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; ••: ••-••.

Aging: silencing the PKA and AkT/PKB signaling pathways alters the antioxidant capacity of resveratrol.

One of the theories related to aging is the increase in oxidative stress. Given this, the objective of the study is to evaluate the cellular mechanisms responsible for the resveratrol antioxidant effect on leukocytes from donors aged between 20 and 80 years old. For this, leukocytes from donors of three age groups (20-39, 40-59 and 60-80) were isolated. Image-iT™LIVE Green Reactive Oxygen Species (ROS) Kit was used. Reactive Nitrogen Species (RNS) analysis was performed by measuring nitric oxide and peroxynitrite. The PKA, Akt/PKB and p38-MAPK were evaluated by chemiluminescence. The statistical analysis between age and treatments were performed by Pearson correlation (*p < 0.05). It was possible to observe the antioxidant effect of resveratrol in all age groups. The correlation results show loss of resveratrol effect in decreasing ROS in leukocytes from older donors. We observed an active antioxidant effect of p38-MAPK in all ages, with resveratrol acting on it. The PKA and Akt/PKB were active in leukocytes from donors aged 20-59. In cells from donors older than 60, these pathways are silenced, and an effect is also not observed in cells treated with resveratrol. Therefore, resveratrol showed antioxidant effect in all age, although it was more pronounced in leukocytes from younger. One of resveratrol's mechanisms is due to the activation of the PKA and Akt/PKB, which were activated in younger donor cells.

Aging: Change in SIRT1 and Enzymatic Profile Promotes a Decrease in the Antioxidant Capacity of Resveratrol in Human Leukocytes In Vitro.

BACKGROUND: One of the most studied theories about aging comes from the accumulation of free radical generation, leading to oxidative stress. Resveratrol (RSV) is a polyphenolic compound that has been shown to act as an antioxidant in medical practice. OBJECTIVE: To verify the antioxidant action of resveratrol (and its correlation with aging) in leukocytes from donors of different ages, mainly through the analysis of the three main enzymes of the antioxidant complex and the analysis of the SIRT1 signaling pathway. METHODS: Luminol-dependent chemiluminescence assay was used to evaluate ROS and SIRT1. Antioxidant enzymes were evaluated by commercial kits. *p<0.05. RESULTS: In all age groups, there was a reduction in reactive oxygen species (ROS) in cells stimulated with RSV. There was a positive correlation between its antioxidant effect and donor age. In younger individuals (20-39 years old), there was an increase in catalase activity in cells exposed to RSV. In the older groups (40-59 years old and 60-80 years old), RSV was able to increase the activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx). Through the analysis of SIRT1 it was possible to observe a silencing of the pathway in leukocytes treated with RSV during aging. CONCLUSION: RSV showed antioxidant activity in all age groups, although more pronounced in younger individuals. One of the mechanisms of action of the RSV is due to the increase in the activity of antioxidant enzymes, which varies according to the individual's age, especially through the modulation of important antioxidant pathways.

Resveratrol has its antioxidant and anti-inflammatory protective mechanisms decreased in aging.

In the elderly, there is an increase in oxidative and inflammatory activity. Resveratrol (RSV) is a polyphenol that has several proven biological activities, such as antioxidant and anti-inflammatory. Thus, the aim of our study was to verify the possible antioxidant and anti-inflammatory effects of RSV on human mononuclear cells (PBMCs) from donors aged between 40 and 59 and 60-80 years old. For this, 6-8 patients were selected by age group. Cells were isolated and divided into 4 groups: Control (C), RSV only, H2O2 (to induce an oxidizing environment - C+) and H2O2+RSV. The quantification of reactive nitrogen species (NO and ONOO-), as well as pro and anti-inflammatory cytokines (TNFα, IL-6 and IL-10) was performed. Pearson's correlation and comparison between groups were performed (p<0.05). Our results showed a greater role of RSV in the middle-aged compared to the elderly group, in relation to the balance of NO/ONOO- and the levels of cytokines IL-6 and TNFα. It was also possible to observe an improvement in the anti-inflammatory profile in both age groups, but more effective in the cells in the middle-aged group. Thus, we could observe that RSV has better activity in the reduction of important biomarkers of oxidation and inflammation.

The preventive use of resveratrol increases its antioxidant effect by SIRT1 and subclinical anti-inflammatory action in Neuro-2A cells.

Currently, the important role of oxidative stress in the aging process and in neurodegenerative diseases has been highlighted, suggesting the beneficial effect of antioxidants as adjuvant therapy. Resveratrol (RSV) is a polyphenolic compound used in the clinic and has been shown as an antioxidant and anti-inflammatory. Therefore, the objective was to verify neuroprotective and modulating effects of RSV on N2-A cells, pre or post inserted into an oxidative stress environment. For this, two treatment conditions were established: pre-stimulus and post-stimulus. The analysis of AMPK and SIRT1 cell signaling pathways was performed through the chemiluminescence assay using the dorsomorphin and EX527 inhibitors, respectively. The inflammatory profile was also evaluated in these neural cells, through the levels of IL-6, TNF, and IL-10. We observed that RSV in N2-A cells has anti-inflammatory effect and antioxidant property and it mechanism is dependent on the SIRT1 signaling pathway. RSV effects occurs most markedly when cells have been pre-stimulated before inducing an oxidative stress environment. These results are important for conducting more adequate protocols in the medical and nutritional clinic.

Metabolic activation enhances the cytotoxicity, genotoxicity and mutagenicity of two synthetic alkaloids with selective effects against human tumour cell lines.

The pharmacological potential of drugs must be evaluated to establish their potential therapeutic benefits and side effects. This evaluation includes assessment of the effects of hepatic enzymes that catalyse their metabolic activation. Previously, our research group synthesized and characterized a set of synthetic 3-alkyl pyridine alkaloid (3-APA) analogues that cause in vitro cytotoxic, genotoxic, and mutagenic effects in various human cancer cell lines. The present study aimed to evaluate these activities with the two most promising synthetic 3-APAs (3-APA 1 and 3-APA 2) against cell lines derived from breast cancer (MDA-MB-231), ovarian cancer (TOV-21 G) and lung fibroblasts (WI-26-VA4) with and without metabolic activation (S9 fraction). The cytotoxicity of the compounds was evaluated employing MTT and clonogenic assays. In addition, comet assays, γH2AX immunocytochemistry labelling assays and cytokinesis-block micronucleus tests were carried out to evaluate the potential of these compounds to induce chromosomal damage. The results obtained in the MTT assay showed that compound 3-APA 2 exhibited high selectivity index (SI) values (ranging between 21.0 and 92.6). In addition, the cytotoxicity of the compounds was clearly enhanced by metabolic activation. Moreover, both compounds were genotoxic and induced double-strand breaks in DNA and chromosomal lesions with and without S9. The cancer cell lines tested showed higher genotoxic sensitivity to the compounds than did the non-tumour cell line used as a reference. The genotoxic and mutagenic effects of the compounds were potentiated in experiments with metabolic activation. The data obtained in this study indicate that compound 3-APA 2 is more active against the human cancer cell lines tested, both with and without metabolic activation, and can therefore be considered a candidate drug to treat human ovarian and breast cancer.

Resveratrol: Change of SIRT 1 and AMPK signaling pattern during the aging process.

One of the causes for aging is free radical damage. Resveratrol (RSV), a polyphenolic compound has been shown to act as an antioxidant and anti-inflammatory. The objective this study was to verify in an oxidative stress environment in Human Mononuclear cells from Middle aged and Elderly donors, the existence of a change in the SIRT1 and AMPK signaling pattern by RSV. In both age groups there was a reduction in reactive oxygen species (ROS) in cells stimulated with RSV. It was observed that in the Elderly group there was a higher production of ROS and that the reduction from RSV was smaller compared to the other group. There was an increased activity of Superoxide Dismutase in cells exposed to RSV in the elderly group. It was observed that for the Middle Aged group, SIRT 1 and AMPK are antioxidant pathways and RSV acts via SIRT1. In the elderly, the SIRT1 remains antioxidant and RSV ceases its operation via SIRT1. RSV has an antioxidant action in both age groups, and that in aging there was a change in the cellular context characterized by the silencing of the AMPK pathway antioxidant character.

Antioxidant effect of Resveratrol: Change in MAPK cell signaling pathway during the aging process.

Aging is characterized by a progressive loss of physiological integrity. One common denominator is the increase of reactive oxygen species (ROS) caused by inhibition of important antioxidant pathways. Resveratrol is a polyphenol known for its potent antioxidant activity. However, antioxidant pathways activated by them change with aging. The objective of our study was to verify the antioxidant effect of resveratrol in an oxidative stress environment in Human Mononuclear Cells (PBMC) from donors with different ages. Resveratrol (5 µM), a stimulus with H2O2 (0,64 % v/v) in addition to inhibitors of PKA, AkT/PKB and MAPK signaling pathways were used in chemiluminescence assay. An incresed basal production of ROS was observed in the elderly than in the middle-aged group. Resveratrol was able to reduce ROS in both groups, but with greater efficiency in the middle-aged group. By inhibiting PKA, Akt/PKB and MAPK signaling pathways we observed that resveratrol presented an altered performance in the aging process, changing signaling pattern of MAPK pathway.