Longevity extension in rats via improved redox homeostasis with high carbohydrate diet intervention from weaning to adulthood: a comprehensive multi-omics study.

Early dietary patterns potentially influence the health status and lifespan throughout adulthood and the entire lifespan. However, dietary behaviors are difficult for everyone to control during adolescence. It is even more important to study the effects of interventions of early dietary patterns on the lifespan under arbitrary feeding conditions. The research involves observing the survival status and lifespan of rats from weaning to adulthood with three different dietary patterns (a high-carbohydrate diet (HC), a high-protein diet (HP), and a high-fat diet (HF)) under ad libitum feeding conditions. The administration of high-carbohydrate diets leads to a significant extension of both median and maximum survival times (P < 0.05) in Wistar rats. Furthermore, it markedly enhanced the spatial memory capacity, mitigated the occurrence of liver and kidney pathological outcomes in elderly rats, and increased the abundance of gut microbiota improving amino acid metabolism. Additionally, feeding rats a high-carbohydrate diet improved glutathione (GSH) synthesis and recycling and activated the expression and upregulation of the lifespan-related proteins Foxo3a/Sirt3 and the key metabolic enzyme GPX-4. The high-carbohydrate diet from weaning to adulthood may potentially extend the lifespan by enhancing rat systemic glutathione synthesis, recycling, and improving the redox state pathway.

Effects of the periodic fasting-mimicking diet on health, lifespan, and multiple diseases: a narrative review and clinical implications.

Dietary restriction and fasting have been recognized for their beneficial effects on health and lifespan and their potential application in managing chronic metabolic diseases. However, long-term adherence to strict dietary restrictions and prolonged fasting poses challenges for most individuals and may lead to unhealthy rebound eating habits, negatively affecting overall health. As a result, a periodic fasting-mimicking diet (PFMD), involving cycles of fasting for 2 or more days while ensuring basic nutritional needs are met within a restricted caloric intake, has gained widespread acceptance. Current research indicates that a PFMD can promote stem cell regeneration, suppress inflammation, extend the health span of rodents, and improve metabolic health, among other effects. In various disease populations such as patients with diabetes, cancer, multiple sclerosis, and Alzheimer's disease, a PFMD has shown efficacy in alleviating disease symptoms and improving relevant markers. After conducting an extensive analysis of available research on the PFMD, it is evident that its advantages and potential applications are comparable to other fasting methods. Consequently, it is proposed in this review that a PFMD has the potential to fully replace water-only or very-low-energy fasting regimens and holds promise for application across multiple diseases.

Aging-related markers in rat urine revealed by dynamic metabolic profiling using machine learning.

The process of aging and metabolism is intimately intertwined; thus, developing biomarkers related to metabolism is critical for delaying aging. However, few studies have identified reliable markers that reflect aging trajectories based on machine learning. We generated metabolomic profiles from rat urine using ultra-performance liquid chromatography/mass spectrometry. This was dynamically collected at four stages of the rat's age (20, 50, 75, and 100 weeks) for both the training and test groups. Partial least squares-discriminant analysis score plots revealed a perfect separation trajectory in one direction with increasing age in the training and test groups. We further screened 25 aging-related biomarkers through the combination of four algorithms (VIP, time-series, LASSO, and SVM-RFE) in the training group. They were validated in the test group with an area under the curve of 1. Finally, six metabolites, known or novel aging-related markers, were identified, including epinephrine, glutarylcarnitine, L-kynurenine, taurine, 3-hydroxydodecanedioic acid, and N-acetylcitrulline. We also found that, except for N-acetylcitrulline (p < 0.05), the identified aging-related metabolites did not differ between tumor-free and tumor-bearing rats at 100 weeks (p > 0.05). Our findings reveal the metabolic trajectories of aging and provide novel biomarkers as potential therapeutic antiaging targets.

Association of Prenatal Famine Exposure With Inflammatory Markers and Its Impact on Adulthood Liver Function Across Consecutive Generations.

Although there has been increasing recognition that famine exposure in the fetal stage damages liver function in adulthood, this deteriorated effect could be extended to the next generation remains vague. This study aimed to explore whether famine exposure was associated with liver function in the two consecutive generations, and its association with the mediation role of inflammatory markers. We analyzed the data of 2,681 participants from Suihua rural area, Heilongjiang Province, China. According to the date of birth, the participants were classified as fetal exposed and nonexposed. The F2 subjects were classified as having no parents exposed to famine, maternal famine exposure, paternal famine exposure, or parental famine exposure. In the mixed-effect models, prenatal exposure to famine was associated with the elevation of Δ aspartate aminotransferase (ΔAST) (ß: 0.22, 95% CI: 0.01, 0.43) and Δ alanine aminotransferase (ΔALT) (ß: 0.42, 95% CI: 0.19, 0.66) levels in F1 adults. The mediation analysis showed that the inflammatory markers including serum C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) might mediate the famine-liver function association. This longitudinal data were consistent with the hypothesis that the inflammatory markers explained part of the influence of prenatal famine exposure on liver function injury, and the natal mechanism was needed to be elucidated in the future study.

Mangiferin Improved Palmitate-Induced-Insulin Resistance by Promoting Free Fatty Acid Metabolism in HepG2 and C2C12 Cells via PPARα: Mangiferin Improved Insulin Resistance.

Elevated free fatty acid (FFA) is a key risk factor for insulin resistance (IR). Our previous studies found that mangiferin could decrease serum FFA levels in obese rats induced by a high-fat diet. Our research was to determine the effects and mechanism of mangiferin on improving IR by regulating FFA metabolism in HepG2 and C2C12 cells. The model was used to quantify PA-induced lipid accumulation in the two cell lines treated with various concentrations of mangiferin simultaneously for 24 h. We found that mangiferin significantly increased insulin-stimulated glucose uptake, via phosphorylation of protein kinase B (P-AKT), glucose transporter 2 (GLUT2), and glucose transporter 4 (GLUT4) protein expressions, and markedly decreased glucose content, respectively, in HepG2 and C2C12 cells induced by PA. Mangiferin significantly increased FFA uptake and decreased intracellular FFA and triglyceride (TG) accumulations. The activity of the peroxisome proliferator-activated receptor α (PPARα) protein and its downstream proteins involved in fatty acid translocase (CD36) and carnitine palmitoyltransferase 1 (CPT1) and the fatty acid ß-oxidation rate corresponding to FFA metabolism were also markedly increased by mangiferin in HepG2 and C2C12 cells. Furthermore, the effects were reversed by siRNA-mediated knockdown of PPARα. Mangiferin ameliorated IR by increasing the consumption of glucose and promoting the FFA oxidation via the PPARα pathway in HepG2 and C2C12 cells.

Epigallocatechin gallate prevents senescence by alleviating oxidative stress and inflammation in WI-38 human embryonic fibroblasts.

Increased levels of oxidative stress and inflammation are the underlying mechanisms behind the aging process and age-related diseases. The purpose of our research is to explore whether epigallocatechin gallate (EGCG) can extend replicative life span by preventing the oxidative stress and inflammatory effects of WI-38 fibroblasts and the involved mechanisms in vitro. WI-38 cells were treated with different concentrations of EGCG (0, 25, 50 and 100 µM) at population doubling (PD) 25. At late-stage cells, we determined the age-associated genes with signaling through transcriptome sequencing. The expression profile of the targets in WI-38 fibroblasts was confirmed by bioinformatics analysis, qPCR and western blot. We found that EGCG markedly decreased reactive oxygen species (ROS), and inflammation factors, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and significantly increased cell proliferation at PD 35 and 45. EGCG treatments significantly decreased p53 and retinoblastoma (Rb) expressions, markedly increased p-Rb and E2F2 expressions as well as antioxidant enzymes and superoxide dismutase (SOD) 1 and SOD2 content, and obviously decreased the expressions of inflammation factors IL-32, TNF-α expressions at PD 45 WI-38 cells. Moreover, the effects were changed by EGCG treatment by p53 siRNA or overexpression. These findings in our studies reveal that EGCG treatments improved senescence and enhanced the replicative life span through alleviating oxidative stress and inflammation in WI-38 fibroblasts.

Dietary manganese and type 2 diabetes mellitus: two prospective cohort studies in China.

AIMS/HYPOTHESIS: The association between dietary Mn and type 2 diabetes is unclear. We aimed to elucidate whether dietary Mn is associated with type 2 diabetes, to investigate whether this association is independent of dietary total antioxidant capacity (TAC) and to explore the underlying mechanisms in their association. METHODS: Two prospective cohorts of 3350 and 7133 Chinese adults (20-74 years old) were enrolled including, respectively, 244 and 578 individuals newly diagnosed with type 2 diabetes, with mean values of 4.2 and 5.3 years of follow-up. Cox's proportional-hazards regression and linear regression were performed to investigate the association between dietary Mn and type 2 diabetes (diagnosed by OGTT) or HbAlc and to analyse the joint association between dietary Mn and TAC. Restricted cubic spline (RCS) regression was applied to the non-linear association between dietary Mn and incidence of type 2 diabetes. Mediation analysis was applied to explore potential mediators in their association in a subgroup of 500 participants. RESULTS: Dietary Mn intakes were 4.58 ± 1.04 and 4.61 ± 1.08 (mean ± SD) mg/day in the two cohorts. Dietary Mn was inversely associated with type 2 diabetes incidence and HbAlc concentration in both cohorts (ptrend < 0.01 and <0.01 for type 2 diabetes, and ptrend < 0.01 and =0.02 for HbAlc, respectively, in each cohort) independent of TAC, adjusted for age, sex, BMI, tobacco use, alcohol consumption, physical activity, diabetes inheritance, total energy, carbohydrate, total fatty acids, fibre, calcium, Mg, hypertension, hyperlipidaemia, and impaired glucose tolerance or FBG (all at baseline). Their inverse association was stronger in the presence of diets with high, compared with low, TAC. In RCS, intakes of >6.01 and 6.10-6.97 mg/day were associated with a significantly lower type 2 diabetes incidence in the two respective cohorts. Mediation analysis showed that high plasma Mn and low oxidative stress (increased Mn superoxide dismutase and decreased 8-hydroxydeoxyguanosine) contributed to the association between dietary Mn and both type 2 diabetes and HbAlc. CONCLUSIONS/INTERPRETATION: Dietary Mn was inversely associated with type 2 diabetes independently of TAC. In addition, this association was stronger in a high- rather than low-TAC diet. Plasma Mn and oxidative stress were mediators in the association between dietary Mn and type 2 diabetes. Future studies on absolute Mn intake should be conducted to study the potential non-linearity and optimal levels of dietary Mn and type 2 diabetes.

Epigallocatechin gallate improves insulin resistance in HepG2 cells through alleviating inflammation and lipotoxicity.

AIMS: High levels of circulating free fatty acids (FFAs), inflammation and oxidative stress are important causes for insulin resistance (IR) and type 2 diabetes mellitus. The aim of this study was to investigate the mechanisms of EGCG in alleviating IR in HepG2 cells. METHODS: HepG2 cells were treated with 25 mM glucose, 0.25 mM palmitic acid (PA), or 50 µM EGCG for 24 h. RESULTS: EGCG increased glucose uptake and decreased glucose content. EGCG markedly decreased the levels of inflammatory and oxidative stress factors including nuclear factor κB (NF-κB), tumor necrosis factor-α, interleukin-6, reactive oxygen species, malondialdehyde and p53 protein, and markedly increased superoxide dismutases (SOD), glutathione peroxidase and SOD2 protein. EGCG significantly downregulated the levels of FFAs, triacylglycerol and cholesterol in HepG2 cells. The glucose transporter 2 (GLUT2) protein and its downstream proteins peroxisome proliferator-activated receptor γ coactivator (PGC)-1ß were significantly increased, and sterol regulatory element-binding-1c (SREBP-1c) protein, and fatty acid synthase (FAS) were significantly decreased by EGCG in HepG2. Moreover, the foregoing effects were reversed by siRNA-mediated knockdown of GLUT2. CONCLUSION: Our data demonstrated that EGCG improved IR, possibly through ameliorating glucose (25 mM) and PA (0.25 mM)-induced inflammation, oxidative stress, and FFAs via the GLUT2/PGC-1ß/SREBP-1c/FAS pathway in HepG2 cells.

[Comparison of the effects between maize germ oil and lard oil loading on blood lipids and fatty acid profile of mice].

OBJECTIVE: To investigate the changes in blood lipids and fatty acids profile of mice after different oil loading, and explore the effects of different dietary fatty acids on postprandial blood lipids and fatty acid profile. METHODS: Ninety-six C57BL/6 mice were randomly divided into 2 groups by weight ,maize germ oil group and lard oil group. The mice were given maize germ oil or lard oil by gavage at a dose of 1 ml/100 mg BW, respectively, after over-night fasting. At 0, 30, 60, 120, 180 and 240 min after oil loading, 8 mice were selected randomly from both groups, respectively, and blood was collected via orbital bleeding for postprandial blood lipids and fatty acid profile analysis. RESULTS: The serum triglycerides and total free fatty acids levels in mice loaded with lard oil were significantly higher than those in mice loaded with maize germ oil, respectively, at 120, 180, 240 min. The serum saturated fatty acids and monounsaturated fatty acids in mice loaded with lard oil were significantly higher, whereas serum polyunsaturated fatty acids were significantly lower than those in mice loaded with maize germ oil at 60, 120, 180 and 240 min (P < 0.05). Serum palmitic oil and oleic oil in mice loaded with lard oil were higher, whereas linoleic oil and arachidonic acid were lower than those in mice loaded with maize germ oil at 60, 120, 180 and 240 min (P < 0.05). CONCLUSION: Compared with maize germ oil, lard oil leads to higher postprandial serum triglycerides and saturated fatty acids levels, that may increase the risk of cardiovascular diseases.

The phytochemical, EGCG, extends lifespan by reducing liver and kidney function damage and improving age-associated inflammation and oxidative stress in healthy rats.

It is known that phytochemicals have many potential health benefits in humans. The aim of this study was to investigate the effects of long-term consumption of the phytochemical, epigallocatechin gallate (EGCG), on body growth, disease protection, and lifespan in healthy rats. 68 male weaning Wistar rats were randomly divided into the control and EGCG groups. Variables influencing lifespan such as blood pressure, serum glucose and lipids, inflammation, and oxidative stress were dynamically determined from weaning to death. The median lifespan of controls was 92.5 weeks. EGCG increased median lifespan to 105.0 weeks and delayed death by approximately 8-12 weeks. Blood pressure and serum glucose and lipids significantly increased with age in both groups compared with the levels at 0 week. However, there were no differences in these variables between the two groups during the whole lifespan. Inflammation and oxidative stress significantly increased with age in both groups compared with 0 week and were significantly lower in serum and liver and kidney tissues in the EGCG group. Damage to liver and kidney function was significantly alleviated in the EGCG group. In addition, EGCG decreased the mRNA and protein expressions of transcription factor NF-κB and increased the upstream protein expressions of silent mating type information regulation two homolog one (SIRT1) and forkhead box class O 3a (FOXO3a). In conclusion, EGCG extends lifespan in healthy rats by reducing liver and kidney damage and improving age-associated inflammation and oxidative stress through the inhibition of NF-κB signaling by activating the longevity factors FoxO3a and SIRT1.

Calcium supplementation increases circulating cholesterol by reducing its catabolism via GPER and TRPC1-dependent pathway in estrogen deficient women.

BACKGROUND: Limited studies have addressed the effects of calcium supplementation (CaS) on serum total cholesterol (TC) in postmenopausal women and the results are inconclusive. Moreover, the potential mechanisms through which CaS regulates cholesterol metabolism in the absence of estrogen are still sealed for the limitation of human being study. METHODS: Cross-sectional survey, animal and in vitro experiments were conducted to investigate the effect of CaS on endogenous cholesterol metabolism in estrogen deficiency and identify its potential mechanisms. Ovariectomized rats were used to mimic estrogen deficiency. In vitro, HepG2 cell line was exposed to estradiol and/or calcium treatment. RESULTS: We demonstrated that CaS significantly increased serum TC and the risk of hypercholesterolemia and myocardial infarction in postmenopausal women. Increased serum TC in estrogen deficiency was caused mainly by decreased cholesterol catabolism rather than increased synthesis. This was mediated by reduced 7α-hydroxylase resulting from increased liver intracellular Ca(2+) concentrations, reduced intracellular basal cAMP and subsequent up-regulation of SREBP-1c and SHP expression. Estrogen had a protective role in preventing CaS-induced TC increase by activating the G-protein coupled estrogen receptor, which mediated the estrogen effect through the transient receptor potential canonical 1 cation channel. CONCLUSIONS: CaS increases endogenous serum TC via decreasing hepatic cholesterol catabolism in estrogen deficiency. G-protein coupled estrogen receptor is shown to be a key target in mediating CaS-induced TC increase. CaS should be monitored for the prevention of serum TC increase during menopause.

Mangiferin decreases plasma free fatty acids through promoting its catabolism in liver by activation of AMPK.

Mangiferin has been shown to have the effect of improving dyslipidemia. Plasma free fatty acids (FFA) are closely associated with blood lipid metabolism as well as many diseases including metabolic syndrome. This study is to investigate whether mangiferin has effects on FFA metabolism in hyperlipidemic rats. Wistar rats were fed a high-fat diet and administered mangiferin simultaneously for 6 weeks. Mangiferin (50, 100, 150 mg/kg BW) decreased dose-dependently FFA and triglycerides (TG) levels in plasma, and their accumulations in liver, but increased the ß-hydroxybutyrate levels in both plasma and liver of hyperlipidemic rats. HepG2 cells were treated with oleic acid (OA, 0.2 mmol/L) to simulate the condition of high level of plasma FFA in vitro, and were treated with different concentrations of mangiferin simultaneously for 24 h. We found that mangiferin significantly increased FFA uptake, significantly decreased intracellular FFA and TG accumulations in HepG2 cells. Mangiferin significantly increased AMP-activated protein kinase (AMPK) phosphorylation and its downstream proteins involved in fatty acid translocase (CD36) and carnitine palmitoyltransferase 1 (CPT1), but significantly decreased acyl-CoA: diacylgycerol acyltransferase 2 (DGAT2) expression and acetyl-CoA carboxylase (ACC) activity by increasing its phosphorylation level in both in vivo and in vitro studies. Furthermore, these effects were reversed by Compound C, an AMPK inhibitor in HepG2 cells. For upstream of AMPK, mangiferin increased AMP/ATP ratio, but had no effect on LKB1 phosphorylation. In conclusion, mangiferin decreased plasma FFA levels through promoting FFA uptake and oxidation, inhibiting FFA and TG accumulations by regulating the key enzymes expression in liver through AMPK pathway. Therefore, mangiferin is a possible beneficial natural compound for metabolic syndrome by improving FFA metabolism.

Histidine and arginine are associated with inflammation and oxidative stress in obese women.

The aims of the present study were to examine the serum amino acid profiles in obese and non-obese women and investigate the relationships between the serum amino acids and inflammation and oxidative stress in a human case-control study. Serum amino acids, inflammatory biomarkers (C-reactive protein and IL-6) and oxidative biomarkers (superoxide dismutase, malondialdehyde and glutathione peroxidase) were measured and compared in 235 obese women and 217 non-obese controls. The relationships between serum amino acids and inflammatory and oxidative biomarkers were examined using multiple linear regression. Among the amino acids determined, serum histidine, arginine, threonine, glycine, lysine and serine were found to be significantly lower in obese women as compared to non-obese controls (P < 0·001). The difference was the greatest for histidine (P < 0·001). In obese women, both histidine and arginine were negatively associated with inflammation and oxidative stress. In non-obese controls, histidine was negatively associated with oxidative stress. The findings in this study indicate that the metabolism of amino acids is abnormal in obese women in whom histidine and arginine have close relationships with inflammation and oxidative stress.

The calcium-sensing receptor promotes adipocyte differentiation and adipogenesis through PPARγ pathway.

Adipocyte differentiation and adipogenesis are closely related to obesity and obesity-induced metabolic disorders. The calcium-sensing receptor (CaSR) has been reported to play an antilipolytic role in human adipocyte and regulate cell differentiation in many tissues. However, the effects of CaSR on adipocyte differentiation and adipogenesis have not been clarified. In the study, we observed that activation of CaSR significantly promoted adipocyte differentiation and adipogenesis in human SW872 adipocytes. Gene expression analysis revealed that the CaSR activation increased the transcription factor proliferator-activated receptor γ (PPARγ) and its downstream genes including CCAAT element binding protein α (C/EBPα), adipose fatty acid-binding protein (aP2), and lipoprotein lipase. The activity of glycerol-3-phosphate dehydrogenase was also increased after the stimulation of CaSR. In addition, levels of cyclic AMP and calcium which have been shown to regulate PPARγ gene expression were significantly affected by the activation of CaSR. These effects could be suppressed by CaSR small interfering RNA (CaSR-siRNA). In conclusion, our findings suggest that activation of CaSR promotes differentiation and adipogenesis in adipocytes, which might be achieved by upregulating PPARγ and its downstream gene expressions. Therefore, CaSR in adipocytes may be involved in the pathogenesis of obesity by promoting adipocyte differentiation and adipogenesis.

[Establishment of a model for evaluating hypolipidemic effect in HepG2 cells].

OBJECTIVE: To establish a model of evaluating hypolipidemic effect in vitro. METHODS: Adding cholesterol to the culture medium for HepG2 cells to induce a hypercholesterolemia model. The content of cellular cholesterol and the expression of protein regulating cholesterol metabolism in HepG2 cells were determined. The validation of the model was identified by lovastatin, a widely used cholesterol-lowering drug. Free fatty acid was added to the culture medium for HepG2 cells to induce a hypertriglyceridemia model. The content of cellular triglyceride and the absorption rate of free fatty acid were determined. The validation of the model was identified by fenofibrate, a triglyceride-lowering drug. RESULTS: Cellular cholesterol content was increased and the expression of HMG-CoA redutase, SREBP-2 and LDLR were decreased after adding cholesterol and 25-hydrocholesterol to the culture medium. Cellular cholesterol was decreased and the expression of SREBP-2 and LDLR were up-regulated by Lovastatin. The absorption of oleic acid in cells was up to 40% after adding oleic acid (50 micromol) to the culture medium for 6 h. The absorption of free fatty acid was increased but the content of cellular triglyceride was not increased in cells by Fenofibrate. CONCLUSION: This model might be an effective method for screening and assessing functional factors for lowing plasma lipids.

Lack of association between TNF 238 G/A polymorphism and type 2 diabetes: a meta-analysis.

The aim of this meta-analysis was to determine the nature of the association between TNF 238 G/A polymorphism and the risk for T2D. We searched databases updated on January 2009 for all publications on the association between this variation and T2D. Data on genotypes and the numbers of cases and controls were assessed using Review Manager 4.2. Meta-analysis of the overall and specific populations was conducted, and odds ratios (OR) and 95% confidence intervals (95% CI) were calculated in the fixed-effect model. I(2) statistic was calculated to examine heterogeneity, and publication bias was evaluated by Egger test. The overall OR (95% CI) for AA and GA genotypes versus GG genotype for TNF-alpha-238 was 1.15 (0.92-1.44), which in European and Asian populations were 1.18 (0.92-1.51) and 1.13 (0.62-2.04), respectively. This first meta-analysis of data from the current and published studies did not detect any association between the polymorphism of TNF 238 G/A and risk for T2D.

[Effects of chromium and fish oil on the level of leptin and insulin in obese rats].

OBJECTIVE: In order to study the effects of chromium and fish oil on the level of leptin and insulin in obese rats, 32 obese model rats were divided randomly into four groups: fish oil group (5 ml/kg bw), chromium group (3 mg/kg bw), fish oil + chromium group and high fat diet group. METHODS: In the end of the experiment (6 weeks) fats around kidney and spermary were weighted and blood samples were collected to determine the level leptin and insulin. RESULTS: The results showed that the level of leptin and insulin in experimental groups were lower than those in high fat diet group. The ratios of fats around kidney and/or around spermary to body weight in experimental groups were lower than those in high fat diet group. CONCLUSION: Chromium and fish oil possible depress the high level of leptin and insulin in obese model rats.