Nrf2 cell signaling pathway is responsible for the antioxidant effect of resveratrol in aging.

INTRODUCTION: One of the markers of aging is oxidative stress, a condition characterized by an increase in free radicals concomitant with a reduction in antioxidant defenses. Within this, resveratrol is a compound that has been shown to act as a potent antioxidant. However, few studies highlight the cellular signaling pathways that are activated or inhibited during aging and that are responsible for this biological effect. AIM: To verify the antioxidant profile of resveratrol (5 µM) in leukocytes from donors in different age groups. METHODS: The project was approved by the Ethics Committee. Individuals were divided into three groups: 20-39, 40-59, and 60-80 years old. After separating the leukocytes, assays were performed to evaluate the AMPK (AMP-activated protein kinase) and Nrf2 (erythroid nuclear factor 2-related factor 2) pathways. In addition, luciferase assay and enzyme-linked immunosorbent assay were performed to evaluate transcription factor activation and Nrf2 expression, respectively. The analysis between age and treatment was performed using Pearson correlation (*P < 0.05). RESULTS: There was a reduction in the antioxidant effect of resveratrol during the aging process. In leukocytes from donors over 60 years of age, the AMPK pathway was silenced. Nrf2 was active at all ages. There was an increase in the activation of the transcription factor and phosphorylated protein in all age groups. CONCLUSIONS: Nrf2 is an important biochemical mechanism responsible for the antioxidant effect of resveratrol. This effect diminishes with aging but is still observed. Geriatr Gerontol Int 2024; ••: ••-••.

Alternative methods in toxicity testing: the current approach

Alternative methods are being developed to reduce, refine, and replace (3Rs) animals used in experiments, aimed at protecting animal welfare. The present study reports alternative tests which are based on the principles of the 3Rs and the efforts made to validate these tests. In Europe, several methodologies have already been implemented, such as tests of irritability, cell viability, and phototoxicity as well as in vitro mathematical models together with the use of in silico tools. This is a complex process that spans from development to regulatory approval and subsequent adoption by various official entities. Within this regulatory framework is REACH, the European Community Regulation for chemicals and their safe use. In Brazil, the BraCVAM (Brazilian Center for the Validation of Alternative Methods) was recently established to validate alternative methods and stimulate incorporation of new methodologies. A new vision of toxicology is emerging for the 21st century (Tox-21), and the subsequent changes are shaping a new paradigm.

Métodos alternativos estão sendo desenvolvidos para a redução, o refinamento e a substituição (3R) do número de animais utilizados em experimentos, visando ao seu bem-estar. Esses testes alternativos baseiam-se no princípio dos 3R e esforços têm sido empregados para que sejam validados. Na Europa, diversas metodologias já foram implantadas tais como: testes de irritabilidade, testes de viabilidade celular, testes de fototoxicidade e modelos matemáticos in vitro, além do uso de ferramentas in silico. Esse é um processo complexo, que abrange desde o seu desenvolvimento até a aceitação regulatória e posterior adoção por diversas organizações oficiais. No contexto regulatório está o REACH, o Regulamento da Comunidade Européia, para produtos químicos e sua utilização segura. No Brasil, o BraCVAM (Centro Brasileiro de Validação de Métodos Alternativos) foi recentemente estabelecido para validação de métodos alternativos e estímulo à incorporação de novas metodologias. Uma nova visão de toxicologia vem surgindo para o século XXI (Tox-21) e as mudanças ocasionadas promoverão um novo paradigma.

Health status of male adult Wistar Rats from two Experimental Animal Houses of UFMG: leukocyte counts, feces and lung histological exams

A study was conducted to compare health status of male adult Wistar rats from two Experimental Animal Houses of UFMG with literature data of SPF (free from specific pathogens) and conventional rats. The animals were divided into two groups: Group I (n=10), rats from the experimental animal houses of FAFICH and Group II (n=10) from ICB and following aspects were studied: a) evident clinical signs (behavior modification, hair loss (alopecia), b) leukocyte counts, c) feces exam and d) histological study of the lungs. The rats did not show clinical signs. However, when compared with SPF and conventional rats, both the groups showed a significant increase (p<0,05) of leukocyte count. On feces exam we detected some parasites and on lung histological exam we observed fungus (Group I) and bacteria (Group II). These results showed that the health status of the rats was not satisfactory and required improvements in the conditions of the animal houses

Effect of gamma radiation on the activity of hemocytes and on the course of Schistosoma mansoni infection in resistant Biomphalaria tenagophila snails

High doses of gamma radiation (10 Krad) in Biomphalaria tenagophila snails (Taim strain), which have been found to be resistant to Schistosoma mansoni, were not sufficient to impair their resistance to the parasite. The number of hemocytes, as well as their phagocytic activity, were not affected by irradiation, thus showing resemblance with mammal macrophages, which are resistant to gamma irradiation also

Avaliação da produção de espécies reativas de oxigênio por granulócitos de sangue periférico de pacientes com fibromialgia primária / Assessment of reactive oxygen species production by peripheral blood granulocytes from primary fibromyalgia patients

Obejetivo: avaliar anormalidades bioquímicas que possam estar relcionadas à fibromialgia, mais especificamente o metabolismo oxidante de granulócitos de pacientes com fibromialgia primária (FMP). Métodos: foram selecionados 10 pacientes (9 mulheres e 1 homem) portadores de FMP, com idade entre 20 e 40 anos, de acordo com os critérios do Colégio Americano de Reumatologia, que não apresentavam qualquer outra doença de curso agudo ou crônico e estavam sem utilizar medicamentos no mínimo durante duas semanas. Controles normais (n = 19) pareados por sexo e idade foram selecionados. Os granulócitos de pacientes e controles foram separados do sangue periférico e utilizados como célula de trabalho. A produção de espécies reativas de oxigênio (ERO) foi determinada por meio de ensaio de quimioluminescência dependente de luminol. Resultados: demonstramos, pela primeira vez, uma produção significantemente elevada de ERO (3,2 vezes maior) em granulócitos de sangue periférico de pacientes com FMP (< 0,05). Conclusões: estes resultados demonstraram um comportamento anormal dos granulócitos de pacientes com FMP, em que uma produção aumentada de espécies reativas do oxigênio foi observada. Estudos futuros serão necessários para melhor esclarecer estes resultados, delineando uma nova perspectiva na compreensão e abordagem destes pacientes