Trends in Natural Nutrients for Oxidative Stress and Cell Senescence

Fibronectin and vitronectin alleviate adipose-derived stem cells senescence during long-term culture through the AKT/MDM2/P53 pathway

Cellular senescence plays a role in the development of aging-associated degenerative diseases. Cell therapy is recognized as a candidate treatment for degenerative diseases. To achieve the goal of cell therapy, the quality and good characteristics of cells are concerned. Cell expansion relies on two-dimensional culture, which leads to replicative senescence of expanded cells. This study aimed to investigate the effect of cell culture surface modification using fibronectin (FN) and vitronectin (VN) in adipose-derived stem cells (ADSCs) during long-term expansion. Our results showed that ADSCs cultured in FN and VN coatings significantly enhanced adhesion, proliferation, and slow progression of cellular senescence as indicated by lower SA-β-gal activities and decreased expression levels of genes including p16, p21, and p53. The upregulation of integrin α5 and αv genes influences phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K), and AKT proteins. FN and VN coatings upregulated AKT and MDM2 leading to p53 degradation. Additionally, MDM2 inhibition by Nutlin-3a markedly elevated p53 and p21 expression, increased cellular senescence, and induced the expression of inflammatory molecules including HMGB1 and IL-6. The understanding of FN and VN coating surface influencing ADSCs, especially senescence characteristics, offers a promising and practical point for the cultivation of ADSCs for future use in cell-based therapies.

Polyphenols and Diets as Current and Potential Nutrition Senotherapeutics in Alzheimer's Disease: Findings from Clinical Trials

Cellular senescence, a hallmark of aging, plays an important role in age-related conditions among older adults. Targeting senescent cells and its phenotype may provide a promising strategy to delay the onset or progression of Alzheimer's disease (AD). In this review article, we investigated efficacy and safety of nutrition senotherapy in AD, with a focus on the role of polyphenols as current and potential nutrition senotherapeutic agents, as well as relevant dietary patterns. Promising results with neuroprotective effects of senotherapeutic agents such as quercetin, resveratrol, Epigallocatechin-gallate, curcumin and fisetin were reported from preclinical studies. However, in-human trials remain limited, and findings were inconclusive. In future, nutrition senotherapeutic agents should be studied both individually and within dietary patterns, through the perspective of cellular senescence and AD. Further studies are warranted to investigate bioavailability, dosing regimen, long term effects of nutrition senotherapy and provide better understanding of the underlying mechanisms. Collaboration between researchers needs to be established, and methodological limitations of current studies should be addressed.

Salvianolic acid A alleviates H2O2-induced endothelial oxidative injury via miR-204-5p

Oxidative stress induced endothelial dysfunction plays a particularly important role in promoting the development of cardiovascular diseases (CVDs). Salvianolic acid A (SalA) is a water-soluble component of traditional Chinese medicine Salvia miltiorrhiza Bunge with anti-oxidant potency. This study aims to explore the regulatory effect of SalA on oxidative injury using an in vitro model of H2O2-induced injury in human umbilical vein endothelial cells (HUVECs). In the study, we determined cell viability, the activities of Lactate dehydrogenase (LDH) and Superoxide dismutase (SOD), cell proliferation rate and intracellular reactive oxygen species (ROS). Flow cytometry was used to detect cell apoptosis. Western-blotting was used to evaluate the expression of cell senescence, apoptosis, autophagy and pyroptosis protein factors. The expression level of miRNA was determined by qRT-PCR. Compared with H2O2-induced HUVECs, SalA promoted cell viability and cell proliferation rate; decreased LDH and ROS levels; and increased SOD activity. SalA also significantly attenuated endothelial senescence, inhibited cell apoptosis, reversed the increase of LC3 II/I ratio and NLRP3 accumulation. Furthermore, miR-204-5p was regulated by SalA. Importantly, miR-204-5p inhibitor had similar effect to that of SalA on H2O2-induced HUVECs. Our results indicated that SalA could alleviate H2O2-induced oxidative injury by downregulating miR-204-5p in HUVECs.

Protective Effect of Curcumin on D-Galactose-Induced Senescence and Oxidative Stress in LLC-PK1 and HK-2 Cells

D-galactose has been widely used as an inducer of cellular senescence and pathophysiological processes related to aging because it induces oxidative stress. On the other hand, the consumption of antioxidants such as curcumin can be an effective strategy to prevent phenotypes related to the enhanced production of reactive oxygen species (ROS), such as aging and senescence. This study aimed to evaluate the potential protective effect of curcumin on senescence and oxidative stress and endoplasmic reticulum stress induced by D-galactose treatment in Lilly Laboratories Culture-Porcine Kidney 1 (LLC-PK1) and human kidney 2 (HK-2) proximal tubule cell lines from pig and human, respectively. For senescence induction, cells were treated with 300 mM D-galactose for 120 h and, to evaluate the protective effect of the antioxidant, cells were treated with 5 µM curcumin for 24 h and subsequently treated with curcumin + D-galactose for 120 h. In LLC-PK1 cells, curcumin treatment decreased by 20% the number of cells positive for senescence-associated (SA)-β-D-galactosidase staining and by 25% the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and increased by 40% lamin B1 expression. In HK-2 cells, curcumin treatment increased by 60% the expression of proliferating cell nuclear antigen (PCNA, 50% Klotho levels, and 175% catalase activity. In both cell lines, this antioxidant decreased the production of ROS (20% decrease for LLC-PK1 and 10 to 20% for HK-2). These data suggest that curcumin treatment has a moderate protective effect on D-galactose-induced senescence in LLC-PK1 and HK-2 cells.

A cross-sectional study exploring the relationship between oxidative balance score and 10-year atherosclerotic cardiovascular disease risk based on the National Health and Nutrition Examination Survey (2011-2020)

BACKGROUND

The intricate interaction between oxidative stress and atherosclerotic cardiovascular disease (ASCVD) is an essential area of research because of the potential role of oxidative homeostasis in regulating ASCVD risk. This study aimed to investigate the relationship between the oxidative balance score (OBS) and the 10-years risk of ASCVD to gain insight into how oxidative balance affects cardiovascular health.

METHODS

This cross-sectional study analyzed National Health and Nutrition Examination Survey (NHANES) 2011-2020 data (40-79 age group), exploring OBS's link to 10-years ASCVD risk. OBS categorized dietary and lifestyle factors. Multivariate logistic regression controlled for age, sex, race, and demographics. A restricted cubic spline examined linear relationships; robustness was ensured through subgroup analyses.

RESULTS

Analysis of 4955 participants reveals a negative association between OBS and 10-years ASCVD risk. Continuous OBS adjusted OR: 0.97 (95% CI: 0.95∼0.99, p < .001). Quartile analysis shows reduced risk in Q2 0.88 (95% CI: 0.63∼1.22, p = .43), Q3 0.92 (95% CI: 0.66∼1.28, p = .614), and Q4 0.59 (95% CI: 0.42∼0.83, p = .002) compare Q1. Quartile analysis indicated decreasing risk in higher OBS quartiles. Lifestyle OBS and Dietary OBS demonstrated similar trends. Stratified analyses highlight race and hypertension as effect modifiers (p < .05).

CONCLUSION

Our study suggests an association between higher OBS and a reduced 10-years ASCVD risk. However, causation should not be inferred, and in the future, more extensive clinical and fundamental research is required to delve deeper into this association.

Naringenin Orchestrates and Regulates the Reactive Oxygen Species-Mediated Pathways and Proinflammatory Signaling: Targeting Hallmarks of Aging-Associated Disorders

The therapeutic application of flavonoids in the management of infectious diseases, cancers, chronic wounds, aging, and neurodegenerative disorders has been well documented in scientific literature. The citric flavonoid naringenin comes under the category of flavanone and exhibits a plethora of health benefits. Very few flavonoids such as curcumin, resveratrol, catechin, quercetin, and kaempferol have been studied to exert their anti-aging properties in humans. The effect of naringenin in the context of age-associated disorders in detail has not been elucidated yet. The databases used for the literature search were Science Direct, Google Scholar, and PubMed. More emphasis has been put on the recent literature on "naringenin" and its effect on "age-associated disorders." Almost all chronic degenerative disorders are characterized by oxidative stress and inflammatory response. The study aims at highlighting the reactive oxygen species-mediated activity of naringenin and the underlying molecular mechanism leading to the prevention of various age-associated disorders. Altogether, the review presents a systematic comprehension of the pharmaceutical and clinicopathological benefits of naringenin in age-associated disorders.

Diet and Aging: The Role of Polyphenol-Rich Diets in Slow Down the Shortening of Telomeres: A Review

The ends of human chromosomes are defended by DNA-protein complexes named telomeres, which inhibit the chromosomes from fusing with each other and from being known as a double-strand break by DNA reparation proteins. Telomere length is a marker of biological aging, and disfunction of telomeres is related to age-related syndromes. Telomere attrition has been shown to be accelerated by oxidative stress and inflammation. Telomere length has been proven to be positively linked with nutritional status in human and animal scientific research as several nutrients influence it through mechanisms that imitate their function in cellular roles including oxidative stress and inflammation. Data reported in this article support the idea that following a low-in-fat and rich-plant polyphenols food diet seems to be able to slow down the shortening of telomeres.

Using chitosan, hyaluronic acid, alginate, and gelatin-based smart biological hydrogels for drug delivery in oral mucosal lesions: A review

AIMS

Oral mucosal diseases can lead to pain, difficulty speaking and eating, psychological distress, and cancer. Topical drug delivery using biological macromolecules, specifically hydrogels, is gaining interest due to the drawbacks of conventional treatments for oral mucosal lesions.

SCOPE

Biological hydrogels made from natural polymers and their derivatives, such as chitosan, hyaluronic acid, alginate, and gelatin, represent promising alternatives to conventional oral medication delivery methods. Topical drug delivery is beneficial for oral mucosal lesions as it can directly target the affected area, especially with the development of smart stimuli-responsive hydrogels, which allow for more controlled drug release. Biological hydrogels have already been used to deliver drugs like lidocaine and nystatin. This review summarizes the current research on applying smart natural polymer-based hydrogels for drug delivery in oral mucosal lesions.

CONCLUSION

Smart biological hydrogels show great promise as topical drug delivery systems for oral mucosal lesions, offering sustained drug release, increased therapeutic efficacy, and minimized systemic complications. Technological advancement is expected to lead to the development of more effective and safer drug delivery systems. The potential benefits of biological polymer-based hydrogels make them an exciting area of research for oral mucosal lesion treatment.

Campomanesia adamantium O Berg. fruit, native to Brazil, can protect against oxidative stress and promote longevity

Campomanesia adamantium O. Berg. is a fruit tree species native to the Brazilian Cerrado biome whose fruits are consumed raw by the population. The present study determined the chemical composition of the C. adamantium fruit pulp (FPCA) and investigated its in vitro antioxidant potential and its biological effects in a Caenorhabditis elegans model. The chemical profile obtained by LC-DAD-MS identified 27 compounds, including phenolic compounds, flavonoids, and organic carboxylic acids, in addition to antioxidant lipophilic pigments and ascorbic acid. The in vitro antioxidant activity was analysed by the radical scavenging method. In vivo, FPCA showed no acute reproductive or locomotor toxicity. It promoted protection against thermal and oxidative stress and increased the lifespan of C. elegans. It also upregulated the antioxidant enzymes superoxide dismutase and glutathione S-transferase and activated the transcription factor DAF-16. These results provide unprecedented in vitro and in vivo evidence for the potential functional use of FPCA in the prevention of oxidative stress and promotion of longevity.

Senescence of bone marrow mesenchymal stem cells in Wistar male rats receiving normal chow/high-calorie diets with/without vitamin D

Bone marrow mesenchymal stem cells (BM-MSCs) have a momentous function in the composition of the bone marrow microenvironment because of their many valuable properties and abilities, such as immunomodulation and hematopoiesis. The features and actions of MSCs are influenced by senescence, which may be affected by various factors such as nutritional/micronutrients status, e.g., vitamin D. This study aimed to examine the effects of a high-calorie diet (HCD) with/without vitamin D on BM-MSCs senescence. In the first phase, 48 middle-aged rats were fed a normal chow diet (NCD, n = 24) and an HCD (n = 24) for 26 weeks. Afterward, the rats in each group were randomly divided into three equal subgroups. Immediately, eight-rat from each diet group were sacrificed to assess the HCD effects on the first phase measurements. In the second phase, the remaining 4 groups of rats were fed either NCD or HCD with (6 IU/g) or without vitamin D (standard intake: 1 IU/g); in other words, in this phase, the animals were fed (a) NCD, (b) NCD plus vitamin D, (c) HCD, and (d) HCD plus vitamin D for 4 months. BM-MSCs were isolated and evaluated for P16INK4a, P38 MAPK, and Bmi-1 gene expression, reactive oxygen species (ROS) levels, SA-β-gal activity, and cell cycle profile at the end of both phases. After 26 weeks (first phase), the ROS level, SA-β-gal-positive cells, and cells in the G1 phase were significantly higher in HCD-fed rats than in NCD-fed ones (P < 0.05). HCD prescription did not significantly affect cells in the S and G2 phases (p > 0.05). Compared with the NCD-fed animals, P16INK4a and P38 MAPK gene expression were up-regulated in the HCD-fed animals; also, Bmi-1 gene expression was down-regulated (P < 0.05). BM-MSCs from vitamin D-treated rats (second phase) exhibited reduced mRNA levels of P16INK4a and P38 MAPK genes and increased Bmi-1 mRNA levels (all P < 0.05). Vitamin D prescription also declined the percentage of SA-β-gal-positive cells, ROS levels, and the cells in the G1 phase and increased the cells in the S phase in both NCD and HCD-fed animals (P < 0.05). The reduction of the cells in the G2 phase in rats fed with an NCD plus vitamin D was statistically non-significant (P = 0.128) and significant in HCD plus vitamin D rats (P = 0.002). HCD accelerates BM-MSCs senescence, and vitamin D reduces BM-MSCs senescence biomarkers.

In Vitro Assessment of Gold Nanoparticles on Telomerase Activity and Telomere Length in Human Fibroblasts

Telomerase activity coincides with lengthening of the ends of chromosomes known as telomeres. Telomere length is used as a marker for cellular aging. Telomeres shorten over time as cells divide, and certain bioactive compounds such as gold nanoparticles (AuNPs) may slow the shortening of telomeres by increasing telomerase activity. The objective of the present study is to assess the effect of AuNPs on telomerase activity and telomere length in human fibroblasts. Telomerase activity was measured using enzyme-linked immunosorbent assay (ELISA) in primary human lung fibroblasts (IMR90) and using quantitative PCR-based telomeric repeat amplification protocol (Q-TRAP) in primary human dermal fibroblasts, neonatal (HDFn). Telomere length was determined by Telomere Analysis Technology (TAT®)assay in HDFn. In IMR90, all AuNP treatments showed significant increases in telomerase activity when compared to earlier passages. HDFn treated with AuNPs at 0 ppm, 0.05 ppm, 0.5 ppm, or 5 ppm did not show significant differences in telomerase activity compared to the control group. Significant differences in telomere length in HDFn were observed at 2 weeks of 0.05 and 0.5 ppm AuNPs under oxidative culture conditions as compared to the control group. The study showed preliminary evidence that AuNPs may increase telomerase activity and decelerate the shortening of telomeres in human fibroblasts, suggesting its potential anti-aging effects, which warrants further investigation.

The Molecular Mechanism of Polyphenols in the Regulation of Ageing Hallmarks

Ageing is a complex process characterized mainly by a decline in the function of cells, tissues, and organs, resulting in an increased risk of mortality. This process involves several changes, described as hallmarks of ageing, which include genomic instability, telomere attrition, epigenetic changes, loss of proteostasis, dysregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell depletion, and altered intracellular communication. The determining role that environmental factors such as diet and lifestyle play on health, life expectancy, and susceptibility to diseases, including cancer and neurodegenerative diseases, is wellestablished. In view of the growing interest in the beneficial effects of phytochemicals in the prevention of chronic diseases, several studies have been conducted, and they strongly suggest that the intake of dietary polyphenols may bring numerous benefits due to their antioxidant and anti-inflammatory properties, and their intake has been associated with impaired ageing in humans. Polyphenol intake has been shown to be effective in ameliorating several age-related phenotypes, including oxidative stress, inflammatory processes, impaired proteostasis, and cellular senescence, among other features, which contribute to an increased risk of ageing-associated diseases. This review aims to address, in a general way, the main findings described in the literature about the benefits of polyphenols in each of the hallmarks of ageing, as well as the main regulatory mechanisms responsible for the observed antiageing effects.

Suppressive effects of pterostilbene on human cytomegalovirus (HCMV) infection and HCMV-induced cellular senescence

BACKGROUND

Human cytomegalovirus (HCMV), a member of the β-herpesvirus family, causes the establishment of a latent infection that persists throughout the life of the host and can be reactivated when immunity is weakened. To date, there is no vaccine to prevent HCMV infection, and clinically approved drugs target the stage of viral replication and have obvious adverse reactions. Thus, development of novel therapeutics is urgently needed.

METHODS

In the current study, we identified a naturally occurring pterostilbene that inhibits HCMV Towne strain replication in human diploid fibroblast WI-38 cells through Western blotting, qPCR, indirect immunofluorescence assay, tissue culture infective dose assays. The time-of-addition experiment was carried out to identify the stage at which pterostilbene acted. Finally, the changes of cellular senescence biomarkers and reactive oxygen species production brought by pterostilbene supplementation were used to partly elucidate the mechanism of anti-HCMV activity.

RESULTS

Our findings revealed that pterostilbene prevented lytic cytopathic changes, inhibited the expression of viral proteins, suppressed the replication of HCMV DNA, and significantly reduced the viral titre in WI-38 cells. Furthermore, our data showed that pterostilbene predominantly acted after virus cell entry and membrane fusion. The half-maximal inhibitory concentration was determined to be 1.315 μM and the selectivity index of pterostilbene was calculated as 26.73. Moreover, cell senescence induced by HCMV infection was suppressed by pterostilbene supplementation, as shown by a decline in senescence-associated β-galactosidase activity, decreased production of reactive oxygen species and reduced expression of p16, p21 and p53, which are considered biomarkers of cellular senescence.

CONCLUSION

Together, our findings identify pterostilbene as a novel anti-HCMV agent that may prove useful in the treatment of HCMV replication.

Preventive Effect of Nuciferine on H2O2-Induced Fibroblast Senescence and Pro-Inflammatory Cytokine Gene Expression

Human dermal fibroblasts play an important role in skin homeostasis by producing and degrading extracellular matrix components. They have more replicative senescence when exposed to environmental and oxidative insults, resulting in human skin aging. However, this phenomenon can be mitigated by antioxidant phytochemicals. The aim of the present study was to investigate the potential of nuciferine (an alkaloid from Nelumbo nucifera leaf) in preventing stress-induced fibroblast senescence by using a hydrogen-peroxide (H₂O₂)-induced senescence model. We found that H₂O₂ treatment resulted in a significant increase in senescence-associated β-galactosidase (SA-β-gal)-positive cells. Nuciferine-treated cells, however, showed a reduction in senescent phenotype. Furthermore, we observed the key molecular markers including the senescence-associated secretory phenotype (SASP) and cell cycle regulators. The mRNA levels of CXCL1, CXCL2, IL-6, and IL-8 (pro-inflammatory cytokines) reduced significantly in nuciferine-treated cells. The extracellular IL-6 and IL-8 levels were also decreased in treated cells, whereas the key cell cycle regulators (p16 and p21) were markedly affected by nuciferine at the highest concentration. The results of the present study clearly show that the preventive activity of nuciferine against H₂O₂-induced senescence in dermal fibroblasts is fundamental and promising for further applications in anti-aging product research and development.

Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration

Stem cell transplantation has been proved a promising therapeutic instrument in intervertebral disc degeneration (IVDD). However, the elevation of oxidative stress in the degenerated region impairs the efficiency of mesenchymal stem cells (BMSCs) transplantation treatment via exaggeration of mitochondrial ROS and promotion of BMSCs apoptosis. Herein, we applied an emulsion-confined assembly method to encapsulate Coenzyme Q10 (Co-Q10), a promising hydrophobic antioxidant which targets mitochondria ROS, into the lecithin micelles, which renders the insoluble Co-Q10 dispersible in water as stable colloids. These micelles are injectable, which displayed efficient ability to facilitate Co-Q10 to get into BMSCs in vitro, and exhibited prolonged release of Co-Q10 in intervertebral disc tissue of animal models. Compared to mere use of Co-Q10, the Co-Q10 loaded micelle possessed better bioactivities, which elevated the viability, restored mitochondrial structure as well as function, and enhanced production of ECM components in rat BMSCs. Moreover, it is demonstrated that the injection of this micelle with BMSCs retained disc height and alleviated IVDD in a rat needle puncture model. Therefore, these Co-Q10 loaded micelles play a protective role in cell survival and differentiation through antagonizing mitochondrial ROS, and might be a potential therapeutic agent for IVDD.

Accumulation of advanced oxidation protein products contributes to age-related impairment of gap junction intercellular communication in osteocytes of male mice

AIMS

Gap junction intercellular communication (GJIC) in osteocytes is impaired by oxidative stress, which is associated with age-related bone loss. Ageing is accompanied by the accumulation of advanced oxidation protein products (AOPPs). However, it is still unknown whether AOPP accumulation is involved in the impairment of osteocytes' GJIC. This study aims to investigate the effect of AOPP accumulation on osteocytes' GJIC in aged male mice and its mechanism.

METHODS

Changes in AOPP levels, expression of connexin43 (Cx43), osteocyte network, and bone mass were detected in 18-month-old and three-month-old male mice. Cx43 expression, GJIC function, mitochondria membrane potential, reactive oxygen species (ROS) levels, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation were detected in murine osteocyte-like cells (MLOY4 cells) treated with AOPPs. The Cx43 expression, osteocyte network, bone mass, and mechanical properties were detected in three-month-old mice treated with AOPPs for 12 weeks.

RESULTS

The AOPP levels were increased in aged mice and correlated with degeneration of osteocyte network, loss of bone mass, and decreased Cx43 expression. AOPP intervention induced NADPH oxidase activation and mitochondrial dysfunction, triggered ROS generation, reduced Cx43 expression, and ultimately impaired osteocytes' GJIC, which were ameliorated by NADPH oxidase inhibitor apocynin, mitochondria-targeted superoxide dismutase mimetic (mito-TEMPO), and ROS scavenger N-acetyl cysteine. Chronic AOPP loading accelerated the degradation of osteocyte networks and decreased Cx43 expression, resulting in deterioration of bone mass and mechanical properties in vivo.

CONCLUSION

Our study suggests that AOPP accumulation contributes to age-related impairment of GJIC in osteocytes of male mice, which may be part of the pathogenic mechanism responsible for bone loss during ageing. Cite this article: Bone Joint Res 2022;11(7):413-425.

The Role of Antioxidants in the Interplay between Oxidative Stress and Senescence

Cellular senescence is an irreversible state of cell cycle arrest occurring in response to stressful stimuli, such as telomere attrition, DNA damage, reactive oxygen species, and oncogenic proteins. Although beneficial and protective in several physiological processes, an excessive senescent cell burden has been involved in various pathological conditions including aging, tissue dysfunction and chronic diseases. Oxidative stress (OS) can drive senescence due to a loss of balance between pro-oxidant stimuli and antioxidant defences. Therefore, the identification and characterization of antioxidant compounds capable of preventing or counteracting the senescent phenotype is of major interest. However, despite the considerable number of studies, a comprehensive overview of the main antioxidant molecules capable of counteracting OS-induced senescence is still lacking. Here, besides a brief description of the molecular mechanisms implicated in OS-mediated aging, we review and discuss the role of enzymes, mitochondria-targeting compounds, vitamins, carotenoids, organosulfur compounds, nitrogen non-protein molecules, minerals, flavonoids, and non-flavonoids as antioxidant compounds with an anti-aging potential, therefore offering insights into innovative lifespan-extending approaches.

Nutrition senolytics - illusion or reality for cognitive ageing?

PURPOSE OF REVIEW

Cell senescence is implicated in numerous age-related conditions. Antiageing therapies and nutritional approaches have been researched for purposes of removing senescent cells (senolytics) to treat or prevent age-related diseases, such as cognitive impairment and Alzheimer's disease. In this updated review, we examined the evidence from the last 18 months regarding nutrition senolytics, with a focus on cognitive ageing among older adults.

RECENT FINDINGS

Overall, 19 systematic reviews and 17 intervention studies were included. Studies failed to provide evidence of nutritional senolytic agents or senescence-associated secretory phenotype (SASP) suppressors, for oral supplements providing beneficial effects on cognitive ageing among older adults. The protective role of food sources such as berries and nuts, and dietary patterns of Mediterranean diet and Mediterranean-DASH diet Intervention for Neurodegenerative Delay diet against cognitive decline or risk of dementia have been mostly supported by recent studies.

SUMMARY

The present review gathered additional evidence for both oral supplements and foods/diets rich in nutritional senolytic agents or SASP suppressors on cognitive health among older adults. In pursuing antiageing strategies, the importance of whole foods and healthy diets should not be overlooked, future studies are warranted on long-term effects and cytotoxicity of nutritional senolytics.

The modulatory potential of herbal antioxidants against oxidative stress and heavy metal pollution: plants against environmental oxidative stress

Free radicals, principally reactive oxygen species (ROS), contribute to oxidative stress in human beings. Free radicals have different mechanisms of action and affect lipids, proteins, and DNA. Heavy metals including cadmium (Cd), lead (Pb), and arsenic are environmental pollutants that may induce oxidative stress and produce ROS, leading to harmful effects on different body systems such as the liver and brain. On the other side, antioxidants can have protective effects against oxidative stress and decrease their toxicity. Herbal antioxidants have potential antioxidative effects. These antioxidants positively affect neurodegenerative diseases, atherosclerotic diseases, lung fibrosis, kidney injuries, and liver toxicities induced by oxidative agents, including heavy metals. In this manuscript, we explained the mechanisms of oxidative stress, and also discussed heavy metals which contribute to human oxidative stress. We further discussed different herbal antioxidants, their mechanisms of action, and their clinical use for various diseases.