Sesamin Activates Skeletal Muscle FNDC5 Expression and Increases Irisin Secretion via the SIRT1 Signaling Pathway

Clinical evidence of sesame (Sesamum indicum L.) products and its bioactive compounds on anthropometric measures, blood pressure, glycemic control, inflammatory biomarkers, lipid profile, and oxidative stress parameters in humans: a GRADE-assessed systematic review and dose-response meta-analysis

This comprehensive systematic review and meta-analysis aimed to assess the impact of sesame (Sesamum indicum L.) supplementation on cardiovascular disease risk factors. Relevant research was discovered via PubMed, Scopus, Web of Science, CENTRAL, and EMBASE up to June 2024. The assessment of study quality was conducted using the Cochrane risk-of-bias tool. Thirteen trials, with interventions ranging from 4 to 12 weeks and involving 521 participants, demonstrated significant reductions in glycated hemoglobin (HbA1c) (Standardized Mean Difference [SMD] = - 0.67; 95% Confidence Interval [CI] - 1.01, - 0.32; P < 0.001), C-reactive protein (CRP) (SMD = - 0.51; 95% CI - 0.96, - 0.05; P = 0.028), and interleukin-6 (IL-6) (SMD = - 0.74; 95% CI - 1.16, - 0.32; P < 0.001), and a marginally significant effect on fasting blood sugar (FBS) (SMD = - 0.57; 95% CI - 1.16, 0.02; P = 0.057). Subgroup analyses revealed that sesame supplementation significantly reduced CRP and malondialdehyde (MDA) in populations without chronic diseases, while total cholesterol (TC) and MDA were reduced in those with chronic diseases. MDA was significantly reduced in females, especially those aged 50 or older. At dosages of 10 g per day or less, CRP, high-density lipoprotein cholesterol (HDL), and TC showed significant improvements. Meta-regression highlighted a significant dose-dependent reduction in TC levels at 10 g/day, and a significant duration-dependent decrease in TG levels at 8 weeks of supplementation. Sesame supplementation demonstrates potential benefits in improving glycemic control, inflammatory markers, and lipid profiles, making it a promising adjunct therapy for reducing cardiovascular disease risk factors.

Effects of Sesamin in Animal Models of Obesity-Associated Diseases: A Systematic Review and Meta-Analysis

CONTEXT

As living standards have improved and lifestyles have undergone changes, metabolic diseases associated with obesity have become increasingly prevalent. It is well established that sesamin (Ses) (PubChem CID: 72307), the primary lignans in sesame seeds and sesame oil, possess antioxidant and anti-inflammatory effects.

OBJECTIVE

In this study, a systematic review and meta-analysis of the effects of Ses on animal models of obesity-related diseases was performed to assess their impact on relevant disease parameters. Importantly, this study sought to provide insights for the design of future human clinical studies utilizing Ses as a nutritional supplement or drug.

DATA SOURCES

This study conducted a comprehensive search in PubMed, Web of Science, Embase, Scopus, and the Cochrane Library, identifying English language articles published from inception to April 2023.

DATA EXTRACTION

The search incorporated keywords such as "sesamin," "obesity," "non-alcoholic fatty liver disease," "type 2 diabetes mellitus," and "metabolic syndrome." The meta-analysis included 17 articles on non-alcoholic fatty liver disease, type 2 diabetes, and metabolic syndrome.

DATA ANALYSIS

Overall, the pooled results demonstrated that Ses significantly reduced levels of total serum cholesterol (P = .010), total serum triglycerides (P = .003), alanine transaminase (P = .003), and blood glucose (P < .001), and increased high-density lipoprotein cholesterol levels (P = .012) in animal models of nonalcoholic fatty liver disease. In the type 2 diabetes model, Ses mitigated drug-induced weight loss (P < .001), high-fat-diet-induced weight gain (P < .001), and blood glucose levels (P = .001). In the metabolic syndrome model, Ses was associated with a significant reduction in body weight (P < .001), total serum cholesterol (P < .001), total serum triglycerides (P < .001), blood glucose (P < .001), and alanine transaminase levels (P = .039).

CONCLUSION

The meta-analysis results of this study suggest that Ses supplementation yields favorable effects in animal models of obesity-related diseases, including hypolipidemic, insulin-lowering, and hypoglycemic abilities, as well as organ protection from oxidative stress and reduced inflammation.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration No. CRD42023438502.

Association between Daily Sesame Consumption and the Risk of Sarcopenia in Elderly Adults: The Tianjin Chronic Low-Grade Systemic Inflammation and Health Cohort Study

BACKGROUND

Sarcopenia is an age-related, progressive, and systemic skeletal muscle disorder that can lead to numerous adverse outcomes. Animal studies have shown that sesame can enhance skeletal muscle blood flow and improve physical performance. However, no studies have yet explored the association between sesame consumption and the incidence of sarcopenia in the general population.

OBJECTIVES

This study aimed to clarify the association between daily sesame consumption and the risk of sarcopenia in a cohort of Chinese elderly aged 60 y and over.

METHODS

This cohort study was conducted in Tianjin, China, involving 3017 elderly participants (1270 men). Sesame consumption frequency was assessed using a validated self-administered food frequency questionnaire. Sarcopenia was defined according to the consensus of the Asian Working Group for Sarcopenia. Multivariable Cox proportional hazards regression models were used to evaluate the association between daily sesame consumption and the risk of sarcopenia.

RESULTS

After adjusting for potential confounders (age, BMI, smoking status, alcohol consumption, physical activity, marital status, educational level, personal history of diseases, depressive state, total energy intake, and dietary patterns), the multivariable hazard ratios and 95% confidence interval for sarcopenia among the elderly with different levels of daily sesame consumption were as follows: almost never consuming sesame (reference value), ≤1 time/wk: 1.06 (0.81, 1.39), and ≥2-3 times/wk: 0.62 (0.46, 0.84), respectively (P values <0.01).

CONCLUSIONS

This study indicates that daily sesame consumption in the elderly aged 60 y and over is associated with a reduced risk of sarcopenia. Further research is needed to explore the causal mechanisms underlying this association.

Luteolin alleviates muscle atrophy, mitochondrial dysfunction and abnormal FNDC5 expression in high fat diet-induced obese rats and palmitic acid-treated C2C12 myotubes

Obesity is associated with a series of skeletal muscle impairments and dysfunctions, which are characterized by metabolic disturbances and muscle atrophy. Luteolin is a phenolic phytochemical with broad pharmacological activities. The present study aimed to evaluate the protective effects of Luteolin on muscle function and explore the potential mechanisms in high-fat diet (HFD)-induced obese rats and palmitic acid (PA)-treated C2C12 myotubes. Male Sprague-Dawley (SD) rats were fed with a control diet or HFD and orally administrated 0.5% sodium carboxymethyl cellulose (vehicle) or Luteolin (25, 50, and 100 mg/kg, respectively) for 12 weeks. The results showed that Luteolin ameliorated HFD-induced body weight gain, glucose intolerance and hyperlipidemia. Luteolin also alleviated muscle atrophy, decreased ectopic lipid deposition and prompted muscle-fiber-type conversion in the skeletal muscle. Meanwhile, we observed an evident improvement in mitochondrial quality control and respiratory capacity, accompanied by reduced oxidative stress. Mechanistic studies indicated that AMPK/SIRT1/PGC-1α signaling pathway plays a key role in the protective effects of Luteolin on skeletal muscle in the obese states, which was further verified by using specific inhibitors of AMPK and SIRT1. Moreover, the mRNA expression levels of markers in brown adipocyte formation were significantly up-regulated post Luteolin supplementation in different adipose depots. Taken together, these results revealed that Luteolin supplementation might be a promising strategy to prevent obesity-induced loss of mass and biological dysfunctions of skeletal muscle.

Roles of natural products on myokine expression and secretion in skeletal muscle atrophy

Skeletal muscles serve both in movement and as endocrine organs. Myokines secreted by skeletal muscles activate biological functions within muscles and throughout the body via autocrine, paracrine, and/or endocrine pathways. Skeletal muscle atrophy can influence myokine expression and secretion, while myokines can impact the structure and function of skeletal muscles. Regulating the expression and secretion of myokines through the pharmacological approach is a strategy for alleviating skeletal muscle atrophy. Natural products possess complex structures and chemical properties. Previous studies have demonstrated that various natural products exert beneficial effects on skeletal muscle atrophy. This article reviewed the regulatory effects of natural products on myokines and summarized the research progress on skeletal muscle atrophy associated with myokine regulation. The focus is on how small-molecule natural products affect the regulation of interleukin 6 (IL-6), irisin, myostatin, IGF-1, and FGF-21 expression. We contend that the development of small-molecule natural products targeting the regulation of myokines holds promise in combating skeletal muscle atrophy.

Vitamin D3 improves glucose metabolism and attenuates inflammation in prediabetic human and mice

Prediabetes is a crucial stage for prevention and treatment of diabetes, and vitamin D (VD) has been found to be linked to the development of prediabetes and diabetes. Thus, we aimed to identify the effect of VD supplementation on glucose metabolism in prediabetic participants and mice. A 1:1 paired design of randomized, placebo-controlled trial with 1600 IU/day VD3 or placebo was administered to individuals with prediabetes, two-way repeated-measures ANCOVA was used to analyze glycolipid and inflammatory factors. A high-fat diet induced prediabetic KKay mice were utilized to evaluate the effects of VD3 with 16 weeks supplementation. Generalized estimation equation, one way ANOVA were used to analyze continuous monitoring indexes and terminal indexes, respectively. Exercise capacity, skeletal muscle pathological features and relevant proteins were examined. The clinical results showed that VD3 could improve insulin secretion and decrease inflammation. Results of KKay mice exhibited that VD3 not only ameliorate glycolipid metabolism and inflammatory indicators, but also regulated pathological changes of skeletal muscle and exercise capacity. Mechanistically, our results demonstrated that VD3 could inhibit the TLR4/NFκB and activate PI3K/AKT signaling pathway. Collectively, the study indicated that VD3 exerts its beneficial effects by inhibiting TLR4/NFκB to decrease inflammatory response, and activating PI3K/AKT signaling pathway to regulate glucose homeostasis.

(-)-epicatechin treatment did not modify the thermogenic pathway in the gastrocnemius muscle of male rat offspring obeses by programming

The aim of this study was to analyse the expression of genes related to the regulation of energy metabolism in skeletal muscle tissue by comparing male offspring in two age groups [at 110 and 245 postnatal days (pnd)] from a mother with obesity induced by a high-fat diet and (-)-epicatechin (Epi) administration. Four groups of six male offspring from different litters were randomly selected for the control groups [C and offspring of mothers with maternal obesity (MO)] or Epi intervention groups. We evaluated the effect of Epi on gastrocnemius tissue by analysing the mRNA and protein expression levels of Fndc5/irisin, Pgc-1α, Ucp3, and Sln. Epi significantly increased the Pgc-1α protein in the MO group of offspring at 110 pnd (p < 0.036, MO vs. MO+Epi), while at 245 pnd, Epi increased Fndc5/irisin mRNA expression in the MO+Epi group versus the MO group (p = 0.006).No differences were detected in Fndc5/irisin, Ucp3 or Sln mRNA or protein levels (including Pgc-1α mRNA) in the offspring at 110 pnd or in Pgc-1α, Ucp3, or Sln mRNA or protein levels (including Fndc5/irisin protein) at 245 pnd among the experimental groups. In conclusion, (-)-epicatechin treatment increased Fndc5/irisin mRNA expression and Pgc-α protein levels in the gastrocnemius muscle of offspring at postnatal days 110 and 245. Furthermore, it is suggested that the flavonoid effect in a model of obesity and its impact on thermogenesis in skeletal muscle are regulated by a different pathway than Fndc5/irisin.

Sirtuins: Promising Therapeutic Targets to Treat Ischemic Stroke

Stroke is a major cause of mortality and disability globally, with ischemic stroke (IS) accounting for over 80% of all stroke cases. The pathological process of IS involves numerous signal molecules, among which are the highly conserved nicotinamide adenine dinucleotide (NAD+)-dependent enzymes known as sirtuins (SIRTs). SIRTs modulate various biological processes, including cell differentiation, energy metabolism, DNA repair, inflammation, and oxidative stress. Importantly, several studies have reported a correlation between SIRTs and IS. This review introduces the general aspects of SIRTs, including their distribution, subcellular location, enzyme activity, and substrate. We also discuss their regulatory roles and potential mechanisms in IS. Finally, we describe the current therapeutic methods based on SIRTs, such as pharmacotherapy, non-pharmacological therapeutic/rehabilitative interventions, epigenetic regulators, potential molecules, and stem cell-derived exosome therapy. The data collected in this study will potentially contribute to both clinical and fundamental research on SIRTs, geared towards developing effective therapeutic candidates for future treatment of IS.

Accounting Gut Microbiota as the Mediator of Beneficial Effects of Dietary (Poly)phenols on Skeletal Muscle in Aging

Sarcopenia, the age-related loss of muscle mass and function increasing the risk of disability and adverse outcomes in older people, is substantially influenced by dietary habits. Several studies from animal models of aging and muscle wasting indicate that the intake of specific polyphenol compounds can be associated with myoprotective effects, and improvements in muscle strength and performance. Such findings have also been confirmed in a smaller number of human studies. However, in the gut lumen, dietary polyphenols undergo extensive biotransformation by gut microbiota into a wide range of bioactive compounds, which substantially contribute to bioactivity on skeletal muscle. Thus, the beneficial effects of polyphenols may consistently vary across individuals, depending on the composition and metabolic functionality of gut bacterial communities. The understanding of such variability has recently been improved. For example, resveratrol and urolithin interaction with the microbiota can produce different biological effects according to the microbiota metabotype. In older individuals, the gut microbiota is frequently characterized by dysbiosis, overrepresentation of opportunistic pathogens, and increased inter-individual variability, which may contribute to increasing the variability of biological actions of phenolic compounds at the skeletal muscle level. These interactions should be taken into great consideration for designing effective nutritional strategies to counteract sarcopenia.