Antioxidants and the skin: understanding formulation and efficacy

Microemulsions Improve the Cutaneous Co-Localization of Lipoic Acid and Quercetin and Antioxidant Effects in Cutaneous Cells and Tissue

Quercetin and α-lipoic acid are antioxidants with potential applications in the treatment of various skin conditions, such as wounds and chemoprevention of skin cancer. To enable their effective topical co-delivery and co-localization in the tissue, we developed microemulsions (ME). The selected ME (ME-50) formed a stable system with a mean droplet size of 134.4 ± 17.9 nm, increasing to 224.9 ± 19.9 nm upon antioxidants co-incorporation. The ME preserved the antioxidant capacities of the molecules, with DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay showing an IC50 of 6.2 ± 0.1 µg/mL, similar to the solution. Skin penetration studies revealed a 2.4-fold increase in quercetin (Q) accumulation in the stratum corneum and a 3.5-fold increase in the delivery to viable epidermis and dermis (ED) after a 12 h-treatment with the ME compared to control solutions; α-lipoic acid (LA) penetration improved up to 1.9-fold in ED upon ME incorporation. Treatment with Q + LA co-loaded ME enhanced the antioxidant activity in the stratum corneum and ED by 1.3-fold and 2.0-fold, respectively, compared to solutions. Treatment with the ME for 24 h also reduced oxidative species levels by 55% in H2O2-exposed keratinocytes compared to the control (untreated) cells. Taken together, these results suggest that ME-50 is a promising delivery system for enhancing the cutaneous co-delivery of quercetin and α-lipoic acid and the antioxidant effects in the tissue, offering a potential topical treatment for oxidative stress-related skin conditions.

Effects of Thioglycolate Compounds in an Emerging Technique in the World of Cosmetics-Brow Lamination

BACKGROUND

The side effects of two related chemicals, ammonium thioglycolate (ATG) and thioglycolic acid (TGA) have been widely highlighted in the world of cosmetics. These thioglycolate compounds are considered essential ingredients in a new technique known as brow lamination. This technique is widely used nowadays, with the aim of changing the eyebrow shape.

AIMS

To our knowledge, this is the first study to address the possible side effects of brow lamination.

RESULTS

The hydrophilic characteristic of ATG and TGA reflects their transdermal absorption through the intracellular and transappendageal pathways. These compounds can affect the skin through allergic contact dermatitis (ACD), characterized by skin irritation, dryness, and erythema. Moreover, these thioglycolates can alter several mechanical and chemical reactions in the eyebrows' hair, therefore affecting their shape, structure, and pigmentation. In addition, these chemicals contained in brow lamination can exert systemic manifestations, at the level of the reproductive, ocular, respiratory, and endocrine systems.

CONCLUSION

More studies should be elaborated to shed light on the possible side effects of this trend. Additionally, further regulations should be taken into consideration to ensure the concentration and the measures applied are convenient to minimize these side effects.

The Potential of Plant Extracts Used in Cosmetic Product Applications-Antioxidants Delivery and Mechanism of Actions

Natural ingredients have been used in skincare products for thousands of years. The current focus is on novel natural bioactivities that shield the skin from UV rays and free radicals, among other damaging elements, while enhancing skin health. Free radicals significantly contribute to skin damage and hasten ageing by interfering with defence and restorative processes. Plants contain natural chemicals that can scavenge free radicals and have antioxidant capabilities. Plant materials are becoming increasingly popular as natural antioxidants related to the expanding interest in plant chemistry. This review focuses on the significance of medicinal plants in skin health and ageing and their potential as a source of antioxidant substances such as vitamins, polyphenols, stilbenes, flavonoids, and methylxanthines.

Unraveling the Impact of the Oil Phase on the Physicochemical Stability and Skin Permeability of Melatonin Gel Formulations

Melatonin's antioxidant properties make it a valuable component in anti-aging semisolid topical products. This study explores the role of Pemulen®, an acrylic-based viscosifying agent, in stabilizing cream-gel formulations. Remarkably, even at low concentrations (0.4%), Pemulen® successfully produced physicochemical stable topical formulations. In this work, the impact of the ratio of the oily phase-comprising olive oil and isopropyl myristate from 0 to 20%-was investigated to understand the internal microstructure effect on skin permeability, rheological properties, and stability. The formulations exhibited pseudoplastic behavior, with a significant positive correlation (p-value < 0.1) between the oily phase ratio, viscosity, spreadability, skin adhesiveness, and permeability. Formulations without the oil phase exhibited greater skin permeability. However, higher oily phase content enhanced viscosity, spreadability, and skin adhesion. Given that melatonin primarily degrades through oxidation, incorporating antioxidant excipients in semisolid formulations is crucial for maintaining its chemical stability. A quality by design (QbD) approach was used to assess the impact of four excipients-(a) DL-α-tocopheryl acetate (0.05%), (b) ascorbic acid (0.1%), (c) ethylene diamine tetraacetic acid (0.1%), and (d) sodium metabisulphite (0.5%)-on melatonin's stability. Our findings indicate that maintaining the physical stability of the formulation with a 20% oil phase is more critical for protecting melatonin from oxidation than merely adding antioxidant excipients.

Protective Effects of the Postbiotic Levilactobacillus brevis BK3 against H2O2-Induced Oxidative Damage in Skin Cells

Postbiotics have various functional effects, such as antioxidant, anti-inflammatory, and anti-obesity. Levilactobacillus brevis BK3, the subject of this study, was derived from lactic acid bacteria isolated from Kimchi, a traditional Korean fermented food. The antioxidant activity of BK3 was confirmed through the measurements of 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and total antioxidant capacity (TAC). The wrinkle improvement effect was validated by assessing elastase inhibitory activity and collagenase inhibitory activity. The intracellular activity was confirmed using human keratinocytes (HaCaT) and human fibroblasts (HFF-1). BK3 protects skin cells from oxidative stress induced by H2O2 and reduces intracellular reactive oxygen species (ROS) production. In addition, the expressions of the antioxidant genes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were upregulated. Meanwhile, matrix metalloproteinase-1 (MMP-1) and collagen type I alpha 1 (COL1A1), involved in collagen degradation and synthesis, were significantly regulated. These results suggest the possibility of utilizing BK3 as a functional ingredient with antioxidant and wrinkle-improving effects.

The Impact of Phospholipid-Based Liquid Crystals' Microstructure on Stability and Release Profile of Ascorbyl Palmitate and Skin Performance

The drug delivery potential of liquid crystals (LCs) for ascorbyl palmitate (AP) was assessed, with the emphasis on the AP stability and release profile linked to microstructural rearrangement taking place along the dilution line being investigated by a set of complementary techniques. With high AP degradation observed after 56 days, two stabilization approaches, i.e., the addition of vitamin C or increasing AP concentration, were proposed. As a rule, LC samples with the lowest water content resulted in better AP stability (up to 52% of nondegraded AP in LC1 after 28 days) and faster API release (~18% in 8 h) as compared to the most diluted sample (29% of nondegraded AP in LC8 after 28 days, and up to 12% of AP released in 8 h). In addition, LCs exhibited a skin barrier-strengthening effect with up to 1.2-fold lower transepidermal water loss (TEWL) and 1.9-fold higher skin hydration observed in vitro on the porcine skin model. Although the latter cannot be linked to LCs' composition or specific microstructure, the obtained insight into LCs' microstructure contributed greatly to our understanding of AP positioning inside the system and its release profile, also influencing the overall LCs' performance after dermal application.

Determination of Post-Fermentation Waste from Fermented Vegetables as Potential Substitutes for Preservatives in o/w Emulsion

Post-fermentation wastes are rich sources of various biologically active compounds with antimicrobial activity, whose potential is not being fully exploited. One of the possible applications of post-fermentation waste may be its use as a natural preservative that effectively combats pathogens found in formulations. The study aims included the following: (1) compare the antimicrobial and antioxidant activity of fermented vegetable extracts (FVEs), (2) examine the inhibition of cosmetic-borne pathogens by FVEs, and (3) estimate the preservative effectiveness of FVEs in o/w emulsions. It was found that fermented white cabbage, cucumber, celery, and the mixture of fermented white cabbage, cucumber, and celery (1:1:1) showed antibacterial and antifungal activity against all the tested reference microbial strains. The addition of fermented cucumber, celery, and the mixture of fermented white cabbage, cucumber, and celery (1:1:1) to the o/w emulsion fulfilled criterion A of the preservative effectiveness test for S. aureus, E. coli, and A. brasiliensis, but did not fulfill the criterion for P. aeruginosa and C. albicans. The tested FVEs have comparable activity to inhibit pathogens in o/w emulsion as sodium benzoate. The results of our study prove that FVEs can be valuable raw materials supporting the preservative system, which, in turn, can significantly reduce the concentration of preservatives used in o/w emulsion.

NAD-Driven Sirtuin Activation by Cordyceps sinensis Extract: Exploring the Adaptogenic Potential to Promote Skin Longevity

In recent years, there has been increasing interest in utilizing Traditional Chinese Medicine principles and natural bioactive compounds to combat age-related ailments and enhance longevity. A Cordyceps sinensis mycelium hydroethanolic extract (CsEx), which was standardized in cordycepin and adenosine using UHPLC-DAD, was investigated for its adaptogenic properties using in vitro assays and a double-blind, placebo-controlled clinical trial involving 40 subjects. The CsEx demonstrated activity at a concentration of 0.0006%, significantly increasing sirtuin expression (SirT1: +33%, SirT3: +10%, SirT6: +72%, vs. CTR, p < 0.05) and NAD+ synthesis in HaCat cells (+20% vs. CTR, p < 0.001). Moreover, the CsEx boosted ATP production by 68% in skin cells, correlating with higher skin energy values (+52.0% at D28, p < 0.01) in the clinical trial. Additionally, CsEx notably reduced cytosolic reactive oxygen species (ROS) by 30% in HaCaT cells (p < 0.05) and enhanced collagen production both in vitro (+69% vs. CTR, p < 0.01) and in vivo (+10% vs. D0, p < 0.01), confirmed by ultrasound examination. Furthermore, CsEx's stimulation of fibroblasts, coupled with its antioxidant and energizing properties, led to a significant reduction in wrinkles by 28.0% (D28, p < 0.001). This study underscores Cordyceps sinensis hydroethanolic extract's potential in regulating skin cell energy metabolism and positively influencing the mechanisms associated with skin longevity control.

Chlorine-Induced Toxicity on Murine Cornea: Exploring the Potential Therapeutic Role of Antioxidants

Chlorine (Cl2) exposure poses a significant risk to ocular health, with the cornea being particularly susceptible to its corrosive effects. Antioxidants, known for their ability to neutralize reactive oxygen species (ROS) and alleviate oxidative stress, were explored as potential therapeutic agents to counteract chlorine-induced damage. In vitro experiments using human corneal epithelial cells showed decreased cell viability by chlorine-induced ROS production, which was reversed by antioxidant incubation. The mitochondrial membrane potential decreased due to both low and high doses of Cl2 exposure; however, it was recovered through antioxidants. The wound scratch assay showed that antioxidants mitigated impaired wound healing after Cl2 exposure. In vivo and ex vivo, after Cl2 exposure, increased corneal fluorescein staining indicates damaged corneal epithelial and stromal layers of mice cornea. Likewise, Cl2 exposure in human ex vivo corneas led to corneal injury characterized by epithelial fluorescein staining and epithelial erosion. However, antioxidants protected Cl2-induced damage. These results highlight the effects of Cl2 on corneal cells using in vitro, ex vivo, and in vivo models while also underscoring the potential of antioxidants, such as vitamin A, vitamin C, resveratrol, and melatonin, as protective agents against acute chlorine toxicity-induced corneal injury. Further investigation is needed to confirm the antioxidants' capacity to alleviate oxidative stress and enhance the corneal healing process.

Topical glutathione amino acid precursors protect skin against environmental and oxidative stress

BACKGROUND

Although glutathione (GSH) has long been considered a master antioxidant, poor stability and bioavailability limit its application in skin protection. To overcome the challenges, Unilever R&D formulated a Glutathione Amino acid Precursors blend (named GAP) to boost GSH de novo synthesis.

OBJECTIVE

Determine whether GAP can boost GSH levels and provide skin protection against stressors.

METHODS

Normal human epidermal keratinocytes were treated with GAP, with or without stressors, namely, menadione, blue light or pollutants. Ascorbic acid was used as a benchmark. The levels of GSH, glutathione disulfide (GSSG), adenosine triphosphate (ATP) and reactive oxygen species (ROS) were quantified. A placebo-controlled clinical study was conducted on 21 female subjects who received product applications and subsequent UV radiation. Tape strip samples were collected from the subjects for GSH and GSSG quantification using ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS). The UV-protective effect of GAP was investigated using ex vivo skin. Biomarkers related to DNA damage and the skin barrier were analysed using immunohistochemistry.

RESULTS

Glutathione amino acid precursors significantly increased the GSH levels and GSH/GSSG ratio in normal human epidermal keratinocytes. Menadione treatment resulted in excessive ROS production and a decline in ATP levels, which were effectively abrogated by GAP. The protective effects of GAP against menadione-induced oxidative stress were superior to those of ascorbic acid. In addition, GAP effectively protected the cells against blue light-induced ROS production and pollutant-induced ATP depletion. Topical application of the GAP formulation significantly elevated the skin GSH/GSSG ratio in a clinical study. Ex vivo skin treated with the GAP formulation displayed a reduction in DNA damage and high levels of barrier proteins after UV exposure.

CONCLUSIONS

Glutathione amino acid precursors effectively increases cellular GSH levels to protect the skin from oxidative and environmental stresses.

Tanshinone Alleviates UVA-induced Melanogenesis in Melanocytes via the Nrf2-regulated Antioxidant Defense Signaling Pathway

BACKGROUND

As a complex of natural plant compounds, tanshinone is renowned for its remarkable antioxidant properties. However, the potential impact of tanshinone on melanocyte pigmentation regulation has yet to be elucidated. This study aimed to explore the protective effects of tanshinone I (T-I) and dihydrotanshinone (DHT) on melanogenesis by modulating nuclear factor E2-related factor 2 (Nrf2) signaling and antioxidant defenses in human epidermal melanocyte (HEM) cells.

METHODS

HEM cells and Nrf2 knockdown HEM cells were subjected to ultraviolet A (UVA) and treated with T-I and/or DHT. Then, the anti-melanogenic properties of T-I and DHT were examined by assessing tyrosinase activity, melanogenesis-related proteins, and melanin content in UVA-irradiated HEM cells. Furthermore, the antioxidant activities of T-I and DHT were evaluated by assessing oxidant formation and modulation of Nrf2-related antioxidant defenses, including reactive oxygen species (ROS), glutathione (GSH) content, and the activity and expression of antioxidant enzymes, such as catalase (CAT), heme oxygenase-1 (HO-1), and superoxide dismutase (SOD).

RESULTS

Our findings revealed that T-I and DHT diminished melanogenesis in UVAirradiated HEM cells, activated Nrf2-antioxidant response element signaling, and enhanced antioxidant defenses in the irradiated cells. Furthermore, Nrf2 knockdown by shRNA abolished the anti-melanogenesis effects of T-I and DHT on HEM cells against oxidative damage.

CONCLUSION

These results suggest that T-I and DHT inhibit UVA-induced melanogenesis in HEM cells, possibly through redox mechanisms involving Nrf2 signaling activation and increased antioxidant defenses. This indicates that T-I and DHT have potential as whitening agents in cosmetics and medical treatments for hyperpigmentation disorders.

Nephroprotective Effects of Caffeine, Vanillin, and Their Combination against Experimental AlCl3-Induced Renal Toxicity in Adult Male Wistar Rats

Aluminum (Al) is known to be a nephrotoxic metal that can cause renal toxicity in both humans and animals. The use of functional foods has been reported to have significance in managing the toxic effects associated with such metals. This study aimed to assess the potential protective effects of caffeine, vanillin, and their combination in mitigating AlCl3-induced renal toxicity in adult male Wistar rats. A total of thirty (30) adult male Wistar rats weighing between 150 and 200 g were randomly divided into five groups, each consisting of six rats (n = 6). Group 1 served as the control, while the remaining treatment groups received a daily oral dose of 100 mg/kg AlCl3 for a duration of 21 days. In addition, groups 3-5 were coadministered 50 mg/kg body weight (bw) of caffeine, vanillin, and a combination (50/50 mg/kg bw) of both substances, respectively. In the results, AlCl3-treated showed a significant (p < 0.05) increase in serum biomarkers such as ALT, ALP, urea, and creatinine, and a significant (p < 0.05) decrease in serum total proteins (TPs). The renal tissue's antioxidant system, including SOD, CAT, GPx, and GSH, exhibited a significant (p < 0.05) reduction, accompanied by an elevated MDA level. However, the administration of caffeine, vanillin, and their combination resulted in a significant (p < 0.05) decrease in serum ALT, ALP, urea, and creatinine, and a significant (p < 0.05) increase in serum TP. Furthermore, following the treatment, there was a significant (p < 0.05) increase in renal SOD, CAT, GPx, and GSH levels, along with a reduction in the MDA level. In addition, the treatment for 21 days caused a significant (p < 0.05) reversal to the altered histomorphological architecture. These findings suggest that caffeine, vanillin, and their combination could potentially be an effective regimen in managing AlCl3-induced renal toxicity.

Acetyl Zingerone: A Photostable Multifunctional Skincare Ingredient That Combats Features of Intrinsic and Extrinsic Skin Aging

The cumulative damage skin sustains from exposure to environmental stressors throughout life exerts significant effects on skin aging and cancer development. One of the main ways by which environmental stressors mediate their effects within skin is through induction of reactive oxygen species (ROS). In this review, we chronicle the multiple properties by which acetyl zingerone (AZ) as a skincare ingredient can benefit skin (1) by helping manage overproduction of ROS through multiple routes as an antioxidant, physical quencher and selective chelator, (2) by fortifying protection after UV exposure ends to prevent the type of epidermal DNA damage that correlates with development of skin cancer, (3) by modulating matrisome activity and nurturing the integrity of the extracellular matrix (ECM) within the dermis and (4) through its proficient ability to neutralize singlet oxygen, by stabilizing the ascorbic acid precursor tetrahexyldecyl ascorbate (THDC) in the dermal microenvironment. This activity improves THDC bioavailability and may blunt pro-inflammatory effects of THDC, such as activation of type I interferon signaling. Moreover, AZ is photostable and can sustain its properties during UV exposure, in contrast to α-tocopherol. All these properties of AZ translate into measurable clinical benefits to improve the visual appearance of photoaged facial skin and to strengthen the skin's own defenses against sun damage.

Delivery of superoxide dismutase by TAT and abalone peptides for the protection of skin cells against oxidative stress

Trichoderma reesei superoxide dismutase (TrSOD) is a well-characterized enzyme being stable between 30 and 90°C for 1 h with activity at pH between 2.6 and 9.0. This work aimed to clone, express, purify, and evaluate the protective effect antioxidant of this enzyme on skin cells when fused to transactivator of transcription (TAT) protein transduction domain of HIV-1 and abalone (Ab) peptides to allow cell penetration. TrSOD, TAT-TrSOD-Yfp (fused to yellow fluorescent protein), and Ab-TrSOD were expressed in E. coli and purified as soluble proteins. The cytotoxicity of the enzymes, at the concentrations of 1, 3, and 6 μmol/L, was evaluated for a period of 24 and 48 h of incubation, with no cytotoxic effect on 3T3 fibroblasts. The 3T3 cells were exposed to the oxidant agent tert-butyl hydroperoxide and evaluated for reactive oxygen species (ROS) generation, in the presence or not of the recombinant enzymes. TAT-TrSOD-Yfp was able to decrease the generation of ROS by 15% when used in the concentrations of 3 and 6 μmol/L in comparison to the control, but there was no difference in relation to the effect of TrSOD. Ab-TrSOD, when compared to TrSOD, promoted a decrease in the formation of ROS of 19% and 14% at the concentrations of 1 and 6 μmol/L, respectively, indicating that this recombinant form was more effective in reducing oxidative stress compared to SOD without the cell-penetrating peptide (CPP). Together, these results indicate that the fusion of SOD with these CPP increased the antioxidant capacity of fibroblasts, identified by the reduction in the generation of ROS. In addition, such molecules, in the concentrations initially used, were not toxic to the cells, opening perspectives for the development of products for antioxidant protection of the skin that may have therapeutic and cosmetic application.

Formulation, Characterization and Evaluation of Innovative O/W Emulsions Containing Curcumin Derivatives with Enhanced Antioxidant Properties

In the present study, a series of semisolid Oil in Water (O/W) emulsions containing different Curcumin (Cur) derivatives (Cur powder, Cur extract and Cur complexed with β-cyclodextrin) in varying concentrations, were prepared. Initially, Dynamic Light Scattering (DLS), microscopy, pH and viscosity measurements were performed to evaluate their stability over time. Moreover, the effect of the active cosmetic substances on the Sun Protection Factor (SPF), antimicrobial and antioxidant properties of the prepared emulsions was investigated. It was observed that emulsions containing Cur extract and Cur β-cyclodextrin complex presented great viscosity and pH stability for up to 90 days of storage contrary to the emulsions containing Cur powder which showed unstable behavior due to the formation of agglomerates. All samples presented SPF values between 2.6 and 3.2. The emulsions with Cur in all forms exhibited high antioxidant activity, whereas the emulsion containing Cur β-cyclodextrin complex presented the highest value. Despite their improved stability and antioxidant activity, the emulsions containing Cur extract and Cur-β-cyclodextrin exhibited a low percentage of antimicrobial activity against E. coli and Staphylococcus bacteria. Instead, the emulsions containing Cur powder presented a reduction rate over 90 % against E. coli and Staphylococcus colonies.

Development and validation of a gradient HPLC-UV method for mitragynine following in vitro skin permeation studies

Mitragynine is a promising candidate for pain relief and opiate replacement but the investigations for drug delivery are lacking. This study aims to investigate the potential of mitragynine to be delivered through the skin with an emphasis on developing and validating a gradient HPLC-UV analytical method to determine mitragynine in the samples collected during in vitro skin permeation studies. The optimised method involves a gradient elution using a C18 column with a mobile phase comprising acetonitrile and 0.1 %v/v of formic acid (0-1 min: 30:70 to 70:30 (v/v) and hold up to 4 min; 4-6 min: return to 30:70 (v/v) and hold up to 10 min) at a flow rate of 1.2 mL/min. This method was validated based on the standards set by the International Council on Harmonisation guidelines. The method showed mitragynine elution at ∼ 4 min with adequate linearity (R2 ≥ 0.999 for concentration ranges of 0.5-10 and 10-175 μg/mL) and acceptable limits of detection and quantification at 0.47 and 1.43 μg/mL, respectively. The analytical performance is robust with excellent precision and accuracy. This method was used to evaluate the in vitro skin permeation of mitragynine (5 %w/v) from simple solvent systems over 48 hr. The results showed a cumulative amount of mitragynine permeated at ∼ 11 μg/cm2 for dimethyl sulfoxide and ∼ 4 μg/cm2 for propylene glycol. The study not only addressed the issues of the currently available HPLC-UV methods that limit the direct application but also affirmed the potential of mitragynine to be delivered through the skin.

Focus on the Contribution of Oxidative Stress in Skin Aging

Skin aging is one of the most evident signs of human aging. Modification of the skin during the life span is characterized by fine lines and wrinkling, loss of elasticity and volume, laxity, rough-textured appearance, and pallor. In contrast, photoaged skin is associated with uneven pigmentation (age spot) and is markedly wrinkled. At the cellular and molecular level, it consists of multiple interconnected processes based on biochemical reactions, genetic programs, and occurrence of external stimulation. The principal cellular perturbation in the skin driving senescence is the alteration of oxidative balance. In chronological aging, reactive oxygen species (ROS) are produced mainly through cellular oxidative metabolism during adenosine triphosphate (ATP) generation from glucose and mitochondrial dysfunction, whereas in extrinsic aging, loss of redox equilibrium is caused by environmental factors, such as ultraviolet radiation, pollution, cigarette smoking, and inadequate nutrition. During the aging process, oxidative stress is attributed to both augmented ROS production and reduced levels of enzymatic and non-enzymatic protectors. Apart from the evident appearance of structural change, throughout aging, the skin gradually loses its natural functional characteristics and regenerative potential. With aging, the skin immune system also undergoes functional senescence manifested as a reduced ability to counteract infections and augmented frequency of autoimmune and neoplastic diseases. This review proposes an update on the role of oxidative stress in the appearance of the clinical manifestation of skin aging, as well as of the molecular mechanisms that underline this natural phenomenon sometimes accelerated by external factors.

Contribution of Nanoscience Research in Antioxidants Delivery Used in Nutricosmetic Sector

Nanoscience applications in the food and cosmetic industry offer many potential benefits for consumers and society. Nanotechnologies permit the manipulation of matter at the nanoscale level, resulting in new properties and characteristics useful in food and cosmetic production, processing, packaging, and storage. Nanotechnology protects sensitive bioactive compounds, improves their bioavailability and water solubility, guarantees their release at a site of action, avoids contact with other constituents, and masks unpleasant taste. Biopolymeric nanoparticles, nanofibers, nanoemulsions, nanocapsules, and colloids are delivery systems used to produce food supplements and cosmetics. There are no barriers to nanoscience applications in food supplements and cosmetic industries, although the toxicity of nano-sized delivery systems is not clear. The physicochemical and toxicological characterization of nanoscale delivery systems used by the nutricosmeceutic industry is reviewed in this work.

Preclinical evaluation from in-silico to in-vivo study of polyherbal microsponge sunscreen gel

BACKGROUND

Electromagnetic spectrum of the UV region predominantly becomes the reason for skin's detrimental effects that give the genesis of innumerable skin ailments; because of this reason, the sunscreen products are required before condition in day to day lifestyle; products such as moisturizers, lotions, creams, shampoos, and other hair and skin preparations are accessible and accompanied by sunscreen properties, but they do not provide extended effect, also causes side effects due to harsh chemicals.

AIM

The present study focuses on the effects of polyherbal extracts containing Microsponge gel for the protection of skin from ultraviolet rays.

MATERIALS AND METHODS

In the present research, already prepared Microsponge gel through quasi-emulsion solvent diffusion (QESD) technique was used for the HPLC, in-silico, in-vitro antioxidant activity, and in-vivo study. AdmetSAR software tool was utilized for the in-silico study, whereas for the in-vivo study, UV radiations are given on Albino rats using solarimeter.

RESULTS

Results shown the active constituents are non-carcinogenic and non-toxic; IC50 values show good antioxidant activity and minimal effect of UV radiations after application of the gel formulation on animal skin.

DISCUSSION

The results manifest prominent effects on animal skin further test for presence of ascorbic acid level and total protein in blood further verify the efficacy of the formulation.

CONCLUSION

The study consequently established a strong ground for further extensive clinical studies.

Cliona varians-Derived Actinomycetes as Bioresources of Photoprotection-Related Bioactive End-Products

Sunscreen and sunblock are crucial skincare products to prevent photoaging and photocarcinogenesis through the addition of chemical filters to absorb or block ultraviolet (UV) radiation. However, several sunscreen and sunblock ingredients, mostly UV filters, have been associated with human and environmental safety concerns. Therefore, the exploration and discovery of promising novel sources of efficient and safer compounds with photoprotection-related activities are currently required. Marine invertebrates, particularly their associated microbiota, are promising providers of specialized metabolites with valuable biotechnological applications. Nevertheless, despite Actinobacteria members being a well-known source of bioactive metabolites, their photoprotective potential has been poorly explored so far. Hence, a set of methanolic extracts obtained from Cliona varians-derived actinomycetes was screened regarding their antioxidant and UV-absorbing capacities (i.e., photoprotection-related activities). The active extract-producing strains were identified and classified within genera Streptomyces, Micrococcus, Gordonia, and Promicromonospora. This is the first report of the isolation of these microorganisms from C. varians (an ecologically important Caribbean coral reef-boring sponge). The in vitro cytotoxicity on dermal fibroblasts of oxybenzone and the selected active extracts revealed that oxybenzone exerted a cytotoxic effect, whereas no cytotoxic effect of test extracts was observed. Accordingly, the most active (SPFi > 5, radical scavenging > 50%) and nontoxic (cell viability > 75%) extracts were obtained from Streptomyces strains. Finally, LC-MS-based characterization suggested a broad chemical space within the test strains and agreed with the reported streptomycetes' chemodiversity. The respective metabolite profiling exposed a strain-specific metabolite occurrence, leading to the recognition of potential hits. These findings suggest that marine Streptomyces produce photoprotectants ought to be further explored in skincare applications.

Luteolin Prevents UVB-Induced Skin Photoaging Damage by Modulating SIRT3/ROS/MAPK Signaling: An in vitro and in vivo Studies

The aim of this study was to investigate the role of luteolin in the mechanism of ultraviolet radiation B (UVB)-induced photoaging. An in vivo photoaging model was established using UVB irradiation of bare skin on the back of rats, and an in vitro photoaging model was established using UVB irradiation of human dermal fibroblasts (HDF). Skin damage was observed using hematoxylin-eosin (HE) and Masson staining, skin and cellular reactive oxygen species (ROS) levels were detected by DHE and DCF fluorescent probes, mitochondrial membrane potential was detected by JC-1 staining, and protein expressions were detected by immunofluorescence and Western Blot. Results from animal experiments showed that luteolin reduced UVB-induced erythema and wrinkle formation. Results from cellular assays showed that luteolin inhibited UVB-induced decrease in cell viability. In addition, in vitro and in vivo experiments showed that luteolin reduced oxidative stress levels, decreased activation of matrix metalloproteinases (MMPs) and increased collagen expression. Continued cellular experiments using 3-TYP, an inhibitor of Sirtuin 3 (SIRT3), revealed a loss of cellular protection by luteolin and a decrease in collagen, suggesting that luteolin acts by targeting and promoting SIRT3. luteolin is involved in the protection of skin cells against UVB radiation-induced ageing via the SIRT3/ROS/mitogen-activated protein kinases (MAPK) axis and it may be a promising therapeutic agent for the prevention of UVB photoaging.

Hydrogel sunscreen based on yeast /gelatin demonstrates excellent UV-shielding and skin protection performance

Traditional organic and inorganic sunscreens suffer from the disadvantages of low stability and poor biocompatibility. In the study, we developed a novel hydrogel sunscreen based on the yeast and gelatin, which demonstrated excellent UV protection property and broad absorption of UV across UVA and UVB region. Yeast was used as effective component and gelatin as matrix to fabricate the hydrogel, which is high hydrated and reasonable to simulate natural living tissue. As a common probiotic, yeast shows safety and satisfactory UV protection capability. Furthermore, the hydrogel sunscreen shows excellent biocompatibility and UV protection performance both in vitro and in vivo. Moreover, they can be prepared conveniently and provide an eco-friendly strategy, which provides experience and inspiration of probiotics in the cosmetics application.

A comprehensive topical antioxidant inhibits oxidative stress induced by blue light exposure and cigarette smoke in human skin tissue

OBJECTIVE

Skin damage from visible light predominantly results from exposure to the blue light spectrum (400-500 nm) which generates Reactive Oxygen Species (ROS) causing a cascade of harmful effects to skin. Topical antioxidants reduce the effects of free radical damage caused by environmental exposures. This study evaluated a comprehensive topical antioxidant's ability to inhibit ROS production induced by blue light and cigarette smoke (CS) in human skin.

METHODS

Two experiments were conducted utilizing human skin (Fitzpatrick Skin Types III and V; N = 3, each). After confirmed reactivity of untreated tissues at 412 nm, 20J/cm2 , untreated and pretreated (WEL-DS, 2 mg/cm2 ) skin tissue was exposed to blue light and blue light plus CS and left overnight. A nonfluorescent probe (DCFH-DA) was added to skin and exposed to blue light (412 nm, 20J/cm2 ) and blue light plus CS. Fluorescent 2',7'-DCF was generated upon enzymatic reduction and subsequent oxidation by ROS.

RESULTS

ROS increased at least tenfold following initial exposure to blue light and blue light plus CS in untreated skin. Pretreatment with WEL-DS decreased ROS in FST III exposed to blue light by 51% and 46% in skin exposed to blue light plus CS vs. untreated skin (both, P < .001). In FST V, pretreatment with WEL-DS decreased ROS exposed to blue light by 54% (P < .001) and 50% in skin exposed to blue light plus CS vs. untreated skin (P < .0001).

CONCLUSION

WEL-DS demonstrated significant reduction in ROS induced by blue light and blue light in combination with CS compared with untreated, exposed skin.

Importance of Redox Equilibrium in the Pathogenesis of Psoriasis-Impact of Antioxidant-Rich Diet

Psoriasis is a common, chronic, hyperproliferative, inflammatory skin disease occurring in most ethnic groups in the world. The disease is hereditary but the process of its inheritance is complex and still not fully understood. At the same time, it has been observed that psoriatic lesions may be triggered by certain prooxidative external factors: using narcotics, smoking, drinking alcohol, physical and mental stress, as well as bacterial infections and injury. Since the main physiological marker of psoriasis relates to disorders in the organism's antioxidative system, it is necessary to develop a well-balanced combination of pharmaceuticals and dietary antioxidants to facilitate the effective treatment and/or prevention of the disease. The dietary sources of antioxidants must be adequate for chronic use regardless of the patient's age and be easily available, e.g., as ingredients of regular food or dietary supplements. Diet manipulation is a promising therapeutic approach in the context of modulating the incidence of chronic diseases. Another potentially viable method entails the use of nutrigenomics, which guarantees a multiaspectual approach to the problem, including, in particular, analyses of the genetic profiles of psoriasis patients with the view to more accurately targeting key problems. The present paper pertains to the significance of redox equilibrium in the context of psoriasis. Based on information published in worldwide literature over the last decade, the impact of dietary exogenous antioxidants on the course of this chronic disease was analysed.

Protective effects of a comprehensive topical antioxidant against ozone-induced damage in a reconstructed human skin model

Tropospheric ozone (O₃) is a source of oxidative stress. This study examined the ability of a topical antioxidant (WEL-DS) to inhibit O₃-mediated damage in a human epidermal skin model. Four groups of tissues (N = 24) were compared: Group 1 (control) were untreated and unexposed; Group 2 were untreated and exposed to O₃ (0.4 ppm, 4 h); Group 3 were pretreated with WEL-DS and unexposed; Group 4 were pretreated with WEL-DS and exposed to O₃ (0.4 ppm, 4 h). Pretreated tissues were topically treated with 20 uL of WEL-DS and incubated for up to 20 h at 37 °C [humidified, 5% carbon dioxide (CO₂)]. After 24 h, tissues were re-treated with WEL-DS and exposed to O_3. Tissues were evaluated for Reactive Oxygen Species (ROS), hydrogen peroxide (H₂O₂), 4-hydroxynonenal (4-HNE) protein adducts, NF-κB p65 response and histology. In O₃-exposed groups, WEL-DS significantly inhibited ROS formation vs. untreated tissues (p < 0.05). Pretreatment with WEL-DS inhibited H₂O₂ production vs. untreated tissues (p < 0.05), and decreased NF-κB p65 transcription factor signal. Oxidative stress induction in O₃-exposed tissues was confirmed by increased levels of 4-HNE protein adducts (marker of lipid peroxidation); WEL-DS application reduced this effect. WEL-DS inhibited damage in tissues exposed to O₃ with no significant changes in epidermal structure. A comprehensive topical antioxidant significantly diminished O₃-induced oxidative damage in a human epidermal skin model.

Evolution of the use of antioxidants in anti-ageing cosmetics

OBJECTIVE

Skin health and beauty are a cornerstone of general well-being in humans. Anti-ageing cosmetics are used to provide a healthy and youthful appearance. Among the different cosmetic actives, antioxidants are incorporated in anti-ageing products due to their beneficial effects in preventing and minimizing the signs of skin ageing. This work aims to understand how anti-ageing formulations changed in the past 7 years regarding pure antioxidants composition.

METHODS

Data were collected from anti-ageing formulations commercialized in main stores and pharmacies in the Portuguese market. The study started on 2011 and was updated with products launched or whose composition has been renewed on 2013, 2015 or 2018.

RESULTS

Ascorbic acid and tocopherol and their derivatives were consistently the most used antioxidants in anti-ageing formulations; followed by niacinamide and retinyl palmitate. Seven ascorbic acid derivatives are currently used in anti-ageing formulations while only three tocopherol derivatives were identified in this study. Several combinations of antioxidants were routinely found, mainly tocopherol (or tocopherol derivatives) with other antioxidants and tocopherol with tocopherol derivatives. We have not identified emerging antioxidants with great impact in anti-ageing formulations even though niacinamide and retinyl palmitate exhibited over 10% more usage in 2018.

CONCLUSION

This insight is relevant to the cosmetic industry providing a better understanding of the scientific-based formulation of modern cosmetics and supports the need for innovative antioxidants in anti-ageing cosmetics.

Hypericum olympicum L. recovers DNA damage and prevents MMP-9 activation induced by UVB in human dermal fibroblasts

ETHNOPHARMACOLOGICAL RELEVANCE

Hypericum olympicum L. (Hypericaceae) flowering aerial parts has been utilized in Turkish folk medicine as a remedy against inflamed skin problems.

AIM OF THE STUDY

This study was designed to state the effect of H. olympicum on dermatological problems. For this purpose effect of the plant extract on the DNA strand break and matrix metalloproteinase (MMP)-9 activity of human dermal fibroblast (HDFs) cells irradiated with UVB as well as antioxidant activity potential were studied.

MATERIALS AND METHODS

The methanolic extract of Hypericum olympicum (HOM) was prepared by maceration at room temperature. DNA damage and increased MMP-9 activity in HDFs were induced by UVB irradiation. The cell viability was measured by water-soluble tetrazolium salt (WST)-1 assay. The effects on DNA strand break was investigated by single gel electrophoresis (commonly known as Comet assay), while MMP-9 activity was observed by gelatin zymography assay. In vitro antioxidant tests were performed to indicate the effect on reactive oxygen species (ROS). The major metabolites were identified and their concentrations were measured by high performance thin layer chromatography (HPTLC).

RESULTS

HOM was found to recover DNA damage dose-dependently. The enzymatic activity of MMP-9 was inhibited almost 100% by the treatment of 1.5 mg/mL of the extract. It also enhanced cell proliferation in those cells, and also it was shown to possess antioxidant activity. The major metabolites of HOM were identified as chlorogenic acid and quercetin glycosides (rutin, hyperoside, isoquercitrin).

CONCLUSION

Experimental studies have proven the traditional use of Hypericum olympicum in inflamed skin problems acting by inhibition of the inflammatory pathway and recovery of DNA damage induced experimentally.

Development and Characterization of New Topical Hydrogels Based on Alpha Lipoic Acid—Hydrotalcite Hybrids

Alpha lipoic acid (ALA) is a well-known anti-aging compound. The activity of this molecule is limited by two important factors: (i) The low stability to oxidation and thermal processes and (ii) the low solubility. Particularly the latter limits ALA formulation in hydrophilic bases. The purpose of this paper is to present a new technological approach to stabilize lipoic acid in topical hydrogels for cosmetic use. With this aim, ALA was intercalated in two different lamellar anionic clays (hydrotalcites), MgAl and ZnAl, obtaining the hybrids MgAl-ALA and ZnAl-ALA. The intercalation allows to obtain a more manageable product in comparison to raw ALA. After the preliminary characterization, hydrogels containing the hybrids were prepared and characterized, also in comparison to the commercial product Tiobec® in terms of rheological properties, stability to temperature and centrifugation, release, and cytotoxicity. The obtained results highlighted that the hydrogel containing MgAl-ALA is a suitable alternative to the products currently available on the market.

Liposomes for delivery of antioxidants in cosmeceuticals: Challenges and development strategies

Antioxidants (AOs) play a crucial role in the protection and maintenance of health and are also integral ingredients in beauty products. Unfortunately, most of them are sensitive due to their instability and insolubility. The use of liposomes to protect AOs and expand their applicability to cosmeceuticals, thereby, is one of the most effective solutions. Notwithstanding their offered advantages for the delivery of AOs, liposomes, in their production and application, present many challenges. Here, we provide a critical review of the major problems complicating the development of liposomes for AO delivery. Along with issues related to preparation techniques and encapsulation efficiency, the loss of protective function and inefficiency of skin permeability are the main disadvantages of liposomes. Corresponding development strategies for resolving these problems, with their respective advantages and drawbacks, are introduced, discussed in some depth, and summarized in these pages as well. Advanced liposomes have a vital role to play in the development and delivery of AOs in practical cosmeceutical product applications.

Mussel-Inspired Electroactive and Antioxidative Scaffolds with Incorporation of Polydopamine-Reduced Graphene Oxide for Enhancing Skin Wound Healing

Wound repair and tissue regeneration are complex processes that involve many physiological signals. Thus, employing novel wound dressings with potent biological activity and physiological signal response ability to accelerate wound healing is a possible solution. Herein, inspired by mussel chemistry, we developed a polydopamine (PDA)-reduced graphene oxide (pGO)-incorporated chitosan (CS) and silk fibroin (SF) (pGO-CS/SF) scaffold with good mechanical, electroactive, and antioxidative properties as an efficient wound dressing. First, pGO with good dispersibility and cell affinity was obtained upon reduction by PDA under alkali conditions. Second, pGO was dispersed into a CS/SF mixture, and then CS and SF chains were dual-cross-linked by poly(ethylene glycol) diglycidyl ether and glutaraldehyde to obtain a pGO-incorporated gel. Finally, the gel underwent a freeze-dry process to obtain the pGO-CS/SF scaffold. Owing to PDA reduction and functionalization, pGO in the scaffold plays important roles for the performances of the scaffolds. First, the pGO acts as nanoreinforcement to enhance the mechanical properties of the scaffold by combining the dual-cross-linked CS/SF network. Second, the uniformly distributed pGO in the scaffolds comprises a well-connected electric pathway, which can provide a channel for the transmission of electrical signals in the scaffold. Moreover, pGO in the scaffolds serves as an antioxidant agent to scavenge reactive oxygen species (ROS) and therefore terminates excessive ROS oxidation. In vitro studies show that electroactive pGO-CS/SF scaffolds can respond to electrical signals and promote cytological behavior. In addition, the pGO-CS/SF scaffolds can reduce cellular oxidation by removing excessive ROS. The in vivo full-thickness skin defect model demonstrates that the electroactive and antioxidative pGO-CS/SF scaffold can efficiently enhance wound healing. In summary, the pGO-CS/SF scaffold is a promising wound dressing because of its ability to promote physiological electrical signal transmission for cell growth and reduce ROS oxidation, resulting in an improved wound regeneration effect.

Inhibitory effect of Carnosol on UVB-induced inflammation via inhibition of STAT3

Ultraviolet B (UVB) irradiation causes sunburn, inflammatory responses, dysregulation of immune function, oxidative stress, DNA damage and photocarcinogenesis on skin. Rosemary (Rosmarinus officinalis L.) has been reported to inhibit inflammation. Carnosol, a major component of Rosemary, has prominent anti-inflammatory effects. However, its protective effect on UVB-induced inflammatory skin responses has not yet been reported. Here, we investigated the effectiveness of carnosol on UVB-induced inflammation. We examined the anti-inflammation effect of topical application of carnosol (0.05 µg/cm²) on UVB (540 mJ/cm², for 3 successive days)-induced skin inflammation in HR1 mice. Topical application of carnosol inhibited UVB-induced erythema, epidermal thickness, inflammatory responses in HR1 mice. Carnosol reduced the level of Immunoglobulin-E and IL-1β in blood serum of UVB-induced mice. Carnosol also significantly inhibited the UVB-induced expression of inflammatory marker protein (iNOS and COX-2) in back skin of mice. In addition, carnosol treated skin decreased activation of STAT3, a transcriptional factor regulating inflammatory genes. Our study suggested that carnosol has protective effects on skin inflammatory skin damages by UVB.

The potential role of antioxidants in mitigating skin hyperpigmentation resulting from ultraviolet and visible light-induced oxidative stress

Oxidative stress is an integral element that influences a variety of biochemical reactions throughout the body and is known to play a notable role in melanogenesis. Exogenous triggers of oxidative stress, such as ultraviolet radiation (UVR) and visible light (VL), lead to pigment formation through somewhat different pathways, but both share a common endpoint-the potential to generate cosmetically undesirable hyperpigmentation. Though organic and inorganic sunscreens are available to protect against the UVR portion of the electromagnetic spectrum, coverage is lacking to protect against the VL spectrum. In this manuscript, we review the phases of tanning, pathways of melanogenesis triggered by UVR and VL, and the associated impact of oxidative stress. We also discuss the known intrinsic mechanisms and paracrine regulation of melanocytes that influence their response to UVR. Understanding these mechanisms and their role in UVR-induced hyperpigmentation should potentially lead to identification of useful targets that can be coupled with antioxidant therapy to alleviate this effect.

Protective effects of Scutellaria baicalensis Georgi against hydrogen peroxide-induced DNA damage and apoptosis in HaCaT human skin keratinocytes

Oxidative stress due to excessive accumulation of reactive oxygen species (ROS) is one of the risk factors for the development of several chronic diseases. In this study, we investigated the protective effects of Scutellaria baicalensis rhizome ethanol extract (SBRE) against oxidative stress-induced cellular damage and elucidated the underlying mechanisms in the HaCaT human skin keratinocyte cell line. Our results revealed that treatment with SBRE prior to hydrogen peroxide (H₂O₂) exposure significantly increased viability of HaCaT cells. SBRE also effectively attenuated H₂O₂-induced comet tail formation and inhibited the H₂O₂-induced phosphorylation levels of the histone γH2AX, as well as the number of apoptotic bodies and Annexin V-positive cells. In addition, SBRE exhibited scavenging activity against intracellular ROS generation and restored the mitochondrial membrane potential loss by H₂O₂. Moreover, H₂O₂ enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with SBRE. Furthermore, SBRE increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, SBRE is able to protect HaCaT cells from H₂O₂-induced DNA damage and apoptosis through blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating the Nrf2/HO-1 signaling pathway.

trans-Chalcone, a flavonoid precursor, inhibits UV-induced skin inflammation and oxidative stress in mice by targeting NADPH oxidase and cytokine production

trans-Chalcone inhibits UV-induced skin inflammation and also indirectly reduces oxidative stress.

Nutritional Status and Habitual Dietary Intake Are Associated with Frail Skin Conditions in Community-Dwelling Older People

OBJECTIVE

Prevention of frail skin is important in older people because frail skin is associated with a risk of injury in this population. In this study, we investigated the association of nutritional status and habitual dietary intake with skin conditions in community-dwelling older people.

DESIGN

Cross-sectional study.

SETTING

Three community settings in Japan from autumn to winter.

PARTICIPANTS

Older people aged ≥65 years without care-need certification (n=118).

MEASUREMENTS

Malnutrition and obesity were evaluated to assess the nutritional status. Nutrient and food group intakes per 1000 kcal were evaluated using a brief self-administered diet history questionnaire. Dietary patterns based on food groups were evaluated by principal component analysis. Skin condition parameters, including stratum corneum hydration, appearance of xerosis (specific symptom sum score [SRRC score]), and dermal intensity by high-frequency ultrasonography, were measured on a lower leg. Multiple linear regression analysis was performed with adjustment for confounders.

RESULTS

The mean (standard deviation) age was 74.1 (4.8) years, and 83.1% of participants were female. A higher intake of plant fat (p=0.018) was associated with a lower SRRC score. Higher intakes of α-tocopherol (p=0.050) and vitamin C (p=0.017) were associated with increased dermal intensity. A body mass index ≥25 (p=0.016) was associated with decreased dermal intensity. A dietary pattern characterized by higher vegetable and fruit intake was associated with a better skin condition.

CONCLUSION

Plant fat, antioxidant vitamins, and a dietary pattern characterized by vegetables and fruits showed positive and obesity showed negative associations for frail skin in community-dwelling older people.

Skincare Bootcamp: The Evolving Role of Skincare

Background:

Although cosmetic procedures have a significant impact on certain aspects of aging, such as deep, wrinkling, sagging, and volume loss, they fail to address the overall quality of the skin.

Methods:

Daily skincare routines potentially can have a significant long-term impact on the overall quality of a person’s complexion.

Results:

By expanding our product knowledge, we can help our patients individualize their at-home skincare routine using effective products and ingredients designed to address their specific skin concern and support the professional care we deliver.

Conclusions:

Here, we discuss the types of products and ingredients suitable for the most common dermatologic concerns, from wrinkling to skin sensitivity, acne to sun damage.

RETRACTED: Ambient UV-B exposure reduces the binding of ofloxacin with bacterial DNA gyrase and induces DNA damage mediated apoptosis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The study is retracted due to image duplication reasons: The article contains an image that had already appeared in Free Radic Res, 48.3 (2014): 333–346. DOI 10.3109/10715762.2013.869324. The images are used in both papers but to conclude something entirely different, and suggested that the images have an entirely different biological meaning and treatment. Duplicating images in this way is ethically not acceptable.

Topical formulation containing hesperidin methyl chalcone inhibits skin oxidative stress and inflammation induced by ultraviolet B irradiation

Skin exposure to UVB irradiation has increased significantly in recent years due to ozone depletion, and it represents the main cause of many skin diseases.

Encapsulation of cosmetic active ingredients for topical application--a review

Microencapsulation is finding increasing applications in cosmetics and personal care markets. This article provides an overall discussion on encapsulation of cosmetically active ingredients and encapsulation techniques for cosmetic and personal care products for topical applications. Some of the challenges are identified and critical aspects and future perspectives are addressed. Many cosmetics and personal care products contain biologically active substances that require encapsulation for increased stability of the active materials. The topical and transdermal delivery of active cosmetic ingredients requires effective, controlled and safe means of reaching the target site within the skin. Preservation of the active ingredients is also essential during formulation, storage and application of the final cosmetic product. Microencapsulation offers an ideal and unique carrier system for cosmetic active ingredients, as it has the potential to respond to all these requirements. The encapsulated agent can be released by several mechanisms, such as mechanical action, heat, diffusion, pH, biodegradation and dissolution. The selection of the encapsulation technique and shell material depends on the final application of the product, considering physical and chemical stability, concentration, required particle size, release mechanism and manufacturing costs.