Anti-aging effects of Ribes meyeri anthocyanins on neural stem cells and aging mice

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

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

Therapeutic Effects of Plant Anthocyanin against Alzheimer's Disease and Modulate Gut Health, Short-Chain Fatty Acids

Alzheimer's disease (AD) is the most common form of dementia and neurogenerative disease (NDD), and it is also one of the leading causes of death worldwide. The number of AD patients is over 55 million according to 2020 Alzheimer's Disease International (ADI), and the number is increasing drastically without any effective cure. In this review, we discuss and analyze the potential role of anthocyanins (ACNs) against AD while understanding the molecular mechanisms. ACNs have been reported as having neuroprotective effects by mitigating cognitive impairments, apoptotic markers, neuroinflammation, aberrant amyloidogenesis, and tauopathy. Taken together, ACNs could be an important therapeutic agent for combating or delaying the onset of AD.

Therapeutic effect of dietary ingredients on cellular senescence in animals and humans: A systematic review

BACKGROUND

Cellular senescence has been regarded as a therapeutic target for ageing and age-related diseases. Several senotherapeutic agents have been proposed, including compounds derived from natural products which hold the translational potential to promote healthy ageing. This systematic review examined the association of dietary ingredients with cellular senescence in animals and humans, with an intent to identify dietary ingredients with senotherapeutic potential.

METHODS

This systematic review was registered at PROSPERO International prospective register of systematic reviews (Reg #: CRD42022338885). The databases PubMed and Embase were systematically searched for key terms related to cellular senescence, senescence markers, diets, nutrients and bioactive compounds. Intervention and observational studies on human and animals investigating the effects of dietary ingredients via oral administration on cellular senescence load were included. The SYRCLE's risk of bias tool and Cochrane risk of bias tool v2.0 were used to assess the risk of bias for animal and human studies respectively.

RESULTS

Out of 5707 identified articles, 83 articles consisting of 78 animal studies and 5 human studies aimed to reduce cellular senescence load using dietary ingredients. In animal studies, the most-frequently used senescence model was normative ageing (26 studies), followed by D-galactose-induced models (17 studies). Resveratrol (8 studies), vitamin E (4 studies) and soy protein isolate (3 studies) showed positive effects on reducing the level of senescence markers such as p53, p21, p16 and senescence-associated ß-galactosidase in various tissues of physiological systems. In three out of five human studies, ginsenoside Rg1 had no positive effect on reducing senescence in muscle tissues after exercise. The risk of bias for both animal and human studies was largely unclear.

CONCLUSION

Resveratrol, vitamin E and soy protein isolate are promising senotherapeutics studied in animal models. Studies testing dietary ingredients with senotherapeutic potential in humans are limited and translation is highly warranted.

An Integrated Strategy for Investigating Antioxidants from Ribes himalense Royle ex Decne and Their Potential Target Proteins

Natural products have been used extensively around the world for many years as therapeutic, prophylactic, and health-promotive agents. Ribes himalense Royle ex Decne, a plant used in traditional Tibetan medicine, has been demonstrated to have significant antioxidant and anti-inflammatory properties. However, the material basis of its medicinal effects has not been sufficiently explored. In this study, we established an integrated strategy by online HPLC-1,1-diphenyl-2-picrylhydrazyl, medium-pressure liquid chromatography, and HPLC to achieve online detection and separation of antioxidants in Ribes himalense extracts. Finally, four antioxidants with quercetin as the parent nucleus were obtained, namely, Quercetin-3-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside, Quercetin-3-O-β-D-xylopyranosyl(1-2)-β-D-glucopyranoside, Quercetin-3-O-β-D-glucopyranoside, and Quercetin-3-O-β-D-galactoside. Until now, the four antioxidants in Ribes himalense have not been reported in other literatures. Meanwhile, the free-radical-scavenging ability of them was evaluated by DPPH assay, and potential antioxidant target proteins were explored using molecular docking. In conclusion, this research provides insights into the active compounds in Ribes himalense which will facilitate the advancement of deeper studies on it. Moreover, such an integrated chromatographic strategy could be a strong driver for more efficient and scientific use of other natural products in the food and pharmaceutical industries.

Dietary Flavonoids and Adult Neurogenesis: Potential Implications for Brain Aging

Adult neurogenesis deficiency has been proposed to be a common hallmark in different age-related neurodegenerative diseases. The administration of flavonoids is currently reported as a potentially beneficial strategy for preventing brain aging alterations, including adult neurogenesis decline. Flavonoids are a class of plant-derived dietary polyphenols that have drawn attention for their neuroprotective and pro-cognitive effects. Although they undergo extensive metabolism and localize in the brain at low concentrations, flavonoids are now believed to improve cerebral vasculature and interact with signal transduction cascades involved in the regulation of adult neurogenesis. Furthermore, many dietary flavonoids have been shown to reduce oxidative stress and neuroinflammation, improving the neuronal microenvironment where adult neurogenesis occurs. The overall goal of this review is to summarize the evidence supporting the role of flavonoids in modulating adult neurogenesis as well as to highlight how these dietary agents may be promising candidates in restoring healthy brain function during physiological and pathological aging.

Nutritional components as mitigators of cellular senescence in organismal aging: a comprehensive review

The process of cellular senescence is rapidly emerging as a modulator of organismal aging and disease. Targeting the development and removal of senescent cells is considered a viable approach to achieving improved organismal healthspan and lifespan. Nutrition and health are intimately linked and an appropriate dietary regimen can greatly impact organismal response to stress and diseases including during aging. With a renewed focus on cellular senescence, emerging studies demonstrate that both primary and secondary nutritional elements such as carbohydrates, proteins, fatty acids, vitamins, minerals, polyphenols, and probiotics can influence multiple aspects of cellular senescence. The present review describes the recent molecular aspects of cellular senescence-mediated understanding of aging and then studies available evidence of the cellular senescence modulatory attributes of major and minor dietary elements. Underlying pathways and future research directions are deliberated to promote a nutrition-centric approach for targeting cellular senescence and thus improving human health and longevity.

The Potential Roles of Dietary Anthocyanins in Inhibiting Vascular Endothelial Cell Senescence and Preventing Cardiovascular Diseases

Cardiovascular disease (CVD) is a group of diseases affecting the heart and blood vessels and is the leading cause of morbidity and mortality worldwide. Increasingly more evidence has shown that the senescence of vascular endothelial cells is the key to endothelial dysfunction and cardiovascular diseases. Anthocyanin is a type of water-soluble polyphenol pigment and secondary metabolite of plant-based food widely existing in fruits and vegetables. The gut microbiome is involved in the metabolism of anthocyanins and mediates the biological activities of anthocyanins and their metabolites, while anthocyanins also regulate the growth of specific bacteria in the microbiota and promote the proliferation of healthy anaerobic flora. Accumulating studies have shown that anthocyanins have antioxidant, anti-inflammatory, and anti-aging effects. Many animal and in vitro experiments have also proven that anthocyanins have protective effects on cardiovascular-disease-related dysfunction. However, the molecular mechanism of anthocyanin in eliminating aging endothelial cells and preventing cardiovascular diseases is very complex and is not fully understood. In this systematic review, we summarize the metabolism and activities of anthocyanins, as well as their effects on scavenging senescent cells and cardioprotection.

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

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

A geroscience motivated approach to treat Alzheimer's disease: Senolytics move to clinical trials

The pathogenic processes driving Alzheimer's disease (AD) are complex. An incomplete understanding of underlying disease mechanisms has presented insurmountable obstacles for developing effective disease-modifying therapies. Advanced chronological age is the greatest risk factor for developing AD. Intervening on biological aging may alter disease progression and represents a novel, complementary approach to current strategies. Toward this end, cellular senescence has emerged as a promising target. This complex stress response harbors damaged cells in a cell cycle arrested, apoptosis-resistant cell state. Senescent cells accumulate with age where they notoriously secrete molecules that contribute to chronic tissue dysfunction and disease. Thus, benefits of cell survival in a senescent fate are countered by their toxic secretome. The removal of senescent cells improves brain structure and function in rodent models at risk of developing AD, and in those with advanced Aβ and tau pathology. The present review describes the path to translating this promising treatment strategy to AD clinical trials. We review evidence for senescent cell accumulation in the human brain, considerations and strategies for senescence-targeting trials specific to AD, approaches to detect senescent brain cells in biofluids, and summarize the goals of the first senolytic trials for the treatment of AD (NCT04063124 and NCT04685590). This article is part of the Special Issue - Senolytics - Edited by Joao Passos and Diana Jurk.

Genus Ribes Linn. (Grossulariaceae): A comprehensive review of traditional uses, phytochemistry, pharmacology and clinical applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Ribes Linn., which belongs to the Grossulariaceae family, contains 160 species distributed mainly in temperate and cold regions of the Northern Hemisphere. There are 59 species in southwest, northwest and northeast China. Some species of Ribes have been used as traditional and local medicines for the treatment of glaucoma, cardiovascular disease, stomachache, hepatitis, hyperlipidemia, hypertension and other ailments. However, the data provided in recent years have not been collated and compared.

AIM OF THE STUDY

This review aims to summarize the current status of ethnopharmacological uses, phytochemistry, pharmacology, clinical applications, and pharmacokinetics of the genus Ribes to better understand the therapeutic potential of the genus Ribes in the future and hope to provide a relatively novel perspective for further clinical application on the genus.

MATERIALS AND METHODS

The literature on Ribes was collected through a series of scientific search engines including Elsevier, ACS, Springer, Web of Science, PubMed, Google Scholar, Baidu Scholar, Wiley, China National Knowledge Infrastructure (CNKI) and books.

RESULTS

Ribes species have been used for detoxification, glaucoma, cardiovascular disease, stomachache, hepatitis, hyperlipidemia, hypertension and other ailments. These plants mainly contain phenolic glycosides, flavonoids, proanthocyanidins, polysaccharides, etc. Most traditional uses are related to biological activity and have been confirmed by modern research. Pharmacological studies in vitro and in vivo revealed that the extracts and pure compounds possessed significant hypolipidemic, antioxidant, anti-inflammatory, antitumor, antibacterial, and antiviral activity, eyesight protection and other effects.

CONCLUSIONS

The traditional uses, phytochemistry, pharmacology, pharmacokinetics, and clinical applications described in this article explained that the Ribes species has numerous activities, and these findings will promote further action in the area of mechanism research. However, very few preclinical and clinical studies have focused on the toxicology and pharmacokinetics of crude extracts and pure compounds from the genus Ribes. Moreover, several clinical evidence to support the health benefits of Ribes plants. The development of new medicines based on Ribes species as ingredients may be restricted. The pharmacological activity, clinical efficacy and safety of Ribes species need to be verified by systematic and comprehensive preclinical studies and clinical trials.

Targeting Inflammation by Anthocyanins as the Novel Therapeutic Potential for Chronic Diseases: An Update

Low-grade chronic inflammation (LGCI) and oxidative stress act as cooperative and synergistic partners in the pathogenesis of a wide variety of diseases. Polyphenols, including anthocyanins, are involved in regulating the inflammatory state and activating the endogenous antioxidant defenses. Anthocyanins' effects on inflammatory markers are promising and may have the potential to exert an anti-inflammatory effect in vitro and in vivo. Therefore, translating these research findings into clinical practice would effectively contribute to the prevention and treatment of chronic disease. The present narrative review summarizes the results of clinical studies from the last 5 years in the context of the anti-inflammatory and anti-oxidative role of anthocyanins in both health and disease. There is evidence to indicate that anthocyanins supplementation in the regulation of pro-inflammatory markers among the healthy and chronic disease population. Although the inconsistencies between the result of randomized control trials (RCTs) and meta-analyses were also observed. Regarding anthocyanins' effects on inflammatory markers, there is a need for long-term clinical trials allowing for the quantifiable progression of inflammation. The present review can help clinicians and other health care professionals understand the importance of anthocyanins use in patients with chronic diseases.

Evidence of the Cellular Senescence Stress Response in Mitotically Active Brain Cells-Implications for Cancer and Neurodegeneration

Cellular stress responses influence cell fate decisions. Apoptosis and proliferation represent opposing reactions to cellular stress or damage and may influence distinct health outcomes. Clinical and epidemiological studies consistently report inverse comorbidities between age-associated neurodegenerative diseases and cancer. This review discusses how one particular stress response, cellular senescence, may contribute to this inverse correlation. In mitotically competent cells, senescence is favorable over uncontrolled proliferation, i.e., cancer. However, senescent cells notoriously secrete deleterious molecules that drive disease, dysfunction and degeneration in surrounding tissue. In recent years, senescent cells have emerged as unexpected mediators of neurodegenerative diseases. The present review uses pre-defined criteria to evaluate evidence of cellular senescence in mitotically competent brain cells, highlights the discovery of novel molecular regulators and discusses how this single cell fate decision impacts cancer and degeneration in the brain. We also underscore methodological considerations required to appropriately evaluate the cellular senescence stress response in the brain.

Preparative isolation of 1,1-diphenyl-2-picrylhydrazyl inhibitors from Ribes himalense using medium-pressure and two-dimensional reversed-phase/reversed-phase liquid chromatography guided by an online HPLC-1, 1-diphenyl-2-picrylhydrazyl assay

The lack of suitable chromatographic purification methods makes it a challenge to effectively isolate the chemical components of traditional Tibetan medicines. Ribes himalense is a rarely studied Tibetan medicine, reputed to have free radical-scavenging effects. In the present work, we utilized it as a model herb to highlight an approach for the separation of 1,1-diphenyl-2-picrylhydrazyl inhibitors via medium-pressure chromatography and two-dimensional reversed-phase/reversed-phase interaction liquid chromatography under the guidance of an online high-performance liquid chromatography-1,1-diphenyl-2-picrylhydrazyl assay. Finally, we obtained two free radical inhibitors (>95% purity) from the R. himalense extract. This is the first report of the rapid isolation of these free radical inhibitors from R. himalense. This method can be useful in quality standard assessment and further pharmacological activity research, and may be used as a reference for the composition research of various natural products.

Flavonoids as a Natural Enhancer of Neuroplasticity-An Overview of the Mechanism of Neurorestorative Action

Neuroplasticity is a complex physiological process occurring in the brain for its entire life. However, it is of particular importance in the case of central nervous system (CNS) disorders. Neurological recovery largely depends on the ability to reestablish the structural and functional organization of neurovascular networks, which must be pharmacologically supported. For this reason, new forms of therapy are constantly being sought. Including adjuvant therapies in standard treatment may support the enhancement of repair processes and restore impaired brain functions. The common hallmark of nerve tissue damage is increased by oxidative stress and inflammation. Thus, the studies on flavonoids with strong antioxidant and anti-inflammatory properties as a potential application in neuro intervention have been carried out for a long time. However, recent results have revealed another important property of these compounds in CNS therapy. Flavonoids possess neuroprotective activity, and promote synaptogenesis and neurogenesis, by, among other means, inhibiting oxidative stress and neuroinflammation. This paper presents an overview of the latest knowledge on the impact of flavonoids on the plasticity processes of the brain, taking into account the molecular basis of their activity.