Current Aging Science - Current Issue

Our group at Yuvan Research has conducted several experiments in recent years that have demonstrated the reversibility of aging through the use of a young plasma fraction, following a historical line of research that began with heterochronic parabiosis. However, a one-of-a-kind discovery, in the form of anecdotal evidence, has recently clarified many doubts about the nature of aging and rejuvenation, and the conclusions that can be drawn from this discovery allow us to form a relatively clear picture of the mechanics of the aging and rejuvenation processes.

The natural process of skin aging is influenced by a variety of factors, including oxidative stress, inflammation, collagen degradation, and UV radiation exposure. The potential of polyphenols in controlling skin aging has been the subject of much investigation throughout the years. Due to their complex molecular pathways, polyphenols, a broad class of bioactive substances present in large quantities in plants, have emerged as attractive candidates for skin anti-aging therapies. This review aims to provide a comprehensive overview of the molecular mechanisms through which polyphenols exert their anti-aging effects on the skin. Various chemical mechanisms contribute to reducing skin aging signs and maintaining a vibrant appearance. These mechanisms include UV protection, moisturization, hydration, stimulation of collagen synthesis, antioxidant activity, and anti-inflammatory actions. These mechanisms work together to reduce signs of aging and keep the skin looking youthful. Polyphenols, with their antioxidant properties, are particularly noteworthy. They can neutralize free radicals, lessening oxidative stress that might otherwise cause collagen breakdown and DNA damage. The anti-inflammatory effects of polyphenols are explored, focusing on their ability to suppress pro-inflammatory cytokines and enzymes, thereby alleviating inflammation and its detrimental effects on the skin. Understanding these mechanisms can guide future research and development, leading to the development of innovative polyphenol-based strategies for maintaining healthy skin.

Ageing is the most significant risk factor for a number of non-communicable diseases, manifesting as cognitive, metabolic, and cardiovascular diseases. Although multifactorial, mitochondrial dysfunction and oxidative stress have been proposed to be the driving forces of ageing. Peroxisome proliferator-activated receptor γ coactivator α (PGC-1α) is a transcriptional coactivator central to various metabolic functions, of which mitochondrial biogenesis is the most prominent function. Inducible by various stimuli, including nutrient limitations, PGC-1α is a molecule of interest in the maintenance of mitochondrial function and, therefore, the prevention of degenerative diseases. This review involves a literature search for articles retrieved from PubMed using PGC-1α, ageing, and dietary restriction as keywords. Dietary restriction has been shown to promote tissue-specific PGC-1α expression. Both dietary restriction and PGC-1α upregulation have been shown to prolong the lifespans of both lower and higher-level organisms; the incidence of non-communicable diseases also decreased in fasting mammals. In conclusion, dietary interventions may delay ageing by regulating healthy mitochondria in various organs, presenting the possibility of a new primary prevention for many age-related diseases.

Neurodegenerative diseases, such as Alzheimer's, Parkinson's, and prion disease, are characterized by the conversion of normally soluble proteins or peptides into aggregated amyloidal fibrils. These diseases result in the permanent loss of specific types of neurons, making them incurable and devastating. Research on animal models of memory problems mentioned in this article contributes to our knowledge of brain health and functionality. Neurodegenerative disorders, which often lead to cognitive impairment and dementia, are becoming more prevalent as global life expectancy increases. These diseases cause severe neurological impairment and neuronal death, making them highly debilitating. Exploring and understanding these complex diseases offer significant insights into the fundamental processes essential for maintaining brain health. Exploring the intricate mechanisms underlying neurodegenerative diseases not only holds promise for potential treatments but also enhances our understanding of fundamental brain health and functionality. By unraveling the complexities of these disorders, researchers can pave the way for advancements in diagnosis, treatment, and ultimately, improving the lives of individuals affected by neurodegenerative diseases.

Background: Chlorpyrifos (CPF) is an organophosphate pesticide that inhibits acetylcholinesterase (AChE) activity. Investigations have also focused on its neurotoxicity, which is independent of AChE inhibition. Here, we evaluated the effect of CPF on oxidative indices in the brain tissue and explored the protective effect of curcumin (Cur) against its toxicity. Methods: Forty male Wistar rats were divided into five groups, each consisting of eight rats (n = 8) per group. Animals were administrated by oral gavage for 90 days with the following treatments: control (C), CPF, CPF + CUR 25 mg/kg, CPF + CUR50, and CPF + cur 100 received olive oil, CPF, CPF plus 25 mg/kg of CUR, CPF plus 50 mg/kg of CUR, and CPF plus 100 mg/kg of CUR, respectively. After anesthetization, animal brain tissues were obtained for assessment of oxidative stress indices. Results: The concentration of MDA significantly increased in the brains of the CPF group as compared to the control group (p < 0.01). Also, a significant decrease in MDA concentrations was observed in the brains of rats in the CPF + Cur 100 group compared to the CPF group (p < 0.05). A significant decrease was noted in the GSH concentration in the brains of the CPF group compared to the control group (p < 0.05). Treatment with Cur at 100 mg/kg exhibited a significant increase in GSH concentrations in the brains of the CPF-exposed group compared to the CPF group without Cur administration (p < 0.05). The concentration of NO exhibited a significant increase in the brains of the CPF group when compared to the control group (p < 0.05). Also, a significant decrease in NO concentration was observed in the brain tissue of the CPF + Cur 100 group compared to the CPF group (p < 0.05). Conclusion: Our data establish that chronic exposure to CPF induced oxidative stress in brain tissue, which was reversed by CUR administration. Additional experimental and clinical investigations are needed to validate the efficacy of CUR as a potential antidote for CPF poisoning.

Background: Loss of functional capacity negatively impacts the quality of life in older adults. Objective: This single-site randomized controlled study examined whether short- (one week) and long-term (three months) blackcurrant supplementations combined with habitual physical activity would improve functional capacity and quality of life in previously sedentary older women. Methods: Thirty sedentary, healthy older women were randomly assigned to receive blackcurrant supplementation (400 mg of blackcurrant extract) (Polyphenol group, n=15; 74.2±10.0 years) or no supplementation (capsules of 400 mg of corn flour) (Placebo group, n=15; 72.8±8.7 years). Each group consumed two capsules daily for one week and three months, with a washout period of one week between the two phases. The polyphenol group was required to increase habitual activity levels. Participants underwent a functional capacity assessment consisting of a sixminute walk, sit-to-stand test, Berg balance scale measurement and quality of life evaluation with the Scale of Life Satisfaction Index (LSI) at the start, after one week, and after three months of supplementation. Results: Walking distance and time to sit-to-stand improved by 2.5% (p=0.005) and 7.5% (p=0.005), respectively, after one week in the polyphenol group. After 3 months, walking distance in the six-minute walk test increased by 12.3% (p=0.001) while the time to sit-to-stand decreased by 16% (p=0.002) in the polyphenol compared to placebo group, respectively. No differences in Berg balance scale were observed. Quality of life, indexed by LSI, improved by 39% (p=0.001) in the polyphenol compared to the placebo group. Conclusion: Blackcurrant supplementation, combined with habitual activity, may enhance functional capacity and quality of life in older women, offering a potential strategy to maintain independence. However, future studies should address longer durations to validate these findings.

Background: Excessive manganese exposure can lead to neurotoxicity with detrimental effects on the brain. Neuroinflammatory responses and redox regulation play pivotal roles in this process. Exploring the impact of hyperoside in a Wistar rat model offers insights into potential neuroprotective strategies against manganese-induced neurotoxicity. Objective: The study investigated the neuroprotective efficacy of hyperoside isolated from the ethanol leaf extract of Gongronema latifolium (HELEGL), in the brain tissue of Wistar rats following 15 consecutive days of exposure to 30 mg/L of MnCl2. Methods: Control animals in Group 1 had access to regular drinking water, while animals in groups 2-4 were exposed to MnCl2 in their drinking water. Groups 3 and 4 also received additional HELEGL at doses of 100 mg/kg and 200 mg/kg of body weight, respectively. In Group 5, HELEGL at a dose of 100 mg/kg of body weight was administered alone. Treatment with HELEGL commenced on day 8 via oral administration. Results: HELEGL effectively mitigated MnCl2-induced memory impairment, organ-body weight discrepancies, and fluid intake deficits. Exposure to MnCl2 increased the activities or levels of various markers such as acyl peptide hydrolase, tumour necrosis factor-α, dipeptidyl peptidase IV, nitric oxide, IL-1β, prolyl oligopeptidase, caspase-3, myeloperoxidase, H2O2, and malondialdehyde, while it decreased the activities or levels of others, including AChE, BChE, DOPA, serotonin, epinephrine, norepinephrine, GST, GPx, CAT, SOD, GSH, and T-SH (p < 0.05). In contrast, HELEGL effectively counteracted the adverse effects of MnCl2 by alleviating oxidative stress, inflammation, apoptosis, mitochondrial dysfunction, cognitive deficits, and bolstering the antioxidant status. Moreover, HELEGL restored the normal histoarchitecture of the brain, which had been distorted by MnCl2. Conclusion: In summary, HELEGL reversed the causative factors of neurodegenerative diseases induced by MnCl2 exposure, suggesting its potential for further exploration as a prospective therapeutic agent in the management of Alzheimer's disease and related forms of dementia.

Background: Dizziness and balance disorders are directly related to aging in humans- Dizziness is one of the most important factors causing the burden of disability after the age of 65. Bearing in mind the increase in the elderly population in Iran and the world and the prevalence of dizziness in old age, early diagnosis of dizziness and determination of the factors affecting its severity facilitate its treatment and are effective in preventing its adverse consequences. Objective: To determine the prevalence of dizziness and its related factors among older adults in Ardakan city, Yazd province, Iran, in 2022. Methods: This cross-sectional study was conducted in four comprehensive health centers of Ardakan city with the participation of 260 elderly people aged ≥60 years, who were randomly included in the study. Data were collected using a series of questionnaires which were completed by interviewing the participants. The variables of this study included demographic information, information related to the dizziness status, diseases, medications, use of mobility aids, physical activity level, fear of falling, quality of life and depression. Results: The prevalence of dizziness among older adults of Ardakan city was 48.5%. In terms of the severity of dizziness, 38.8% had substantial dizziness, and 9.6% had mild dizziness. Dizziness was significantly related to physical activity (p<0.05), fear of falling (p <0.01), depression (p <0.05), history of falling (p <0.01), use of mobility aids (p <0.01), age (p<0.01), education level (p<0.01), gender (p <0.05) and diseases such as high blood pressure (p<0.05), hypothyroidism (p <0.01) and ear diseases(p <0.01). Also, elderly people with dizziness used significantly more medications such as sedatives (p<0.01), antihypertensive drugs (p <0.05) and cytotoxic drugs (p <0.01). Conclusion: About half of the older adults experience dizziness, and this problem is associated with depression, fear of falling, history of falling, low physical activity, age, female gender, ear diseases, high blood pressure, and hypothyroidism. In addition, the use of medications such as anti- hypertensives, sedatives and cytotoxic drugs is related to dizziness. Families with elderly people, doctors and healthcare workers need to be educated and pay more attention to the above.

Introduction: The purpose of this study is to compare the loneliness, psychological well- being, depression, and social participation of elderly people living in Turkish society between rural and urban areas. The sample group of the study, in which a correlational survey model was used, consisted of 610 elderly adults. Method: The study population consists of two groups: the first group consists of individuals over 65 years of age living in the city (Istanbul) (n= 291), and the second group consists of individuals over 65 years of age living in rural areas (rural areas of Ordu) (n= 319). Socio-demographic Information Form, Loneliness in the Elderly Scale, Geriatric Depression Scale, Psychological Well-Being in the Elderly Scale, and Social Inclusion Scale were applied online. Statistical analyses of the study were conducted using SPSS 27.00, and the Independent Samples t-test and ANOVA test were used. Results: According to the findings of this study, statistically significant results were found in psychological well-being, social inclusion, social relations, loneliness and depression, and place of residence. It was observed that the social isolation and social acceptance levels of those living in urban areas were higher than those living in rural areas. Social, loneliness, and depression scores of those living in the village/town were found to be higher than those living in the city centre. Furthermore, the social relationship scores of those living in the village/town were found to be higher than those living in the city centre. Conclusion: The increasing elderly population worldwide has become an issue that requires global measures. Place of residence is one of the factors thought to affect older people's health and well- being. It is thought that the study data will contribute to new policies that will ensure the protection and promotion of elderly health and those working in this field. In addition, the study, which provides information about Turkish culture, will also enable intercultural comparisons.