A promising strategy for investigating the anti-aging effect of natural compounds: a case study of caffeoylquinic acids

Molecular mechanism of culinary herb Artemisia argyi in promoting lifespan and stress tolerance

Artemisia argyi Lévl. et Vant. (A. argyi) leaf possesses various health promoting functions contributed by its main bioactive flavonoids. In this study, the anti-aging effect and mechanism of Artemisia argyi leaf extract (AALE) were identified using Caenorhabditis elegans (C. elegans) as a model. The results showed that the AALE promoted the lifespan and stress resistance of C. elegans. It was found that the AALE boosted the expression of oxidative stress-related proteins by regulating the insulin/ IGF-1 signaling (IIS) pathway, which then activated the transcription factors DAF-16/FOXO. The results of RNA-sequence analysis indicated that the changes of genes in nematodes treated with AALE were associated with the responses against oxidative stress, cell maturation, and immune reaction, and stress. The positive results suggest that Artemisia argyi leaf could have the robust benefits for improving healthy aging as well as preventing aging-related diseases in the human body.

Unraveling anti-aging mystery of green tea in C. elegans: Chemical truth and multiple mechanisms

Tea drinking impacts aging and aging-related diseases. However, knowledge of anti-aging molecules other than the major catechins in complex tea extracts remains limited. Here we used Caenorhabditis elegans to analyze the longevity effects of tea extracts and constituents comprehensively. We found that the hot water extract of green tea prolonged lifespan and heathspan. Further, the MeOH fraction prolonged lifespan significantly longer than other fractions. Correlation analysis between mass spectroscopic data and anti-aging activity suggests that ester-type catechins (ETCs) are the major anti-aging components, including 4 common ETCs, 6 phenylpropanoid-substituted ester-type catechins (PSECs), 5 cinnamoylated catechins (CCs), 7 ester-type flavoalkaloids (ETFs), and 4 cinnamoylated flavoalkaloids (CFs). CFs (200 μM) are the strongest anti-aging ETCs (with the longest 73% lifespan extension). Green tea hot water extracts and ETCs improved healthspan by enhancing stress resistance and reducing ROS accumulation. The mechanistic study suggests that they work by multiple pathways. Moreover, ETCs modulated gut microbial homeostasis, increased the content of short-chain fatty acids, and reduced fat content. Altogether, our study provides new evidence for the anti-aging benefits of green tea and insights into a deep understanding of the chemical truth and multi-target mechanism.

Discovery and Development of Caffeic Acid Analogs as Versatile Therapeutic Agents

Caffeic acid (CA) is a polyphenolic acid compound widely distributed in plant seeds. As natural compounds with high research interest, caffeic acid and its derivatives show good activity in the treatment of tumors and inflammation and have antibacterial properties. In recent years, caffeic acid derivatives have been studied extensively, and these derivatives fall roughly into three categories: (1) caffeic acid ester derivatives, (2) caffeic acid amide derivatives, (3) caffeic acid hybrids. These caffeic acid analogues exert mainly antibacterial and antioxidant activities. Among the caffeic acid analogues summarized in this paper, compounds 1g and CAP10 have good activity against Candida albicans, and their MIC50 is 32 µg/mL and 13 μM, respectively. In a DPPH assay, compounds 3k, 5a, CS2, Phellinsin A and 8j showed strong antioxidant activity, and their IC50 values are 18.6 μM, 67.85 μM, 40.29 μM, 0.29 ± 0.004 mM, 4774.37 ± 137.20 μM, respectively. Overall, compound CAP10 had the best antibacterial activity and compound 3k had the best antioxidant activity. This paper mainly summarizes and discusses some representative caffeic acid analogs, hoping to provide better drug design strategies for the subsequent development of caffeic acid analogs.

Agroprospecting of Biowastes: Globe Artichoke (Cynara scolymus L. Cultivar Tema, Asteraceae) as Potential Source of Bioactive Compounds

Artichokes (Cynara scolymus L.) are valuable foods, thanks to their health benefits, but they generate significant waste during their production, harvesting, and processing, which poses sustainability issues. This study applied an agroprospecting approach to convert Tema artichoke biowaste (TB) into valuable resources, starting from a global perspective of the production chain to the targeted applications based on chemical and biological analysis. The major TB was identified in the outer bracts of the immature flower heads, which were collected throughout the harvesting season, extracted, and analyzed. The most abundant compounds were phenolic acids including chlorogenic acid and caffeoylquinic derivatives. Among flavonoids, cynaroside was the most abundant compound. Multivariate analysis distinguished batches by collection period, explaining 77.7% of the variance, with most compounds increasing in concentration later in the harvest season. Subsequently, TB extracts were analyzed for their potential in wound healing and anti-aging properties. Fibroblasts were used to assess the effect of selected extracts on cell migration through a scratch wound assay and on cellular senescence induced by etoposide. The results show a significant decrease in senescence-associated β-galactosidase activity, γH2AX nuclear accumulation, and both p53 and p21 protein levels. Overall, this study ascribes relevant anti-skin aging effects to TB, thus increasing its industrial value in cosmeceutical and nutraceutical applications.

Nutritional and functional perspectives of pseudocereals

An increase in the consumption of carbohydrate-rich cereals over past few decades has led to increased metabolic disorders in population. This nutritional imbalance in diets may be corrected by substituting cereal grains with pseudocereals that are richer in high-quality proteins, dietary fibers, unsaturated fats, and bioactive compounds (e.g., polyphenols and phytosterols) as compared to cereal grains. These nutrients have been associated with numerous health benefits, such as hypolipidemic, anti-inflammatory, anti-hypertensive, anti-cancer, and hepatoprotective properties, and benefits against obesity and diabetes. In this review, the nutritional composition and health benefits of quinoa, amaranth, and buckwheat are compared against wheat, maize, and rice. Subsequently, the processing treatments applied to quinoa, amaranth, and buckwheat and their applications into food products are discussed. This is relevant since there is substantial market potential for both pseudocereals and functional foods formulated with pseudocereals. Despite clear benefits, the current progress is slowed down by the fact that the cultivation of these pseudocereals is limited to its native regions. Therefore, to meet the global needs, it is imperative to support worldwide cultivation of these nutrient-rich pseudocereals.

Astragalin from Thesium chinense: A Novel Anti-Aging and Antioxidant Agent Targeting IGFR/CD38/Sirtuins

Astragalin (AG), a typical flavonoid found in Thesium chinense Turcz (T. chinense), is abundant in various edible plants and possesses high nutritional value, as well as antioxidant and antibacterial effects. In this study, we initially predicted the mechanism of action of AG with two anti-aging and antioxidant-related protein targets (CD38 and IGFR) by molecular docking and molecular dynamics simulation techniques. Subsequently, we examined the anti-aging effects of AG in Caenorhabditis elegans (C. elegans), the antioxidant effects in zebrafish, and verified the related molecular mechanisms. In C. elegans, AG synergistically extended the lifespan of C. elegans by up-regulating the expression of daf-16 through inhibiting the expression of daf-2/IGFR and also activating the AMPK and MAPK pathways to up-regulate the expression of sir-2.1, sir-2.4, and skn-1. In oxidatively damaged zebrafish embryos, AG demonstrated a synergistic effect in augmenting the resistance of zebrafish embryos to oxidative stress by up-regulating the expression levels of SIRT1 and SIRT6 within the zebrafish embryos system via the suppression of CD38 enzymatic activity and then inhibiting the expression of IGFR through high levels of SIRT6. These findings highlight the antioxidant and anti-aging properties of AG and indicate its potential application as a supplementary ingredient in aquaculture for enhancing fish health and growth.

Paeonol promotes longevity and fitness in Caenorhabditis elegans through activating the DAF-16/FOXO and SKN-1/Nrf2 transcription factors

Paeonol, as one of the most abundant plant-derived polyphenols, has multiple bioactivities including anti-inflammatory, anti-tumor, and anti-cardiovascular diseases. Nevertheless, the anti-aging effects and related mechanisms of paeonol are rarely reported. In this study, we found that paeonol significantly prolonged the mean lifespan of Caenorhabditis elegans (C. elegans) by 28.49% at a dose of 200 μM. Moreover, paeonol promoted the health of C. elegans by increasing the body bending and pharyngeal pumping rates and reducing the lipofuscin accumulation level. Meanwhile, paeonol induced the expression of stress-related genes or proteins by activating the transcription factors DAF-16/FOXO, SKN-1/Nrf2, and HSF-1, which in turn enhanced oxidative and thermal stress tolerance. The mechanism behind the anti-aging effect of paeonol occurred by down-regulating the insulin/IGF-1 signaling (IIS) pathway. Our findings shed new light on the application of paeonol for longevity promotion and human health.

Beneficial Effects of Sideritis clandestina Extracts and Sideridiol against Amyloid β Toxicity

Alzheimer's disease (AD) is the most common form of dementia. Given the link between oxidative stress and AD, many studies focus on the identification of natural antioxidants against AD. Although their antioxidant capacity is important, increasing data suggest that additional activities are related to their beneficial effects, including properties against amyloid beta (Aβ) aggregation. Sideritis spp. (mountain tea) extracts possess not only antioxidant activity but also other bioactivities that confer neuroprotection. Although various Sideritis spp. extracts have been extensively studied, there are scarce data on S. clandestina subsp. peloponnesiaca (SCP) phytochemical composition and neuroprotective potential, while nothing is known of the responsible compounds. Given that SCP is a weaker antioxidant compared to other Sideritis spp., here, we investigated its potential beneficial properties against Aβ aggregation. We characterized different SCP extracts and revealed their anti-aggregation activity by taking advantage of established C. elegans AD models. Importantly, we identified two pure compounds, namely, sideridiol and verbascoside, being responsible for the beneficial effects. Furthermore, we have revealed a potential anti-Aβ aggregation mechanism for sideridiol. Our results support the use of mountain tea in the elderly against dementia and demonstrate the activity of sideridiol against Aβ aggregation that could be exploited for drug development.

Anti-Wrinkling Effect of 3,4,5-tri-O-caffeoylquinic Acid from the Roots of Nymphoides peltata through MAPK/AP-1, NF-κB, and Nrf2 Signaling in UVB-Irradiated HaCaT Cells

Nymphoides peltata has been widely used pharmacologically in traditional Chinese medicine to treat heat strangury and polyuria. The aim of this study was to isolate the bioactive components from N. peltata and evaluate their potential use as antioxidant and anti-wrinkle agents. Phytochemical investigation of the methanolic extract of N. peltata roots led to the isolation of 15 compounds (1-15), which were structurally determined as α-spinasterol (1), 3-O-β-D-glucopyranosyl-oleanolic acid 28-O-β-D-glucuronopyranoside (2), 4-hydroxybenzoic acid (3), protocatechuic acid (4), vanillic acid (5), p-coumaric acid (6), caffeic acid (7), ferulic acid (8), neochlorogenic acid (neo-CQA) (9), chlorogenic acid (CQA) (10), cryptochlorogenic acid (crypto-CQA) (11), isochlorogenic acid B (3,4-DCQA) (12), isochlorogenic acid A (3,5-DCQA) (13), isochlorogenic acid C (4,5-DCQA) (14), and 3,4,5-tri-O-caffeoylquinic acid (TCQA) (15). Of these 15 compounds, compound 2 was a new oleanane saponin, the chemical structure of which was characterized by 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data and high-resolution electrospray ionization mass spectrometry (HRESIMS), as well as chemical reaction. Biological evaluation of the isolated compounds revealed that 3,4,5-tri-O-caffeoylquinic acid (TCQA) significantly improved Nrf2 levels in an Nrf2-ARE reporter HaCaT cell screening assay. TCQA was found to potently inhibit the Nrf2/HO-1 pathway and to possess strong anti-wrinkle activity by modulating the MAPK/NF-κB/AP-1 signaling pathway and thus inhibiting MMP-1 synthesis in HaCaT cells exposed to UVB. Our results suggest that TCQA isolated from N. peltata might be useful for developing effective antioxidant and anti-wrinkle agents.

Effect of dietary restriction on health span in Caenorhabditis elegans: A systematic review

Dietary restriction (DR) interventions have demonstrated their efficacy in extending lifespan; however, the association between lifespan extension and health span remains unclear. This article aims to analyze the relationship between DR-induced lifespan and health span in Caenorhabditis elegans (C. elegans), a widely used animal model in lifespan studies. By examining various parameters such as lipofuscin accumulation (an aging marker) and locomotor and feeding capacities (indicators of muscle degradation rate), we have compiled papers that investigate and report on these DR-induced effects.The majority of the papers reviewed consistently demonstrate that DR improves both lifespan and health span in C. elegans. Worms subjected to DR exhibit slower lipofuscin accumulation compared to those fed ad libitum, indicating a reduction in age-related cellular damage. Additionally, DR-treated worms display a higher locomotion capacity, suggesting a slower rate of muscle degradation. However, it is worth noting that there are some discrepancies among the papers regarding feeding capacity. These contradictions can be attributed to the different methods employed to initiate DR. While many approaches slow muscle degeneration and enhance pumping rates through adaptation to limited food sources, other methods, such as using eat-2 mutant worms or interventions that mimic the effects of eat-2, reduce feeding capacity and consequently restrict food intake. In conclusion, the findings suggest a strong correlation between DR-induced longevity and the extension of health span in C. elegans, as evidenced by improvements in various health span parameters. DR interventions not only extend lifespan but also mitigate age-related markers and preserve locomotor capacity. Although conflicting results are observed regarding feeding capacity, the overall evidence supports the notion that DR promotes healthier aging in this animal model.

3,5-diCQA suppresses colorectal cancer cell growth through ROS/AMPK/mTOR mediated mitochondrial dysfunction and ferroptosis

3,5-diCQA has been shown to have anti-tumor effect by decreasing cancer cell growth. However, the molecular mechanism by which 3,5-diCQA impacts colorectal cancer (CRC) cells is unknown. This study discovered that 3,5-diCQA had a suppressive effect on CRC cells, mainly in the inhibition of proliferation, migration, and the enhancement of apoptosis in HCT116 and SW480 cells. Additionally, 3,5-diCQA was found to cause cell cycle arrest in CRC cells. Meanwhile, we found that 3,5-diCQA activates the AMPK pathway through the generation of ROS, mediates mitochondrial damage, and reduces mitochondrial aerobic glycolysis and oxidative phosphorylation levels. 3,5-diCQA promoted oxidative damage and ferroptosis in CRC cells. Hence, we added ROS inhibitor NAC and found that the NAC reversed the effects of 3,5-diCQA on proliferation, apoptosis, ROS generation, and ferroptosis in CRC cells. Moreover, 3,5-diCQA was also shown to suppress the development of CRC tumor in a tumor-forming model of nude mice. In conclusion, we found that 3,5-diCQA enhances the oxidative damage and ferroptosis while reducing proliferation and migration of CRC cells, depending on mitochondrial dysfunction caused by the ROS/AMPK/mTOR pathway.

A Multilevel Study of Eupatorin and Scutellarein as Anti-Amyloid Agents in Alzheimer's Disease

Today, Alzheimer's disease (AD)-the most common neurodegenerative disorder, which affects 50 million people-remains incurable. Several studies suggest that one of the main pathological hallmarks of AD is the accumulation of abnormal amyloid beta (Aβ) aggregates; therefore, many therapeutic approaches focus on anti-Aβ aggregation inhibitors. Taking into consideration that plant-derived secondary metabolites seem to have neuroprotective effects, we attempted to assess the effects of two flavones-eupatorin and scutellarein-on the amyloidogenesis of Aβ peptides. Biophysical experimental methods were employed to inspect the aggregation process of Aβ after its incubation with each natural product, while we monitored their interactions with the oligomerized Aβ through molecular dynamics simulations. More importantly, we validated our in vitro and in silico results in a multicellular organismal model-namely, Caenorhabditis elegans-and we concluded that eupatorin is indeed able to delay the amyloidogenesis of Aβ peptides in a concentration-dependent manner. Finally, we propose that further investigation could lead to the exploitation of eupatorin or its analogues as potential drug candidates.

Health-Promoting Activities and Associated Mechanisms of Polygonati Rhizoma Polysaccharides

Polygonati Rhizoma, a typical homology of medicine and food, possesses remarkable anti-fatigue, anti-aging, metabolic regulatory, immunomodulatory, anti-inflammatory, neuroprotective, anti-diabetes, and anti-cancer effects. Among bioactive phytochemicals in Polygonati Rhizoma, polysaccharides play important roles in the health-promoting activities through the mechanisms mentioned above and potential synergistic effects with other bioactives. In this review, we briefly introduce the updated biosynthesis of polysaccharides, the purification method, the structure characterization, and food applications, and discuss in detail the biological activities of Polygonati Rhizoma polysaccharides and associated mechanisms, aiming at broadening the usage of Polygonati Rhizoma as functional food and medicine.

Healthspan improvement and anti-aggregation effects induced by a marine-derived structural proteasome activator

Proteasome activation has been shown to promote cellular and organismal healthspan and to protect against aggregation-related conditions, such as Alzheimer's disease (AD). Various natural compounds have been described for their proteasome activating properties but scarce data exist on marine metabolites that often possess unique chemical structures, exhibiting pronounced bioactivities with novel mechanisms of action. In this study, we have identified for the first time a marine structural proteasome activator, namely (1R,3E,6R,7Z,11S,12S)-dolabella-3,7,18-trien-6,17-olide (DBTO). DBTO activates the 20S proteasome complex in cell-free assays but also in cellulo. Continuous supplementation of human primary fibroblasts with DBTO throughout their cellular lifespan confers an improved healthspan while ameliorated health status is also observed in wild type (wt) Caenorhabditis elegans (C. elegans) nematodes supplemented with DBTO. Furthermore, treatment of various AD nematode models, as well as of human cells of neuronal origin challenged with exogenously added Aβ peptide, with DBTO results in enhanced protection against Aβ-induced proteotoxicity. In total, our results reveal the first structural proteasome activator derived from the marine ecosystem and highlight its potential as a compound that might be used for healthspan maintenance and preventive strategies against proteinopathies, such as AD.

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(1R,3E,6R,7Z,11S,12S)-dolabella-3,7,18-trien-6,17-olide (DBTO) is a structural proteasome activator.

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DBTO is the first identified marine structural proteasome activator.

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DBTO positively modulates cellular healthspan and organismal health status.

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DBTO confers protection against Aβ-induced proteotoxicity.

Two new catechins from Zijuan green tea enhance the fitness and lifespan of Caenorhabditis elegans via insulin-like signaling pathways

Green tea polyphenols show positive effects on human health and longevity. However, knowledge of the antiaging properties of green tea is limited to the major catechin epigallocatechin gallate (EGCG). The search for new ingredients in tea with strong antiaging activity deserves further study. Here we isolated and identified two new catechins from Zijuan green tea, named zijuanin E (1) and zijuanin F (2). Their structures were identified by extensive high-resolution mass spectroscopy (HR-MS), nuclear magnetic resonance (NMR), ultraviolet-vis (UV), infrared (IR) and circular dichroism (CD) spectroscopic analyses, and their ¹³C NMR and CD data were calculated. We used the nematode Caenorhabditis elegans (C. elegans) to analyze the health benefits and longevity effects of 1 and 2. Compounds 1 and 2 (100 μM) remarkably prolonged the lifespan of C. elegans by 67.2% and 56.0%, respectively, delaying the age-related decline of phenotypes, enhancing stress resistance, and reducing ROS and lipid accumulation. Furthermore, 1 and 2 did not affect the lifespan of daf-16, daf-2, sir-2.1, and skn-1 mutant worms, suggesting that they might work via the insulin/IGF and SKN-1/Nrf2 signaling pathways. Meanwhile, 1 and 2 also exhibited strong antioxidant activity in vitro. Surface plasmon resonance (SPR) evidence suggests that zijuanins E and F have strong human serum albumin (HSA) binding ability. Together, zijuanins E and F represent a new valuable class of tea components that promote healthspan and could be developed as potential dietary therapies against aging.

Vitexin and Isovitexin Act Through Inhibition of Insulin Receptor to Promote Longevity and Fitness in Caenorhabditis elegans

SCOPE

Vitexin and isovitexin are natural plant nutraceuticals for human health and longevity. This research investigated the underlying mechanism of vitexin and isovitexin on aging and health. The vital role of DAF-2/IGFR was illustrated in the insulin/insulin-like growth signaling pathway (IIS) modulated by vitexin and isovitexin.

METHODS AND RESULTS

In vitro, in vivo models and molecular docking methods were performed to explore the antiaging mechanism of vitexin and isovitexin. Vitexin and isovitexin (50 and 100 μM) extended the lifespan of C. elegans. The declines of pharyngeal pumping and body bending rates, and the increase of intestinal lipofuscin accumulation, three markers of aging, were postponed by vitexin and isovitexin. These compounds inhibited the IIS pathway in a daf-16-dependent manner, subsequently increasing the expression of DAF-16 downstream proteins and genes in nematodes. Molecular docking studies demonstrated that these compounds might inhibit insulin signal transduction by binding to the crucial amino acid residue ARG1003 in the pocket of the insulin-like growth factor-1 receptor (IGFR). Western blot indicated that IGFR, PI3K and AKT kinase expressions in senescent cells is decreased after vitexin and isovitexin treatment.

CONCLUSION

Vitexin and isovitexin might inhibit IIS pathway by occupying the ATP-binding site pocket of IGFR, subsequently decreasing IGFR expression, thereby promoting longevity and fitness. This article is protected by copyright. All rights reserved.

Oxidation and Antioxidation of Natural Products in the Model Organism Caenorhabditiselegans

Natural products are small molecules naturally produced by multiple sources such as plants, animals, fungi, bacteria and archaea. They exert both beneficial and detrimental effects by modulating biological targets and pathways involved in oxidative stress and antioxidant response. Natural products’ oxidative or antioxidative properties are usually investigated in preclinical experimental models, including virtual computing simulations, cell and tissue cultures, rodent and nonhuman primate animal models, and human studies. Due to the renewal of the concept of experimental animals, especially the popularization of alternative 3R methods for reduction, replacement and refinement, many assessment experiments have been carried out in new alternative models. The model organism Caenorhabditis elegans has been used for medical research since Sydney Brenner revealed its genetics in 1974 and has been introduced into pharmacology and toxicology in the past two decades. The data from C. elegans have been satisfactorily correlated with traditional experimental models. In this review, we summarize the advantages of C. elegans in assessing oxidative and antioxidative properties of natural products and introduce methods to construct an oxidative damage model in C. elegans. The biomarkers and signaling pathways involved in the oxidative stress of C. elegans are summarized, as well as the oxidation and antioxidation in target organs of the muscle, nervous, digestive and reproductive systems. This review provides an overview of the oxidative and antioxidative properties of natural products based on the model organism C. elegans.