Oxidative Stress In Skin Research Articles

The anthocyanin extracts from purple-fleshed sweet potato exhibited anti-photoaging effects on ultraviolent B-irradiated BALB/c-nu mouse skin

Abstract This study investigated the effect of anthocyanin extracts from purple-fleshed sweet potato (PSP-AE) on ultraviolet B (UVB)-induced skin photoaging in BALB/c-nu mice. UPLC-QTOF-MS analysis showed six compounds were identified from PSP-AE. Administration of PSP-AE ameliorated the UVB-irradiated macroscopic and histopathological lesions of the skin via suppressing epidermal hyperplasia and collagen degradation, while improving the content of skin moisture and hydroxyproline. Additionally, PSP-AE inhibited the UVB-induced oxidative stress and increased the antioxidant enzyme activities. Results showed PSP-AE inhibited the UVB-irradiated levels of pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 6. Furthermore, Western blot analysis revealed PSP-AE remarkably decreased the protein levels of phosphorylated c-Jun-Nterminal kinase, extracellular signal-regulated kinase, and p38. Likewise, UVB induced nuclear translocation of nuclear factor kappa-B and the expression of matrix metalloproteinase 1 were diminished by pretreatment of PSP-AE. Therefore, PSP-AE had the potential to attenuate the UVB-irradiated skin oxidative stress and inflammatory response.

30-days effects of vildagliptin on vascular function, plasma viscosity, inflammation, oxidative stress, and intestinal peptides on drug-na\xefve women with diabetes and obesity: a randomized head-to-head metformin-controlled study

BackgroundObesity is the main risk factor for diabetes and excessive visceral fat triggers low-grade inflammatory process, mediated by activation and release of cytokines and high flow of free fatty acids that contribute to insulin resistance, increased oxidative stress, and impaired endothelial function. Metformin and vildagliptin have known vasculoprotective actions, but the value of these drugs on drug-naïve diabetic patients during 30 days use warrants investigation. Our purpose was to observe their effects on endothelial function, oxidative stress, inflammatory biomarkers, and plasma viscosity.Methods38 women with obesity and type 2 diabetes drug-naïve, aged between 19 and 50 years, BMI ≥ 30 kg/m2, were recruited and subjected to measurements of endothelial function, nutritive skin microvascular reactivity, plasma viscosity, inflammatory and oxidative stress biomarkers at baseline and randomized 1:1 to ingest metformin (850 mg twice/day) or vildagliptin (50 mg twice/day) during 30 days, and then, re-evaluated.ResultsNo differences between groups were noticed at baseline. After treatment, vildagliptin promoted an improvement on endothelial-dependent and -independent vasodilatations, at arteriole level, while metformin resulted in improved nutritive microvascular reactivity, at the capillary level. Intragroup analysis showed that vildagliptin reduced insulin, C-peptide and oxidized LDL, and increased adiponectin and glucagon-like peptide-1 while metformin reduced weight, plasma glucose, total cholesterol, HDL-c, LDL-c, and dipeptidyl peptidase-4 activity, with an unexpected increase on tumor necrosis factor-α. No significant difference in plasma viscosity was noted.ConclusionsIn the vascular beds investigated, both drugs used for only 30 days improved endothelial function, through distinct, and possibly, complementary mechanisms on drug-naïve diabetic women.Trial Registration ClinicalTrials.gov: NCT01827280

Colloidal (-)-epigallocatechin-3-gallate vesicular systems for prevention and treatment of skin cancer: A comprehensive experimental study with preclinical investigation

Skin carcinogenesis is a common malignancy affecting humans worldwide, which could benefit from nutraceuticals as a solution to the drawbacks of conventional skin cancer treatment. (−)-epigallocatechin-3-gallate (EGCG) is a promising nutraceutical in this regard; however, it suffers chemical instability and low bioavailability resulting in inefficient delivery. Therefore, EGCG encapsulation in ultradeformable colloidal vesicular systems, namely: penetration enhancer-containing vesicles (PEVs), ethosomes and transethosomes (TEs) for topical administration has been attempted in this study to overcome the problems associated with the use of free EGCG. The prepared vesicles were characterized for their entrapment efficiency, TEM visualization, chemical compatibility, antioxidant properties, ex-vivo skin deposition, photodegradation and physical stability after storage. Most of the prepared vesicles exhibited reasonable skin deposition and preservation of the inherent antioxidant properties of EGCG with good physical stability. EGCG-loaded PEVs and TEs exhibited an inhibitory effect on epidermoid carcinoma cell line (A431) in addition to reduced tumor sizes in mice, confirmed with histopathological analysis and biochemical quantification of skin oxidative stress biomarkers; glutathione, superoxide dismutase and catalase, as well as lipid peroxidation. EGCG PEVs succeeded in offering an effective delivery system targeting skin cancer, which is worthy of further experimentation.

Electrochemical Methodology for Evaluating Skin Oxidative Stress Status (SOSS).

For the purpose of human disease prevention, several methods have been developed, and are still developing, to assess the oxidative stress status (OSS) of individuals. In the present paper, we describe an approach based on electrochemical detection able to evaluate skin oxidative stress status (SOSS) as a PAOT (Pouvoir AntiOxydant Total)-Skin Score®. Normal reference values for the PAOT-Skin Score® were: 0–62.94 (n = 263). Intra- and inter-assay coefficients of variation were, respectively, 12.47 ± 4.29% and 7.0 ± 2.5%. Our technology showed increased skin antioxidant activity following topical application of reduced coeznyme Q10 cream or vitamin C intake as orange juice or supplements. Moreover, we found significant correlations between some blood oxidative stress biomarkers and the PAOT-Skin Score® (γ-tocopherol/α-tocopherol ratio (r = 0.43, p = 0.020); copper (r = −0.42, p = 0.022); copper/zinc ratio (r = −0.49, p = 0.006), and lipid peroxides (r = −0.43, p = 0.002)). In addition to being non–invasive, the present electrochemical methodology is also not expensive, fast, and easy to use.

Skin protective effects of an antipollution, antioxidant serum containing Deschampsia antartica extract, ferulic acid and vitamin C: a controlled single-blind, prospective trial in women living in urbanized, high air pollution area.

Introduction: Air pollution causes skin damage and favors skin aging processes such as dark spots and wrinkles, through oxidative stress. Pollutant substances accelerate skin aging through a specific activation of intracellular receptors called AhR (aryl-hydrocarbon receptors). Deschampsia antartica aqueous extract (DAE) has shown to counteract the pollutant-induced AhR activation. Ferulic acid (FA) and vitamin C (VC) are potent antioxidant substances. A serum containing DAE/FA/VC has been recently developed. So far, no clinical data are available regarding the protective actions of this serum against the detrimental effects of air pollution on the skin.Objective: We conducted a prospective, single-blind, 28-day study to assess efficacy and protective effects against air pollution skin damage of a new serum containing Deschampsia antartica extract.Materials and methods: Twenty, photo type I–III, women (mean age 42 years) with at least three dark spots on the face, living in a homogenous urbanized, high pollution area (Rome) were evaluated. The objectives of the study were to evaluate the effects of treatment on skin barrier function, assessed by transepidermal water loss (TEWL) measurement (Tewameter), the effect on dark spots, evaluated by means of colorimetry (Colorimeter CL 400), and the effect on squalene peroxide (SQOOH)/squalene (SQ) skin ratio assessed with face swabs.Results: The trial was conducted between November 20 and December 19, 2018. In comparison with baseline, the product induced a significant improvement of skin hydration (−19% of TEWL), a significant improvement of dark spots (+7%) and a significant improvement of SQOOH/SQ ratio (−16%). The product was evaluated very well by >90% of the treated subjects regarding cosmetic acceptability.Discussion: A serum containing DAE/FA/VC has shown to improve skin barrier function, to reduce dark spots and to counteract the skin oxidative stress in women living in high pollution urban area.

646 Activated-Grape Seed Extract (AGSE) inhibits oxidative stress and demethylation of PP2A in human skin

Environmental stimuli attack the skin daily resulting in oxidative stress and the generation of reactive oxygen species (ROS) and inflammation. One pathway that regulates oxidative stress in skin involves Protein phosphatase 2A (PP2A), a phosphatase that has been previously linked to Alzheimer’s Disease and aging. Oxidative stress bursts via hydrogen peroxide (H2O2) and Ultraviolet A (UVA) treatments have previously been shown to dramatically decrease PP2A methylation in human dermal fibroblasts (HDFs), moreover, in vivo studies demonstrate that oxidative stress induces PP2A inactivation. Thus, we hypothesize, agents that increase PP2A methylation and activity will promote skin health and combat aging. To discover novel inhibitors of PP2A demethylation activity, we screened a small library of ∼30 natural botanical extracts. We discovered Grape Seed Extract (GSE), which has previously been reported to have several benefits for skin to be one of the most potent PP2A demethylating extracts (IC50 = 0.96 μg/mL). Via several fractionation and extraction steps, we developed a novel grape seed extract called Activated-Grape Seed Extract (AGSE) which is enriched for PP2A-activating flavonoids resulting in a ∼5-fold increased potency (IC50 = 0.22 μg/mL) in preventing PP2A demethylation when compared to commercial GSE. We then investigated the antioxidant potential of AGSE and demonstrate it dose-dependently protects PP2A against oxidative stress-induced demethylation in HDFs by reducing ROS levels in cell-based and cell-free assays equal to or better than Vitamin C, E and Ferulic acid. Moreover, AGSE shows anti-inflammatory activity, dose-dependently inhibiting UVA induced IL-6 release in HDFs and TPA IL-8 release from NHEKs. These results demonstrate that AGSE is a novel, multi-functional extract that modulates methylation of PP2A with increased potency as compared to commercial GSE and supports the hypothesis of PP2A as a master regulator for oxidative stress signaling and aging in skin.

Seroprevalence of Sarcoptes scabiei var suis infestation in swine population and its effect on haemato-biochemical and oxidative stress indices and its management with special reference to herbal ointmen

The study was undertaken to know the sero-prevalence of sarcoptic infestation in pig in Mizoram and its effect on haemato-biochemical and oxidative stress indices and to develop cost effective herbal therapeutic management. Total 600 pigs of three district of Mizoram, Aizawl, Kolasib and Mamit were screened by using commercial indirect ELISA SARCOPTES 2001H Pig (AFOSA GmbH, Blankenfelde-Mahlow, Germany) to detect anti-Sarcoptic antibodies. The results cleared that out of 600 inspected pigs, 100 (16.66%) were found to be seropositive with sarcoptic mange. Geographically, pigs from Aizawl areas were more exposed to mange infestation (56/200, 28%) than Kolashib (32/200, 16%) and Mamit (12/200, 6%). The neutrophil and eosinophil was significantly (Pd£ 0.05) increase and RBCs, Hb and PCV were significantly (Pd£ 0.05) decreased in infested groups. There were significant ELISA SARCOPTES-ELISA 2001H Pig decrease in values of total protein, albumin, while there were significant (Pd£ 0.05) increase in values of AST, ALT, ALP, BUN and creatinine In regard to oxidative stress, there was a significant (Pd£ 0.05) increase in malonyldialdehyde (LPO) and NO and significant (Pd£ 0.05) decrease in reduced GSH, SOD and TAA in infested group. In the present study, polyherb formulation showed similar efficacy to improve skin lesion, haemato-biochemical and oxidative stress indices with Ivermectin on 15th day of post therapeutic application against sarcoptic infestation in pigs. ELISA SARCOPTES-ELISA 2001H Pig represent a useful tool for population surveys and the plant extracts can be used as alternatives to drugs of synthetic origin.

A Serum Containing Deschampsia antartica Extract, Ferulic Acid and Vitamin C has Anti-Pollutant Effects on Skin Exposed to High Tropospheric Ozone Levels: A Controlled Single-Blind, Prospective Clinical Trial in Women Living in Urbanized, High Air Pollution Area during the Summer Season

Introduction: Air pollution induces skin damage and accelerating skin aging processes, mainly through oxidative stress. Pollutant substances, such as particulate matter (PM10, PM2.5) and tropospheric ozone (O3), can activate specific intracellular receptors called AhR (Aryl-Hydrocarbon Receptors) and this activation is involved in the skin aging process. Deschampsia antartica aqueous extract (DAE) has shown, in vitro, to reduce the pollutant-induced AhR activation. Ferulic acid (FA) and vitamin C (VC) are well known potent anti-oxidant substances. A dermatological product in serum formulation containing DAE/FA/VC has been recently commercialized. This product has demonstrated in vivo to protect skin from pollution damage during winter season when PM10 levels are very high. No data have been published so far regarding the protective effect of this serum during summer months when the main atmospheric pollutant is O3. Objective and materials and methods: We carried out a prospective, single-blind, controlled 28-day study during the summer season (characterized by elevated O3 tropospheric levels) in 20, photo type II-III, women (mean age 38 years) with mild-moderate skin aging, living in an urbanized, high pollution area (City of Rome) compelling to spend at least 2 hours daily outdoor. The study’s outcomes were to evaluate the effects of treatment on skin barrier function, assessed by TEWL measurement (Tewameter) and corneometry, skin appearance by high resolution photographs with Visioface Quick (Courage and Khazaka) and the effect on squalene peroxide (SQOOH)/squalene (SQ) skin ratio measured with face swabs. Results: The trial was conducted between July the first, and August 2, 2019. All the subjects concluded the trial. During the study period, elevated O3 concentration (>120 microg/m3) were registered in 22 out of 31 days (71%) (The ARPA official database, Agenzia regionale per la protezione ambientale). The product induced, in comparison with baseline values, a significant improvement of skin barrier function and hydration (-14% of TEWL and +16% skin hydration), significant improvements in skin appearance and SQOOH/SQ ratio (-19%) were also observed. The 90% of the subjects involved in the trial evaluated the product very well regarding cosmetic acceptability. Discussion: The results of the present study has demonstrated that a serum containing DAE/FA/VC can improve skin barrier function, skin appearance and counteract skin oxidative stress in women living in high O3 pollution urban area during the summer period.

Tectorigenin, a Flavonoid-Based Compound of Leopard Lily Rhizome, Attenuates UV-B-Induced Apoptosis and Collagen Degradation by Inhibiting Oxidative Stress in Human Keratinocytes.

Ultraviolet (UV) light, a major risk factor for external skin photoaging, induces oxidative stress in skin. UV causes a breakdown of skin homeostasis by impairing the extracellular matrix and inducing cell death. Tectorigenin, a constituent of leopard lily (Belamcanda chinensis L.) rhizome, has been reported to possess antioxidant, hair-darkening, and anti-inflammatory activities; however, the effect of tectorigenin on UV-B-induced skin damage is unknown. Here, we investigated the anti-skin-damage effects of tectorigenin against UV-B-stimulated oxidative stress in human keratinocytes. We irradiated HaCaT cells with UV-B (25 mJ/cm2), followed by treatment with tectorigenin for 24 h. We found that tectorigenin decreased the levels of intracellular reactive oxygen species by increasing the expression of anti-oxidative enzymes, such as glutathione and catalase. Furthermore, tectorigenin inhibited apoptosis by reducing caspase-3- and Bcl-2-associated protein-X levels, and increasing Bcl-2 protein levels. Tectorigenin also decreased matrix metalloproteinase-1 levels and increased type 1 collagen levels, thus preventing collagen degradation. These data demonstrate that tectorigenin exerts anti-skin-damage effects in human keratinocytes by attenuating UV-B-induced hyper-oxidation, apoptosis, and collagen degradation.

The Lipid Mediator Resolvin D1 Reduces the Skin Inflammation and Oxidative Stress Induced by UV Irradiation in Hairless Mice.

UV irradiation-induced oxidative stress and inflammation contribute to the development of skin diseases. Therefore, targeting oxidative stress and inflammation might contribute to reduce skin diseases. Resolvin D1 (RvD1) is a bioactive metabolite generated during inflammation to actively orchestrate the resolution of inflammation. However, the therapeutic potential of RvD1 in UVB skin inflammation remains undetermined, which was, therefore, the aim of the present study. The intraperitoneal treatment with RvD1 (3-100 ng/mouse) reduced UVB irradiation-induced skin edema, myeloperoxidase activity, matrix metalloproteinase 9 activity, and reduced glutathione depletion with consistent effects observed with the dose of 30 ng/mouse, which was selected to the following experiments. RvD1 inhibited UVB reduction of catalase activity, and hydroperoxide formation, superoxide anion production, and gp91phox mRNA expression. RvD1 also increased the Nrf2 and its downstream targets NQO1 and HO-1 mRNA expression. Regarding cytokines, RvD1 inhibited UVB-induced production of IL-1β, IL-6, IL-33, TNF-α, TGF-β, and IL-10. These immuno-biochemical alterations by RvD1 treatment had as consequence the reduction of UVB-induced epidermal thickness, sunburn and mast cell counts, and collagen degradation. Therefore, RvD1 inhibited UVB-induced skin oxidative stress and inflammation, rendering this resolving lipid mediator as a promising therapeutic agent.

Icariin and icaritin recover UVB-induced photoaging by stimulating Nrf2/ARE and reducing AP-1 and NF-κB signaling pathways: a comparative study on UVB-irradiated human keratinocytes.

Icariin (ICA) and icaritin (ICT) exhibit many pharmacological functions including anti-osteoporosis, anti-cardiovascular, and anti-cancer activities; however, there are few comprehensive studies that track the detailed effects on UVB-induced photoaging. The recovery effects of ICA and ICT were investigated in UVB-irradiated human keratinocytes (HaCaTs). The results indicated that ICT and ICA showed strong radical scavenging activity, and the reactive oxygen species (ROS) scavenging activity of ICT was superior. UVB-induced matrix metalloproteinase-1 (MMP-1) expression was blocked by ICA via the inhibition of mitogen-activated protein kinase/activator protein 1 (MAPK/AP-1), which directly reduced extracellular matrix (ECM) degradation. ICT activated nuclear factor erythroid 2 related factor 2 (Nrf2) to improve the anti-oxidative stress capacity and suppress nuclear factor-κB (NF-κB) activation, decreasing vascular endothelial growth factor (VEGF) protein, and inflammatory cytokines induced ECM degrading enzyme secretion. Moreover, ICT was more advantageous to improve transforming growth factor beta 1 (TGF-β1) and procollagen type I expression than ICA, promoting the synthesis of collagen. Therefore, ICA and ICT have potential to treat UVB-induced oxidative stress, inflammation and photoaging, and will be posited as a novel strategy to alleviate photodamage.

Topical emulsion containing pyrrolidine dithiocarbamate: effectiveness against ultraviolet B irradiation-induced injury of hairless mouse skin.

To evaluate the effects of a topical emulsion containing pyrrolidine dithiocarbamate (PDTC) (EcPDTC) in skin oxidative stress and inflammation triggered by ultraviolet B (UVB) irradiation (dose of 4.14J/cm2 ). Hairless mouse received treatment with 0.5g of EcPDTC or control emulsion (CTRLE) on the dorsal surface skin 12h, 6h and 5min before and 6h after the irradiation. Oxidative stress was evaluated by ferric reducing antioxidant power (FRAP), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) scavenging capacity, reduced glutathione quantitation, catalase activity, superoxide anion production and lipid peroxidation products. Inflammation parameters were as follows: skin oedema, myeloperoxidase activity (neutrophil marker), matrix metalloproteinase-9 activity, collagen fibre damage, mast cell and sunburn cell counts, and cytokine production. Topical treatment with EcPDTC protected from UVB-induced skin injury by maintaining the antioxidant capacity levels similar to non-irradiated control group. Furthermore, EcPDTC inhibited UVB irradiation-induced superoxide anion production, lipid peroxidation and reduced skin inflammation by inhibiting skin oedema, neutrophil recruitment, metalloproteinase-9 activity, collagen fibre damage, mast cell and sunburn cell counts, and cytokine (TNF-α and IL-1β) production. Topical treatment with EcPDTC improves antioxidant systems and inhibits inflammation, protecting the skin from the damaging effects of UVB irradiation.

Moringa oleifera stem extract protect skin keratinocytes against oxidative stress injury by enhancement of antioxidant defense systems and activation of PPARα

Oxidative stress is an important cause of skin injury induced by UVB radiation. Moringa oleifera also known as horseradish tree or drumstick tree, have multiple nutraceutical or pharmacological functions. However, whether Moringa oleifera protects skin against oxidative stress injury remains unknown. To investigate the effects of the ethanol extract of Moringa oleifera stem (MSE) on skin oxidative stress injury and its molecular mechanism, we first determined the effect of MSE on epidermal oxidative stress injury induced by H2O2 in keratinocytes (HaCaT cells) and by UVB-radiation in mice. Then we investigated the effect of MSE on the enhancement of antioxidant system and activation of PPARα in vitro and in vivo. Furthermore, the flavonoids compositions in MSE were assayed by high-performance liquid chromatography (HPLC), and then molecular docking study was used to assess the major component in MSE to activate PPARα. Our results indicate that MSE (100–400 μg/mL) protected the epidemic cell against oxidative stress injury in vitro and topical treatment with MSE cream (6%) inhibit UVB-induced oxidative stress injury in the epidermis of the mouse skin. PPARα activation is involved in the protective effect of MSE. HPLC assay and molecular docking study indicated that rutin might be the main component in MSE to activate PPARα. These results confirm that MSE exerts the protective effect on oxidative stress induced skin keratinocytes injury. Moreover, the protective effect of MSE is mediated by enhancement of antioxidant defense systems and activation of PPARα in skin keratinocytes.

Changes in dermal structure and skin oxidative stress in overweight and obese Japanese males after weight loss: a longitudinal observation study.

Previous studies have reported decreased dermal echogenicity and increased skin oxidative stress in overweight males. However, it is unknown whether these skin parameters of overweight and obese people are similar to those of individuals exhibiting a normal body weight following weight loss. The purpose of this study was to (1) compare the changes in the dermal structure parameters and levels of skin oxidative stress before and after weight loss in overweight and obese people in Japan and (2) to clarify how these aspects changed when body weight would be reduced to normal body weight. Male volunteers with a body mass index of ≥25kg/m2 were recruited. The dermal structure was visualized and dermal echogenicity and thickness were measured using ultrasound scanners. The mRNA expression level of heme oxygenase-1 in the hair follicles was quantitatively analyzed as a marker of skin oxidative stress. When overweight individuals in their 20s to 30s reduced their weight to normal, decreased dermal thickness in the abdominal region was observed in 50% of the subjects; however, no increase in dermal echogenicity was observed. A decrease in dermal thickness and an increase in dermal echogenicity in the thighs was observed in 83.3% of the subjects. No decrease in the level of dermal oxidative stress was observed. The dermal structure in the thighs of overweight young individuals can be improved to the level of the structure in those of normal body weight individuals following weight loss.

Skin Intrinsic Fluorescence and Age-Related Macular Degeneration: The Beaver Dam Eye Study.

PurposeTo determine if skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation endproducts and oxidative stress in skin is associated with AMD.MethodsSIF was measured with the SCOUT DS skin fluorescence spectrometer in a cross-sectional cohort study of 969 persons aged 68 to 102 years from the 1181 who participated in the 25-year follow-up examination in the Beaver Dam Eye Study (BDES) in 2014 to 2016. The SCOUT DS skin fluorescence spectrometer uses five light-emitting diodes, centered at 375 nm to 456 nm. AMD was assessed by grading of digital color 45° stereoscopic fundus photographs of the macula using the Wisconsin Age-Related Maculopathy grading scheme. Analyses included logistic regression with generalized estimating equations to account for correlation between the eyes of a person.ResultsThere were data for 1827 eyes for analyses. Early AMD was present in 22% and late AMD in 4% of the eyes. While adjusting for age, sex, smoking status, and history of cardiovascular disease, there were no significant associations of any SIF measure with any AMD or exudative AMD. SIF01 (odds ratio per 1 SD difference on the log scale, 95% confidence interval) (1.66, 1.00–2.74, P = 0.05) and SIF03 (1.81, 1.16–2.81, P = 0.008) were associated with geographic atrophy.ConclusionsThere was a suggestive relationship of two SIF measures, SIF01 and SIF03, using different correction factors from the excitation centered at 375 nm, with the prevalence of geographic atrophy in the BDES. Longitudinal follow-up is indicated to assess a temporal relationship.

Gallic Acid-Loaded Gel Formulation Combats Skin Oxidative Stress: Development, Characterization and Ex Vivo Biological Assays.

Oxidative stress, which is a result of overproduction and accumulation of free radicals, is the main cause of several skin degenerative diseases, such as aging. Polyphenols, such as gallic acid, are an important class of naturally occurring antioxidants. They have emerged as strong antioxidants that can be used as active cosmetics. The purpose of this study was to develop a gallic acid-loaded cosmetic gel formulation and characterize it using rheological, mechanical, and bioadhesive tests. Its antioxidant effect in the stratum corneum was evaluated by a non-invasive method. According to the characterization tests, the formulation exhibited skin adhesiveness and pseudoplastic behavior without thixotropy, rendering it suitable for use as a cosmetic formulation. Furthermore, the non-invasive method indicated the antioxidant effect in the stratum corneum, with the global lipid peroxide reduction being 33.97 ± 11.66%. Thus, we were able to develop a promising gallic acid-loaded gel formulation that could reduce lipid peroxides and thus combat skin oxidative stress.

Skin changes in streptozotocin-induced diabetic rats

Diabetes can cause serious health complications, which can affect every organ of the body, including the skin. The molecular etiology has not yet been clarified for all diabetic skin conditions. Thus, this study aimed to investigate the changes of diabetes in skin compared to non-diabetic skin in rats. Fifteen days after establishing the diabetic status, skin samples from the dorsum-cervical region were harvested for subsequent analysis of alterations caused by diabetes. Our results demonstrate that diabetes stimulated higher inflammation and oxidative stress in skin, but antioxidant defense levels were lower compared to the non-diabetic group (p < 0.05). This could have been related to a decreased number of blood vessels and low expression of VEGF, eNOS and TGF-β1. Finally, insulin signaling proteins IRS, Akt, Shc and ERK showed a low expression in the diabetic group. Thus, our study shows that the pathology of diabetes induced immunohistopathological and biochemical skin changes compared to non-diabetic skin in rats.

P 146 - The effect of anti-aging agents in skin oxidative stress induced by UV Radiation in vivo

UV radiation is related to oxidative stress and skin aging. UV induced reactive oxygen species lead to progressive degradation of dermal collagen and elastin. Four of the most known anti-aging agents were examined in the photoaged skin of hairless SKH-hr2 mice. 50 mice were irradiated with increasing UVR doses (0.5–2 MED) 3 times per week for 4 weeks. After the end of the irradiations, 5 formulations containing retinoic acid 0.05%, lactic acid 10%, salicylic acid 3%, epidermal growth factor 3.3% and the vehicle were applied on the back of the mice for 3 weeks. Hydration, transepidermal water loss (TEWL), elasticity and skin thickness, were frequently measured. After the end of applications, oxidative stress was evaluated in skin biopsies and strippings of stratum corneum using fluorescence spectroscopy, as well endogenous antioxidants using HPLC–EC detection. Epidermal thickening was evident in all mice after UV exposure. After treatment with lactic acid the thickness decreased significantly. Highest TEWL was observed in the retinoic acid group. The skin treated with salicylic acid demonstrated the lowest levels of ascorbic and uric acid. In strippings, lactic acid icreased the levels of antioxidants. Highest elasticity was measured in the retinoic acid group. In conclusion, retinoic and lactic acids seem to be the most effective treatments for the photodamaged skin.

Seasonal variation in HSP70 expression and oxidative stress in skin of zebu (Tharparkar) and crossbred (Karan Fries) cattle under tropical climate

The study aimed to evaluate inducible HSP70 (HSP70.1 and HSP70.2) gene expression and oxidative stress status in skin of cattle during different seasons. Ten each of Tharparkar (zebu) and Karan Fries (crossbred) heifers were selected from NDRI herd, Karnal. Animals were maintained under standard managemental practices followed at the farm. Skin biopsies were aseptically collected from each animal during winter, spring, and summer. Real time PCR was performed to examine HSP70 expression. Reactive oxygen species (ROS) and antioxidant enzymes (SOD and CAT) were determined by ELISA. In both the breeds, significantly higher (p < 0.05) levels of HSP70 expression, ROS, caspases, and antioxidant enzymes were observed during summer followed by winter and spring. Breeds showed no significant difference during winter and spring. During summer, HSP70 expression, ROS, and antioxidant enzymes were higher (p < 0.05) in Karan Fries than Tharparkar, whereas caspases levels were higher in Tharparker than Karan Fries. The study concludes that levels of HSP70 expression, ROS, caspases, and antioxidant enzymes in skin of cattle were strongly affected by seasonal change in temperature. Differences exist in skin tissue thermotolerance of Tharparkar and Karan Fries cattle. This might be an efficient and centrally important mechanism for better adaptability of zebu cattle to heat stress.

Association of Skin Intrinsic Fluorescence with Retinal Microvascular Complications of Long Term Type 1 Diabetes in the Wisconsin Epidemiologic Study of Diabetic Retinopathy

ABSTRACTObjective: To determine the association between skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation endproducts and oxidative stress in skin, and retinal microvascular complications of long duration type 1 diabetes, proliferative diabetic retinopathy (PDR) and macular edema.Methods: A cross-sectional cohort study of persons with type 1 diabetes in the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) who participated in a 32-year follow-up examination in 2012–2014. Subjects underwent a physical examination, answered a health questionnaire, and had fundus photographs taken. SIF was measured on the underside of the left forearm near the elbow with the SCOUT DS® skin fluorescence spectrometer. Two representative SIF measures were used for these analyses: SIF01 excited by an LED centered at 375 nm with correction factors Kx = 0.6 and Km = 0.2 and SIF15 excited by an LED centered at 456 nm with correction factors Kx = 0.4 and Km = 0.9.Results: The 414 participants had mean diabetes duration of 42.2 years (standard deviation 6.8 years, range 32.9–67.9 years). PDR was statistically significantly associated (p < 0.05) with both SIF measures in multivariate models including other relevant factors (odds ratio [OR] = 1.17 for SIF01 and 1.20 for SIF15).Conclusion: Skin intrinsic fluorescence measures are independently associated with PDR in the WESDR. Incidence information is needed to evaluate whether there is a causal relationship.