation was similar in UV-irradiated mice, regardless of alpha-tocopherol treatment. Therefore, the lower level of cyclobutane pyrimidine dimers in UV-irradiated mice treated with alpha-tocopherol than in control UV-irradiated mice resulted from the prevention of formation of the dimers, and not from enhanced repair of these lesions. Our results indicate that alpha-tocopherol acts as an effective sunscreen in vivo, preventing the formation of premutagenic DNA lesions in a gene known to be important in skin carcinogenesis.
The aim of this study was to investigate the effects of topical alpha-tocopherol application on epidermal and dermal antioxidants and its ability to prevent ultraviolet (UV)-induced oxidative damage. Hairless mice received topical applications of alpha-tocopherol 24 h before a single, acute UV irradiation (10 x minimal erythemal dose). The four major antioxidant enzymes (catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase), hydrophilic and lipophilic antioxidants, and lipid hydroperoxides, markers of oxidative damage, were assayed in both epidermis and dermis of hairless mice. Topical alpha-tocopherol treatment increased dermal superoxide dismutase activity by 30% (P < 0.01) and protected epidermal glutathione peroxidase and superoxide dismutase from depletion after UV irradiation. Total and reduced glutathione levels in the epidermis increased by 50% after the topical treatment (P < 0.05), as did dermal ascorbate levels (by 40%: P < 0.01). The topical treatment increased alpha-tocopherol levels both in the epidermis (62-fold) and the dermis (22-fold: P < 0.001 in each layer). Furthermore, alpha-tocopherol treatment significantly reduced the formation of epidermal lipid hydroperoxides after UV irradiation (P < 0.05). These results demonstrate that topical administration of alpha-tocopherol protects cutaneous tissues against oxidative damage induced by UV irradiation in vivo, and suggest that the underlying mechanism of this effect involves the up-regulation of a network of enzymatic and non-enzymatic antioxidants.
We have assessed the hydrolysis of alpha-tocopherol acetate (alpha-TAc) to the active antioxidant alpha-tocopherol (alpha-TH) in mouse epidermis and in supernatant from epidermal homogenates. Topically administered alpha-TH prevents UVB photocarcinogenesis in C3H mice, whereas alpha-TAc does not. Hydrolysis in skin was monitored in mice treated topically with deuterium labeled alpha-TAc (d3-alpha-TAc). Epidermal samples were isolated from mice and analyzed for endogenous (d0-alpha-TAc) and d3-alpha-TH by gas chromatography-mass spectrometry. Within 24 h, the levels of d3-alpha-TH increased up to 10-fold over endogenous d0-alpha-TH levels; however, in mice irradiated with UVB prior to the application of d3-alpha-TAc, levels of d3-alpha-TH increased up to 30-40-fold over endogenous d0-alpha-TH. This enhancement of alpha-TAc hydrolysis increased with increasing UVB dose. Prior UVB exposure may increase hydrolysis of alpha-TAc by increasing epidermal esterase activity. Nonspecific esterase activity was measured in the 2000 x g supernatant from epidermis of unirradiated and irradiated mice. Alpha-napthyl acetate, a nonspecific esterase substrate, was converted to alpha-napthol in supernatants from unirradiated mice. Hydrolysis to alpha-napthol increased approximately 3-fold in supernatants from irradiated mice. Hydrolysis of alpha-TAc to alpha-TH also occurred in supernatant from unirradiated mice, and this hydrolysis increased approximately 3-fold in supernatant from irradiated animals. These data indicate that nonspecific esterase activity was increased by UVB in the skin, that alpha-TAc is converted to alpha-TH in the homogenate fraction containing nonspecific esterase, and that UVB exposure modulates the metabolism of alpha-TAc to alpha-TH in vivo.