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Role of mitochondria, oxidative stress and the response to antioxidants in myalgic encephalomyelitis/chronic fatigue syndrome: A possible approach to SARS-CoV-2 'long-haulers'?
Wood, E, Hall, KH, Tate, W
Chronic diseases and translational medicine. 2021;7(1):14-26
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Cases of chronic fatigue have been reported following recovery from Covid-19, in what is termed ‘Long Covid’, with symptoms likened to that of sufferers from chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME). How CFS/ME develop and treatments may help to further understand Covid-19. This review study of 111 studies aimed to identify where urgent research is required to help understand the potential of chronic fatigue therapies in Covid-19. The study first reviewed disrupted cellular energy production in ME/CFS and increased presence of damaging oxidants. Current therapies for improving cellular energy production in CFS/ME were then reviewed and Ritalin, ubiquinone and mitoquinol mesylate were heavily featured. Antioxidant therapies in CFS/ME were reviewed and observations would suggest that trials in patients with long covid are needed. It was concluded that research in cellular energy production in CFS/ME has been increasing, however remains contradictory due to a lack of a definitive diagnosis, differing disease severity and the huge differences between patients who suffer from CFS/ME. Further research is required in ME/CFS and Covid-19. This study could be used by health care professionals to understand the importance of monitoring symptoms of fatigue post Covid-19 infection and the possible use of ME/CFS treatments.
Abstract
A significant number of SARS-CoV-2 (COVID-19) pandemic patients have developed chronic symptoms lasting weeks or months which are very similar to those described for myalgic encephalomyelitis/chronic fatigue syndrome. This study reviews the current literature and understanding of the role that mitochondria, oxidative stress and antioxidants may play in the understanding of the pathophysiology and treatment of chronic fatigue. It describes what is known about the dysfunctional pathways which can develop in mitochondria and their relationship to chronic fatigue. It also reviews what is known about oxidative stress and how this can be related to the pathophysiology of fatigue, as well as examining the potential for specific therapy directed at mitochondria for the treatment of chronic fatigue in the form of antioxidants. This study identifies areas which require urgent, further research in order to fully elucidate the clinical and therapeutic potential of these approaches.
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Dissecting the interaction between COVID-19 and diabetes mellitus.
Chee, YJ, Tan, SK, Yeoh, E
Journal of diabetes investigation. 2020;11(5):1104-1114
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Several countries have reported higher death rates and more severe cases of covid-19 amongst individuals with chronic diseases such as type 2 diabetes. This review of 100 papers aimed to investigate the interconnecting factors which may contribute to poorer prognosis in individuals with covid-19 and type 2 diabetes. Although the evidence suggests that patients with type 2 diabetes have poorer outcomes after contracting covid-19, they are not more susceptible to infection. The paper reported that mechanisms which may increase severity in type 2 diabetics are abnormal immune function, increased susceptibility to inflammation, the increased adherence of the virus to target cells and reduced ability to fight infection. It is important to manage blood sugars when suffering from covid-19. The paper reviewed the use of several medications such as metformin, dipeptidyl peptidase-4 inhibitors (DPP4), glucagon-like peptide-1 agonists and insulin in the context of individuals suffering from covid-19, with insulin being the treatment of choice in the acutely ill patient. Current treatments of covid-19 were also reviewed such as chloroquine and hydroxychloroquine, Lopinavir-ritonavir, IL-6 receptor agonists, type 1 interferon and remdesivir. It was concluded that clinicians should be aware of the risks in patients with type 2 diabetes and covid-19. However as new data is made available, the chronic and long-term implications will become clearer. This study could be used by health care professionals to ensure that patients with type 2 diabetes do everything they can to avoid covid-19 infection and that if contracted these patients are closely monitored for severe disease.
Abstract
Coronavirus disease 2019 (COVID-19) is a global pandemic that is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus-2. Data from several countries have shown higher morbidity and mortality among individuals with chronic metabolic diseases, such as diabetes mellitus. In this review, we explore the contributing factors for poorer prognosis in these individuals. As a significant proportion of patients with COVID-19 also have diabetes mellitus, this adds another layer of complexity to their management. We explore potential interactions between antidiabetic medications and renin-angiotensin-aldosterone system inhibitors with COVID-19. Suggested recommendations for the use of antidiabetic medications for COVID-19 patients with diabetes mellitus are provided. We also review pertinent clinical considerations in the management of diabetic ketoacidosis in COVID-19 patients. In addition, we aim to increase clinicians' awareness of the metabolic effects of promising drug therapies for COVID-19. Finally, we highlight the importance of timely vaccinations for patients with diabetes mellitus.
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Effect of Hesperidin on Cardiovascular Disease Risk Factors: The Role of Intestinal Microbiota on Hesperidin Bioavailability.
Mas-Capdevila, A, Teichenne, J, Domenech-Coca, C, Caimari, A, Del Bas, JM, Escoté, X, Crescenti, A
Nutrients. 2020;12(5)
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Cardiovascular diseases (CVDs) cause around 31% of all deaths worldwide. Certain dietary patterns have been associated with a reduction in CVDs and so the use of natural-based products has gained importance as a preventive strategy. Hesperidin is a bioactive compound found in high levels in citrus fruits. The reported beneficial properties include antitumor, antioxidant, anti-inflammatory; cholesterol and glucose lowering effects. Many animal studies show multiple beneficial effects but are inconclusive in human studies. The aim of this review is to describe the effects of hesperidin on CVD factors and to highlight the individual differences in its bioavailability and effectiveness. The gut bacteria play an important role in this. Hesperidin is not broken down by the normal digestive process and reaches the colon largely intact. It is the job of the gut bacteria to break it down into bioavailable substances that can be absorbed and utilised. The discrepancies observed in some of the results from human clinical trials may be partly due to individual differences, including that of the gut bacteria. Further clinical trials should be considered as well as classifying individuals according to individual differences in metabotypes.
Abstract
Recently, hesperidin, a flavonone mainly present in citrus fruits, has emerged as a new potential therapeutic agent able to modulate several cardiovascular diseases (CVDs) risk factors. Animal and in vitro studies demonstrate beneficial effects of hesperidin and its derived compounds on CVD risk factors. Thus, hesperidin has shown glucose-lowering and anti-inflammatory properties in diabetic models, dyslipidemia-, atherosclerosis-, and obesity-preventing effects in CVDs and obese models, and antihypertensive and antioxidant effects in hypertensive models. However, there is still controversy about whether hesperidin could contribute to ameliorate glucose homeostasis, lipid profile, adiposity, and blood pressure in humans, as evidenced by several clinical trials reporting no effects of treatments with this flavanone or with orange juice on these cardiovascular parameters. In this review, we focus on hesperidin's beneficial effects on CVD risk factors, paying special attention to the high interindividual variability in response to hesperidin-based acute and chronic interventions, which can be partly attributed to differences in gut microbiota. Based on the current evidence, we suggest that some of hesperidin's contradictory effects in human trials are partly due to the interindividual hesperidin variability in its bioavailability, which in turn is highly dependent on the α-rhamnosidase activity and gut microbiota composition.
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Potential Adverse Effects of Resveratrol: A Literature Review.
Shaito, A, Posadino, AM, Younes, N, Hasan, H, Halabi, S, Alhababi, D, Al-Mohannadi, A, Abdel-Rahman, WM, Eid, AH, Nasrallah, GK, et al
International journal of molecular sciences. 2020;21(6)
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Resveratrol is a polyphenol compound found naturally in plant foods. It has several therapeutic effects including antioxidant, anti-inflammatory and cardio protective properties. This review focuses however on the potential adverse effects of resveratrol to better understand the nutrient and its use in therapy. Evidence suggests that dosage is important with low doses of resveratrol having beneficial effects, whilst high doses can be associated with toxicity. However, many studies also report poor bioavailability of resveratrol meaning the body is unable to absorb it efficiently. This may also be influenced by differences in gut bacteria. So, toxicity will differ from one patient to the next. It is also noted that most studies focus on short-term usage and outcomes whilst more data may be required to understand the effects of longer-term usage. The differences in studies, and usage of resveratrol, means the characteristics of patients and symptoms reported vary greatly. This makes it hard to rigorously evaluate adverse effects as there is a high level of variability between one study and another. The review concludes that if there was more uniformity in study designs it would be easier to evaluate both beneficial and adverse effects.
Abstract
Due to its health benefits, resveratrol (RE) is one of the most researched natural polyphenols. Resveratrol's health benefits were first highlighted in the early 1990s in the French paradox study, which opened extensive research activity into this compound. Ever since, several pharmacological activities including antioxidant, anti-aging, anti-inflammatory, anti-cancerous, anti-diabetic, cardioprotective, and neuroprotective properties, were attributed to RE. However, results from the available human clinical trials were controversial concerning the protective effects of RE against diseases and their sequelae. The reason for these conflicting findings is varied but differences in the characteristics of the enrolled patients, RE doses used, and duration of RE supplementation were proposed, at least in part, as possible causes. In particular, the optimal RE dosage capable of maximizing its health benefits without raising toxicity issues remains an area of extensive research. In this context, while there is a consistent body of literature on the protective effects of RE against diseases, there are relatively few reports investigating its possible toxicity. Indeed, toxicity and adverse effects were reported following consumption of RE; therefore, extensive future studies on the long-term effects, as well as the in vivo adverse effects, of RE supplementation in humans are needed. Furthermore, data on the interactions of RE when combined with other therapies are still lacking, as well as results related to its absorption and bioavailability in the human body. In this review, we collect and summarize the available literature about RE toxicity and side effects. In this process, we analyze in vitro and in vivo studies that have addressed this stilbenoid. These studies suggest that RE still has an unexplored side. Finally, we discuss the new delivery methods that are being employed to overcome the low bioavailability of RE.
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Role of Probiotics in Non-alcoholic Fatty Liver Disease: Does Gut Microbiota Matter?
Xie, C, Halegoua-DeMarzio, D
Nutrients. 2019;11(11)
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Non-alcoholic fatty liver disease (NAFLD) is characterised by an excessive accumulation of fat in the liver tissue, without excessive alcohol consumption, and appears to be related to metabolic syndrome. It is thought to have a prevalence of 25% globally and there are no pharmacological treatments available. This review discusses the connection between the gut microbiota (GM) and NAFLD. Various mechanisms by which the GM may be involved in the development of NAFLD are discussed. As probiotics and prebiotics can normalise GM and reverse dysbiosis their use may benefit patients with NAFLD. This has been confirmed in animal models. The authors review 26 randomised controlled trials (RCTs) of probiotics and/or prebiotics in the treatment of NAFLD which evaluate biochemical markers, as well as five meta-analyses, and found that overall there is strong evidence that probiotics and/or prebiotics can lower ALT and AST (markers of NAFLD), although results for other biochemical markers were mixed. They also reviewed RCTs assessing NAFLD by imaging and histological means, and again found benefits from probiotic and/or prebiotic supplementation.
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the hepatic consequence of metabolic syndrome, which often also includes obesity, diabetes, and dyslipidemia. The connection between gut microbiota (GM) and NAFLD has attracted significant attention in recent years. Data has shown that GM affects hepatic lipid metabolism and influences the balance between pro/anti-inflammatory effectors in the liver. Although studies reveal the association between GM dysbiosis and NAFLD, decoding the mechanisms of gut dysbiosis resulting in NAFLD remains challenging. The potential pathophysiology that links GM dysbiosis to NAFLD can be summarized as: (1) disrupting the balance between energy harvest and expenditure, (2) promoting hepatic inflammation (impairing intestinal integrity, facilitating endotoxemia, and initiating inflammatory cascades with cytokines releasing), and (3) altered biochemistry metabolism and GM-related metabolites (i.e., bile acid, short-chain fatty acids, aromatic amino acid derivatives, branched-chain amino acids, choline, ethanol). Due to the hypothesis that probiotics/synbiotics could normalize GM and reverse dysbiosis, there have been efforts to investigate the therapeutic effect of probiotics/synbiotics in patients with NAFLD. Recent randomized clinical trials suggest that probiotics/synbiotics could improve transaminases, hepatic steatosis, and reduce hepatic inflammation. Despite these promising results, future studies are necessary to understand the full role GM plays in NAFLD development and progression. Additionally, further data is needed to unravel probiotics/synbiotics efficacy, safety, and sustainability as a novel pharmacologic approaches to NAFLD.
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Medical and Dietary Uses of N-Acetylcysteine.
Šalamon, Š, Kramar, B, Marolt, TP, Poljšak, B, Milisav, I
Antioxidants (Basel, Switzerland). 2019;8(5)
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N-Acetylcysteine (NAC) is an antioxidant naturally found in plants of the Allium species such as onions. As well as having antioxidant and anti-inflammatory properties, it is also needed to make glutathione which is an important antioxidant in cells. NAC has been used as a drug since the 1960s and is a popular dietary supplement. NAC is considered safe but the results of clinical trials are controversial or incomplete. This aim of this review is to provide a balanced view of further uses of NAC as a dietary supplement. It discusses the antioxidant properties in relation to conditions such as heart disease, diabetes and ageing; its medical uses, in the complementary treatment of cancer, as a sports supplement and as an anti-aging supplement. More information is needed on NAC and further clinical trials looking at its use in neurodegenerative diseases, addiction, and mental health disorders are underway. This may be relevant to the supplement users and may also help people suffering from chronic degenerative conditions.
Abstract
N-acetylcysteine (NAC), a plant antioxidant naturally found in onion, is a precursor to glutathione. It has been used as a drug since the 1960s and is listed on the World Health Organization (WHO) Model List of Essential Medicines as an antidote in poisonings. There are numerous other uses or proposed uses in medicine that are still in preclinical and clinical investigations. NAC is also used in food supplements and cosmetics. Despite its abundant use, there are projections that the NAC global market will grow in the next five years; therefore, the purpose of this work is to provide a balanced view of further uses of NAC as a dietary supplement. Although NAC is considered a safe substance, the results among clinical trials are sometimes controversial or incomplete, like for many other antioxidants. More clinical trials are underway that will improve our understanding of NAC applicability.
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Treatment of Obesity: Weight Loss and Bariatric Surgery.
Wolfe, BM, Kvach, E, Eckel, RH
Circulation research. 2016;118(11):1844-55
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Individuals with obesity who have been unable to lose weight through non-surgical means may be candidates for bariatric surgery. Criteria was established over 20 years ago and stated that individuals with a BMI >40 and individuals with a BMI >35-40 with other related conditions who have failed to achieve weight loss medically, are appropriate for surgery. However, individuals with less severe obesity who have type 2 diabetes have now been highlighted as possible candidates also, indicating that it is an evolving process. This review of 123 papers focused on the indications, safety and reasons for bariatric surgery and its role in the reduction of heart disease. The reason for bariatric surgery is to achieve weight loss and decrease an individual’s risk of death and conditions associated with obesity. Indications for surgery were discussed and the types of surgery that are available. Safety has improved due to a number of changes such as recognition of experience of surgeons and centres, the enactment of care protocols and a switch to minimally invasive procedures. However less invasive surgeries appear to accomplish considerably less weight loss. Benefits to body fat, blood fat levels, high blood pressure, diabetes, non-alcoholic fatty liver disease, inflammation, the ability of the blood vessels to dilate and sleep apnoea were all discussed. These were all used as evidence to support the argument that surgery improves an individual’s chances of survival compared to lifestyle interventions, as sufficiently designed trials to support this have not been performed. It was concluded that bariatric surgery has greater improved heart disease and death compared to lifestyle interventions due to the significantly higher weight loss that results.
Abstract
This review focuses on the mechanisms underlying, and indications for, bariatric surgery in the reduction of cardiovascular disease (CVD), as well as other expected benefits of this intervention. The fundamental basis for bariatric surgery for the purpose of accomplishing weight loss is the determination that severe obesity is a disease associated with multiple adverse effects on health, which can be reversed or improved by successful weight loss in patients who have been unable to sustain weight loss by nonsurgical means. An explanation of possible indications for weight loss surgery as well as specific bariatric surgical procedures is presented, along with review of the safety literature of such procedures. Procedures that are less invasive or those that involve less gastrointestinal rearrangement accomplish considerably less weight loss but have substantially lower perioperative and longer-term risk. The ultimate benefit of weight reduction relates to the reduction of the comorbidities, quality of life, and all-cause mortality. With weight loss being the underlying justification for bariatric surgery in ameliorating CVD risk, current evidence-based research is discussed concerning body fat distribution, dyslipidemia, hypertension, diabetes mellitus, inflammation, obstructive sleep apnea, and others. The rationale for bariatric surgery reducing CVD events is discussed and juxtaposed with impacts on all-cause mortalities. Given the improvement of established obesity-related CVD risk factors after weight loss, it is reasonable to expect a reduction of CVD events and related mortality after weight loss in populations with obesity. The quality of the current evidence is reviewed, and future research opportunities and summaries are stated.
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Current experience in testing mitochondrial nutrients in disorders featuring oxidative stress and mitochondrial dysfunction: rational design of chemoprevention trials.
Pagano, G, Aiello Talamanca, A, Castello, G, Cordero, MD, d'Ischia, M, Gadaleta, MN, Pallardó, FV, Petrović, S, Tiano, L, Zatterale, A
International journal of molecular sciences. 2014;15(11):20169-208
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Many conditions are associated with mitochondrial dysfunction (MDF) and oxidative stress (OS). For example; some genetic diseases, aging and age-associated disorders, neurologic and psychiatric diseases, malignancies and autoimmune diseases. This review looks at the clinical trials focused on the use of mitochondrial cofactors (mitochondrial nutrients - MN) such as alpha-lipoic acid (ALA), Coenzyme Q 10 (CoQ10) and L-carnitine (CARN) which are essential in the functioning of mitochondria. Of the trials that were used in the review, 81 tested ALA, 107 tested CoQ10, 74 reports tested CARN, only 7 reports were retrieved testing double MN associations, while no report was found testing a triple MN combination. A total of 28 reports tested MN associations with “classical” antioxidants, such as antioxidant nutrients or drugs. Combinations of MN showed better outcomes than individual MN. Further studies are therefore needed.
Abstract
An extensive number of pathologies are associated with mitochondrial dysfunction (MDF) and oxidative stress (OS). Thus, mitochondrial cofactors termed "mitochondrial nutrients" (MN), such as α-lipoic acid (ALA), Coenzyme Q10 (CoQ10), and l-carnitine (CARN) (or its derivatives) have been tested in a number of clinical trials, and this review is focused on the use of MN-based clinical trials. The papers reporting on MN-based clinical trials were retrieved in MedLine up to July 2014, and evaluated for the following endpoints: (a) treated diseases; (b) dosages, number of enrolled patients and duration of treatment; (c) trial success for each MN or MN combinations as reported by authors. The reports satisfying the above endpoints included total numbers of trials and frequencies of randomized, controlled studies, i.e., 81 trials testing ALA, 107 reports testing CoQ10, and 74 reports testing CARN, while only 7 reports were retrieved testing double MN associations, while no report was found testing a triple MN combination. A total of 28 reports tested MN associations with "classical" antioxidants, such as antioxidant nutrients or drugs. Combinations of MN showed better outcomes than individual MN, suggesting forthcoming clinical studies. The criteria in study design and monitoring MN-based clinical trials are discussed.