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.

A systematic review exploring the significance of measuring epicardial fat thickness in correlation to B-type natriuretic peptide levels as prognostic and diagnostic markers in patients with or at risk of heart failure.

Emerging evidence suggests that epicardial fat thickness (EFT) may be a critical feature to understand cardiac health and determine the risk of heart failure. The current review critically assesses and discusses evidence on the efficiency of measuring EFT, in comparison to the well-known markers B-type natriuretic peptide (BNP) and its N-terminal fragment pro-B-type natriuretic peptide (NT-proBNP), as a prognostic and diagnostic approach in individuals with or at risk of heart failure. A systematic approach was undertaken to search major databases, PubMed, Scopus, Google Scholar and the Cochrane library to identify studies that quantified EFT and serum BNP/NT-proBNP levels in individuals with or at risk of heart failure. Twelve studies met the inclusion criteria and a total of 1983 participants were included in this systematic review. Evidence shows a clear association between increased EFT and elevated BNP/NT-proBNP levels in individuals with metabolic disease and suggests that both methods can be used for heart failure diagnosis and prognosis. However, due to the broad spectrum of challenges linked with measuring EFT, BNP/Pro-BNP is the predominant method used for heart failure diagnosis and prognosis in clinical practice. Nonetheless, measuring EFT provides a powerful and reproducible diagnostic tool for risk stratification and heart failure diagnosis and prognosis. Importantly, measuring EFT proves valuable to validate BNP/NT-proBNP levels to predict heart failure, especially due to its non-invasive nature.

Prognostic markers in patients with chronic lymphocytic leukaemia on targeted therapy, chemoimmunotherapy with anti-CD20 monoclonal antibody: a systematic review and meta-analysis of prognostic factors.

Combination chemoimmunotherapy (CIT) consisting of anti-CD20 has improved the progression-free survival (PFS) and overall survival (OS) of patients with chronic lymphocytic leukaemia (CLL). We performed a comprehensive synthesis of prognostic factors in patients with CLL on combined CIT with anti-CD20 antibodies compared with standard chemotherapy alone or targeted therapy.We searched the MEDLINE and academic search complete electronic databases as well as clinicaltrials.gov (from inception up to 01 August 2022) for randomised controlled trials examining chemoimmunotherapy and targeted therapy in patients with CLL. The risk of bias and the quality of evidence was assessed using the quality in prognostic studies tool (QUIPS).A total of 10 prognostic factors were identified and evaluated in patients with CLL on anti-CD20 antibody-containing CIT. The predictive value of the following prognostic factors was confirmed and associated with poor patient outcomes; deletion 17p (HR = 3.39), Immunoglobulin heavy chain variable region gene mutation status (HR = 0.96) and ß2-microglobulin (HR = 1.41).Conventional predictive factors may have retained prognostic value and could be useful in the stratification of patients who may be non-responsive to CIT.Trial registration: International Prospective Register of Systematic Reviews (PROSPERO) registry (CRD42021218997).

Epigallocatechin gallate as a nutraceutical to potentially target the metabolic syndrome: novel insights into therapeutic effects beyond its antioxidant and anti-inflammatory properties.

Epigallocatechin gallate (EGCG) is one of the most abundant and powerful flavonoids contained in green tea. Because of the global increase in green tea consumption, there has been a general interest in understanding its health benefits, including its bioactive compounds like EGCG. Indeed, preclinical evidence already indicates that EGCG demonstrated a strong antioxidant and anti-inflammatory properties that could be essential in protecting against metabolic syndrome. The current review explores clinical evidence reporting on the beneficial effects of EGCG supplementation in obese subjects or patients with diverse metabolic complications that include type 2 diabetes and cardiovascular disease. The discussion incorporates the impact of different formulations of EGCG, as well as the effective doses and treatment duration. Importantly, besides highlighting the potential use of EGCG as a nutraceutical, the current review also discusses crucial evidence related to its pharmaceutical development as an agent to hinder metabolic diseases, including its bioavailability and metabolism profile, as well as its well-known biological properties.

Association between the type of allergen and T-helper 2 mediated inflammation in allergic reactions: a systematic review and a meta-analysis.

OBJECTIVES: To determine whether the levels of T-helper (TH) 2 cytokines (interleukin (IL)-4 and IL-5) in allergic reactions are allergen dependent and evaluate the impact of various treatment strategies on the levels of these cytokines. METHODS: The PubMed search engine was used from inception until January 2021. The random-effects residual maximum likelihood model was performed, and effect sizes were estimated using the Hedge's g statistic. All data analysis was performed using STATA 16.0 (StataCorp LP, TX, USA). RESULTS: Fourteen studies reporting on 794 participants were included in this study. House dust mite was associated with eliciting a stronger immune response mediated by both IL-4 and IL-5 when compared to pollen. Whereas a mixture of house dust mite and pollen was associated with IL-4-weighted inflammation. Comparisons of IL-4 and IL-5 levels amongst the allergens showed significant differences. The treatment with anti-corticosteroids or allergen-specific immunotherapy was effective in normalising the TH2 responses and alleviating allergy symptoms. CONCLUSION: TH2-mediated inflammation in allergic reactions is allergen-dependent. Therefore, the type of allergen should be considered when using cytokine-targeting biologics in allergic reactions.

Metformin and heart failure-related outcomes in patients with or without diabetes: a systematic review of randomized controlled trials.

Metformin is considered a safe anti-hyperglycemic drug for patients with type 2 diabetes (T2D); however, information on its impact on heart failure-related outcomes remains inconclusive. The current systematic review explored evidence from randomized clinical trials (RCTs) reporting on the impact of metformin in modulating heart failure-related markers in patients with or without T2D. Electronic databases such as MEDLINE, Cochrane Library, and EMBASE were searched for eligible studies. Included studies were those assessing the use of metformin as an intervention, and also containing the comparison group on placebo, and all articles had to report on measurable heart failure-related indices in individuals with or without T2D. The modified Downs and Black checklist was used to evaluate the risk of bias. Overall, nine studies met the inclusion criteria, enrolling a total of 2486 patients. Although summarized evidence showed that metformin did not affect left ventricular function, this antidiabetic drug could improve myocardial oxygen consumption concomitant to reducing prominent markers of heart failure such as n-terminal pro-brain natriuretic peptide and low-density lipoprotein levels, inconsistently between diabetic and nondiabetic patients. Effective modulation of some heart failure-related outcomes with metformin treatment was related to its beneficial effects in ameliorating insulin resistance and blocking pro-inflammatory markers such as the aging-associated cytokine CCL11 (C-C motif chemokine ligand 11). Overall, although such beneficial effects were observed with metformin treatment, additional RCTs are necessary to improve our understanding on its modulatory effects on heart failure-related outcomes especially in diabetic patients.

Adipokines as a therapeutic target by metformin to improve metabolic function: A systematic review of randomized controlled trials.

Metformin is a widely used glucose-lowering drug, although its impact on adipose tissue function remains elusive. Adipose tissue-derived molecules regulate diverse physiological mechanisms, including energy metabolism, insulin sensitization, and inflammatory response. Alternatively, it has remained relevant to understand the therapeutic regulation of adipokines in efforts to alleviate inflammation in conditions associated with the metabolic syndrome. The current qualitative analysis of available literature focused on randomized clinical trials (RCTs) assessing the association between administration of metformin and adipokine regulation in individuals with metabolic syndrome. The major electronic databases such as MEDLINE, Cochrane Library, Scopus, and EMBASE were searched for eligible RCTs. Overall, 13 RCTs met the inclusion criteria, with a total of 4605 participants. Patients with metabolic syndrome were characterized by a state of obesity, impaired glucose tolerance, insulin resistance, and type 2 diabetes. Cumulative evidence from these RCTs supported the blood glucose lowering effects of metformin, in addition to promoting weight loss, ameliorating insulin resistance, and reducing pro-inflammatory markers such as interleukin-6 and tumor necrosis factor-α in patients with metabolic syndrome. Importantly, these therapeutic effects are associated with the upregulation of adiponectin and suppression of leptin and resistin.

The Potential Role of Polyphenols in Modulating Mitochondrial Bioenergetics within the Skeletal Muscle: A Systematic Review of Preclinical Models.

Polyphenols are naturally derived compounds that are increasingly being explored for their various health benefits. In fact, foods that are rich in polyphenols have become an attractive source of nutrition and a potential therapeutic strategy to alleviate the untoward effects of metabolic disorders. The last decade has seen a rapid increase in studies reporting on the bioactive properties of polyphenols against metabolic complications, especially in preclinical models. Various experimental models involving cell cultures exposed to lipid overload and rodents on high fat diet have been used to investigate the ameliorative effects of various polyphenols against metabolic anomalies. Here, we systematically searched and included literature reporting on the impact of polyphenols against metabolic function, particularly through the modulation of mitochondrial bioenergetics within the skeletal muscle. This is of interest since the skeletal muscle is rich in mitochondria and remains one of the main sites of energy homeostasis. Notably, increased substrate availability is consistent with impaired mitochondrial function and enhanced oxidative stress in preclinical models of metabolic disease. This explains the general interest in exploring the antioxidant properties of polyphenols and their ability to improve mitochondrial function. The current review aimed at understanding how these compounds modulate mitochondrial bioenergetics to improve metabolic function in preclinical models on metabolic disease.

Natural killer cell levels in adults living with type 2 diabetes: a systematic review and meta-analysis of clinical studies.

BACKGROUND: Chronic immune activation and hyperglycaemia are a hallmark of type 2 diabetes mellitus (T2D) while natural killer (NK) cells are involved in the pathogenesis of T2D. Dysregulated NK cell responses are associated with an increased risk of cardiovascular disease in patients living with T2D. OBJECTIVE: To provide a comprehensive and systematic evidence-based estimate on the levels of NK cells in patients living with T2D. RESULTS: This systematic review and meta-analysis included 13 studies reporting on 491 adult patients with T2D and 1064 nondiabetic controls. The pooled effect estimates showed increased levels of NK cells in adult patients with T2D compared to controls (MD: 0.03 [- 3.20, 3.26], I2 = 97%, p < 0.00001). CONCLUSION: Overall, the evidence presented in this systematic review shows that the changes in NK cells in patients living with T2D are still unclear and further studies are needed.

Platelet activation in adult HIV-infected patients on antiretroviral therapy: a systematic review and meta-analysis.

BACKGROUND: Antiretroviral therapy (ART) alters platelet reactivity, and as a consequence, patients living with HIV may be at an increased risk of cardiovascular disease (CVD). The current evidence on platelet activation levels in patients with HIV remains inconclusive. We therefore aimed to systematically synthesise evidence on the association of platelet activation in HIV-infected patients on successful treatment. METHODS: Electronic databases were searched from inception until November 2019. Studies were included if the primary or secondary outcome of the study was to assess platelet activation in HIV-infected patients on ART. The primary outcome of this review included the levels of platelet activation. The pooled effect estimates were calculated using a random-effects meta-analysis model. RESULTS: We identified 30 studies comprising of 2325 participants. The pooled estimates showed elevated levels of platelet activation in treatment-naïve HIV-infected patients compared to uninfected controls (Hedges' g 2.00 [95%CI 1.05, 2.94]; z = 4.12, p < 0.0001). These remained elevated despite successful ART (Hedges' g 2.05 [95%CI 0.58, 3.52]; z = 2.71, p = 0.0067). CONCLUSION: The levels of platelet activation are elevated in treatment-naïve HIV-infected patients, and these persist during successful ART. Further studies should assess the clinical relevance of monitoring the levels of platelet activation in HIV-infected patients on ART.

Elevated T-helper 2 cytokine levels in high fat diet-fed C57BL/6 mice are attenuated by short-term 6-week treatment with a combination of low-dose aspirin and metformin.

OBJECTIVE: To evaluate T-helper cytokine responses in a short-term high fat diet (HFD) induced impaired glucose metabolism. To further evaluate the modulation of T-helper 1 (Th1) and T-helper 2 (Th2) cytokines using short-term low-dose aspirin in combination with metformin. DESIGN: Two experiments were carried out in this study in order to evaluate the T-helper cytokine profiles in a state of impaired glucose metabolism. A total of 28 six-week-old male C57BL/6 mice were used in this study. In the first experiment, mice were fed either a high fat diet or low fat diet for a duration of 10 weeks. We then determined the Th1, Th2 and T-helper 17 (Th17) cytokine profiles. In the second experiment, we evaluated whether the short term 6-week treatment with low-dose aspirin in combination with metformin modulates T-helper cytokine profiles of the HFD-fed mice. MEASUREMENTS: In the first experiment, we measured the body weights, blood glucose levels, insulin levels, lipid profiles and haematological parameters. We further performed oral glucose tolerance testing following an 8-hour fast and serum Th1, Th2 and Th17 cytokine levels were also determined following short-term 8-week diet-feeding and 6-week low-dose aspirin and combined metformin with low-dose aspirin treatment. RESULTS: High fat diet-feeding caused a marked increase in circulating peripheral blood lymphocytes, which was attenuated by short-term low-dose aspirin treatment. Moreover, the HFD feeding resulted in 2-fold increase in total cholesterol and a 4-fold increase in low-density lipoprotein cholesterol when compared to the low-fat diet-fed group (p < 0.05). In the high fat diet group, impaired glucose metabolism was associated with skewed Th2 responses without alterations in the Th1 and Th17 cytokine profiles. Interestingly the short-term treatment with low-dose aspirin showed no effect on the selected T-helper 1 cytokine IFN-Ƴ (P > 0.05). While the combination of low-dose aspirin with metformin considerably reduced the levels of serum IFN-Ƴ (P < 0.05). Furthermore low-dose aspirin treatment showed the modest attenuation of the selected Th2 cytokines, IL-10 and IL-13 when compared to low-dose aspirin with metformin (P < 0.01). CONCLUSION: The early immunological and metabolic changes that occur in a state impaired glucose tolerance are accompanied by the increased production of Th2 cell cytokines. The short-term treatment using low-dose aspirin combined with metformin may provide therapeutic benefits in preventing complications associated with dysregulated Th2 cell responses.

A systematic review on the functional role of Th1/Th2 cytokines in type 2 diabetes and related metabolic complications.

The T-helper (Th1/Th2) paradigm is widely studied for its role in modulating an adaptive immune response, especially in relation to the onset of various autoimmune diseases. In fact, emerging evidence clearly shows an inverse relationship between Th1/Th2 cytokines and the development of type 2 diabetes (T2D) complications, which is accelerated by an exacerbated inflammatory state. Here, relevant studies reporting on any association between the levels of Th1/Th2 cytokines and the development of T2D were retrieved through major electronic databases such as The Cochrane Library, Embase and PubMed. Extracted evidence which mostly involved animal models and human subjects with T2D or metabolic syndrome was assessed for quality and risk of bias using the Downs and Black checklist and Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. Results strongly correlated raised Th1/Th2 cytokines such as interferon-gamma (IFN-γ)/interleukin (IL)-5 and IL-2/IL-5 ratios to T2D, and this was positively linked with the other complications including retinopathy and cardiovascular complications. Further, logistic regression analysis demonstrated that the Th1/Th2 ratios were significantly associated with impaired glucose homeostasis, abnormally enhanced lipid profiles, and insulin resistance. Although more studies making use of a larger sample size are required, current data suggest that optimal modulation of Th1/Th2 cytokines may be an important aspect in the management of T2D and its associated complications.

Coenzyme Q10 Supplementation Improves Adipokine Levels and Alleviates Inflammation and Lipid Peroxidation in Conditions of Metabolic Syndrome: A Meta-Analysis of Randomized Controlled Trials.

Evidence from randomized controlled trials (RCTs) suggests that coenzyme Q10 (CoQ10) can regulate adipokine levels to impact inflammation and oxidative stress in conditions of metabolic syndrome. Here, prominent electronic databases such as MEDLINE, Cochrane Library, and EMBASE were searched for eligible RCTs reporting on any correlation between adipokine levels and modulation of inflammation and oxidative stress in individuals with metabolic syndrome taking CoQ10. The risk of bias was assessed using the modified Black and Downs checklist, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool was used to evaluate the quality of evidence. Results from the current meta-analysis, involving 318 participants, showed that CoQ10 supplementation in individuals with metabolic syndrome increased adiponectin levels when compared to those on placebo (SMD: 1.44 [95% CI: -0.13, 3.00]; I2 = 96%, p < 0.00001). Moreover, CoQ10 supplementation significantly lowered inflammation markers in individuals with metabolic syndrome in comparison to those on placebo (SMD: -0.31 [95% CI: -0.54, -0.08]; I2 = 51%, p = 0.07). Such benefits with CoQ10 supplementation were related to its ameliorative effects on lipid peroxidation by reducing malondialdehyde levels, concomitant to improving glucose control and liver function. The overall findings suggest that optimal regulation of adipokine function is crucial for the beneficial effects of CoQ10 in improving metabolic health.

A Meta-Analysis of the Impact of Resveratrol Supplementation on Markers of Renal Function and Blood Pressure in Type 2 Diabetic Patients on Hypoglycemic Therapy.

Evidence on the beneficial effects of resveratrol supplementation on cardiovascular disease-related profiles in patients with type 2 diabetes (T2D) is conflicting, while its impact on renal function and blood pressure measurements remains to be established in these patients. The current meta-analysis included randomized controlled trials (RCTs) reporting on the impact of resveratrol supplementation on markers of renal function and blood pressure in patients with T2D on hypoglycemic medication. Electronic databases such as MEDLINE, Cochrane Library, Scopus, and EMBASE were searched for eligible studies from inception up to June 2020. The random and fixed effects model was used in the meta-analysis. A total of five RCTs met the inclusion criteria and involved 388 participants with T2D. Notably, most of the participants were on metformin therapy, or metformin in combination with other hypoglycemic drugs such as insulin and glibenclamide. Pooled estimates showed that resveratrol supplementation in patients with T2D lowered the levels of fasting glucose (SMD: -0.06 [95% CI: -0.24, 0.12]; I2 = 4%, p = 0.39) and insulin (SMD: -0.08 [95% CI: -0.50, 0.34], I2 = 73%, p = 0.002) when compared to those on placebo. In addition, supplementation significantly lowered systolic blood pressure (SMD: -5.77 [95% CI: -8.61, -2.93], I2 = 66%, p = 0.02) in these patients. Although resveratrol supplementation did not affect creatinine or urea levels, it reduced the total protein content (SMD: -0.19 [95% CI: -0.36, -0.02]; I2 = 91%, p = 0.001). In all, resveratrol supplementation in hypoglycemic therapy improves glucose control and lowers blood pressure; however, additional evidence is necessary to confirm its effect on renal function in patients with T2D.

The beneficial effects of N-acetyl cysteine (NAC) against obesity associated complications: A systematic review of pre-clinical studies.

Excessive adiposity in an obese state is known to drive the onset of metabolic dysregulations, mostly involving chronic immune activation and oxidative stress. Prolonged inflammation and oxidative stress have been linked to impaired adipose tissue function and the development of the metabolic syndrome. Currently available therapies offer minimal prophylactic effects, while substantial experimental evidence supports the ameliorative effects of N-acetylcysteine (NAC) against various metabolic complications associated with obesity. The current review provides a comprehensive synthesis of studies published in major search engines such as PubMed, Cochrane library, Embase, and Google Scholar assessing the therapeutic effect of NAC against obesity associated complications. Overwhelming literature included in this review supports the ameliorative effects of NAC against such complications in both in vitro and in vivo models of obesity. In addition to attenuating an abnormal pro-inflammatory response and limiting oxidative damage, NAC could inhibit lipid accumulation by targeting adipogenic transcription factors such as peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein beta (C/EBPß), and improve insulin sensitivity through augmenting phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway. Although necessary evidence informing on its optimal dose and its comparative effect with other well-studied pharmacological compounds is demonstrated, it is clear that future investigations are required to confirm the therapeutic effect of NAC in obese human subjects.

Immune-related adverse events associated with the use of immunotherapy in patients with B-cell lymphoblastic leukemia: A protocol for a systematic review and meta-analysis.

BACKGROUND: B-cell acute lymphoblastic leukemia (B-ALL) is a neoplasm of immature B-cells that is more prevalent in children. Despite successful remission rates in patients with B-ALL on chemotherapy, the risk of relapse is high. This has paved way for highly active immune and cell therapies to be intensively explored. However, the efficacy and immune-related adverse events (AE) associated with the use of immunotherapies remain elusive. METHODS: This protocol has been prepared in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 guidelines. Cochrane Central Register of Controlled Trials, MEDLINE, and Embase electronic databases will be searched to retrieve relevant interventional studies. Two reviewers (BKK and EH) will autonomously search and identify relevant studies using a preset inclusion and exclusion criteria. A predefined data extraction sheet will be used to extract relevant data items. The risk of bias will be assessed by 2 reviewers (BKK and BBN) using the Cochrane risk-of-bias tool for randomized controlled trials and the Downs and Black Checklist for nonrandomized controlled trials. A third reviewer (TMN) will be consulted for any discrepancies. The Grading of Recommendations Assessment Development and Evaluation will be used to assess the strengths of evidence by 2 reviewers (BBK and TMN). The I² and Chi-squared statistical tests will be used to investigate statistical heterogeneity across studies. An I² value of > 50% will be considered substantial heterogeneity and a random-effects model will be used. Data analysis will be performed using Review Manager (RevMan V.5.3) statistical software.

Impact of dyslipidemia in the development of cardiovascular complications: Delineating the potential therapeutic role of coenzyme Q10.

Dyslipidemia is one of the major risk factors for the development of cardiovascular disease (CVD) in patients with type 2 diabetes (T2D). This metabolic anomality is implicated in the generation of oxidative stress, an inevitable process involved in destructive mechanisms leading to myocardial damage. Fortunately, commonly used drugs like statins can counteract the detrimental effects of dyslipidemia by lowering cholesterol to reduce CVD-risk in patients with T2D. Statins mainly function by blocking the production of cholesterol by targeting the mevalonate pathway. However, by blocking cholesterol synthesis, statins coincidently inhibit the synthesis of other essential isoprenoid intermediates of the mevalonate pathway like farnesyl pyrophosphate and coenzyme Q10 (CoQ10). The latter is by far the most important co-factor and co-enzyme required for efficient mitochondrial oxidative capacity, in addition to its robust antioxidant properties. In fact, supplementation with CoQ10 has been found to be beneficial in ameliorating oxidative stress and improving blood flow in subjects with mild dyslipidemia.. Beyond discussing the destructive effects of oxidative stress in dyslipidemia-induced CVD-related complications, the current review brings a unique perspective in exploring the mevalonate pathway to block cholesterol synthesis while enhancing or maintaining CoQ10 levels in conditions of dyslipidemia. Furthermore, this review disscusses the therapeutic potential of bioactive compounds in targeting the downstream of the mevalonate pathway, more importantly, their ability to block cholesterol while maintaining CoQ10 biosynthesis to protect against the destructive complications of dyslipidemia.

An insight into brown/beige adipose tissue whitening, a metabolic complication of obesity with the multifactorial origin.

Brown adipose tissue (BAT), a thermoregulatory organ known to promote energy expenditure, has been extensively studied as a potential avenue to combat obesity. Although BAT is the opposite of white adipose tissue (WAT) which is responsible for energy storage, BAT shares thermogenic capacity with beige adipose tissue that emerges from WAT depots. This is unsurprising as both BAT and beige adipose tissue display a huge difference from WAT in terms of their secretory profile and physiological role. In obesity, the content of BAT and beige adipose tissue declines as these tissues acquire the WAT characteristics via the process called "whitening". This process has been rarely explored for its implication in obesity, whether it contributes to or exacerbates obesity. Emerging research has demonstrated that BAT/beige adipose tissue whitening is a sophisticated metabolic complication of obesity that is linked to multiple factors. The current review provides clarification on the influence of various factors such as diet, age, genetics, thermoneutrality, and chemical exposure on BAT/beige adipose tissue whitening. Moreover, the defects and mechanisms that underpin the whitening are described. Notably, the BAT/beige adipose tissue whitening can be marked by the accumulation of large unilocular lipid droplets, mitochondrial degeneration, and collapsed thermogenic capacity, by the virtue of mitochondrial dysfunction, devascularization, autophagy, and inflammation.

Expression of Caspase-3 in Circulating Innate Lymphoid Cells Subtypes Is Altered by Treatment with Metformin and Fluvastatin in High-Fat Diet Fed C57BL/6 Mice.

The current study aimed to determine the expression levels of caspase-3 in circulating innate lymphoid cell subtypes (ILCs) in a high-fat diet (HFD)-induced prediabetes mouse model. Another critical point was to assess the therapeutic effects of metformin and fluvastatin in modulating caspase-3 activation in ILCs within these HFD-fed mice. Prominent results showed that mice exposed to HFD for 14 weeks displayed impaired glucose tolerance that was accompanied by elevated levels of low-density lipoprotein cholesterol (LDL-c) and altered haematological profile as characterised by significantly increased concentrations of red blood cell count, white cell count and lymphocytes when compared to those fed a low-fat diet (LFD). Moreover, the expression of caspase-3 in ILC1 and ILC3 was significantly increased in the HFD groups in comparison to the LFD-fed group. Notably, six-week treatment with metformin and fluvastatin reduced the caspase-3 activation in ILC subtypes. The reduced caspase-3 activation in ILC1 was inversely associated with HDL-c levels following metformin treatment. Interestingly, the reduced caspase-3 activation in ILC3 was associated with lower total cholesterol following fluvastatin treatment in these HFD-fed mice. However, there were no differences in activation of caspase-3 on ILC2 or any association between caspase-3 activation and changes in body weight or fasting blood glucose. Thus, while HFD-feeding clearly modulates ILCs, potentially leading to pro-apoptotic mechanisms, metformin and fluvastatin may play a major role in protecting against such metabolic disturbances.

Impact of physical exercise and caloric restriction in patients with type 2 diabetes: Skeletal muscle insulin resistance and mitochondrial dysfunction as ideal therapeutic targets.

Skeletal muscle insulin resistance and mitochondrial dysfunction are some of the major pathological defects implicated in the development of type 2 diabetes (T2D). Therefore, it has become necessary to understand how common interventions such as physical exercise and caloric restriction affect metabolic function, including physiological processes that implicate skeletal muscle dysfunction within a state of T2D. This review critically discusses evidence on the impact of physical exercise and caloric restriction on markers of insulin resistance and mitochondrial dysfunction within the skeletal muscle of patients with T2D or related metabolic complications. Importantly, relevant information from clinical studies was acquired through a systematic approach targeting major electronic databases and search engines such as PubMed, Google Scholar, and Cochrane library. The reported evidence suggests that interventions like physical exercise and caloric restriction, within a duration of approximately 2 to 4 months, can improve insulin sensitivity, in part by targeting the phosphoinositide 3-kinases/protein kinase B pathway in patients with T2D. Furthermore, both physical exercise and caloric restriction can effectively modulate markers related to improved mitochondrial function and dynamics. This was consistent with an improved modulation of mitochondrial oxidative capacity and reduced production of reactive oxygen species in patients with T2D or related metabolic complications. However, such conclusions are based on limited evidence, additional clinical trials are required to better understand these interventions on pathological mechanisms of T2D and related abnormalities.