Mechanisms of aging and potential role of selected polyphenols in extending healthspan

An integrative pan-cancer analysis of the molecular characteristics of dietary restriction in tumour microenvironment

BACKGROUND

Dietary restriction (DR), a general term for dieting, has been demonstrated as an effective intervention in reducing the occurrence of cancers. Molecular activities associated with DR are crucial in mediating its anti-cancer effects, yet a comprehensive exploration of the landscape of these activities at the pan-cancer level is still lacking.

METHODS

We proposed a computational approach for quantifying DR-related molecular activities and delineating the landscape of these activities across 33 cancer types and 30 normal tissues within 27,320 samples. We thoroughly examined the associations between DR-related molecular activities and various factors, including the tumour microenvironment, immunological phenotypes, genomic features, and clinical prognosis. Meanwhile, we identified two DR genes that show potential as prognostic predictors in hepatocellular carcinoma and verified them by immunohistochemical assays in 90 patients.

FINDINGS

We found that DR-related molecular activities showed a close association with tumour immunity and hold potential for predicting immunotherapy responses in various cancers. Importantly, a higher level of DR-related molecular activities is associated with improved overall survival and cancer-specific survival. FZD1 and G6PD are two DR genes that serve as biomarkers for predicting the prognosis of patients with hepatocellular carcinoma.

INTERPRETATION

This study presents a robust link between DR-related molecular activities and tumour immunity across multiple cancer types. Our research could open the path for further investigation of DR-related molecular processes in cancer treatment.

FUNDING

National Natural Science Foundation of China (Grant No. 82000628) and the Guangdong-Hong Kong-Macao University Joint Laboratory of Interventional Medicine Foundation of Guangdong Province (Grant No. 2023LSYS001).

Auricularia auricula Peptides Nutritional Supplementation Delays H2O2-Induced Senescence of HepG2 Cells by Modulation of MAPK/NF-κB Signaling Pathways

Auricularia auricula is a traditional medicinal and edible mushroom with anti-aging effects. Many studies focused on polysaccharides and melanin. However, the anti-aging effects and mechanism of the nutritional supplementation of Auricularia auricula peptides (AAPs) were not elucidated. In this study, AAPs were prepared by enzymolysis of flavor protease and the protective effects on H2O2-induced senescence of HepG2 cells were explored for the first time. The potential mechanism was also investigated. AAPs were mostly composed of low molecular weights with less than 1000 Da accounting for about 79.17%, and contained comprehensive amino acids nutritionally, including seven essential amino acids, aromatic, acidic, and basic amino acids. AAPs nutritional supplementation could significantly decrease the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and increase the activities of antioxidant enzymes (SOD, CAT, and GSH-Px). In addition, the senescence-associated-β-galactosidase (SA-β-gal) activity was restrained, and the expression levels of senescence-associated secretory phenotype (SASP) (IL-6, IL-8, IL-1β, and CXCL2) were also decreased. Ribonucleic acid sequencing (RNA-Seq) was carried out to screen the differentially expressed genes (DEGs) between different groups. GO and KEGG enrichment analysis showed that the mechanism was related to the MAPK/NF-κB signaling pathways. Quantitative real-time PCR (qRT-PCR) analysis and Western blot were carried out to verify the key genes and proteins in the pathways, respectively. AAPs nutritional supplementation resulted a significant down-regulation in key the genes c-fos and c-jun and up-regulation in DUSP1 of the MAPK signaling pathway, and down-regulation in the key genes CXCL2 and IL-8 of the NF-κB signaling pathway. The results of Western blot demonstrate that AAPs nutritional supplementation could inhibit MAPK/NF-κB pathways by reducing the expression levels of IKK, IκB, P65, and phosphorylation of ERK, thus decreasing the inflammatory reaction and delaying cell senescence. It is the first time that AAPs nutritional supplementation was proved to have protective effects on H2O2-induced oxidative damage in HepG2 cells. These results implicate that dietary AAPs could be used as nutrients to reduce the development or severity of aging.

Mulberry leaves attenuate D-galactose-induced aging in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Mulberry leaves contain many bioactive compounds and have been widely used in traditional medicines and functional foods for prevention and treatment of age-related diseases, such as diabetes, cognitive impairment and obesity-mediated liver cancer. Aging has an irreversible negative impact on human health for many years, even decades, before death, which is a social and economic burden on society.

AIM OF THE STUDY

The objective of this study was to investigate the antioxidant and anti-aging effects of mulberry leaf extract (MLE) in vivo and in vitro.

MATERIALS AND METHODS

The Caenorhabditis elegans (C. elegans) was used as a model organism to observe the effects of different concentrations of MLE (1, 2, 4, 8 mg/mL) on nematodes' healthy lifespan, reproductive capacity, locomotion, stress resistance, and antioxidation. In addition, D-galactose (D-gal) induced liver aging in mice and L-02 cells were established. The antioxidant and anti-aging effects of MLE were evaluated by body weight, organ indexes, malondialdehyde (MDA), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), aspartate and alanine aminotransferases (AST and ALT), reactive oxygen species (ROS), mitochondrial membrane potential (MMP), hematoxylin and eosin (H&E), senescence-associated β-galactosidase (SA-β-Gal). Besides, the expressions of AMPK/SIRT1/PGC-1α and Nrf2-Keap1 were detected by Western blotting.

RESULTS

MLE could significantly prolonged nematodes' average life span and improved most physiological indicators related to aging of C. elegans. Moreover, Treatment with MLE ameliorated the decreased body weight and organ index (weight of organ/body weight) in model mice, and protected against oxidative stress in mice and liver cells, in a dose-dependent manner, up-regulating T-SOD and T-AOC, while reducing ROS and MDA levels. MLE decreased both liver and cell levels of AST and ALT, and enhanced the mitochondrial membrane potential. MLE activated the AMPK/SIRT1/PGC-1α pathways, participated in mitochondrial biosynthesis and oxidative metabolism and delayed D-gal-induced aging. MLE promoted the accumulation of Nrf2 in the nucleus, indicating that the improved oxidative stress response was mediated by the Nrf2-Keap1 pathway in vivo and in vitro.

CONCLUSION

MLE appeared to have great potential for stimulating the oxidative stress response and attenuating the aging process of in vivo and in vitro, and provide a novel health-promoting resource against aging and aging-related diseases.

Senolytic Flavonoids Enhance Type-I and Type-II Cell Death in Human Radioresistant Colon Cancer Cells through AMPK/MAPK Pathway

Resistance to cancer therapies remains a clinical challenge and an unsolved problem. In a previous study, we characterized a new colon cancer cell line, namely HT500, derived from human HT29 cells and resistant to clinically relevant levels of ionizing radiation (IR). Here, we explored the effects of two natural flavonoids, quercetin (Q) and fisetin (F), well-known senolytic agents that inhibit genotoxic stress by selectively removing senescent cells. We hypothesized that the biochemical mechanisms responsible for the radiosensitising effects of these natural senolytics could intercept multiple biochemical pathways of signal transduction correlated to cell death resistance. Radioresistant HT500 cells modulate autophagic flux differently than HT29 cells and secrete pro-inflammatory cytokines (IL-8), commonly associated with senescence-related secretory phenotypes (SASP). Q and F inhibit PI₃K/AKT and ERK pathways, which promote p16^INK4 stability and resistance to apoptosis, but they also activate AMPK and ULK kinases in response to autophagic stress at an early stage. In summary, the combination of natural senolytics and IR activates two forms of cell death: apoptosis correlated to the inhibition of ERKs and lethal autophagy dependent on AMPK kinase. Our study confirms that senescence and autophagy partially overlap, share common modulatory pathways, and reveal how senolytic flavonoids can play an important role in these processes.

Characterization of Cell Death Induced by Imine Analogs of Trans-Resveratrol: Induction of Mitochondrial Dysfunction and Overproduction of Reactive Oxygen Species Leading to, or Not, Apoptosis without the Increase in the S-Phase of the Cell Cycle

Trans-resveratrol (RSV) is a non-flavonoid polyphenol (stilbene) with numerous biological activities, such as anti-tumor activities. However, RSV is rapidly metabolized, which limits its therapeutic use. The availability of RSV analogues with similar activities for use in vivo is therefore a major challenge. For this purpose, several isomeric analogues of RSV, aza-stilbenes (AZA-ST 1a–g), were synthesized, and their toxicities were characterized and compared to those of RSV on murine N2a neuronal cells using especially flow cytometric methods. All AZA-ST 1a–g have an inhibitory concentration 50 (IC50) between 11.3 and 25 µM when determined by the crystal violet assay, while that of RSV is 14.5 µM. This led to the characterization of AZA-ST 1a–g—induced cell death, compared to RSV, using three concentrations encompassing the IC50s (6.25, 12.5 and 25 µM). For AZA-ST 1a–g and RSV, an increase in plasma membrane permeability to propidium iodide was observed, and the proportion of cells with depolarized mitochondria measured with DiOC6(3) was increased. An overproduction of reactive oxygen species (ROS) was also observed on whole cells and at the mitochondrial level using dihydroethidium and MitoSox Red, respectively. However, only RSV induced a mode of cell death by apoptosis associated with a marked increase in the proportion of cells with condensed and/or fragmented nuclei (12.5 µM: 22 ± 9%; 25 µM: 80 ± 10%) identified after staining with Hoechst 33342 and which are characteristic of apoptotic cells. With AZA-ST, a slight but significant increase in the percentage of apoptotic cells was only detected with AZA-ST 1b (25 µM: 17 ± 1%) and AZA-ST 1d (25 µM: 26 ± 4%). Furthermore, only RSV induced significant cell cycle modifications associated with an increase in the percentage of cells in the S phase. Thus, AZA-ST 1a–g—induced cell death is characterized by an alteration of the plasma membrane, an induction of mitochondrial depolarization (loss of ΔΨm), and an overproduction of ROS, which may or may not result in a weak induction of apoptosis without modification of the distribution of the cells in the different phases of the cell cycle.

Stillage Waste from Strawberry Spirit Production as a Source of Bioactive Compounds with Antioxidant and Antiproliferative Potential

The production of fruit distillates generates solid residues which are potentially rich in bioactive compounds worthy of valorization and exploitation. We report herein the in vitro antioxidant and antiproliferative properties of an extract obtained from the waste of fermented strawberry distillate production. The main low molecular weight phenolic components of the extract were identified as ellagic acid and p-coumaric acid using spectroscopic and chromatographic analysis. The extract exhibited high antioxidant properties, particularly in the ferric reducing/antioxidant power (FRAP) assay, and a high total phenolic content (TPC). It was also able to induce an antiproliferative effect on different human cancer cell lines. A strong decrease in viability in human promyelocytic leukemia (HL-60) cells through a rapid and massive apoptosis were observed. Moreover, at an early time (<30 min), reactive oxygen species (ROS) production and inactivation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway were detected. Notably, the antiproliferative activity of the sample was comparable to that observed with an analogous extract prepared from unfermented, fresh strawberries. These results bring new opportunities for the valorization of fruit distillery by-products as low-cost resources for the design of bioactive formulations of comparable value to that from fresh food.

Bone-targeted delivery of senolytics to eliminate senescent cells increases bone formation in senile osteoporosis

Systemic elimination of senescent cells using senolytic drugs presents therapeutic effects on age-related diseases, including senile osteoporosis. However, low bioavailability and potential side effects of senolytics restrict clinical application. Therefore, we developed a bone-targeted delivery system for senolytics to effective treatment of senile osteoporosis. In this study, quercetin was screened out as the ideal senolytics for eliminating senescent BMSCs. Treatment of quercetin efficiently decreased the senescence markers in senescent BMSCs models. After treatment with quercetin in vitro, cell mitosis and calcification staining assay confirmed that the proliferation and osteogenesis of the senescent BMSCs populations were enhanced. To enhance the effectiveness and minimize the side effect of treatment, liposomes decorated with bone affinity peptide (DSS)₆ were constructed for bone-targeted delivery of quercetin. After administration of liposomes loading quercetin in two aged mice models, histological and cellular analysis confirmed that bone-targeted treatment with quercetin efficiently eliminated senescent cells in bone, restored the function of BMCSs, and promoted bone formation in aged mice models when compared to non-targeted treatment. Taken together, the bone-targeted delivery of senolytics efficiently eliminates senescent cells to recover bone mass and microarchitecture, showing an effective treatment for senile osteoporosis. STATEMENT OF SIGNIFICANCE: Senile osteoporosis, a common and hazardous chronic disease, has been still lacking effective therapy. How to effectively eliminate the hazards of senescent cells in skeleton to bone formation remains challenge. In this study, quercetin was screened out as the ideal senolytic drug for senescent BMSCs and could effectively eliminated senescent BMSCs to restore the cellular functions of senescent BMSCs models in vitro. Then, the bone-targeted liposomes were designed to encapsulate and deliver senolytics efficiently to senile bone tissue. Based on two aged mice models, we confirmed that bone-targeted delivery of quercetin efficiently eliminated senescent cells in skeleton and enhanced bone formation in vivo, suggesting the bone-targeted elimination of senescent cells is an effective treatment for senile osteoporosis.

A Cocktail of Polyherbal Bioactive Compounds and Regular Mobility Training as Senolytic Approaches in Age-dependent Alzheimer's: the In Silico Analysis, Lifestyle Intervention in Old Age

Alzheimer's is a principal concern globally. Machine learning is a valuable tool to determine protective and diagnostic approaches for the elderly. We analyzed microarray datasets of Alzheimer's cases based on artificial intelligence by R statistical software. This study provided a screened pool of ncRNAs and coding RNAs related to Alzheimer's development. We designed hub genes as cut points in networks and predicted potential microRNAs and LncRNA to regulate protein networks in aging and Alzheimer's through in silico algorithms. Notably, we collected effective traditional herbal medicines. A list of bioactive compounds prepared including capsaicin, piperine, crocetin, safranal, saffron oil, coumarin, thujone, rosmarinic acid, sabinene, thymoquinone, ascorbic acid, vitamin E, cyanidin, rhaponticin, isovitexin, coumarin, nobiletin, evodiamine, gingerol, curcumin, quercetin, fisetin, and allicin as an effective fusion that potentially modulates hub proteins and molecular signaling pathways based on pharmacophore model screening and chemoinformatics survey. We identified profiles of 21 mRNAs, 272 microRNAs, and eight LncRNA in Alzheimer's based on prediction algorithms. We suggested a fusion of senolytic herbal ligands as an alternative therapy and preventive formulation in dementia. Also, we provided ncRNAs expression status as novel monitoring strategies in Alzheimer's and new cut-point proteins as novel therapeutic approaches. Synchronizing fusion drugs and lifestyle could reverse Alzheimer's hallmarks to amelioration via an offset of the signaling pathways, leading to increased life quality in the elderly.

Anti-aging effects of dietary phytochemicals: From Caenorhabditis elegans, Drosophila melanogaster, rodents to clinical studies

Anti-aging research has become critical since the elderly population is increasing dramatically in this era. With the establishment of frailty phenotype and frailty index, the importance of anti-frailty research is concurrently enlightened. The application of natural phytochemicals against aging or frailty is always intriguing, and abundant related studies have been published. Various models are designed for biological research, and each model has its strength and weakness in deciphering the complex aging mechanisms. In this article, we attempt to show the potential of Caenorhabditis elegans in the study of phytochemicals' effects on anti-aging by comparing it to other animal models. In this review, the lifespan extension and anti-aging effects are demonstrated by various physical, cellular, or molecular biomarkers of dietary phytochemicals, including resveratrol, curcumin, urolithin A, sesamin, fisetin, quercetin, epigallocatechin-3-gallate, epicatechin, spermidine, sulforaphane, along with extracts of broccoli, cocoa, and blueberry. Meanwhile, the frequency of phytochemicals and models studied or presented in publications since 2010 were analyzed, and the most commonly mentioned animal models were rats, mice, and the nematode C. elegans. This up-to-date summary of the anti-aging effect of certain phytochemicals has demonstrated powerful potential for anti-aging or anti-frailty in the human population.

Potential implications of oxidative modification on dietary protein nutritional value: A review

During food processing and storage, proteins are sensitive to oxidative modification, changing the structural characteristics and functional properties. Recently, the impact of dietary protein oxidation on body health has drawn increasing attention. However, few reviews summarized and highlighted the impact of oxidative modification on the nutritional value of dietary proteins and related mechanisms. Therefore, this review seeks to give an updated discussion of the effects of oxidative modification on the structural characteristics and nutritional value of dietary proteins, and elucidate the interaction with gut microbiota, intestinal tissues, and organs. Additionally, the specific mechanisms related to pathological conditions are also characterized. Dietary protein oxidation during food processing and storage change protein structure, which further influences the in vitro digestion properties of proteins. In vivo research demonstrates that oxidized dietary proteins threaten body health via complicated pathways and affect the intestinal microenvironment via gut microbiota, metabolites, and intestinal morphology. This review highlights the influence of oxidative modification on the nutritional value of dietary proteins based on organs and the intestinal tract, and illustrates the necessity of appropriate experimental design for comprehensively exploring the health consequences of oxidized dietary proteins.

Phenolic Extract from Extra Virgin Olive Oil Induces Different Anti-Proliferative Pathways in Human Bladder Cancer Cell Lines

Regular consumption of olive oil is associated with protection against chronic-degenerative diseases, such as cancer. Epidemiological evidence indicates an inverse association between olive oil intake and bladder cancer risk. Bladder cancer is among the most common forms of cancer; in particular, the transitional cell carcinoma histotype shows aggressive behavior. We investigated the anti-proliferative effects of a phenolic extract prepared from an extra virgin olive oil (EVOOE) on two human bladder cancer cell lines, namely RT112 and J82, representing the progression from low-grade to high-grade tumors, respectively. In RT112, the EVOOE reduced cell viability (IC50 = 240 μg/mL at 24 h), triggering a non-protective form of autophagy, evidenced by the autophagosome formation and the increase in LC-3 lipidation. In J82, EVOOE induced a strong decrease in cell viability after 24 h of treatment (IC50 = 65.8 μg/mL) through rapid and massive apoptosis, assessed by Annexin V positivity and caspase-3 and -9 activation. Moreover, in both bladder cancer cell lines, EVOOE reduced intracellular reactive oxygen species, but this antioxidant effect was not correlated with its anti-proliferative outcomes. Data obtained suggest that the mixture of phenolic compounds in extra virgin olive oil activates different anti-proliferative pathways.

Physical Activity on Telomere Length as a Biomarker for Aging: A Systematic Review

Background

Overall life expectancy continues to rise, approaching 80 years of age in several developed countries. However, healthy life expectancy lags far behind, which has, in turn, contributed to increasing costs in healthcare. One way to improve health and attenuate the socio-economic impact of an aging population is to increase overall fitness through physical activity. Telomere attrition or shortening is a well-known molecular marker in aging. As such, several studies have focused on whether exercise influences health and aging through telomere biology. This systematic review examines the recent literature on the effect of physical activity on telomere length (TL) and/or telomerase activity as molecular markers of aging.

Methods

A focused search was performed in the databases PubMed and Web of Science for retrieving relevant articles over the past ten years. The search contained the following keywords: exercise, sport, physical activity, fitness, sedentary, physical inactivity, telomere, telomere length, t/s ratio, and telomerase. PRISMA guidelines for systematic reviews were observed.

Results

A total of 43 articles were identified and categorized into randomized controlled trials (RCT), observational or interventional studies. RCTs (n = 8) showed inconsistent findings of increased TL length with physical activity in, e.g. obese, post-menopausal women. In comparison with a predominantly sedentary lifestyle, observational studies (n = 27) showed significantly longer TL with exercise of moderate to vigorous intensity; however, there was no consensus on the duration and type of physical activity and training modality. Interventional studies (n = 8) also showed similar findings of significantly longer TL prior to exercise intervention; however, these studies had smaller numbers of enrolled participants (mostly of high-performance athletes), and the physical activities covered a range of exercise intensities and duration. Amongst the selected studies, aerobic training of moderate to vigorous intensity is most prevalent. For telomere biology analysis, TL was determined mainly from leukocytes using qPCR. In some cases, especially in RCT and interventional studies, different sample types such as saliva, sperm, and muscle biopsies were analyzed; different leukocyte cell types and potential genetic markers in regulating telomere biology were also investigated.

Conclusions

Taken together, physical activity with regular aerobic training of moderate to vigorous intensity appears to help preserve TL. However, the optimal intensity, duration of physical activity, as well as type of exercise still need to be further elucidated. Along with TL or telomerase activity, participants’ fitness level, the type of physical activity, and training modality should be assessed at different time points in future studies, with the plan for long-term follow-up. Reducing the amount of sedentary behavior may have a positive effect of preserving and increasing TL. Further molecular characterization of telomere biology in different cell types and tissues is required in order to draw definitive causal conclusions on how physical activity affects TL and aging.

Polyphenols in Metabolic Diseases

Polyphenols (PPs) are a large group of phytochemicals containing phenolic rings with two or more hydroxyl groups. They possess powerful antioxidant properties, multiple therapeutic effects, and possible health benefits in vivo and in vitro, as well as reported clinical studies. Considering their free-radical scavenging and anti-inflammatory properties, these substances can be used to treat different kinds of conditions associated with metabolic disorders. Many symptoms of metabolic syndrome (MtS), including obesity, dyslipidemia, atherosclerosis, elevated blood sugar, accelerating aging, liver intoxication, hypertension, as well as cancer and neurodegenerative disorders, are substantially relieved by dietary PPs. The present study explores the bioprotective properties and associated underlying mechanisms of PPs. A detailed understanding of these natural compounds will open up new opportunities for producing unique natural PP-rich dietary and medicinal plans, ultimately affirming their health benefits.

Therapeutic and Nutraceutical Effects of Polyphenolics from Natural Sources

The prevalence of cardiovascular disease, oxidative stress-related complications, and chronic age-related illnesses is gradually increasing worldwide. Several causes include the ineffectiveness of medicinal treatment therapies, their toxicity, their inability to provide radical solutions in some diseases, and the necessity of multiple drug therapy in certain chronic diseases. It is therefore necessary for alternative treatment methods to be sought. In this review, polyphenols were identified and classified according to their chemical structure, and the sources of these polyphenol molecules are indicated. The cardioprotective, ROS scavenging, anti-aging, anticancer properties of polyphenolic compounds have been demonstrated by the results of many studies, and these natural antioxidant molecules are potential alternative therapeutic agents.

Therapeutics That Can Potentially Replicate or Augment the Anti-Aging Effects of Physical Exercise

Globally, better health care access and social conditions ensured a significant increase in the life expectancy of the population. There is, however, a clear increase in the incidence of age-related diseases which, besides affecting the social and economic sustainability of countries and regions around the globe, leads to a decrease in the individual’s quality of life. There is an urgent need for interventions that can reverse, or at least prevent and delay, the age-associated pathological deterioration. Within this line, this narrative review aims to assess updated evidence that explores the potential therapeutic targets that can mimic or complement the recognized anti-aging effects of physical exercise. We considered pertinent to review the anti-aging effects of the following drugs and supplements: Rapamycin and Rapamycin analogues (Rapalogs); Metformin; 2-deoxy-D-glucose; Somatostatin analogues; Pegvisomant; Trametinib; Spermidine; Fisetin; Quercetin; Navitoclax; TA-65; Resveratrol; Melatonin; Curcumin; Rhodiola rosea and Caffeine. The current scientific evidence on the anti-aging effect of these drugs and supplements is still scarce and no recommendation of their generalized use can be made at this stage. Further studies are warranted to determine which therapies display a geroprotective effect and are capable of emulating the benefits of physical exercise.

Tea Polyphenols as Prospective Natural Attenuators of Brain Aging

No organism can avoid the process of aging, which is often accompanied by chronic disease. The process of biological aging is driven by a series of interrelated mechanisms through different signal pathways, including oxidative stress, inflammatory states, autophagy and others. In addition, the intestinal microbiota play a key role in regulating oxidative stress of microglia, maintaining homeostasis of microglia and alleviating age-related diseases. Tea polyphenols can effectively regulate the composition of the intestinal microbiota. In recent years, the potential anti-aging benefits of tea polyphenols have attracted increasing attention because they can inhibit neuroinflammation and prevent degenerative effects in the brain. The interaction between human neurological function and the gut microbiota suggests that intervention with tea polyphenols is a possible way to alleviate brain-aging. Studies have been undertaken into the possible mechanisms underpinning the preventative effect of tea polyphenols on brain-aging mediated by the intestinal microbiota. Tea polyphenols may be regarded as potential neuroprotective substances which can act with high efficiency and low toxicity.

Health benefits of polyphenols: A concise review

Plants produce polyphenols, which are considered highly essential functional foods in our diet. They are classified into several groups according to their diverse chemical structures. Flavanoids, lignans, stilbenes, and phenolic acids are the four main families of polyphenols. Several in vivo and in vitro research have been conducted so far to evaluate their health consequences. Polyphenols serve a vital function in the protection of the organism from external stimuli and in eliminating reactive oxygen species (ROS), which are instigators of several illnesses. Polyphenols are present in tea, chocolate, fruits, and vegetables with the potential to positively influence human health. For instance, cocoa flavan-3-ols have been associated with a decreased risk of myocardial infarction, stroke, and diabetes. Polyphenols in the diet also help to improve lipid profiles, blood pressure, insulin resistance, and systemic inflammation. Quercetin, a flavonoid, and resveratrol, a stilbene, have been linked to improved cardiovascular health. Dietary polyphenols potential to elicit therapeutic effects might be attributed, at least in part, to a bidirectional association with the gut microbiome. This is because polyphenols are known to affect the gut microbiome composition in ways that lead to better human health. Specifically, the gut microbiome converts polyphenols into bioactive compounds that have therapeutic effects. In this review, the antioxidant, cytotoxicity, anti-inflammatory, antihypertensive, and anti-diabetic actions of polyphenols are described based on findings from in vivo and in vitro experimental trials. PRACTICAL APPLICATIONS: The non-communicable diseases (NCDs) burden has been increasing worldwide due to the sedentary lifestyle and several other factors such as smoking, junk food, etc. Scientific literature evidence supports the use of plant-based food polyphenols as therapeutic agents that could help to alleviate NCD's burden. Thus, consuming polyphenolic compounds from natural sources could be an effective solution to mitigate NCDs concerns. It is also discussed how natural antioxidants from medicinal plants might help prevent or repair damage caused by free radicals, such as oxidative stress.

4,4'-Dimethoxychalcone protects the skin from AAPH-induced senescence and UVB-induced photoaging by activating autophagy

Aging can lead to the occurrence of many degenerative diseases, and the most intuitive consequences are mainly manifested on the skin, which is affected by both endogenous and exogenous aging factors and can be used as an ideal model organ for studying aging. 4,4'-Dimethoxychalcone (DMC), a natural flavonoid compound from Angelica sinensis, has been proven to prolong the lifespan of multiple species. However, it is not clear whether it has the effect of delaying skin aging. This study aimed to establish a skin senescent cell model induced by oxidative stress, and further, to analyze the inhibitory effect of DMC on cellular senescence, and explore its molecular mechanisms. We found that treatment of HaCaT cells with 1 mM 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) for 48 h showed significant senescent characteristics, which could be effectively alleviated by pretreatment with the antioxidant N-acetyl-L-cysteine (NAC). DMC significantly inhibited AAPH-induced senescence, and further mechanism studies showed that the activation of autophagy which depended on the phosphorylation of ULK1 at Ser555 was necessary for DMC to alleviate senescence of HaCaT cells. In addition, the mitogen-activated protein kinase (MAPK) signal pathway was also involved in the regulation of autophagy induced by DMC. These results were also validated in UVB-induced photoaging mice. In conclusion, we successfully establish a skin senescent cell model and prove that DMC can be used as a potential therapeutic agent to intervene in skin aging.

The Composition and Anti-Aging Activities of Polyphenol Extract from Phyllanthus emblica L. Fruit

Phyllanthus emblica L. (PE) is commonly known as a medicine and food homologous plant, which is abundant in natural products polyphenols. In the present study, polyphenols were extracted from PE fruit by response surface method, and the anti-aging ability was determined. PE fruit polyphenols exhibited strong antioxidant capacities in scavenging free radicals, and anti-cholinesterase ability by inhibition of AChE (IC50 0.2186 ± 0.0416 mg/mL) and BuChE (IC50 0.0542 ± 0.0054 mg/mL) in vitro. Moreover, PE fruit polyphenols showed strong protective effect against the aging process in Caenorhabditis elegans model, including increased thermal resistance, extended lifespan by 18.53% (p < 0.05), reduced activity of AChE by 34.71% and BuChE by 45.38% (p < 0.01). This was accompanied by the enhancement in antioxidant enzymes activity of SOD by 30.74% (p < 0.05) and CAT by 8.42% (p > 0.05), while decrease in MDA level by 36.25% (p < 0.05). These properties might be interrelated with the presence of abundant flavonols and phenolic acids identified by UPLC-ESI-QTOF-MS, such as quercetin, myricetin, ellagic, gallic, and chlorogenic acids, together with their glycosides. The remarkable antioxidant and anti-aging potential of PE fruit polyphenols could be implemented in the food and pharmaceutical industry.

Design and optimization of cranberry extract loaded bile salt augmented liposomes for targeting of MCP-1/STAT3/VEGF signaling pathway in DMN-intoxicated liver in rats

Cranberry extract (CBE) is a major source of the antioxidant polyphenolics but suffers from limited bioavailability. The goal of this research was to encapsulate the nutraceutical (CBE), into bile salt augmented liposomes (BSALs) as a promising oral delivery system to potentiate its hepatoprotective impact against dimethylnitrosamine (DMN) induced liver injury in rats. The inclusion of bile salt in the liposomal structure can enhance their stability within the gastrointestinal tract and promote CBE permeability. CBE loaded BSALs formulations were fabricated utilizing a (2³) factorial design to explore the impact of phospholipid type (X₁), phospholipid amount (X₂), and sodium glycocholate (SGC) amount (X₃) on BSALs properties, namely; entrapment efficiency percent, (EE%); vesicle size, (VS); polydispersity index; (PDI); zeta potential, (ZP); and release efficiency percent, (RE%). The optimum formulation (F1) exhibited spherical vesicles with EE% of 71.27 ± 0.32%, VS; 148.60 ± 6.46 nm, PDI; 0.38 ± 0.02, ZP; −18.27 ± 0.67 mV and RE%; 61.96 ± 1.07%. Compared to CBE solution, F1 had attenuated DMN-induced hepatic injury, as evidenced by the significant decrease in serum level of ALT, AST, ALP, MDA, and elevation of GSH level, as well as SOD and GPX activities. Furthermore, F1 exhibited an anti-inflammatory character by suppressing TNF-α, MCP-1, and IL-6, as well as downregulation of VEGF-C, STAT-3, and IFN-γ mRNA levels. This study verified that when CBE was integrated into BSALs, F1, its hepatoprotective effect was significantly potentiated to protect the liver against DMN-induced damage. Therefore, F1 could be deliberated as an antioxidant, antiproliferative, and antifibrotic therapy to slow down the progression of hepatic damage.

Interplay between Inflammaging, Frailty and Nutrition in Covid-19: Preventive and Adjuvant Treatment Perspectives

As humans age, their immune system undergoes modifications, including a low-grade inflammatory status called inflammaging. These changes are associated with a loss of physical and immune resilience, amplifying the risk of being malnourished and frail. Under the COVID-19 scenario, inflammaging increases the susceptibility to poor prognostics. We aimed to bring the current concepts of inflammaging and its relationship with frailty and COVID-19 prognostic; highlight the importance of evaluating the nutritional risk together with frailty aiming to monitor older adults in COVID-19 scenario; explore some compounds with potential to modulate inflammaging in perspective to manage the COVID-19 infection. Substances such as probiotics and senolytics can help reduce the high inflammatory status. Also, the periodic evaluation of nutrition risk and frailty will allow interventions, assuring the appropriate care.

GANE can Improve Lung Fibrosis by Reducing Inflammation via Promoting p38MAPK/TGF-β1/NF-κB Signaling Pathway Downregulation

There is a trend to use nanoparticles as distinct treatments for cancer treatment because they have overcome many of the limitations of traditional drug delivery systems. Gallic acid (GA) is an effective polyphenol in the treatment of tissue injuries. In this study, GA was loaded onto niosomes to produce gallic acid nanoemulsion (GANE) using a green synthesis technique. GANE's efficiency, morphology, UV absorption, release, and Fourier-transform infrared spectroscopy (FTIR) analysis were evaluated. An in vitro study was conducted on the A549 lung carcinoma cell line to determine the GANE cytotoxicity. Also, our study was extended to evaluate the protective effect of GANE against lipopolysaccharide (LPS)-induced pulmonary fibrosis in rats. GANE showed higher encapsulation efficiency and strong absorption at 280 nm. Transmission electron microscopy presented a spherical shape of the prepared nanoparticles, and FTIR demonstrated different spectra for the free gallic acid sample compared to GANE. GANE showed cytotoxicity for the A549 carcinoma lung cell line with a low IC₅₀ value. It was found that oral administration of GANE at 32.8 and 82 mg/kg.b.w. and dexamethasone (0.5 mg/kg) provided significant protection against LPS-induced pulmonary fibrosis. GANE enhanced production of superoxide dismutase, GPx, and GSH. It simultaneously reduced the MDA level. The GANE and dexamethasone, induced the production of IL-4, but suppressed TNF-α and IL-6. On the other hand, the lung p38MAPK, TGF-β1, and NF-κB gene expression was downregulated in rats administrated with GANE when compared with the LPS-treated rats. Histological studies confirmed the effective effect of GANE as it had a lung-protective effect against LPS-induced lung fibrosis. It was noticed that GANE can inhibit oxidative stress, lipid peroxidation, and cytokines and downregulate p38MAPK, TGF-β1, and NF-κB gene expression to suppress the proliferation and migration of lung fibrotic cells.

Current advances of functional phytochemicals in Nicotiana plant and related potential value of tobacco processing waste: A review

Tobacco is grown in large quantities worldwide as a widely distributed commercial crop. From the harvest of the field to the process into the final product, a series of procedures generate enormous amount of waste materials that are rarely recycled. In recent years, numerous potential bioactive compounds have been isolated from tobacco, and the molecular regulatory mechanisms related to the performance of some functionalities have been identified. This review describes the source of tobacco waste and expounds a large amount of biomass during the tobacco processing, and the necessity of exploring the reuse of tobacco waste. In addition, the review summarizes the bioactive compounds from tobacco that have been discovered so far, and links them to various functions from tobacco extracts, including anti-inflammatory, antitumor, antibacterial, and antioxidant, thus proving the potential value from tobacco waste reuse. In this regard, nornicotine in tobacco is the culprit of many health issues, while the polyphenols and polysaccharides often contribute to the health benefits of tobacco extract. In addition, it is hard to ignore that realization of these functions of tobacco extracts require the involvement of intestinal flora metabolism, which should be considered in the development of new product dosage forms.

Haematococcus Pluvialis Extends Yeast Lifespan and Improves Slc25a46 Gene Knockout-Associated Mice Phenotypic Defects

SCOPE

Aging has become one of major concern worldwide. It is therefore of great significance in finding food resources as therapeutic candidates for aging-related functional decline improvement and prevention. This study aimed to define the potency of Haematococcus pluvialis (H. pluvialis) as an anti-aging food resource.

METHODS AND RESULTS

Yeast is used to explore the anti-aging effects of H. pluvialis. The result showed that H. pluvialis extract could effectively extend yeast chronological lifespan (CLS) by reducing intracellular reactive oxygen species (ROS) levels, promoting mitochondrial membrane potential (MMP) levels and accumulating storage carbohydrate (glycogen). Subsequently, Slc25a46 knockout (Slc25a46^-/- ) mice with mitochondrial dysfunction are fed with 100 mg kg^-1 H. pluvialis extracts for 10 days. The in vivo data demonstrated that H. pluvialis extract could effectively improve the phenotypic deficits, including underweight, muscle weakness, redox imbalance, and mitochondrial respiratory chain dysfunction, etc., in Slc25a46^-/- mice.

CONCLUSIONS

This work highlights that the mitochondria may be a potential therapeutic target for combating aging, and demonstrated that H. pluvialis, as a dietary supplement, may potentially be an effective preventive substance that may contribute to the promotion of healthy aging.

Targeting Wnt signaling pathway by polyphenols: implication for aging and age-related diseases

Age is an important risk factor for different diseases. The same mechanisms that promote aging are involved in the development and progression of age-associated diseases. Polyphenols are organic compounds found in fruits and vegetables. Due to their beneficial properties (e.g. antioxidant and anti-inflammatory), polyphenols have been extensively used for treating chronic diseases. To exert their functions, polyphenols target various molecular mechanisms and signaling pathways, such as mTOR, NF-κB, and Wnt/β-catenin. Wnt signaling is a critical pathway for developmental processes. Besides, dysregulation of this signaling pathway has been observed in various diseases. Several investigations have been conducted on Wnt inhibitors at pre-clinical stages, showing promising results. Herein, we review the studies dealing with the role of polyphenols in targeting the Wnt signaling pathways in aging processes and age-associated diseases, including cancer, diabetes, Alzheimer's disease, osteoporosis, and Parkinson's disease.

Computational Identification of Dithymoquinone as a Potential Inhibitor of Myostatin and Regulator of Muscle Mass

The skeletal muscle (SM) is the largest organ in the body and has tremendous regenerative power due to its myogenic stem cell population. Myostatin (MSTN), a protein produced by SM, is released into the bloodstream and is responsible for age-related reduced muscle fiber development. The objective of this study was to identify the natural compounds that inhibit MSTN with therapeutic potential for the management of age-related disorders, specifically muscle atrophy and sarcopenia. Sequential screening of 2000 natural compounds was performed, and dithymoquinone (DTQ) was found to inhibit MSTN with a binding free energy of −7.40 kcal/mol. Furthermore, the docking results showed that DTQ reduced the binding interaction between MSTN and its receptor, activin receptor type-2B (ActR2B). The global energy of MSTN-ActR2B was found to be reduced from −47.75 to −40.45 by DTQ. The stability of the DTQ–MSTN complex was subjected to a molecular dynamics analysis for up to 100 ns to check the stability of the complex using RMSD, RMSF, Rg, SASA, and H-bond number. The complex was found to be stable after 10 ns to the end of the simulation. These results suggest that DTQ blocks MSTN signaling through ActR2B and that it has potential use as a muscle growth-promoting agent during the aging process.

The Potential Role of Polyphenols in Oxidative Stress and Inflammation Induced by Gut Microbiota in Alzheimer's Disease

Gut microbiota (GM) play a role in the metabolic health, gut eubiosis, nutrition, and physiology of humans. They are also involved in the regulation of inflammation, oxidative stress, immune responses, central and peripheral neurotransmission. Aging and unhealthy dietary patterns, along with oxidative and inflammatory responses due to gut dysbiosis, can lead to the pathogenesis of neurodegenerative diseases, especially Alzheimer's disease (AD). Although the exact mechanism between AD and GM dysbiosis is still unknown, recent studies claim that secretions from the gut can enhance hallmarks of AD by disturbing the intestinal permeability and blood-brain barrier via the microbiota-gut-brain axis. Dietary polyphenols are the secondary metabolites of plants that possess anti-oxidative and anti-inflammatory properties and can ameliorate gut dysbiosis by enhancing the abundance of beneficial bacteria. Thus, modulation of gut by polyphenols can prevent and treat AD and other neurodegenerative diseases. This review summarizes the role of oxidative stress, inflammation, and GM in AD. Further, it provides an overview on the ability of polyphenols to modulate gut dysbiosis, oxidative stress, and inflammation against AD.

Curcumin as Prospective Anti-Aging Natural Compound: Focus on Brain

The nutrients and their potential benefits are a new field of study in modern medicine for their positive impact on health. Curcumin, the yellow polyphenolic compound extracted from Curcuma longa species, is widely used in traditional Ayurvedic medicine to prevent and contrast many diseases, considering its antioxidant, immunomodulatory, anti-inflammatory, anti-microbial, cardio-protective, nephron-protective, hepato-protective, anti-neoplastic, and anti-rheumatic proprieties. In recent years, the investigations of curcumin have been focused on its application to aging and age-associated diseases. Aging is a physiological process in which there is a decreasing of cellular function due to internal or external stimuli. Oxidative stress is one of the most important causes of aging and age-related diseases. Moreover, many age-related disorders such as cancer, neuroinflammation, and infections are due to a low-grade chronic systemic inflammation. Curcumin acting on different proteins is able to contrast both oxidative stress than inflammation. In the brain, curcumin is able to modulate inflammation induced by microglia. Finally in brain tumors curcumin is able to reduce tumor growth by inhibition of telomerase activity. This review emphasizes the anti-aging role of curcumin focusing on its mechanism to counteract aging in the brain. Moreover, new formulations to increase the bioavailability of curcumin are discussed.

Synthesis and Testing of Novel Isomeric Mitochondriotropic Derivatives of Resveratrol and Quercetin

Resveratrol and quercetin are among the most studied plant polyphenols, and have many health-promoting actions. Strategies to accumulate them into mitochondria may be of therapeutic relevance, since these compounds are redox active and are well known to impact mitochondria and mitochondrial proteins. We report here the procedures to synthesize mitochondria-targeted resveratrol and quercetin derivatives; the synthetic strategies reported are however expected to be adaptable to other polyphenols with similar reactivity at the phenolic hydroxyls. Mitochondrial targeting can be achieved by conjugation with triphenylphosphonium , a lipophilic cation; this was linked via a butyl spacer forming an ether bond with one of the phenolic oxygens. The first step toward the synthesis of all mitochondriotropic derivatives described in this work is the production of a regiospecific -(4-O-chlorobutyl) derivative. Triphenylphosphonium (P⁺Ph₃I^-) is then introduced through two consecutive nucleophilic substitution steps: -Cl → -I → -P⁺Ph₃I^-. Pure mono-substituted chlorobutyl regioisomers are obtained by purification from the reaction mixture in the case of resveratrol , while specific protection strategies are required for quercetin to favor alkylation of one specific hydroxyl.Functionalization of the remaining hydroxyls can be exploited to modulate the physicochemical properties of the derivatives (i.e., water solubility, affinity for cell membranes); we report here synthetic protocols to obtain acetylated and methylated analogs.A brief description of some methods to assess the accumulation of the derivatives in mitochondria is also given; the proposed techniques are the use of a TPP ⁺-selective electrode (with isolated rat liver mitochondria ) and fluorescence microscopy (with cultured cells).

Curcumin nanoformulations to combat aging-related diseases

Aging increases the susceptibility to a diverse set of diseases and disorders, including neurodegeneration, cancer, diabetes, and arthritis. Natural compounds are currently being explored as alternative or complementary agents to treat or prevent aging-related malfunctions. Curcumin, a phytochemical isolated from the spice turmeric, has garnered great interest in recent years. With anti-oxidant, anti-inflammatory, anti-microbial, and other physiological activities, curcumin has great potential for health applications. However, the benefits of curcumin are restricted by its low bioavailability and stability in biological systems. Curcumin nanoformulations, or nano-curcumin, may overcome these limitations. This review discusses different forms of nano-curcumin that have been evaluated in vitro and in vivo to treat or prevent aging-associated health impairments. We describe current barriers for the routine use of curcumin nanoformulations in the clinic. Our review highlights outstanding questions and future work that is needed to ensure nano-curcumin is efficient and safe to lessen the burden of aging-related health problems.

From Sea to Skin: Is There a Future for Natural Photoprotectants?

In the last few decades, the thinning of the ozone layer due to increased atmospheric pollution has exacerbated the negative effects of excessive exposure to solar ultraviolet radiation (UVR), and skin cancer has become a major public health concern. In order to prevent skin damage, public health advice mainly focuses on the use of sunscreens, along with wearing protective clothing and avoiding sun exposure during peak hours. Sunscreens present on the market are topical formulations that contain a number of different synthetic, organic, and inorganic UVR filters with different absorbance profiles, which, when combined, provide broad UVR spectrum protection. However, increased evidence suggests that some of these compounds cause subtle damage to marine ecosystems. One alternative may be the use of natural products that are produced in a wide range of marine species and are mainly thought to act as a defense against UVR-mediated damage. However, their potential for human photoprotection is largely under-investigated. In this review, attention has been placed on the molecular strategies adopted by marine organisms to counteract UVR-induced negative effects and we provide a broad portrayal of the recent literature concerning marine-derived natural products having potential as natural sunscreens/photoprotectants for human skin. Their chemical structure, UVR absorption properties, and their pleiotropic role as bioactive molecules are discussed. Most studies strongly suggest that these natural products could be promising for use in biocompatible sunscreens and may represent an alternative eco-friendly approach to protect humans against UV-induced skin damage.

Grape-Seed Proanthocyanidin Extract Reverts Obesity-Related Metabolic Derangements in Aged Female Rats

Obesity and ageing are current issues of global concern. Adaptive homeostasis is compromised in the elderly, who are more likely to suffer age-related health issues, such as obesity, metabolic syndrome, and cardiovascular disease. The current worldwide prevalence of obesity and higher life expectancy call for new strategies for treating metabolic disorders. Grape-seed proanthocyanidin extract (GSPE) is reported to be effective in ameliorating these pathologies, especially in young animal models. In this study, we aimed to test the effectiveness of GSPE in modulating obesity-related pathologies in aged rats fed an obesogenic diet. To do so, 21-month-old rats were fed a high-fat/high-sucrose diet (cafeteria diet) for 11 weeks. Two time points for GSPE administration (500 mg/kg body weight), i.e., a 10-day preventive GSPE treatment prior to cafeteria diet intervention and a simultaneous GSPE treatment with the cafeteria diet, were assayed. Body weight, metabolic parameters, liver steatosis, and systemic inflammation were analysed. GSPE administered simultaneously with the cafeteria diet was effective in reducing body weight, total adiposity, and liver steatosis. However, the preventive treatment was effective in reducing only mesenteric adiposity in these obese, aged rats. Our results confirm that the simultaneous administration of GSPE improves metabolic disruptions caused by the cafeteria diet also in aged rats.

Antioxidant and Cytoprotective Properties of Plant Extract from Dry Flowers as Functional Dyes for Cosmetic Products

Nowadays, natural dyes are expected by the cosmetic and food industries. In contrast to synthetic dyes, colorants derived from natural sources are more environmentally friendly and safer for human health. In this work, plant extracts from Gomphrena globasa L., Clitoria ternatea L., Carthamus tinctorius L., Punica granatum L. and Papaver rhoeas L. as the natural and functional dyes for the cosmetics industry were assessed. Cytotoxicity on keratinocyte and fibroblast cell lines was determined as well as antioxidant and anti-aging properties by determining their ability to inhibit the activity of collagenase and elastase enzymes. In addition, the composition of the extracts was determined. The obtained extracts were also applied in face cream formulation and color analyses were performed. It has been shown that the obtained extracts were characterized by no cytotoxicity and a high antioxidant potential. The extracts also show strong ability to inhibit the activity of collagenase and moderate ability to inhibit elastase and provide effective and long-lasting hydration after their application on the skin. Application analyses showed that the extracts of P. rhoeas L., C. ternatea L. and C. tinctorius L. can be used as effective cosmetic dyes that allow for attainment of an intense and stable color during the storage of the product. The extracts of P. granatum L. and G. globasa L., despite their beneficial effects as active ingredients, did not work effectively as cosmetic dyes, because cosmetic emulsions with these extracts did not differ significantly in color from emulsions without the extract.

COVID-19: A Challenge to Physiology of Aging

The death toll of the current COVID-19 pandemic is strongly biased toward the elderly. COVID-19 case fatality rate (CFR) increases with age exponentially, its doubling time being about 7 years, irrespective of countries and epidemic stages. The same age-dependent mortality pattern known as the Gompertz law is featured by the total mortality and its main constituents attributed to cardiovascular, metabolic, neurological, and oncological diseases. Among patients dying of COVID-19, most have at least one of these conditions, whereas none is found in most of those who pass it successfully. Thus, gerontology is indispensable in dealing with the pandemic, which becomes a benchmark for validating the gerontological concepts and advances. The two basic alternative gerontological concepts imply that either aging results from the accumulation of stochastic damage, or is programmed. Based on these different grounds, several putative anti-aging drugs have been proposed as adjuvant means for COVID-19 prevention and/or treatment. These proposals are reviewed in the context of attributing the molecular targets of these drugs to the signaling pathways between the sensors of resource availability and the molecular mechanisms that allocate resources to storage, growth and reproduction or to self-maintenance and repair. Each of the drugs appears to reproduce only a part of the physiological responses to reduced resource availability caused by either dietary calories restriction or physical activity promotion, which are the most robust means of mitigating the adverse manifestations of aging. In the pathophysiological terms, the conditions of the endothelium, which worsen as age increases and may be significantly improved by the physical activity, is a common limiting factor for the abilities to withstand both physical stresses and challenges imposed by COVID-19. However, the current anti-epidemic measures promote sedentary indoor lifestyles, at odds with the most efficient behavioral interventions known to decrease the vulnerability to both the severe forms of COVID-19 and the prevalent aging-associated diseases. To achieve a proper balance in public health approaches to COVID-19, gerontologists should be involved in crosstalk between virologists, therapists, epidemiologists, and policy makers. The present publication suggests a conceptual background for that.

Age-related mitochondrial dysfunction as a key factor in COVID-19 disease

SARS-CoV-2 causes a severe pneumonia (COVID-19) that affects essentially elderly people. In COVID-19, macrophage infiltration into the lung causes a rapid and intense cytokine storm leading finally to a multi-organ failure and death. Comorbidities such as metabolic syndrome, obesity, type 2 diabetes, lung and cardiovascular diseases, all of them age-associated diseases, increase the severity and lethality of COVID-19. Mitochondrial dysfunction is one of the hallmarks of aging and COVID-19 risk factors. Dysfunctional mitochondria is associated with defective immunological response to viral infections and chronic inflammation. This review discuss how mitochondrial dysfunction is associated with defective immune response in aging and different age-related diseases, and with many of the comorbidities associated with poor prognosis in the progression of COVID-19. We suggest here that chronic inflammation caused by mitochondrial dysfunction is responsible of the explosive release of inflammatory cytokines causing severe pneumonia, multi-organ failure and finally death in COVID-19 patients. Preventive treatments based on therapies improving mitochondrial turnover, dynamics and activity would be essential to protect against COVID-19 severity.

Effects of caloric restriction on immunosurveillance, microbiota and cancer cell phenotype: Possible implications for cancer treatment

Fasting, caloric restriction and foods or compounds mimicking the biological effects of caloric restriction, known as caloric restriction mimetics, have been associated with a lower risk of age-related diseases, including cardiovascular diseases, cancer and cognitive decline, and a longer lifespan. Reduced calorie intake has been shown to stimulate cancer immunosurveillance, reducing the migration of immunosuppressive regulatory T cells towards the tumor bulk. Autophagy stimulation via reduction of lysine acetylation, increased sensitivity to chemo- and immunotherapy, along with a reduction of insulin-like growth factor 1 and reactive oxygen species have been described as some of the major effects triggered by caloric restriction. Fasting and caloric restriction have also been shown to beneficially influence gut microbiota composition, modify host metabolism, reduce total cholesterol and triglyceride levels, lower diastolic blood pressure and elevate morning cortisol level, with beneficial modulatory effects on cardiopulmonary fitness, body fat and weight, fatigue and weakness, and general quality of life. Moreover, caloric restriction may reduce the carcinogenic and metastatic potential of cancer stem cells, which are generally considered responsible of tumor formation and relapse. Here, we reviewed in vitro and in vivo studies describing the effects of fasting, caloric restriction and some caloric restriction mimetics on immunosurveillance, gut microbiota, metabolism, and cancer stem cell growth, highlighting the molecular and cellular mechanisms underlying these effects. Additionally, studies on caloric restriction interventions in cancer patients or cancer risk subjects are discussed. Considering the promising effects associated with caloric restriction and caloric restriction mimetics, we think that controlled-randomized large clinical trials are warranted to evaluate the inclusion of these non-pharmacological approaches in clinical practice.

Special Issue "Flavonoids and Their Disease Prevention and Treatment Potential": Recent Advances and Future Perspectives

In recent years, the interest in flavonoids as dietary bioactives to prevent human diseases, as well as their candidacy as pharmaceutical leads, has exponentially expanded [...].

Cellular senescence as a potential mediator of COVID-19 severity in the elderly

SARS-CoV-2 is a novel betacoronavirus which infects the lower respiratory tract and can cause coronavirus disease 2019 (COVID-19), a complex respiratory distress syndrome. Epidemiological data show that COVID-19 has a rising mortality particularly in individuals with advanced age. Identifying a functional association between SARS-CoV-2 infection and the process of biological aging may provide a tractable avenue for therapy to prevent acute and long-term disease. Here, we discuss how cellular senescence-a state of stable growth arrest characterized by pro-inflammatory and pro-disease functions-can hypothetically be a contributor to COVID-19 pathogenesis, and a potential pharmaceutical target to alleviate disease severity. First, we define why older COVID-19 patients are more likely to accumulate high levels of cellular senescence. Second, we describe how senescent cells can contribute to an uncontrolled SARS-CoV-2-mediated cytokine storm and an excessive inflammatory reaction during the early phase of the disease. Third, we discuss the various mechanisms by which senescent cells promote tissue damage leading to lung failure and multi-tissue dysfunctions. Fourth, we argue that a high senescence burst might negatively impact on vaccine efficacy. Measuring the burst of cellular senescence could hypothetically serve as a predictor of COVID-19 severity, and targeting senescence-associated mechanisms prior and after SARS-CoV-2 infection might have the potential to limit a number of severe damages and to improve the efficacy of vaccinations.

Regulation of p27Kip1 and p57Kip2 Functions by Natural Polyphenols

In numerous instances, the fate of a single cell not only represents its peculiar outcome but also contributes to the overall status of an organism. In turn, the cell division cycle and its control strongly influence cell destiny, playing a critical role in targeting it towards a specific phenotype. Several factors participate in the control of growth, and among them, p27^Kip1 and p57^Kip2, two proteins modulating various transitions of the cell cycle, appear to play key functions. In this review, the major features of p27 and p57 will be described, focusing, in particular, on their recently identified roles not directly correlated with cell cycle modulation. Then, their possible roles as molecular effectors of polyphenols’ activities will be discussed. Polyphenols represent a large family of natural bioactive molecules that have been demonstrated to exhibit promising protective activities against several human diseases. Their use has also been proposed in association with classical therapies for improving their clinical effects and for diminishing their negative side activities. The importance of p27^Kip1 and p57^Kip2 in polyphenols’ cellular effects will be discussed with the aim of identifying novel therapeutic strategies for the treatment of important human diseases, such as cancers, characterized by an altered control of growth.

Polyphenols as Potential Agents in the Management of Temporomandibular Disorders

Temporomandibular disorders (TMD) consist of multifactorial musculoskeletal disorders associated with the muscles of mastication, temporomandibular joint (TMJ), and annexed structures. This clinical condition is characterized by temporomandibular pain, restricted mandibular movement, and TMJ synovial inflammation, resulting in reduced quality of life of affected people. Commonly, TMD management aims to reduce pain and inflammation by using pharmacologic therapies that show efficacy in pain relief but their long-term use is frequently associated with adverse effects. For this reason, the use of natural compounds as an effective alternative to conventional drugs appears extremely interesting. Indeed, polyphenols could represent a potential therapeutic strategy, related to their ability to modulate the inflammatory responses involved in TMD. The present work reviews the mechanisms underlying inflammation-related TMD, highlighting the potential role of polyphenols as a promising approach to develop innovative management of temporomandibular diseases.

Tectochrysin increases stress resistance and extends the lifespan of Caenorhabditis elegans via FOXO/DAF-16

Aging is related to the lowered overall functioning and increased risk for various age-related diseases in humans. Tectochrysin is a flavonoid compound and rich in a traditional Chinese Medicine Alpinia oxyphylla Miq., which has antioxidant, anti-inflammatory, anti-cancer, anti-bacterial, anti-diarrhea, hepatoprotective, and neuro-protective effects. Therefore, we tested if tectochrysin had an effect on aging in Caenorhabditis elegans (C. elegans). Our results showed that tectochrysin could extend the lifespan of C. elegans by up to 21.0%, delay the age-related decline of body movement, improve high temperature-stress resistance and anti-infection capacity, and protected worms against Aβ1-42-induced toxicity. Tectochrysin could not extend the lifespan of the mutants from genes daf-2, daf-16, eat-2, aak-2, skn-1, and hsf-1. Tectochrysin could increase the expression of DAF-16 regulated genes. The extension of lifespan by tectochrysin requires FOXO/DAF-16 and HSF-1. Overall, our findings suggest that tectochrysin may have a potential effect on extending lifespan and age-related diseases.