Skin Catalase Research Articles

Preparation, identification, computational analysis of antioxidative peptides derived from Lumbricus protein and prevention of UV-B radiation-induced skin damaged

Present study aimed to prepare, identify and computational analysis antioxidative peptides from Lumbricus protein, meanwhile to investigate their bioavailability and preventive effects against oxidative stress-related diseases, namely UV-B radiation-induced skin damaged. Antioxidative peptides from Lumbricus protein (Mw < 5 kDa, LPs) hydrolyzed by alcalase reached the highest ABTS·+ scavenging activity and Fe2+ chelating activity with the EC50 values of 0.175 and 1.003 mg/mL, respectively. Additionally, UV-B radiation-induced skin damaged mice model showed that skin catalase (CAT) and glutathione (GSH) were enhanced, while malondialdehyde (MDA) was decreased by LPs significantly (p < 0.05). LPs could inhibit skin oxidative stress via regulating the expression and distribution of B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X (Bax). Moreover, eighty peptides were identified in LPs, peptides such as PGAGAVY and KDLY showed the lowest binding energies with ABTS, and their binding affinities were confirmed by molecular docking. At the concentration of 0.0625 mg/mL, the ABTS·+ scavenging activity of PGAGAVY and KDLY reached 63.016%, and 52.884%, respectively, which were better than that of LPs (EC50 = 0.175 mg/mL). Overall, these findings provide a new perspective for Lumbricus antioxidative peptides as natural antioxidants.

New concepts for transdermal delivery of oxygen based on catalase biochemical reactions studied by oxygen electrode amperometry

The development of formulation concepts for improved skin tissue oxygenation, including methods for measuring oxygen (O2) transport across biological barriers, are important research topics with respect to all processes that are affected by the O2 concentration, such as radiation therapy in oncology treatments, wound healing, and the general health status of skin. In this work we approach this topic by a novel strategy based on the antioxidative enzyme catalase, which is naturally present in the skin organ where it enables conversion of the reactive oxygen species hydrogen peroxide (H2O2) into O2. We introduce various applications of the skin covered oxygen electrode (SCOE) as an in-vitro tool for studies of catalase activity and function. The SCOE is constructed by placing an excised skin membrane directly on an O2 electrode and the methodology is based on measurements of the electrical current generated by reduction of O2 as a function of time (i.e. chronoamperometry). The results confirm that a high amount of native catalase is present in the skin organ, even in the outermost stratum corneum (SC) barrier, and we conclude that excised pig skin (irrespective of freeze-thaw treatment) represents a valid model for ex vivo human skin for studying catalase function by the SCOE setup. The activity of native catalase in skin is sufficient to generate considerable amounts of O2 by conversion from H2O2 and proof-of-concept is presented for catalase-based transdermal O2 delivery from topical formulations containing H2O2. In addition, we show that this concept can be further improved by topical application of external catalase on the skin surface, which enables transdermal O2 delivery from 50 times lower concentrations of H2O2. These important results are promising for development of novel topical or transdermal formulations containing low and safe concentrations of H2O2 for skin tissue oxygenation. Further, our results indicate that the O2 production by catalase, derived from topically applied S. epidermidis (a simple model for skin microbiota) is relatively low as compared to the O2 produced by the catalase naturally present in skin. Still, the catalase activity derived from S. epidermidis is measurable. Taken together, this work illustrates the benefits and versatility of the SCOE as an in vitro skin research tool and introduces new and promising strategies for transdermal oxygen delivery, with simultaneous detoxification of H2O2, based on native or topically applied catalase.

Electrochemical monitoring of native catalase activity in skin using skin covered oxygen electrode

A skin covered oxygen electrode, SCOE, was constructed with the aim to study the enzyme catalase, which is part of the biological antioxidative system present in skin. The electrode was exposed to different concentrations of H2O2 and the amperometric current response was recorded. The observed current is due to H2O2 penetration through the outermost skin barrier (referred to as the stratum corneum, SC) and subsequent catalytic generation of O2 by catalase present in the underlying viable epidermis and dermis. By tape-stripping the outermost skin layers we demonstrate that SC is a considerable diffusion barrier for H2O2 penetration. Our experiments also indicate that skin contains a substantial amount of catalase, which is sufficient to detoxify H2O2 that reaches the viable epidermis after exposure of skin to high concentrations of peroxide (0.5–1mM H2O2). Further, we demonstrate that the catalase activity is reduced at acidic pH, as compared with the activity at pH 7.4. Finally, experiments with often used penetration enhancer thymol shows that this compound interferes with the catalase reaction. Health aspect of this is briefly discussed. Summarizing, the results of this work show that the SCOE can be utilized to study a broad spectrum of issues involving the function of skin catalase in particular, and the native biological antioxidative system in skin in general.

Effects of blueberry extract supplementation on antioxidant activity in chronically stressed rats

The study was conducted to elucidate the effects of blueberry(Vaccinium cyanococcus) supplementation on antioxidant enzyme activities in rat blood, skin and brain tissue. Forty‐eight 10‐week‐old male Sprague‐Dawley rats were assigned to four groups (n=12/group); no stress‐normal diet(−CON), stress‐normal diet(+CON), no stress‐normal diet + 5% blueberry water(−BB), and stress‐ normal diet + 5% blueberry water(+BB). The +CON and +BB groups were given the stress during all experimental period and stress scheme was followed the chronic mild stress model. Body weight gain and feed efficiency ratio were decreased in given stress groups compared with non stress groups (p&lt;0.05). Antioxidant activity levels in blueberry supplemented rats tended to increase compared to control groups. The stressed rats groups tended to have low antioxidant levels compared with unstressed rats groups. The superoxide dismutase(SOD) activity in serum and brain was not different among the treatments. The serum glutathione peroxidase activity was the highest in −BB group, but +BB group was lower than +CON(p&lt;0.05). The skin SOD activity was significantly higher in blueberry supplementation groups than that of −CON and +CON groups. The skin catalase activity was higher in blueberry groups(p&lt;0.05). From the findings, blueberry supplementation might provide the protection against oxidative stress induced by chronic stress.

Gender Bias in Skin Cancer: Role of Catalase Revealed

Sullivan et al. describe their finding that lower skin catalase activity in male as compared with female mice may be responsible for the increased skin carcinogenesis observed in UVB radiation-exposed male mice. This adds to the growing literature that points toward a gender bias in the pathogenesis of skin cancer. Delineating the events between UV exposure and carcinogenesis in relation to skin's antioxidant activity will provide insight into disease progression, prognosis, and responses to therapy. If substantiated with further studies in humans, this information may aid in designing gender-specific preventive measures aimed at reversing immune suppression through targeting the altered redox status in UV-exposed individuals.

UV Light B–Mediated Inhibition of Skin Catalase Activity Promotes Gr-1+CD11b+ Myeloid Cell Expansion

Skin cancer incidence and mortality are higher in men compared to women, but the causes of this sex discrepancy remain largely unknown. Ultraviolet light exposure induces cutaneous inflammation and neutralizes cutaneous antioxidants. Gr-1+CD11b+ myeloid cells are heterogeneous bone marrow-derived cells that promote inflammation-associated carcinogenesis. Reduced activity of catalase, an antioxidant present within skin, has been associated with skin carcinogenesis. We utilized the outbred, immune competent Skh-1 hairless mouse model of ultraviolet light B (UVB)-induced inflammation and non-melanoma skin cancer to further define sex discrepancies in UVB-induced inflammation. Our results demonstrated that male skin had relatively lower baseline catalase activity, which was inhibited following acute UVB exposure in both sexes. Further analysis revealed that skin catalase activity inversely correlated with splenic Gr-1+CD11b+ myeloid cell percentage. Acute UVB exposure induced Gr-1+CD11b+ myeloid cell skin infiltration, which was inhibited to a greater extent in males by topical catalase treatment. In chronic UVB studies, we demonstrated that the percentage of splenic Gr-1+CD11b+ myeloid cells was 55% higher in male tumor-bearing mice compared to their female counterparts. Together, our findings indicate that lower skin catalase activity in male mice may at least in part contribute to increased UVB-induced Gr-1+CD11b+ myeloid cells and subsequent skin carcinogenesis.

Determination of oxidative stress in vitiligo by measuring superoxide dismutase and catalase levels in vitiliginous and non-vitiliginous skin

Vitiligo is an acquired disorder characterized by circumscribed depigmented macules devoid of identifiable melanocytes. Complex genetic, immunological, neural and self destructive mechanisms interplay in its pathogenesis. According to autocytotoxic hypothesis, oxidative stress has been suggested to be the initial pathogenic event in melanocyte degeneration. The aim of our investigation was to evaluate the role of oxidative stress by measuring levels of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in lesional and normal skin of patients with vitiligo and in the skin of normal controls. We determined the activity of SOD in lesional and non-lesional skin and CAT in lesional skin only of 25 vitiligo patients and 25 controls by using the spectrophotometric assay and Aebi's method, respectively. There was statistically significant increase in the levels of SOD in vitiliginous and non vitiliginous skin of patient group compared to the control group (P < 0.001). No significant difference was found between the levels of SOD in lesional skin and non-lesional skin of vitiligo patients. The levels of CAT in the skin of patients were found to be significantly lower than those of controls (P < 0.001). There is increased oxidative stress in vitiligo as is indicated by high levels of SOD and low levels of CAT in the skin of vitiligo patients.

UVR-induced oxidative stress in human skin in vivo: effects of oral vitamin C supplementation.

Previous studies of cultured skin cells and murine skin in vivo have indicated that UVR-induced damage involves the generation of reactive oxygen species and depletion of endogenous antioxidant systems. In order to explore the relevance of this to UVR-induced damage to human skin, we have undertaken a detailed examination of the time-course of changes in markers of oxidative stress in human skin following exposure to physiological amounts of UVR in vivo. In addition, we have examined the skin bioavailability of a common nutritional antioxidant, vitamin C, and have assessed the effects of supplementation on markers of oxidative stress. Our hypothesis was that acute exposure of human skin to UVR in vivo would lead to oxidation of cellular biomolecules that could be prevented by prior vitamin C treatment. A UVR-challenge of 120 mJ/cm2 of broadband UVB (peak 310 nm, range 270-400 nm) was applied to buttock skin of 8 healthy volunteers. This caused a rapid and significant rise in activity of skin catalase at 1 h and an increase in the oxidized/total glutathione ratio at 6 h post-UVR. AP-1 DNA binding also peaked at 1-6 h post-UVR, then declined rapidly to baseline levels. No significant changes were seen in skin malonaldehyde content. Oral vitamin C supplements (500 mg/day) were taken by 12 volunteers for 8 weeks resulting in significant rises in plasma and skin vitamin C content. Supplementation had no effect on the UVR-induced erythemal response. The skin malonaldehyde content was reduced by vitamin C supplementation, but surprisingly, reductions in the skin content of total glutathione and protein thiols were also seen. We speculate that this apparently paradoxical effect could be due to regulation of total reductant capacity by skin cells, such that vitamin C may have been replacing other reductants in these cells. No evidence was obtained for an effect of the supplementary vitamin C on the mild oxidative stress seen in human skin following UVR exposure.

Catalase in the stratum corneum of patients with polymorphic light eruption.

UV radiation generates reactive oxygen species, which may be involved in polymorphic light eruption. The endogenous enzymatic defense system includes catalase in the epidermis. Thirteen patients with a history of polymorphic light eruption, but free from lesions, and 13 controls were investigated from November to March. Catalase was analysed in the upper horny layer according to Colin et al.'s spectrophotometric technique. In polymorphic light eruption, catalase values were about 30% lower than in control subjects. Such deficiency was observed in patients free from the disease and not recently sun-exposed. The diminished skin catalase in irradiated polymorphic light eruption makes it possible that a longer restoration time of catalase is involved in the pathogenesis.

CATALASE ACTIVITY IN THE EPIDERMIS OF PATIENTS WITH ADVANCED CANCER.

HUMAN liver catalase is depressed in patients with advanced cancer. Clinical improvement may cause a rise in liver catalase1. An investigation was, therefore, undertaken to determine whether skin catalase was subject to the same variations. As depression of human liver catalase has been shown to be related to loss in weight2, attention was directed to this aspect of the problem. Determinations were performed before and during cancer chemotherapy with the following cytostatics: 5-fluoroura-cil (5FU), cyclophosphamide, SPG827 (benzylidene compounds of the glucosides of Podophyllum emodi), SPI 77 (ethyl hydrazide of podophyllic acid) and 6W54 (ethyl-N-N-bis (2-chloropropyl) carbamate). This forms part of work on skin changes occurring during cancer chemotherapy3–5.