RESUMO
The pathological consequences of inflammation persist in people living with the human immunodeficiency virus (PLWH), regardless of the positive outcomes of highly active antiretroviral therapy (HAART). The current systematic review and meta-analysis aims to understand and explore the levels of high-sensitivity C-reactive protein (hs-CRP) and other cardiovascular disease (CVD)-risk factors including lipid profiles among PLWH on HAART. Major electronic databases including PubMed, Scopus, and Web of Science were searched to retrieve relevant global literature reporting on hs-CRP levels in PLWH on HAART. A total of twenty-two studies with an average participant age of 40 years were eligible for this systematic review and meta-analysis. Majority of the included studies were from Africa (n = 11), the United States (n = 6), and Europe (n = 5). Our systemic review showed that most studies reported increased levels of hs-CRP among PLWH on HAART when compared to controls (PLWH not on HAART or those without HIV), especially in studies from Africa. This was supported by a meta-analysis showing significantly elevated levels of hs-CRP in PLWH on HAART when compared to PLWH not on HAART (standardised mean difference [SMD] = 0.56; 95% CI = 0.101.01, z = 2.41; p = 0.02) or those without HIV (SMD = 1.19; 95% CI = 0.761.63, z = 5.35; p < 0.001). Where lipid profiles, as a major predictor for CVD risk, were also impaired in PLWH on HAART when compared to PLWH not on HAART and HIV-negative participants. In conclusion, elevated levels of hs-CRP and lipid levels are prevalent in PLWH on HAART, this may increase the risk of CVD complications, especially for those people living in Africa. However, more evidence in larger population studies is required to confirm these outcomes and unveil any possible clinical implications of HAART-induced modulation of hs-CRP levels in PLWH.
Assuntos
Doenças Cardiovasculares , Infecções por HIV , Humanos , Adulto , Terapia Antirretroviral de Alta Atividade , Proteína C-Reativa , HIV , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , LipídeosRESUMO
Sarcopenia remains one of the major pathological features of type 2 diabetes (T2D), especially in older individuals. This condition describes gradual loss of muscle mass, strength, and function that reduces the overall vitality and fitness, leading to increased hospitalizations and even fatalities to those affected. Preclinical evidence indicates that dysregulated mitochondrial dynamics, together with impaired activity of the NADPH oxidase system, are the major sources of oxidative stress that drive skeletal muscle damage in T2D. While patients with T2D also display relatively higher levels of circulating inflammatory markers in the serum, including high sensitivity-C-reactive protein, interleukin-6, and tumor necrosis factor-α that are independently linked with the deterioration of muscle function and sarcopenia in T2D. In fact, beyond reporting on the pathological consequences of both oxidative stress and inflammation, the current review highlights the importance of strengthening intracellular antioxidant systems to preserve muscle mass, strength, and function in individuals with T2D.
RESUMO
Insulin resistance and pancreatic ß-cell dysfunction are major pathological mechanisms implicated in the development and progression of type 2 diabetes (T2D). Beyond the detrimental effects of insulin resistance, inflammation and oxidative stress have emerged as critical features of T2D that define ß-cell dysfunction. Predominant markers of inflammation such as C-reactive protein, tumor necrosis factor alpha, and interleukin-1ß are consistently associated with ß-cell failure in preclinical models and in people with T2D. Similarly, important markers of oxidative stress, such as increased reactive oxygen species and depleted intracellular antioxidants, are consistent with pancreatic ß-cell damage in conditions of T2D. Such effects illustrate a pathological relationship between an abnormal inflammatory response and generation of oxidative stress during the progression of T2D. The current review explores preclinical and clinical research on the patho-logical implications of inflammation and oxidative stress during the development of ß-cell dysfunction in T2D. Moreover, important molecular mechanisms and relevant biomarkers involved in this process are discussed to divulge a pathological link between inflammation and oxidative stress during ß-cell failure in T2D. Underpinning the clinical relevance of the review, a systematic analysis of evidence from randomized controlled trials is covered, on the potential therapeutic effects of some commonly used antidiabetic agents in modulating inflammatory makers to improve ß-cell function.
RESUMO
Cardiovascular diseases (CVDs) continue to be the leading cause of death in people with diabetes mellitus. Severely suppressed intracellular antioxidant defenses, including low plasma glutathione (GSH) levels, are consistently linked with the pathological features of diabetes such as oxidative stress and inflammation. In fact, it has already been established that low plasma GSH levels are associated with increased risk of CVD in people with diabetes. Dietary supplements are widely used and may offer therapeutic benefits for people with diabetes at an increased risk of developing CVDs. However, such information remains to be thoroughly scrutinized. Hence, the current systematic review explored prominent search engines, including PubMed and Google Scholar, for updated literature from randomized clinical trials reporting on the effects of dietary supplements on plasma GSH levels in people with diabetes. Available evidence indicates that dietary supplements, such as coenzyme Q10, selenium, curcumin, omega-3 fatty acids, and vitamin E or D, may potentially improve cardiometabolic health in patients with diabetes. Such beneficial effects are related to enhancing plasma GSH levels and reducing cholesterol, including biomarkers of oxidative stress and inflammation. However, available evidence is very limited and additional clinical studies are still required to validate these findings, including resolving issues related to the bioavailability of these bioactive compounds.
Assuntos
Doenças Cardiovasculares , Diabetes Mellitus , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Suplementos Nutricionais , Antioxidantes/farmacologia , Diabetes Mellitus/tratamento farmacológico , Glutationa , Estresse Oxidativo , Doenças Cardiovasculares/etiologia , Inflamação/tratamento farmacológicoRESUMO
Unlike the white adipose tissue (WAT) which mainly stores excess energy as fat, brown adipose tissue (BAT) has become physiologically important and therapeutically relevant for its prominent role in regulating energy metabolism. The current study makes use of an established animal model of type 2 diabetes (T2D) db/db mice to determine the effect of the disease progression on adipose tissue morphology and gene regulatory signatures. Results showed that WAT and BAT from db/db mice display a hypertrophied phenotype that is consistent with increased expression of the pro-inflammatory cytokine, tumor necrosis factor-alpha (Tnf-α). Moreover, BAT from both db/db and non-diabetic db/+ control mice displayed an age-related impairment in glucose homeostasis, inflammatory profile, and thermogenic regulation, as demonstrated by reduced expression of genes like glucose transporter (Glut-4), adiponectin (AdipoQ), and uncoupling protein 1 (Ucp-1). Importantly, gene expression of the batokines regulating sympathetic neurite outgrowth and vascularization, including bone morphogenic protein 8b (Bmp8b), fibroblast growth factor 21 (Fgf-21), neuregulin 4 (Nrg-4) were altered in BAT from db/db mice. Likewise, gene expression of meteorin-like (Metrnl), growth differentiation factor 15 (Gdt-15), and C-X-C motif chemokine-14 (Cxcl-14) regulating pro- and anti-inflammation were altered. This data provides some new insights into the pathophysiological mechanisms involved in BAT hypertrophy (or whitening) and the disturbances of batokines during the development and progression of T2D. However, these are only preliminary results as additional experiments are necessary to confirm these findings in other experimental models of T2D.
Assuntos
Tecido Adiposo Marrom , Diabetes Mellitus Tipo 2 , Progressão da Doença , Animais , Camundongos , Adiponectina/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Camundongos Endogâmicos C57BL , TermogêneseRESUMO
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.
RESUMO
Moringa oleifera is one of the popular plants that have shown significant health benefits. Certainly, preclinical evidence (predominantly from animal models) summarized in the current review supports the beneficial effects of Moringa oleifera leaf extracts in combating the prominent characteristic features of diabetes mellitus. This includes effective control of blood glucose or insulin levels, enhancement of insulin tissue sensitivity, improvement of blood lipid profiles, and protecting against organ damage under sustained conditions of hyperglycemia. Interestingly, as major complications implicated in the progression of diabetes, including organ damage, Moringa oleifera leaf and seed extracts could efficiently block the detrimental effects of oxidative stress and inflammation in these preclinical models. Notably, these extracts (especially leaf extracts) showed enhanced effects in strengthening intracellular antioxidant defences like catalase, superoxide dismutase, and glutathione to lower lipid peroxidation products and reduce prominent pro-inflammatory markers such as tumor necrosis factor-α, interleukin (1L)-ß, IL-6, monocyte chemoattractant protein-1 and nitric oxide synthase. From animal models of diabetes, the common and effective dose of leaf extracts of Moringa oleifera was 100-300 mg/kg, within the treatment duration of 2-8 weeks. Whereas supplementation with approximately 20 g leaf powder of Moringa oleifera for at least 2 weeks could improve postprandial blood glucose in subjects with prediabetes or diabetes. Although limited clinical studies have been conducted on the antidiabetic properties of Moringa oleifera, current findings provide an important platform for future research directed at developing this plant as a functional food to manage diabetic complications.
RESUMO
Chronic inflammation remains an essential complication in the pathogenesis and aggravation of metabolic diseases. There is a growing interest in the use of medicinal plants or food-derived bioactive compounds for their antioxidant and anti-inflammatory properties to improve metabolic function. For example, rutin, a flavonol derivative of quercetin that is found in several medicinal plants and food sources has displayed therapeutic benefits against diverse metabolic diseases. Here, we searched the major electronic databases and search engines such as PubMed/MEDLINE, Scopus and Google Scholar to systematically extract and critically discuss evidence reporting on the impact of rutin against metabolic diseases by affecting inflammation. In fact, available preclinical evidence suggests that rutin, through its strong antioxidant properties, can effectively ameliorate inflammation by reducing the levels of pro-inflammatory markers such as tumor necrosis factor-α, interleukin (IL)-6, cyclooxygenase-2, IL-1ß, as well as blocking nuclear factor kappa B (NF-κB)/mitogen-activated protein kinase (MAPK) activation to improve metabolic function. Notably, although clinical data on the impact of rutin on inflammation is limited, food-derived sources rich in this flavonol such as Fagopyrum tataricum, Coffea arabica and Aspalathus linearis (rooibos) have shown promise in improving metabolic function, in part by reducing markers of oxidative stress and inflammation. However, additional studies are still required to confirm the therapeutic properties of rutin in a clinical setting, including the enhancement of it low bioavailability profile.
Assuntos
Antioxidantes , Rutina , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Interleucina-6/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo , Rutina/farmacologia , Rutina/uso terapêuticoRESUMO
Currently, liver transplantation is considered as the definitive treatment option for individuals with complete liver failure. However, the detrimental effects of oxidative stress and inflammation remain the predominant feature that drives hepatic ischemia-reperfusion injury during liver transplantation. As such, therapeutic drugs that hinder oxidative stress and attenuate inflammation, have become ideal targets to curb liver injuries during transplantation. The current review analyses available clinical evidence on the importance of using N-acetyl cysteine (NAC) during liver transplantation. Thus, prominent online search engines such as PubMed and Google Scholar were accessed to retrieve literature from randomized clinical trials reporting on the use of NAC during liver transplantation. Overwhelming evidence suggests that established therapeutic properties of NAC, through enhancing endogenous antioxidants like glutathione to block oxidative stress and attenuate inflammation, remain essential to improve liver function in patients undergoing liver transportation. However, to the contrary, some clinical studies did not show any beneficial effects in patients receiving NAC during liver transplantation. Thus, such controversies, in addition to discussing the implications of oxidative stress and inflammation in relation to hepatic ischemia-reperfusion injury remain the major subject of the current review.
Assuntos
Acetilcisteína/farmacologia , Acetilcisteína/uso terapêutico , Inflamação/tratamento farmacológico , Transplante de Fígado/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Humanos , Inflamação/patologia , Falência Hepática/patologia , Estresse Oxidativo/fisiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/prevenção & controleRESUMO
Low grade inflammation is associated with the progression of atherosclerosis. Patients with type 2 diabetes (T2D) have altered cholesterol levels, which are targeted by free radicals to promote lipid peroxidation. Elevated levels of monocyte-associated cytokines such as interleukin (IL)-6, monocyte chemoattractant protein 1 (MCP-1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and tumor necrosis factor-alpha (TNF-α), subsequently drive endothelial tissue injury. In fact, the levels of circulating platelet-monocyte aggregates in patients with T2D is a robust marker for atherosclerosis and a cardiovascular disease (CVD)-risk factor. To identify eligible studies, we searched the major online databases using PubMed and Google Scholar. The cumulative evidence synthesized in the current review suggests that, traditional therapies which include thiazolidinediones, statins and some calcium channel blockers can be useful in the primary prevention of atherosclerosis by inhibiting the formation of monocyte-derived microparticles, and pro-inflammatory cytokines such as IL-6, TNF-α, MCP-1, and NF-κB in patients with T2D. Future studies are needed to ascertain whether the combination of dietary interventions and glucose or lipid lowering agents can provide an enhanced cardioprotection in patients with T2D.
Assuntos
Anti-Inflamatórios/farmacologia , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Hipoglicemiantes/farmacologia , Monócitos/efeitos dos fármacos , Fatores de Risco de Doenças Cardíacas , Humanos , Inflamação/metabolismoRESUMO
Oxidative stress is a key pathological feature implicated in both acute and chronic liver diseases, including drug-induced liver injury (DILI). The latter describes hepatic injury arising as a direct toxic effect of administered drugs or their metabolites. Although still underreported, DILI remains a significant cause of liver failure, especially in developed nations. Currently, it is understood that mitochondrial-generated oxidative stress and abnormalities in phase I/II metabolism, leading to glutathione (GSH) suppression, drive the onset of DILI. N-Acetyl cysteine (NAC) has attracted a lot of interest as a therapeutic agent against DILI because of its strong antioxidant properties, especially in relation to enhancing endogenous GSH content to counteract oxidative stress. Thus, in addition to updating information on the pathophysiological mechanisms implicated in oxidative-induced hepatic injury, the current review critically discusses clinical evidence on the protective effects of NAC against DILI, including the reduction of patient mortality. Besides injury caused by paracetamol, NAC can also improve liver function in relation to other forms of liver injury such as those induced by excessive alcohol intake. The implicated therapeutic mechanisms of NAC extend from enhancing hepatic GSH levels to reducing biomarkers of paracetamol toxicity such as keratin-18 and circulating caspase-cleaved cytokeratin-18. However, there is still lack of evidence confirming the benefits of using NAC in combination with other therapies in patients with DILI.
Assuntos
Acetilcisteína/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Sequestradores de Radicais Livres/farmacologia , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , HumanosRESUMO
Oxidative stress and inflammation remain the major complications implicated in the development and progression of metabolic complications, including obesity, type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD). In fact, due to their abundant antioxidant and anti-inflammatory properties, there is a general interest in understanding the therapeutic effects of some major food-derived bioactive compounds like curcumin against diverse metabolic diseases. Hence, a systematic search, through prominent online databases such as MEDLINE, Scopus, and Google Scholar was done focusing on randomized controlled trials (RCTs) reporting on the impact of curcumin supplementation in individuals with diverse metabolic complications, including obesity, T2D and NAFLD. Summarized findings suggest that curcumin supplementation can significantly reduce blood glucose and triglycerides levels, including markers of liver function like alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in patients with T2D and NAFLD. Importantly, this effect was consistent with the reduction of predominant markers of oxidative stress and inflammation, such as the levels of malonaldehyde (MDA), tumor necrosis factor-alpha (TNF-α), high sensitivity C-reactive protein (hs-CRP) and monocyte chemoattractant protein-1 (MCP-1) in these patients. Although RCTs suggest that curcumin is beneficial in ameliorating some metabolic complications, future research is still necessary to enhance its absorption and bioavailability profile, while also optimizing the most effective therapeutic doses.
Assuntos
Antioxidantes/administração & dosagem , Curcumina/administração & dosagem , Diabetes Mellitus Tipo 2/dietoterapia , Suplementos Nutricionais , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Obesidade/dietoterapia , Biomarcadores/sangue , Diabetes Mellitus Tipo 2/sangue , Alimento Funcional , Humanos , Inflamação , Hepatopatia Gordurosa não Alcoólica/sangue , Obesidade/sangue , Estresse Oxidativo/efeitos dos fármacosRESUMO
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.
Assuntos
Músculo Esquelético/metabolismo , Polifenóis/farmacologia , Animais , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Humanos , Músculo Esquelético/efeitos dos fármacos , Polifenóis/químicaRESUMO
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.
Assuntos
Adipocinas/metabolismo , Hipoglicemiantes/uso terapêutico , Síndrome Metabólica/tratamento farmacológico , Metformina/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Hipoglicemiantes/farmacologia , Resistência à Insulina , Síndrome Metabólica/sangue , Síndrome Metabólica/metabolismo , Metformina/farmacologia , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Impaired adipose tissue function and insulin resistance remain instrumental in promoting hepatic lipid accumulation in conditions of metabolic syndrome. In fact, enhanced lipid accumulation together with oxidative stress and an abnormal inflammatory response underpin the development and severity of non-alcoholic fatty liver disease (NAFLD). There are currently no specific protective drugs against NAFLD, and effective interventions involving regular exercise and healthy diets have proved difficult to achieve and maintain. Alternatively, due to its antioxidant and anti-inflammatory properties, there has been growing interest in understanding the therapeutic effects of N-acetyl cysteine (NAC) against metabolic complications, including NAFLD. Here, reviewed evidence suggests that NAC blocks hepatic lipid accumulation in preclinical models of NAFLD. This is in part through the effective regulation of a fatty acid scavenger molecule (CD36) and transcriptional factors such as sterol regulatory element-binding protein (SREBP)-1c/-2 and peroxisome proliferator-activated receptor gamma (PPARγ). Importantly, NAC appears effective in improving liver function by reducing pro-inflammatory markers such as interleukin (IL)-6 IL-1ß, tumour necrosis factor alpha (TNF-α) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). This was primarily through the attenuation of lipid peroxidation and enhancements in intracellular response antioxidants, particularly glutathione. Very few clinical studies support the beneficial effects of NAC against NAFLD-related complications, thus well-organized randomized clinical trials are still necessary to confirm its therapeutic potential.
RESUMO
The current study explored the effect of isoorientin on the metabolic activity and lipid accumulation in fully differentiated 3T3-L1 adipocytes. To achieve this, the 3T3-L1 pre-adipocytes were differentiated for eight days and treated with various concentrations of isoorientin (0.1-100 µM) for four hours. Subsequently, the metabolic activity, lipid accumulation, and mitochondrial respiration were assessed. Furthermore, to unravel the molecular mechanisms that might elucidate the bioactivity of isoorientin, protein expression of the genes involved in insulin signaling and energy expenditure, such as AKT and AMPK, were investigated. The results showed that isoorientin, at different doses, could block lipid storage and enhance glycerol release, with a concomitant improvement of the metabolic activity and mitochondrial function. Although the observed beneficial effects of isoorientin on these cultured 3T3-L1 adipocytes were not consistent at all concentrations, it was clear that doses between 1 and 10 µM were most effective compared to the untreated control. Moreover, the activity of isoorientin was comparable to tested positive controls of CL-316,2431, isoproterenol, insulin, and metformin. Mechanistically, protein expression of AKT and AMPK, was enhanced with isoorientin exposure, suggesting their partial role in modulating lipid metabolism and mitochondrial biogenesis. Indeed, our results showed that isoorientin has the ability to enhance mitochondrial respiration, as we observed an increase in the ATP and oxygen consumption rate. Therefore, we concluded that isoorientin has a potential to impact mitochondrial activity, lipid metabolism and energy expenditure using an in vitro experimental model of obesity.
Assuntos
Adipócitos/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Luteolina/farmacologia , Mitocôndrias/efeitos dos fármacos , Obesidade/metabolismo , Células 3T3-L1 , Quinases Proteína-Quinases Ativadas por AMP , Trifosfato de Adenosina/metabolismo , Adipócitos/metabolismo , Animais , Dioxóis/farmacologia , Glucose/metabolismo , Insulina/metabolismo , Insulina/farmacologia , Isoproterenol/farmacologia , Metformina/farmacologia , Camundongos , Mitocôndrias/metabolismo , Obesidade/tratamento farmacológico , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Aspalathin is a rooibos flavonoid with established blood glucose lowering properties, however, its efficacy to moderate complications associated with hepatic insulin resistance is unknown. To study such effects, C3A liver cells exposed to palmitate were used as a model of hepatic insulin resistance. These hepatocytes displayed impaired substrate metabolism, including reduced glucose transport and free fatty acid uptake. These defects included impaired insulin signaling, evident through reduced phosphatidylinositol-4,5-bisphosphate 3-kinase/ protein kinase B (PI3K/AKT) protein expression, and mitochondrial dysfunction, depicted by a lower mitochondrial respiration rate. Aspalathin was able to ameliorate these defects by correcting altered substrate metabolism, improving insulin signaling and mitochondrial bioenergetics. Activation of 5'-adenosine monophosphate-activated protein kinase (AMPK) may be a plausible mechanism by which aspalathin increases hepatic energy expenditure. Overall, these results encourage further studies assessing the potential use of aspalathin as a nutraceutical to improve hepatocellular energy expenditure, and reverse metabolic disease-associated complications.