Papers by Francisco Peixoto
Biomedicines, Oct 17, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Developing Drugs, 2015
It has been reported that dyes toxicity may happen due to either the direct action of the origina... more It has been reported that dyes toxicity may happen due to either the direct action of the original compound or its intermediate metabolites such as naphthalene, benzidine and other aromatic amines
Physiologia, Aug 23, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Biomedicines
This study aimed to characterize an animal model of colorectal cancer (CRC) in the early stages o... more This study aimed to characterize an animal model of colorectal cancer (CRC) in the early stages of disease development. Twenty-nine male Wistar rats were divided into two control groups (CTRL1 and CTRL2), receiving EDTA–saline injections and two induced groups (CRC1 and CRC2), receiving 1,2-dimethylhydrazine (DMH) injections for seven consecutive weeks. CRC1 and CTRL1 were euthanized at the 11th week, while CRC2 and CTRL2 were euthanized at the 17th week. DMH treatment decreased microhematocrit values and IL-6, ghrelin, and myostatin serum levels. Histopathological analysis of intestinal sections showed that DMH-treated rats were characterized by moderate to severe epithelial dysplasia. An adenoma was observed in one animal (CRC2 group), and the presence of inflammatory infiltrate at the intestinal level was primarily observed in DMH-treated animals. DMH also induced Ki-67 immunoexpression. The gut microbiota analysis showed a higher abundance of Firmicutes, Clostridia, Clostridiale...
International Journal of Molecular Sciences
Mitochondria are an attractive target to fight neurodegenerative diseases due to their important ... more Mitochondria are an attractive target to fight neurodegenerative diseases due to their important functions for cells and the particularly close relationship between the functional connectivity among brain regions and mitochondrial performance. This work presents a mitochondria-targeted therapy designed to modulate the functionality of the mitochondrial respiratory chain and lipidome, parameters that are affected in neurodegeneration, including in Parkinson’s disease (PD). This therapy is supported by SC-Nanophytosomes constructed with membrane polar lipids, from Codium tomentosum, and elderberry anthocyanin-enriched extract, from Sambucus nigra L. SC-Nanophytosomes are nanosized vesicles with a high negative surface charge that preserve their properties, including anthocyanins in the flavylium cation form, under conditions that mimic the gastrointestinal tract pH changes. SC-Nanophytosomes, 3 µM in phospholipid, and 2.5 mg/L of EAE-extract, delivered by drinking water to a rotenone-...
17th World Congress on Controversies in Obstetrics, Gynecology and Infertility, 2012
GlaxoSmithKline Vaccines, a division of GlaxoSmithKline group, is the world's leading vaccine com... more GlaxoSmithKline Vaccines, a division of GlaxoSmithKline group, is the world's leading vaccine company and a leader in innovation. The company is active in vaccine research, development and production with over 30 vaccines approved and 20 more in development-both in the prophylactic and therapeutic elds. Headquartered in Belgium, GSK Vaccines has 14 manufacturing sites strategically positioned around the globe. In 2011, GSK Vaccines distributed 1.1 billion doses to 173 countries in both the developed and the developing world. Through its accomplished and dedicated workforce, GSK Vaccines applies its expertise to the discovery of innovative vaccines that contribute to the health and well-being of people of all generations around the world. GlaxoSmithKline-one of the world's leading research-based pharmaceutical and healthcare companies-is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For further information, please visit www.gsk.com
Food & Function, 2021
Prostate cancer (PCa) is one of the most common cancers in men, with a huge impact on their health.
Age (Dordrecht, Netherlands), 2015
Regular physical exercise has been shown to be one of the most important lifestyle influences on ... more Regular physical exercise has been shown to be one of the most important lifestyle influences on improving functional performance, decreasing morbidity and all causes of mortality among older people. However, it is known that acute physical exercise may induce an increase in oxidative stress and oxidative damage in several structures, including DNA. Considering this, the purpose of this study was to identify the effects of 16 weeks of combined physical exercise in DNA damage and repair capacity in lymphocytes. In addition, we aimed to investigate the role of oxidative stress involved in those changes. Fifty-seven healthy men (40 to 74 years) were enrolled in this study. The sample was divided into two groups: the experimental group (EG), composed of 31 individuals, submitted to 16 weeks of combined physical exercise training; and the control group (CG), composed of 26 individuals, who did not undergo any specifically orientated physical activity. We observed an improvement of overal...
Experimental and toxicologic pathology : official journal of the Gesellschaft fur Toxikologische Pathologie, Jan 26, 2016
Gentamicin is an aminoglycoside antibiotic widely used to treat many types of bacterial infection... more Gentamicin is an aminoglycoside antibiotic widely used to treat many types of bacterial infections. Although its properties, his clinical use is limited due to the occurrence of nephrotoxicity, which has been related to mitochondrial dysfunction. Carvedilol, an antihypertensive drug with strong antioxidant properties, has been tested in order to prevent gentamicin nephrotoxicity. This study aimed to test this hypothesis using a rat model of gentamicin-induced nephrotoxicity. Animals were treated subcutaneously with DMSO (control) (0.4%/kg/24h bw) for 11days; with carvedilol (2mg/kg/24h bw) for 11days; with gentamicin (60mg/kg/24h bw) for the last 8days and with carvedilol (2mg/kg/24h bw) for 11days and with gentamicin (60mg/kg/24h bw) for the last 8days. Estimations of urine creatinine, urine carboxylic acids, blood urea, serum creatinine and glomerular filtration rate were carried out after the last administered dose of gentamicin. Mitochondria functionality was analyzed by monitor...
Biology
Most studies on the effects of physical exercise have focused on its influence on muscle tissue, ... more Most studies on the effects of physical exercise have focused on its influence on muscle tissue, forgetting its interference in liver function. Ageing leads to the progressive impairment of hepatic functions. Several biochemical and bioenergetics parameters were determined to test the impact of a lifelong aerobic training program in the hepatic age-related and the development of an adaptative response. Liver samples were collected from 28 male Wistar rats (4-week-old, 159.4 ± 11.9 g at the beginning of the protocol), randomly distributed into two groups: non-exercised or exercised and submitted to a treadmill exercise program (60 min/day, 5 days/week, at 70% of maximal running speed), for 24 (n = 9) or 54 weeks (n = 10). A maximal running speed test was performed to determine the training speed. Antioxidant enzyme activity, cellular redox status, oxidative stress, mitochondrial respiratory chain enzymes and respiratory activity were performed in liver samples. Lifelong exercise decr...
International Journal of Molecular Sciences, 2019
Carcinogenesis induced by high-risk human papillomavirus (HPV) involves inflammatory phenomena, p... more Carcinogenesis induced by high-risk human papillomavirus (HPV) involves inflammatory phenomena, partially mediated by cyclooxigenase-2. In pre-clinical models of HPV-induced cancer, cyclooxygenase-2 inhibitors have shown significant efficacy, but also considerable toxicity. This study addresses the chemopreventive effect and hepatic toxicity of a specific cyclooxigensase-2 inhibitor, parecoxib, in HPV16-transgenic mice. Forty-three 20 weeks-old female mice were divided into four groups: I (HPV16−/−, n = 10, parecoxib-treated); II (HPV16−/− n = 11, untreated); III (HPV16+/−, n = 11, parecoxib-treated) and IV (HPV16+/−, n = 11, untreated). Parecoxib (5.0 mg/kg once daily) or vehicle was administered intraperitoneally for 22 consecutive days. Skin lesions were classified histologically. Toxicological endpoints included genotoxic parameters, hepatic oxidative stress, transaminases and histology. Parecoxib completely prevented the onset of epidermal dysplasia in HPV16+/− treated animals ...
Andrologia
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
BioMed Research International, 2017
Purpose.This study aimed to evaluate the effect of chronic treatment with chaetomellic acid A (CA... more Purpose.This study aimed to evaluate the effect of chronic treatment with chaetomellic acid A (CAA) on oxidative stress and renal function in a model of renal mass reduction.Methods. Male Wistar rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been divided into four experimental groups: RMR: RMR rats without treatment(n=14); RMR + CAA: RMR rats treated with CAA(n=13); SO: SO rats without treatment(n=13); and SO + CAA: SO rats treated with CAA(n=13). CAA was intraperitoneally administered in a dose of 0.23 µg/Kg three times a week for six months.Results.RMR was accompanied by a significant reduction in catalase and glutathione reductase (GR) activity(p<0.05)and a decrease in reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. CAA administration significantly increased catalase and GR activity(p<0.05)and increased GSH/GSSG ratio, but no significant difference between the treated and nontreated groups was found in this...
Toxicology in Vitro, 2009
Daphnetoxin is a daphnane type orthoester diterpene found exclusively in plants of the family Thy... more Daphnetoxin is a daphnane type orthoester diterpene found exclusively in plants of the family Thymelaeaceae while daphnoretin, a bis-coumarin derivative that is the major constituent of the bark of some plants of this family, can also be found in Leguminosae and Rutaceae. These two compounds are recognized to have different biological effects, including a possible anti-cancer activity. The subject of the present research was to compare their mitochondrial toxicity and also investigate a possible selectivity towards tumor cell lines. Wistar rat liver mitochondria and three distinct cell lines were used to investigate compound-induced toxicity. The results indicate that both test compounds are toxic to isolated mitochondrial fractions, especially when used at concentrations higher than 100 lM. However, daphnetoxin presented the highest toxicity including increased proton leak in the inner mitochondrial membrane, increased induction of the mitochondrial permeability transition pore, inhibition of ATP synthase and inhibition of the mitochondrial respiratory chain. Both compounds also inhibited cell proliferation, regardless of the cell line used. Up to the maximal concentration tested in cells, no mitochondrial effects were detected by vital epifluorescence imaging, indicating that inhibition of cell proliferation may also originate from mitochondrial-independent mechanisms. The results warrant careful assessment of toxicity vs. pharmacology benefits of both molecules.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2009
Descreve-se um método de isolamento de mitocôndrias acopladas de tilápia-do-nilo Oreochromis nilo... more Descreve-se um método de isolamento de mitocôndrias acopladas de tilápia-do-nilo Oreochromis niloticus, isoladas de células hepáticas de peixes adultos. As mitocôndrias estavam metabolicamente ativas, sendo capazes de realizarem fosforilação oxidativa, de acordo com os valores do quociente de controle respiratório. Os valores de controle respiratório obtidos com malato/piruvato (complexo I) e com succinato (complexo II) foram de 5,8±0,8 e 3,38±0,4, respectivamente. O potencial de membrana exibiu o valor de 197±4mV, quer se utilizasse malato/piruvato ou succinato como substrato. O procedimento de isolamento de mitocôndrias de O. niloticus permite o estudo do efeito de xenobióticos na bioenergética mitocondrial, tendo sido avaliada a ação da oxifluorfena (0,6mgL-1) na bioenergética mitocondrial. Os resultados demonstram que o tratamento com oxifluorfena influencia a capacidade fosforilativa dos peixes, interferindo na sua carga energética, o que poderá levar à sua morte.
Archives of Toxicology, 2013
composition, namely in terms of fatty acyl chains and relative proportions of phospholipid classe... more composition, namely in terms of fatty acyl chains and relative proportions of phospholipid classes, the modified diet inducing a decrease in the saturated to unsaturated molar ratio and an increase in the phosphatidylcholine to phosphatidylethanolamine molar ratio. Mass spectrometry lipid analysis showed significant differences in the major species of cardiolipin, with an apparent increased incorporation of oleic acid as a result of exposure to the modified diet. Rats fed the modified diet during 22 days showed decreased hepatic mitochondrial state 3 respiration and were more susceptible to Ca 2+-induced transition pore opening. Rapeseed oil-enriched diet also appeared to promote a decrease in hydroperoxide production by the respiratory chain, although a simultaneous decrease in vitamin E content was detected. In conclusion, our data indicate that the rapeseed oil diet causes negative alterations on hepatic mitochondrial bioenergetics, which may result from membrane remodeling. Such alterations may have an impact not only on energy supply to the cell, but also on drug-induced hepatic mitochondrial liabilities.
Antioxidants
Since the mid-1920s, parabens have been widely used as antimicrobial preservatives in processed f... more Since the mid-1920s, parabens have been widely used as antimicrobial preservatives in processed foods and beverages, pharmaceuticals, and cosmetic products. Paraben use continues to generate considerable controversy, both in the general population and in the scientific community itself. The primary purpose of our study was to determine whether parabens (methyl and butyl at concentrations of 100 and 200 mg/kg body weight by subcutaneous injection) during pregnancy of adult female Wistar rats can have an impact on the F1 generation. As far as we know, we are the first to demonstrate that using parabens during pregnancy has negative repercussions on the mitochondrial bioenergetics and antioxidant activity of testicular germ cells in the F1 generation. Our study showed that there was a 48.7 and 59.8% decrease in the respiratory control index with 100 and 200 mg/kg of butylparaben, respectively. Cytochrome c oxidase activity was significantly inhibited (45 and 51%) in both groups. In add...
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Papers by Francisco Peixoto