Role of epigenetics in the regulation of skin aging and geroprotective intervention: A new sight

Multiple epigenetic factors play a regulatory role in maintaining the homeostasis of cutaneous components and are implicated in the aging process of the skin. They have been associated with the activation of the senescence program, which is the primary contributor to age-related decline in the skin. Senescent species drive a series of interconnected processes that impact the immediate surroundings, leading to structural changes, diminished functionality, and heightened vulnerability to infections. Geroprotective medicines that may restore the epigenetic balance represent valid therapeutic alliances against skin aging. Most of them are well-known Western medications such as metformin, nicotinamide adenine dinucleotide (NAD+), rapamycin, and histone deacetylase inhibitors, while others belong to Traditional Chinese Medicine (TCM) remedies for which the scientific literature provides limited information. With the help of the Geroprotectors.org database and a comprehensive analysis of the referenced literature, we have compiled data on compounds and formulae that have shown potential in preventing skin aging and have been identified as epigenetic modulators.

Epigenetics in obesity: Mechanisms and advances in therapies based on natural products

Obesity is a major risk factor for morbidity and mortality because it has a close relationship to metabolic illnesses, such as diabetes, cardiovascular diseases, and some types of cancer. With no drugs available, the mainstay of obesity management remains lifestyle changes with exercise and dietary modifications. In light of the tremendous disease burden and unmet therapeutics, fresh perspectives on pathophysiology and drug discovery are needed. The development of epigenetics provides a compelling justification for how environmental, lifestyle, and other risk factors contribute to the pathogenesis of obesity. Furthermore, epigenetic dysregulations can be restored, and it has been reported that certain natural products obtained from plants, such as tea polyphenols, ellagic acid, urolithins, curcumin, genistein, isothiocyanates, and citrus isoflavonoids, were shown to inhibit weight gain. These substances have great antioxidant potential and are of great interest because they can also modify epigenetic mechanisms. Therefore, understanding epigenetic modifications to target the primary cause of obesity and the epigenetic mechanisms of anti-obesity effects with certain phytochemicals can prove rational strategies to prevent the disease and develop novel therapeutic interventions. Thus, the current review aimed to summarize the epigenetic mechanisms and advances in therapies for obesity based on natural products to provide evidence for the development of several potential anti-obesity drug targets.

Amelioration of hyperglycemia and hyperlipidemia in a high-fat diet-fed mice by supplementation of a developed optimized polyherbal formulation

This study evaluated in vivo anti-diabetic and anti-obesity activity of a polyherbal formulation's methanolic extract containing an optimized ratio of edible seeds (Salvia hispanica, Chenopodium quinoa, Nelumbo nucifera). Diet-induced obese mice model (C57BL/6) was developed by feeding the mice a high-fat diet for 10 weeks resulting in hyperglycemia and obesity. Different doses (125, 250 and 500 mg/kg of body weight) of formulation were administered orally daily for 6 weeks. Fasting blood glucose and body weight were monitored throughout the study. At the end of the study, serum parameters were analyzed and histological examinations were performed. There was a significant reduction in fasting blood glucose levels and body weight in animal groups receiving polyherbal formulation. Lipid profile was improved as revealed by a reduction in serum triglycerides and total cholesterol. Histological study showed an improvement in liver, kidney and pancreatic sections of treated mice. High-performance thin layer chromatography was performed to identify the phytochemicals responsible for the above-mentioned bioactivities. The results revealed the presence of flavonoid (rutin) in seeds of N.nucifera and in the polyherbal formulation. For the first time, this study demonstrated the anti-diabetic and anti-obesity potential of the optimized formulation. The formulation can be used as a potential therapy for management of diabesity.

Grapefruit Juice Flavanones Modulate the Expression of Genes Regulating Inflammation, Cell Interactions and Vascular Function in Peripheral Blood Mononuclear Cells of Postmenopausal Women

Grapefruit is a rich source of flavanones, phytochemicals suggested excreting vasculoprotective effects. We previously showed that flavanones in grapefruit juice (GFJ) reduced postmenopausal women’s pulse-wave velocity (PWV), a measure of arterial stiffness. However, mechanisms of flavanone action in humans are largely unknown. This study aimed to decipher molecular mechanisms of flavanones by multi-omics analysis in PBMCs of volunteers consuming GFJ and flavanone-free control drink for 6 months. Modulated genes and microRNAs (miRNAs) were identified using microarrays. Bioinformatics analyses assessed their functions, interactions and correlations with previously observed changes in PWV. GFJ modified gene and miRNA expressions. Integrated analysis of modulated genes and miRNA-target genes suggests regulation of inflammation, immune response, cell interaction and mobility. Bioinformatics identified putative mediators of the observed nutrigenomic effect (STAT3, NF-κB) and molecular docking demonstrated potential binding of flavanone metabolites to transcription factors and cell-signaling proteins. We also observed 34 significant correlations between changes in gene expression and PWV. Moreover, global gene expression was negatively correlated with gene expression profiles in arterial stiffness and hypertension. This study revealed molecular mechanisms underlying vasculoprotective effects of flavanones, including interactions with transcription factors and gene and miRNA expression changes that inversely correlate with gene expression profiles associated with cardiovascular risk factors.

Helichrysum Genus and Compound Activities in the Management of Diabetes Mellitus

The global management of diabetes mellitus (DM) involves the administration of recommended anti-diabetic drugs in addition to a non-sedentary lifestyle upon diagnosis. Despite the success recorded from these synthetic drugs, the traditional method of treatment using medicinal plants is increasingly accepted by the locals due to its low cost and the perceived no side effects. Helichrysum species are used in folk medicine and are documented for the treatment of DM in different regions of the world. This study reviews Helichrysum species and its compounds’ activities in the management of DM. An extensive literature search was carried out, utilizing several scientific databases, ethnobotanical books, theses, and dissertations. About twenty-two Helichrysum species were reported for the treatment of diabetes in different regions of the world. Among these Helichrysum species, only fifteen have been scientifically investigated for their antidiabetic activities, and twelve compounds were identified as bioactive constituents for diabetes. This present review study will be a useful tool for scientists and health professionals working in the field of pharmacology and therapeutics to develop potent antidiabetic drugs that are devoid of side effects.

Glucose metabolism enhancement by 10-hydroxy-2-decenoic acid via the PI3K/AKT signaling pathway in high-fat-diet/streptozotocin induced type 2 diabetic mice

Here, we used high fat diet (HFD) combined with streptozotocin (STZ) injection to establish a diabetes model, with the aim of exploring the hypoglycemic effects of 10-hydroxy-2-decenoic acid (10-HDA), and...

Study on the relationship between DNA methylation of target CpG sites in peripheral blood and gestational diabetes during early pregnancy

Genome-wide DNA methylation profiling have been used to find maternal CpG sites related to the occurrence of gestational diabetes mellitus (GDM). However, none of these differential sites found has been verified in a larger sample. Here, our aim was to evaluate whether first trimester changes in target CpG sites in the peripheral blood of pregnancy women predict subsequent development of GDM. This nested case–control study was based upon an early pregnancy follow-up cohort (ChiCTR1900020652). Target CpG sites were extracted from related published literature and bioinformatics analysis. The DNA methylation levels at 337 CpG sites of 80 GDM cases and 80 matched healthy controls during the early pregnancy (10–15 weeks) were assessed using MethylTarget sequencing. The best cut-off level for methylation of CpG site was determined using the generated ROC curve. The independent effect of CpG site methylation status on GDM was analyzed using conditional logistic regression. Methylation levels at 6 CpG sites were significantly higher in the GDM group than in controls, whereas those at another 6 CpG sites were significantly lower (FDR < 0.05). The area under the ROC curve at each methylation level of the significant CpG sites ranged between 0.593 and 0.650 for the occurrence of GDM. After adjusting for possible confounders, the hypermethylation status of CpG site 68167324 (OR = 3.168, 1.038–9.666) and 24837915 (OR = 5.232, 1.659–16.506) was identified as more strongly associated with GDM; meanwhile, the hypermethylation of CpG site 157130156 (OR = 0.361, 0.135–0.966) and 89438648 (OR = 0.206, 0.065–0.655) might indicate lower risk of GDM. The methylation status of target CpG sites in the peripheral blood of pregnant women during the first trimester may be associated with GDM pathogenesis, and has potential as a predictor of GDM.

Epigenetic signatures underlying inflammation: an interplay of nutrition, physical activity, metabolic diseases, and environmental factors for personalized nutrition

AIM AND OBJECTIVE

Emerging translational evidence suggests that epigenetic alterations (DNA methylation, miRNA expression, and histone modifications) occur after external stimuli and may contribute to exacerbated inflammation and the risk of suffering several diseases including diabetes, cardiovascular diseases, cancer, and neurological disorders. This review summarizes the current knowledge about the harmful effects of high-fat/high-sugar diets, micronutrient deficiencies (folate, manganese, and carotenoids), obesity and associated complications, bacterial/viral infections, smoking, excessive alcohol consumption, sleep deprivation, chronic stress, air pollution, and chemical exposure on inflammation through epigenetic mechanisms. Additionally, the epigenetic phenomena underlying the anti-inflammatory potential of caloric restriction, n-3 PUFA, Mediterranean diet, vitamin D, zinc, polyphenols (i.e., resveratrol, gallic acid, epicatechin, luteolin, curcumin), and the role of systematic exercise are discussed.

METHODS

Original and review articles encompassing epigenetics and inflammation were screened from major databases (including PubMed, Medline, Science Direct, Scopus, etc.) and analyzed for the writing of the review paper.

CONCLUSION

Although caution should be exercised, research on epigenetic mechanisms is contributing to understand pathological processes involving inflammatory responses, the prediction of disease risk based on the epigenotype, as well as the putative design of therapeutic interventions targeting the epigenome.

Antiobesity effects of phytochemicals from an epigenetic perspective

Obesity is an important cause of morbidity and mortality due to its close association with metabolic disorders including diabetes, cardiovascular diseases, and certain types of cancer. According to the Developmental Origins of Adult Health and Disease hypothesis, obesity is likely caused by epigenetic changes. Recent studies have shown an association between epigenetic dysregulation of certain genes and obesity. Due to their reversible characteristic, epigenetic dysregulations can be restored. Restoration of epigenetic dysregulation in obesity-related genes by epigenetic modifiers may be a new treatment option for obesity. Certain phytochemicals such as tea polyphenols, curcumin, genistein, isothiocyanates, and citrus isoflavonoids were shown to prevent weight gain. These phytochemicals are known for their antioxidant effects but they also modify epigenetic mechanisms. These phytochemicals may have a therapeutic potential in the management of obesity. The aim of this study was to review the epigenetic effects of certain phytochemicals on the expression of obesity-related genes.

Epigenetic regulation by polyphenols in diabetes and related complications

Diabetes mellitus (DM) is a chronic metabolic disorder and one of the most challenging health problems worldwide. Left untreated, it may progress causing serious complications. Genetics, epigenetics, and environmental factors are known to play an overlapping role in the pathogenesis of DM. Growing evidence suggests the hypothesis that the environment induces changes in the early phases of growth and development, influencing health and disease in the adulthood through the alteration in genetic expression of an individual, at least in part. DNA methylation, histone modifications and miRNAs are three mechanisms responsible for epigenetic alterations. The daily diet contains a number of secondary metabolites, with polyphenols being highest in abundance, which contribute to overall health and may prevent or delay the onset of many chronic diseases. Polyphenols have the ability to alter metabolic and signaling pathways at various levels, such as gene expression, epigenetic regulation, protein expression and enzyme activity. The potential efficacy of polyphenolic compounds on glucose homeostasis has been evidenced from in vitro, in vivo and clinical studies. The present review is designed to focus on epigenetic regulation exerted by polyphenolic compounds in DM and their complications, as well as to summarize clinical trials involving polyphenols in DM.

Maternal Flavonoids Intake Reverts Depression-Like Behaviour in Rat Female Offspring

Maternal hypercaloric exposure during pregnancy and lactation is a risk factor for developing diseases associated with inflammation such as obesity, diabetes and, neurological diseases in the offspring. Neuroinflammation might modulate neuronal activation and flavonoids are dietary compounds that have been proven to exert anti-inflammatory properties. Thus, the aim of the present study is to evaluate the effect of maternal supplementation with flavonoids (kaempferol-3-O-glucoside and narirutin) on the prevention of depression-like behaviour in the female offspring of dams fed with an obesogenic diet during the perinatal period. Maternal programming was induced by high fat (HFD), high sugar (HSD), or cafeteria diets exposure and depressive like-behaviour, referred to as swimming, climbing, and immobility events, was evaluated around postnatal day 56–60 before and after 30 mg/kg i.p. imipramine administration in the female offspring groups. Central inflammation was analyzed by measuring the TANK binding kinase 1 (TBK1) expression. We found that the offspring of mothers exposed to HSD programming failed to show the expected antidepressant effect of imipramine. Also, imipramine injection, to the offspring of mothers exposed to cafeteria diet, displayed a pro-depressive like-behaviour phenotype. However, dietary supplementation with flavonoids reverted the depression-like behaviour in the female offspring. Finally, we found that HSD programming increases the TBK1 inflammatory protein marker in the hippocampus. Our data suggest that maternal HSD programming disrupts the antidepressant effect of imipramine whereas cafeteria diet exposure leads to depressive-like behaviour in female offspring, which is reverted by maternal flavonoid supplementation.

DNA methylation landscapes in the pathogenesis of type 2 diabetes mellitus

Although genetic variations and environmental factors are vital to the development and progression of type 2 diabetes mellitus (T2DM), emerging literature suggest that epigenetics, especially DNA methylation, play a key role in the pathogenesis of T2DM by affecting insulin secretion of pancreatic β cells and the body’s resistance to insulin. Previous studies have elucidated how DNA methylation interacted with various factors in T2DM pathogenesis. This review summarized the role of related methylation genes in insulin-sensitive organs, such as pancreatic islets, skeletal muscle, liver, brain and adipose tissue, as well as peripheral blood cells, comparing the tissue similarity and specificity of methylated genes, aiming at a better understanding of the pathogenesis of T2DM and providing new ideas for the personalized treatment of this metabolism-associated disease.

Effects of flavonoids on intestinal inflammation, barrier integrity and changes in gut microbiota during diet-induced obesity

Diet-induced obesity is associated with low-grade inflammation, which, in most cases, leads to the development of metabolic disorders, primarily insulin resistance and type 2 diabetes. Although prior studies have implicated the adipose tissue as being primarily responsible for obesity-associated inflammation, the latest discoveries have correlated impairments in intestinal immune homeostasis and the mucosal barrier with increased activation of the inflammatory pathways and the development of insulin resistance. Therefore, it is essential to define the mechanisms underlying the obesity-associated gut alterations to develop therapies to prevent and treat obesity and its associated diseases. Flavonoids appear to be promising candidates among the natural preventive treatments that have been identified to date. They have been shown to protect against several diseases, including CVD and various cancers. Furthermore, they have clear anti-inflammatory properties, which have primarily been evaluated in non-intestinal models. At present, a growing body of evidence suggests that flavonoids could exert a protective role against obesity-associated pathologies by modulating inflammatory-related cellular events in the intestine and/or the composition of the microbiota populations. The present paper will review the literature to date that has described the protective effects of flavonoids on intestinal inflammation, barrier integrity and gut microbiota in studies conducted using in vivo and in vitro models.

Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases

Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA), diabetes mellitus (DM), and cardiovascular disease (CVD). Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes) from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described.

Higher Fruit Intake Is Related to TNF-α Hypomethylation and Better Glucose Tolerance in Healthy Subjects

BACKGROUND/AIM

This study hypothesized an association between healthy dietary patterns, hypermethylation of the tumor necrosis factor-α (TNF-α) promoter and decreased risk of metabolic changes.

METHODS

Forty normal-weight young women were involved in this cross-sectional study. DNA was isolated from white blood cells, and CpG site methylation in TNF-α was analyzed by Sequenom EpiTyper. The quality of the diet was assessed by Healthy Eating Index (HEI-2005).

RESULTS

Contradicting our hypothesis, HEI-2005 score was negatively associated with CpG5 (r = -0.460, p = 0.003) and TNF-α total methylation (r = -0.355, p = 0.026). A higher intake of fruits was related to lower insulin, HOMA-IR, and TNF-α methylation. No other dietary pattern was related to TNF-α methylation. TNF-α total methylation correlated positively with systolic blood pressure (r = 0.323; p = 0.042) and CpG5 methylation with body mass index (r = 0.333, p = 0.036). Furthermore, fiber intake was negatively associated with the CpG5 (r = -0.324, p = 0.041) and TNF-α total methylation (r = -0.434, p = 0.005), whereas vitamin C intake was negatively associated with TNF-α total methylation (r = -0.411, p = 0.009). Intakes of apples and citrus fruits were negatively associated with TNF-α total methylation.

CONCLUSION

A healthy dietary pattern and higher fruit intake (particularly apples and citrus fruits) were related to better glucose tolerance in healthy subjects, which could be mediated by lower TNF-α methylation.

Biocompounds Attenuating the Development of Obesity and Insulin Resistance Produced by a High-fat Sucrose Diet

The use of biocompounds as agents with potential anti-obesity effects might be a feasible alternative to the prescription of traditional drugs in the near future. The goal of the present study was to screen five different compounds in relation to their ability to prevent body weight gain and ameliorate obesity-associated metabolic impairments, namely insulin resistance. For this purpose, seventy Wistar rats were randomly assigned into seven experimental groups. A standard diet-fed control group (control, n=10); a high-fat, high-sucrose diet-fed group (HFS, n=10) and five experimental groups which were fed the HFS diet supplemented with one of the following biocompounds; curcumin (100 mg/kg bw, n=10), chlorogenic acid (50 mg/kg bw, n=10), coumaric acid (100 mg/kg bw, n=10), naringin (100 mg/kg bw, n=10) and leucine (1 % of diet, n=10). These results confirm the effectiveness of all the compounds to reduce significantly food efficiency, despite the significant higher food intake. Moreover, visceral fat mass percentage was significantly decreased after naringin and coumaric acid supplementation. In fact, this finding might be related to the considerable amelioration of HOMA-IR index detected in naringin-treated animals. A significant reduction in serum insulin levels and an improvement in the intraperitoneal glucose tolerance test and AUC were found in leucine- and coumaric acid-treated rats, respectively. In summary, the tested biocompounds, particularly naringin, coumaric acid and leucine, showed potential benefits in the prevention of obesity-related complications in rats, at least at the proved doses.

Hypoglycemic effects of Zanthoxylum alkylamides by enhancing glucose metabolism and ameliorating pancreatic dysfunction in streptozotocin-induced diabetic rats

Alkylamides extracted from Zanthoxylum, a seasoning spice and folk medicine, exhibited hypoglycemic properties by enhancing glucose metabolism and ameliorating pancreatic dysfunction.