Engineered nanoceria modulate neutrophil oxidative response to low doses of UV-B radiation through the inhibition of reactive oxygen species production.

To avoid aging and ultraviolet mediated skin disease the cell repair machinery must work properly. Neutrophils, also known as polymorphonuclear leukocytes, are the first and most abundant cell types which infiltrate sites of irradiation and play an important role in restoring the microenvironment homeostasis. However, the infiltration of neutrophils in ultraviolet-B (UV-B) irradiated skin might also contribute to the pathophysiology of skin disease. The polymorphonuclear leukocytes activation induced by UV-B exposure may lead to prolonged, sustained NADPH oxidase activation followed by an increase in reactive oxygen species (ROS) production. Our previous work showed that cerium oxide nanoparticles can protect L929 fibroblasts from ultraviolet-B induced damage. Herein, we further our investigation of engineered cerium oxide nanoparticles (CNP) in conferring radiation protection specifically in modulation of neutrophils' oxidative response under low dose of UV-B radiation. Our data showed that even low doses of UV-B radiation activate neutrophils' oxidative response and that the antioxidant, ROS-sensitive redox activities of engineered CNPs are able to inhibit the effects of NADPH oxidase activation while conferring catalase and superoxide dismutase mimetic activity. Further, our investigations revealed similar levels of total ROS scavenging for both CNP formulations, despite substantial differences in cerium redox states and specific enzyme-mimetic reaction activity. We therefore determine that CNP activity in mitigating the effects of neutrophils' oxidative response, through the decrease of ROS and of cell damage such as chromatin condensation, suggests potential utility as a radio-protectant/therapeutic against UV-B damage.

Metformin effect on driving cell survival pathway through inhibition of UVB-induced ROS formation in human keratinocytes.

Human skin functions go beyond serving only as a mechanical barrier. As a complex organ, the skin is capable to cope with external stressors cutaneous by neuroendocrine systems to control homeostasis. However, constant skin exposure to ultraviolet (UV) radiation causes progressive damage to cellular skin constituents, mainly due excessive reactive oxygen species (ROS) production. The present study shows new approaches of metformin (MET) as an antioxidant agent. Currently, MET is the first line treatment of type 2 diabetes and has attracted attention, based on its broad mechanism of action. Therefore, we evaluated MET antioxidant potential in cell-free systems and in UVB irradiated human keratinocyte HaCaT cells. In cell-free system assays MET did not show intrinsic scavenging activity on DPPH radicals or superoxide (O2-) xanthine/luminol/xanthine oxidase-generated. Cell-based results demonstrated that MET was able to reduce UVB-induced intracellular ROS and NADPH oxidase-dependent superoxide (O2-) production. MET posttreatment of HaCaT cells reduced ERK 1/2 phosphorylation, NADPH oxidase activity, and cell death by apoptosis. These findings suggest that the protection mechanism of MET may be through the inhibition of ROS formation enzyme. These results showed that MET might be a promising antioxidant agent against UV radiation induced skin damage.

Selective photodynamic effects on cervical cancer cells provided by P123 Pluronic®-based nanoparticles modulating hypericin delivery.

At present, cervical cancer is the fourth leading cause of cancer among women worldwide with no effective treatment options. In this study we aimed to evaluate the efficacy of hypericin (HYP) encapsulated on Pluronic® P123 (HYP/P123) photodynamic therapy (PDT) in a comprehensive panel of human cervical cancer-derived cell lines, including HeLa (HPV 18-positive), SiHa (HPV 16-positive), CaSki (HPV 16 and 18-positive), and C33A (HPV-negative), compared to a nontumorigenic human epithelial cell line (HaCaT). Were investigated: (i) cell cytotoxicity and phototoxicity, cellular uptake and subcellular distribution; (ii) cell death pathway and cellular oxidative stress; (iii) migration and invasion. Our results showed that HYP/P123 micelles had effective and selective time- and dose-dependent phototoxic effects on cervical cancer cells but not in HaCaT. Moreover, HYP/P123 micelles accumulated in endoplasmic reticulum, mitochondria and lysosomes, resulting in photodynamic cell death mainly by necrosis. HYP/P123 induced cellular oxidative stress mainly via type II mechanism of PDT and inhibited cancer cell migration and invasion mainly via MMP-2 inhibition. Taken together, our results indicate a potentially useful role of HYP/P123 micelles as a platform for HYP delivery to more specifically and effectively treat cervical cancers through PDT, suggesting they are worthy for in vivo preclinical evaluations.

Propolis increases neutrophils response against Candida albicans through the increase of reactive oxygen species.

AIM: To investigate whether Brazilian green propolis improves the immune response against recurrent form isolate recurrent vulvovaginal candidiasis (RVVC) caused by Candida albicans by increasing neutrophil oxidative burst. MATERIALS & METHODS: We evaluated oxidant species production, oxygen consumption, microbicidal activity and myeloperoxidase activity in neutrophils previously treated with propolis and activated with different isolates of C. albicans (RVVC), vulvovaginal candidiasis, asymptomatic isolates and the reference strain. RESULTS: Propolis significantly increased oxidant species production, oxygen consumption, microbicidal activity and myeloperoxidase activity of neutrophils against different isolates of C. albicans including RVVC isolate that are considered resistant to the microbicidal activity of neutrophils. CONCLUSION: Brazilian green propolis may increase neutrophil burst oxidative response to RVVC leading to an efficient removal of C. albicans.

Vitamin K3 induces antiproliferative effect in cervical epithelial cells transformed by HPV 16 (SiHa cells) through the increase in reactive oxygen species production.

PURPOSE: Cervical cancer is characterized as an important public health problem. According to latest estimates, cancer of the cervix is the fourth most common cancer among women. Due to its high prevalence, the search for new and efficient drugs to treat this infection is continuous. The progression of HPV-associated cervical cancer involves the expression of two viral proteins, E6 and E7, which are rapidly degraded by the ubiquitin-proteasome system through the increase in reactive oxygen species generation. Vitamins are essential to human substances, participate in the regulation of metabolism, and facilitate the process of energy transfer. METHODS: Some early studies have indicated that vitamin K3 exerts antitumor activity by inducing cell death by apoptosis through an increase in the generation of reactive oxygen species. Thus, we evaluated the antiproliferative effect and a likely mechanism of action of vitamin K3 against cervical epithelial cells transformed by HPV 16 (SiHa cells) assessing the production of total ROS, the mitochondrial membrane potential, the cell morphology, the cell volume, and the cell membrane integrity. RESULTS: Our results show that vitamin K3 induces an increase in ROS production in SiHa cells, triggering biochemical and morphological events, such as depolarization of mitochondrial membrane potential and decreasing cell volume. CONCLUSION: Our data showed that vitamin K3 generates an oxidative imbalance in SiHa cells, leading to mechanisms that induce cell death by apoptosis.

WATER FROM DIFFERENT SOURCES USED FOR THE IRRIGATION OF VEGETABLES TO BE MARKETED: RESEARCH ON Cryptosporidium spp., Giardia spp., AND COLIFORMS IN PARANA, BRAZIL.

The aim of this work was to compare, from a parasitological ( Cryptosporidium spp. and Giardia duodenalis), bacteriological (total and thermotolerants coliforms) and physicochemical perspective, water sources used for drinking and irrigation of vegetables intended to be sold for human consumption. From January 2010 to May 2011, samples of different water sources from vegetable producing properties were collected; 100 liters for parasitological analysis, 200 mL for bacteriological analysis, and five liters for physicochemical analysis. Water samples were filtered under vacuum with a kit containing a cellulose acetate membrane filter, 1.2 µm (Millipore(r), Barueri, SP, Brazil). The material retained on the membrane was mechanically extracted and analyzed by direct immunofluorescence (Merifluor(r)kit). From 20 rural properties investigated, 10 had artesian wells (40 samples), 10 had common wells (40 samples), and one had a mine (four samples), the latter contaminated by Cryptosporidium spp. In samples from artesian wells, 90 to 130 meters depth, 42.5% were positive for total coliforms and 5.0% were identified to have abnormal coloration. From the samples of common wells, 14 to 37 meters depth, 87.5% were contaminated with total coliforms, 82.5% were positive for thermotolerant coliforms, and 12.5% had color abnormalities. We did not detect the presence of Giardia spp. or Cryptosporidium spp. in artesian and common wells. The use of artesian or common wells is an important step in the control of the spreading of zoonoses, particularly Cryptosporidium spp. and Giardia spp., as well as artesian wells for coliform control in local production of vegetables to be marketed.

Water from different sources used for the irrigation of vegetables to be marketed: research on Cryptosporidiumspp, giardiaspp, and Coliforms in Parana, Brazil / Água de diferentes fontes utilizadas na irrigação de hortaliças comercializadas: pesquisa de Cryptosporidiumspp, giardiaspp, e coliformes, Paraná, Brasil

SUMMARYThe aim of this work was to compare, from a parasitological ( Cryptosporidiumspp. and Giardia duodenalis), bacteriological (total and thermotolerants coliforms) and physicochemical perspective, water sources used for drinking and irrigation of vegetables intended to be sold for human consumption. From January 2010 to May 2011, samples of different water sources from vegetable producing properties were collected; 100 liters for parasitological analysis, 200 mL for bacteriological analysis, and five liters for physicochemical analysis. Water samples were filtered under vacuum with a kit containing a cellulose acetate membrane filter, 1.2 µm (Millipore(r), Barueri, SP, Brazil). The material retained on the membrane was mechanically extracted and analyzed by direct immunofluorescence (Merifluor(r)kit). From 20 rural properties investigated, 10 had artesian wells (40 samples), 10 had common wells (40 samples), and one had a mine (four samples), the latter contaminated by Cryptosporidiumspp. In samples from artesian wells, 90 to 130 meters depth, 42.5% were positive for total coliforms and 5.0% were identified to have abnormal coloration. From the samples of common wells, 14 to 37 meters depth, 87.5% were contaminated with total coliforms, 82.5% were positive for thermotolerant coliforms, and 12.5% had color abnormalities. We did not detect the presence of Giardiaspp. or Cryptosporidiumspp. in artesian and common wells. The use of artesian or common wells is an important step in the control of the spreading of zoonoses, particularly Cryptosporidiumspp. and Giardiaspp., as well as artesian wells for coliform control in local production of vegetables to be marketed.

RESUMOO objetivo do estudo foi investigar fontes de água utilizadas para consumo e irrigação de hortaliças a serem comercializadas sob o aspecto parasitológico ( Cryptosporidiumspp. e Giardia duodenalis), bacteriológico (coliformes totais e termotolerantes) e físico-químico. De janeiro de 2010 a maio de 2011 foram coletadas amostras de água de diferentes fontes de abastecimento de propriedades produtoras de hortaliças; 100 litros para análise parasitológica, 200 mL para bacteriológica e cinco litros para análise físico-química. As amostras de água foram filtradas a vácuo com um kit de filtragem contendo uma membrana de acetato de celulose, 1,2 µm, (Millipore(r), Barueri, São Paulo, Brasil). O material retido na membrana foi extraído mecanicamente e analisado por imunofluorescência direta (kit Merifluor(r)). De 20 propriedades rurais, 10 tinham poços artesianos (40 amostras), 10 semi-artesianos (40 amostras) e um possuía uma mina (quatro amostras). Esta última contaminada por Cryptosporidiumspp. Das amostras de poços artesianos com 90 a 130 metros de profundidade, 42,5% foram positivas para coliformes totais e 5,0% apresentavam coloração alterada. Em amostras de poços semi-artesianos com 14 a 37 m de profundidade, 87,5% apresentaram coliformes totais, 82,5% termotolerantes, e 12,5% destas amostras tinham alteração de cor. Não foi detectada a presença de Giardiaspp. e Cryptosporidiumspp. em poços artesianos ou semi-artesianos. A utilização de poços artesianos ou semi artesianos constitui importante medida no controle da disseminação de zoonoses, principalmente Cryptosporidiumspp. e Giardiaspp., assim como de poços artesianos para o controle de coliformes, em locais de produção de hortaliças irrigadas, a serem comercializadas.

Microbicidal activity of neutrophils is inhibited by isolates from recurrent vaginal candidiasis (RVVC) caused by Candida albicans through fungal thioredoxin reductase.

Vulvovaginal candidiasis (VVC) is characterized by an infection of the vulva and vagina, mainly caused by Candida albicans, a commensal microorganism that inhabits the vaginal, digestive, and respiratory mucosae. Vulvovaginal candidiasis affects approximately 75% of women, and 5% develop the recurrent form (RVVC). The aim of the present study was to evaluate whether neutrophils microbicidal response is triggered when activated with RVVC isolates caused by C. albicans. Our results showed that RVVC isolates induced neutrophil migration but significantly decrease the microbicidal activity of neutrophils, compared with VVC and ASS isolates. The microbicidal activity of neutrophils is highly dependent on the production of reactive oxygen species/reactive nitrogen species (ROS/RNS). However, this isolate induced detoxification of ROS/RNS produced by neutrophils, reflected by the high level of thiol groups and by the oxygen consumption. Therefore, RVVC isolates induced biochemical changes in the inflammatory response triggered by neutrophils, and these effects were mainly related to the detoxification of ROS/RNS through the thioredoxin reductase (TR), a key antioxidant enzyme in fungi. This might be one of the resistance mechanisms triggered by RVVC caused by C. albicans.

ß-Glucan induces reactive oxygen species production in human neutrophils to improve the killing of Candida albicans and Candida glabrata isolates from vulvovaginal candidiasis.

Vulvovaginal candidiasis (VVC) is among the most prevalent vaginal diseases. Candida albicans is still the most prevalent species associated with this pathology, however, the prevalence of other Candida species, such as C. glabrata, is increasing. The pathogenesis of these infections has been intensely studied, nevertheless, no consensus has been reached on the pathogenicity of VVC. In addition, inappropriate treatment or the presence of resistant strains can lead to RVVC (vulvovaginal candidiasis recurrent). Immunomodulation therapy studies have become increasingly promising, including with the ß-glucans. Thus, in the present study, we evaluated microbicidal activity, phagocytosis, intracellular oxidant species production, oxygen consumption, myeloperoxidase (MPO) activity, and the release of tumor necrosis factor α (TNF-α), interleukin-8 (IL-8), IL-1ß, and IL-1Ra in neutrophils previously treated or not with ß-glucan. In all of the assays, human neutrophils were challenged with C. albicans and C. glabrata isolated from vulvovaginal candidiasis. ß-glucan significantly increased oxidant species production, suggesting that ß-glucan may be an efficient immunomodulator that triggers an increase in the microbicidal response of neutrophils for both of the species isolated from vulvovaginal candidiasis. The effects of ß-glucan appeared to be mainly related to the activation of reactive oxygen species and modulation of cytokine release.

Antioxidant effects of quercetin and naringenin are associated with impaired neutrophil microbicidal activity.

Naringenin and quercetin are considered antioxidant compounds with promising activity against oxidative damage in human cells. However, no reports have described their effects on reactive oxygen species (ROS) production by phagocytes during microbicidal activity. Thus, the present study evaluated the effects of naringenin and quercetin on ROS production, specifically hypochlorous acid (HOCl), and their involvement in the microbicidal activity of neutrophils. Naringenin and quercetin inhibited HOCl production through different systems, but this inhibition was more pronounced for quercetin, even in the cell-free systems. With regard to the microbicidal activity of neutrophils, both naringenin and quercetin completely inhibited the killing of Staphylococcus aureus. Altogether, these data indicate that the decrease in the oxidant activity of neutrophils induced by these compounds directly impaired the microbicidal activity of neutrophils. Naringenin and quercetin exerted their effects by controlling the effector mechanisms of ROS production, with both positive and negative effects of these antioxidant agents in oxidative stress conditions and on ROS in the microbicidal activity of phagocytes. The present results challenge the traditional view of antioxidants as improvers of pathological conditions.