The Effects of Resveratrol, Metformin, Cold and Strength Training on the Level of Perilipin 5 in the Heart, Skeletal Muscle and Brown Adipose Tissues in Mouse

A systematic review of the effects of cold exposure on pathological cardiac remodeling in mice

Exposure to cold promotes cardiac remodeling, characterized by deleterious effects on structure and function, contributing to increased mortality from cardiovascular diseases. The mechanisms associated with these changes are poorly understood. This review gathers the literature data on the main alterations and mechanisms associated with the adverse cardiac structural and functional remodeling induced by cold exposure in mice. Original studies were identified by searching PubMed, Scopus, and Embase databases from January 1990 to June 2022. This systematic review was conducted in accordance with the criteria established by PRISMA and registered in PROSPERO (CRD42022350637). The risk of bias was evaluated by the SYRCLE. Eligible studies included original papers published in English that evaluated cardiac outcomes in mice submitted to short- or long-time cold exposure and had a control group at room temperature. Seventeen original articles were included in this review. Cold exposure induces pathological cardiac remodeling, characterized by detrimental structural and functional parameters, changes in metabolism and autophagy process, and increases in oxidative stress, inflammation, and apoptosis. In addition, Nppa, AT1_A, Fbp3, BECN, ETA, and MT, appear to play fundamental roles in regulating cardiac remodeling. We suggest that strategies that seek to minimize the CVD risk and adverse effects of cold exposure should target these agents.

Anti-Obesity Effects of Metformin: A Scoping Review Evaluating the Feasibility of Brown Adipose Tissue as a Therapeutic Target

Brown adipose tissue (BAT) is increasingly recognized as the major therapeutic target to promote energy expenditure and ameliorate diverse metabolic complications. There is a general interest in understanding the pleiotropic effects of metformin against metabolic complications. Major electronic databases and search engines such as PubMed/MEDLINE, Google Scholar, and the Cochrane library were used to retrieve and critically discuss evidence reporting on the impact of metformin on regulating BAT thermogenic activity to ameliorate complications linked with obesity. The summarized evidence suggests that metformin can reduce body weight, enhance insulin sensitivity, and improve glucose metabolism by promoting BAT thermogenic activity in preclinical models of obesity. Notably, this anti-diabetic agent can affect the expression of major thermogenic transcriptional factors such as uncoupling protein 1 (UCP1), nuclear respiratory factor 1 (NRF1), and peroxisome-proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) to improve BAT mitochondrial function and promote energy expenditure. Interestingly, vital molecular markers involved in glucose metabolism and energy regulation such as AMP-activated protein kinase (AMPK) and fibroblast growth factor 21 (FGF21) are similarly upregulated by metformin treatment in preclinical models of obesity. The current review also discusses the clinical relevance of BAT and thermogenesis as therapeutic targets. This review explored critical components including effective dosage and appropriate intervention period, consistent with the beneficial effects of metformin against obesity-associated complications.

Resveratrol-induced remodelling of myocellular lipid stores: A study in metabolically compromised humans

In non-athletes, insulin sensitivity correlates negatively with intramyocellular lipid (IMCL) content. In athletes, however, a pattern of benign IMCL storage exists, which is characterized by lipid storage in type I muscle fibres, in small and numerous lipid droplets (LDs) preferable coated with PLIN5, without affecting insulin sensitivity. Administration of resveratrol has been promoted for its beneficial effects on glucose homeostasis. We observed that 30 days of oral resveratrol administration (150 mg/day) in metabolically compromised individuals showed a 33% increase in IMCL (placebo vs. resveratrol; 0.86 ± 0.090 AU vs. 1.14 ± 0.11 AU, p = 0.003) without impeding insulin sensitivity. Thus, the aim of the present study was to examine if a resveratrol-mediated increase in IMCL content, in metabolically compromised individuals, changes the LD phenotype towards the phenotype we previously observed in athletes. For this, we studied IMCL, LD number, LD size, subcellular distribution and PLIN5 coating in different fibre types using high-resolution confocal microscopy. As proof of concept, we observed a 2.3-fold increase (p = 0.038) in lipid accumulation after 48 h of resveratrol incubation in cultured human primary muscle cells. In vivo analysis showed that resveratrol-induced increase in IMCL is predominantly in type I muscle fibres (placebo vs. resveratrol; 0.97 ± 0.16% vs. 1.26 ± 0.09%; p = 0.030) in both the subsarcolemmal (p = 0.016) and intermyofibrillar region (p = 0.026) and particularly in PLIN5-coated LDs (p = 0.024). These data indicate that administration of resveratrol augments IMCL content in metabolically compromised individuals towards a LD phenotype that mimics an 'athlete like phenotype'.

The regulatory role of dietary factors in skeletal muscle development, regeneration and function

Skeletal muscle plays a crucial role in motor function, respiration, and whole-body energy homeostasis. How to regulate the development and function of skeletal muscle has become a hot research topic for improving lifestyle and extending life span. Numerous transcription factors and nutritional factors have been clarified are closely associated with the regulation of skeletal muscle development, regeneration and function. In this article, the roles of different dietary factors including green tea, quercetin, curcumin (CUR), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and resveratrol (RES) in regulating skeletal muscle development, muscle mass, muscle function, and muscle recovery have been summarized and discussed. We also reviewed the potential regulatory molecular mechanism of these factors. Based on the current findings, dietary factors may be used as a potential therapeutic agent to treat skeletal muscle dysfunction as well as its related diseases.

Exploring the Comparative Efficacy of Metformin and Resveratrol in the Management of Diabetes-associated Complications: A Systematic Review of Preclinical Studies

Food-derived bioactive compounds such as resveratrol are increasingly explored for their protective effects against metabolic complications. Evidence supports the strong antioxidant properties and therapeutic effects of resveratrol in managing diabetes and its associated complications. However, evidence informing on the comparative or combination effects of this natural compound with an accomplished and well-characterized antidiabetic agent like metformin has not been revised. Thus, we conducted a comprehensive systematic search of the major electronic databases which included MEDLINE, Cochrane Library, and EMBASE. The cumulative evidence strongly supports the comparative effects of metformin and resveratrol in ameliorating diabetes-associated complications in preclinical settings. In particular, both compounds showed strong ameliorative effects against hyperglycemia, dyslipidemia, insulin resistance, a pro-inflammatory response, and lipid peroxidation in various experimental models of diabetes. Enhancing intracellular antioxidant capacity in addition to activating NAD-dependent deacetylase sirtuin-1 (SIRT1) and AMP-activated protein kinase (AMPK) are the prime mechanisms involved in the therapeutic effects of these compounds. Of interest, preclinical evidence also demonstrates that the combination treatment with these compounds may have a greater efficacy in protecting against diabetes. Thus, confirmation of such evidence in well-organized clinical trials remains crucial to uncover novel therapeutic strategies to manage diabetes and its linked complications.

Effectiveness and therapeutic value of phytochemicals in acute pancreatitis: A review

BACKGROUND

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas that can lead to local and systemic complications. Repeated attacks of AP can lead to chronic pancreatitis, which markedly increases the probability of developing pancreatic cancer. Although many researchers have attempted to identify the pathogenesis involved in the initiation and aggravation of AP, the disease is still not fully understood, and effective treatment is limited to supportive therapy.

METHODS

We aim to summarize available literature focused on phytochemicals (berberine, chlorogenic acid, curcumin, emblica officinalis, ellagic acid, cinnamtannin B-1, resveratrol, piperine and lycopene) and discuss their effectiveness and therapeutic value for improving AP.

RESULTS

This study is based on pertinent papers that were retrieved by a selective search using relevant keywords in PubMed and ScienceDirect databases.

CONCLUSIONS

Many phytochemicals hold potential in improving AP symptoms and may be a valuable and effective addition to standard treatment of AP. It has already been proven that the crucial factor for reducing the severity of AP is stimulation of apoptosis along with/or inhibition of necrosis. Supplementation of phytochemicals, which target the balance between apoptosis and necrosis can be recommended in ongoing clinical studies.