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Journal of the International Society of... Sep 2020L-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of...
BACKGROUND
L-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of prolonged LC supplementation on metabolism and metabolic modifications.
METHODS
A literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from the inception up February 2020. Eligibility criteria included studies on healthy human subjects, treated for at least 12 weeks with LC administered orally, with no drugs or any other multi-ingredient supplements co-ingestion.
RESULTS
The initial search retrieved 1024 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with healthy human subjects, with supplemented dose ranging from 1 g to 4 g per day for either 12 or 24 weeks. LC supplementation, in combination with carbohydrates (CHO) effectively elevated total carnitine content in skeletal muscle. Twenty-four-weeks of LC supplementation did not affect muscle strength in healthy aged women, but significantly increased muscle mass, improved physical effort tolerance and cognitive function in centenarians. LC supplementation was also noted to induce an increase of fasting plasma trimethylamine-N-oxide (TMAO) levels, which was not associated with modification of determined inflammatory nor oxidative stress markers.
CONCLUSION
Prolonged LC supplementation in specific conditions may affect physical performance. On the other hand, LC supplementation elevates fasting plasma TMAO, compound supposed to be pro-atherogenic. Therefore, additional studies focusing on long-term supplementation and its longitudinal effect on the cardiovascular system are needed.
Topics: Age Factors; Body Composition; Carnitine; Cognition; Dietary Carbohydrates; Dietary Supplements; Energy Metabolism; Exercise; Exercise Tolerance; Humans; Lipid Metabolism; Methylamines; Muscle Proteins; Muscle Strength; Muscle, Skeletal; Obesity; Oxidation-Reduction; Physical Conditioning, Human; Sarcopenia
PubMed: 32958033
DOI: 10.1186/s12970-020-00377-2 -
Inflammation Feb 2021Rheumatoid arthritis (RA) is a common systemic autoimmune disease with a prevalence of about 1% in which genetic and environmental risk factors both participate in...
Rheumatoid arthritis (RA) is a common systemic autoimmune disease with a prevalence of about 1% in which genetic and environmental risk factors both participate in performance of disease. Though several studies contributed in identifying its etiology and pathogenesis, the underlying mechanisms are still unknown. To date, so as palliative for RA, cure strategies are still popular. Hypoxia and oxidative stress are implicated to RA development and subsequent ROS-mediated cell death which is a critical feature for RA progression. As for cell death and lipid peroxidation, ferroptosis is a newly discovered, iron-dependent, and non-apoptotic cell death which draws various attention due to its potential strategies for cancer therapy. Meanwhile, ferroptosis-suppressor-protein 1 (FSP1) is recently identified as a seminal breakthrough owing to its property of versus ferroptosis. By virtue of the complicated research progress on FSP1 with ferroptosis, in this review, we summarize the whole region of relevance between ROS and RA. Taken together, we hypothesize that ROS accompanied with ferroptosis may function as a reciprocal with cell death that interplays with RA; besides, FSP1 might become a potential therapeutic target for RA because of its potential interaction with TNF-α/ROS-positive feedback loop. This review systematically concludes the previous understandings about identification of ROS and FSP1 and, in turn, aims to provide references for further achievements of them and hints on elucidation of its thorough underlying mechanisms.
Topics: Animals; Antioxidants; Apoptosis Regulatory Proteins; Arthritis, Rheumatoid; Ferroptosis; Humans; Lipid Peroxidation; Mitochondrial Proteins; Reactive Oxygen Species
PubMed: 32920707
DOI: 10.1007/s10753-020-01338-2 -
Psychiatry Research Oct 2020The association between schizophrenia (SZ) and uric acid (UA) levels has been suggested for many years, but without solid evidence. Therefore, we conducted a systematic... (Meta-Analysis)
Meta-Analysis
The association between schizophrenia (SZ) and uric acid (UA) levels has been suggested for many years, but without solid evidence. Therefore, we conducted a systematic review and meta-analysis of all case-control studies examining the serum and plasma UA levels in SZ subjects in comparison to those in healthy controls. Relevant studies published before October 29, 2018, were searched in the main electronic databases, and 17 studies were finally included into the meta-analysis after screening with the criteria. Our results revealed that there were no statistically significant differences of the UA levels between SZ subjects and healthy controls. Further subgroup analyses of the antipsychotic status reported the same finding. Subgroup analyses of clinical status showed that UA levels were decreased in subjects with first episode psychosis (FEP). The subgroup analyses of gender and ethnicity demonstrated that UA levels were decreased in male subjects and in Americans with SZ. Overall, these findings strengthen the clinical evidence that FEP is accompanied by increased oxidative stress response. Reduced UA levels may be a potential risk factor for SZ in male and in the Americans. However, whether there is a causal relationship between the reduced UA levels and the development of SZ deserves further investigation.
Topics: Antipsychotic Agents; Biomarkers; Case-Control Studies; Humans; Oxidation-Reduction; Oxidative Stress; Risk Factors; Schizophrenia; Uric Acid
PubMed: 32702552
DOI: 10.1016/j.psychres.2020.113305 -
Advanced Drug Delivery Reviews 2020Probiotics are live microorganisms (usually bacteria), which are defined by their ability to confer health benefits to the host, if administered adequately. Probiotics...
Probiotics are live microorganisms (usually bacteria), which are defined by their ability to confer health benefits to the host, if administered adequately. Probiotics are not only used as health supplements but have also been applied in various attempts to prevent and treat gastrointestinal (GI) and non-gastrointestinal diseases such as diarrhea, colon cancer, obesity, diabetes, and inflammation. One of the challenges in the use of probiotics is putative loss of viability by the time of administration. It can be due to procedures that the probiotic products go through during fabrication, storage, or administration. Biocompatible and biodegradable polymers with specific moieties or pH/enzyme sensitivity have shown great potential as carriers of the bacteria for 1) better viability, 2) longer storage times, 3) preservation from the aggressive environment in the stomach and 4) topographically targeted delivery of probiotics. In this review, we focus on polymeric carriers and the procedures applied for encapsulation of the probiotics into them. At the end, some novel methods for specific probiotic delivery, possibilities to improve the targeted delivery of probiotics and some challenges are discussed.
Topics: Animals; Drug Carriers; Drug Compounding; Drug Liberation; Drug Stability; Drug Storage; Enzymes; Humans; Hydrogen-Ion Concentration; Oxidation-Reduction; Particle Size; Polymers; Probiotics; Technology, Pharmaceutical; Temperature
PubMed: 32702378
DOI: 10.1016/j.addr.2020.07.014 -
Environmental Science and Pollution... Oct 2020Carwash wastewater (CWW) is considered as an important source of either water pollution or water consumption. Therefore, its treatment is critical not only from the... (Review)
Review
Carwash wastewater (CWW) is considered as an important source of either water pollution or water consumption. Therefore, its treatment is critical not only from the prevention of environmental contamination but also from the recycling of such high-volume water source. Unfortunately, the effective treatment of CWW is almost unknown, complex, and expensive. To overcome the former challenge, this study aimed to systematically review different technologies for CWW treatment. For this, a comprehensive literature survey was conducted and 48 research articles were found suitable to be included in the investigation. The included studies were of coagulation and adsorption (n = 5), membrane-based technologies (n = 15), and electrochemical (n = 11) and combined (n = 17) systems. This comprehensive review showed that the treatment methods of advanced filtration membrane techniques, electrical and chemical coagulation, and advanced oxidation processes can be effective in the removal of pollutants from carwash wastewater (CWW). The mining of different studies, however, showed that the combined methods are the most promising option in the remediation of such wastewater.
Topics: Adsorption; Oxidation-Reduction; Wastewater; Water Pollutants, Chemical; Water Purification
PubMed: 32632696
DOI: 10.1007/s11356-020-09741-w -
Experimental Gerontology Sep 2020Resistance exercise training (RET) has proven effective at reducing the risk of chronic disease in older populations, and it appears to regulate redox homeostasis. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Resistance exercise training (RET) has proven effective at reducing the risk of chronic disease in older populations, and it appears to regulate redox homeostasis.
AIMS
To determine the effects of RET on redox homeostasis in older people.
STUDY DESIGN
A systematic review and meta-analysis of randomized clinical trials identified by searching MEDLINE, Web of Science, EMBASE, Sportdiscus, LILACS, CENTRAL and CINAHL. We included studies of subjects aged 65 years or older, with or without pathologies, and including RET metrics with quantified molecular oxidation and antioxidant capacity outcomes.
RESULTS
Fifteen studies were included in this review. Agreement between reviewers reached a kappa value of 0.725. There were a total of 614 participants, with an average age of 68.1 years. Five (for molecular oxidation markers) and three (for antioxidant capacity markers) studies included data that quantified the effects of RET on homeostasis redox. The results of the meta-analysis showed that there were no differences in the molecular oxidation markers (SMD = -0.26; 95% CI = -0.57 to 0.05; P = 0.10; I2 = 0%) and antioxidant capacity markers (SMD = 0.53; 95% CI = -0.20 to 1.26; P = 0.16; I2 = 71.5%) in healthy older people after a RET of 8-24 weeks compared to non-intervention.
CONCLUSIONS
Based on a small number of studies of low methodological quality, this systematic review with meta-analysis suggests that RET is not effective at reducing molecular oxidation markers in healthy older people. More research is needed on the effects of RET on redox homeostasis in older people.
PROSPERO REGISTRATION NUMBER
CRD42019121529.
Topics: Aged; Aged, 80 and over; Exercise; Health Status; Homeostasis; Humans; Oxidation-Reduction; Quality of Life; Resistance Training
PubMed: 32615210
DOI: 10.1016/j.exger.2020.111012 -
Sleep & Breathing = Schlaf & Atmung Sep 2020Obstructive sleep apnea (OSA) is associated with an increased risk of developing atherosclerotic cardiovascular disease (ASCVD). Patients with OSA have increased levels... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Obstructive sleep apnea (OSA) is associated with an increased risk of developing atherosclerotic cardiovascular disease (ASCVD). Patients with OSA have increased levels of oxidative stress and several studies have shown higher levels of oxidative stress markers. Oxidized-LDL (Ox-LDL) is an important risk factor for ASCVD and a number of studies have measured its levels in patients with OSA, though results from these studies are conflicting. This meta-analysis aimed to reassess circulating levels of Ox-LDL in patients with OSA in comparison with controls.
METHODS
Studies evaluating Ox-LDL levels in patients with OSA and controls were explored in databases of PubMed, EMBASE, Scopus, and Web of Science. Two authors independently performed the search from January 1990 to February 2019. Two authors independently screened the studies according to title, abstract, and full text. In addition, the Newcastle-Ottawa Quality Assessment Scale was utilized to evaluate the quality of the studies. The impact of OSA on Ox-LDL levels was determined using the random effects model.
RESULTS
Of 195 articles retrieved, 98 were duplicates, 49 were excluded by title, 20 excluded by abstract, and 22 by full texts. Six eligible studies were included in the meta-analysis. Pooled analysis demonstrated that Ox-LDL increased in patients with OSA compared with controls. In addition, subgroup analysis revealed that studies matching age or BMI between OSA patients and controls showed no significant difference between patients with OSA and healthy controls, while unmatched studies had higher levels of Ox-LDL in patients with OSA in comparison with controls.
CONCLUSION
This study demonstrated higher circulating concentrations of Ox-LDL in patients with OSA. However, no significant difference was found in studies in which patients and controls were matched for age and BMI, suggesting the involvement of these two confounding factors as a cause for elevated concentrations of circulating Ox-LDL in patients with OSA.
Topics: Biomarkers; Female; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Oxidative Stress; Polysomnography; Risk Factors; Sleep Apnea, Obstructive
PubMed: 32399700
DOI: 10.1007/s11325-020-02089-y -
Advances in Nutrition (Bethesda, Md.) Jul 2020Fermented dairy foods (FDFs) and probiotics are promising tools for the prevention and management of cardiometabolic diseases (CMDs), respectively. The relation between... (Meta-Analysis)
Meta-Analysis
Fermented dairy foods (FDFs) and probiotics are promising tools for the prevention and management of cardiometabolic diseases (CMDs), respectively. The relation between the regular consumption of FDFs and CMD risk factors was assessed by prospective cohort studies (PCSs), and the effect of probiotic supplementation added into a dairy matrix on CMD parameters was evaluated by randomized controlled trials (RCTs). Moreover, the effects of probiotic supplementation added into a dairy matrix were compared with those administered in capsule/powder form. Twenty PCSs and 52 RCTs met the inclusion criteria for the systematic review and meta-analysis. In PCSs, fermented milk was associated with a 4% reduction in risk of stroke, ischemic heart disease, and cardiovascular mortality [RR (95% CI); 0.96 (0.94, 0.98)]; yogurt intake was associated with a risk reduction of 27% [RR (95% CI); 0.73 (0.70, 0.76)] for type 2 diabetes (T2D) and 20% [RR (95% CI); 0.80 (0.74, 0.87)] for metabolic syndrome development. In RCTs, probiotic supplementation added into dairy matrices produced a greater reduction in lipid biomarkers than when added into capsules/powder in hypercholesterolemic subjects, and probiotic supplementation by capsules/powder produced a greater reduction in T2D biomarkers than when added into dairy matrices in diabetic subjects. Both treatments (dairy matrix and capsules/powder) resulted in a significant reduction in anthropometric parameters in obese subjects. In summary, fermented milk consumption is associated with reduced cardiovascular risk, while yogurt intake is associated with a reduced risk of T2D and metabolic syndrome development in the general population. Furthermore, probiotic supplementation added into dairy matrices could be considered beneficial for lowering lipid concentrations and reducing anthropometric parameters. Additionally, probiotic capsule/powder supplementation could contribute to T2D management and reduce anthropometric parameters. However, these results should be interpreted with caution due to the heterogeneity of the studies and the different probiotic strains used in the studies. This trial is registered with PROSPERO (CRD42018091791) and the protocol can be accessed at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018091791.
Topics: Animals; Cultured Milk Products; Dairy Products; Diet; Humans; Metabolic Syndrome; Milk; Probiotics
PubMed: 32277831
DOI: 10.1093/advances/nmaa030 -
Nutrients Apr 2020Exposure of polyunsaturated fatty acid (PUFA)-rich culinary oils (COs) to high temperature frying practices generates high concentrations of cytotoxic and genotoxic...
Exposure of polyunsaturated fatty acid (PUFA)-rich culinary oils (COs) to high temperature frying practices generates high concentrations of cytotoxic and genotoxic lipid oxidation products (LOPs) via oxygen-fueled, recycling peroxidative bursts. These toxins, including aldehydes and epoxy-fatty acids, readily penetrate into fried foods and hence are available for human consumption; therefore, they may pose substantial health hazards. Although previous reports have claimed health benefits offered by the use of PUFA-laden COs for frying purposes, these may be erroneous in view of their failure to consider the negating adverse public health threats presented by food-transferable LOPs therein. When absorbed from the gastrointestinal (GI) system into the systemic circulation, such LOPs may significantly contribute to enhanced risks of chronic non-communicable diseases (NCDs), e.g. cancer, along with cardiovascular and neurological diseases. Herein, we provide a comprehensive rationale relating to the public health threats posed by the dietary ingestion of LOPs in fried foods. We begin with an introduction to sequential lipid peroxidation processes, describing the noxious effects of LOP toxins generated therefrom. We continue to discuss GI system interactions, the metabolism and biotransformation of primary lipid hydroperoxide LOPs and their secondary products, and the toxicological properties of these agents, prior to providing a narrative on chemically-reactive, secondary aldehydic LOPs available for human ingestion. In view of a range of previous studies focused on their deleterious health effects in animal and cellular model systems, some emphasis is placed on the physiological fate of the more prevalent and toxic α,β-unsaturated aldehydes. We conclude with a description of targeted nutritional and interventional strategies, whilst highlighting the urgent and unmet clinical need for nutritional and epidemiological trials probing relationships between the incidence of NCDs, and the frequency and estimated quantities of dietary LOP intake.
Topics: Cooking; Dietary Fats, Unsaturated; Fatty Acids, Unsaturated; Food Quality; Gastrointestinal Tract; Hot Temperature; Humans; Intestinal Absorption; Lipid Peroxidation; Mutagens; Noncommunicable Diseases; Nutritional Physiological Phenomena; Public Health; Risk
PubMed: 32244669
DOI: 10.3390/nu12040974 -
The Science of the Total Environment Jun 2020The fate and transport of Hg species in natural aquatic environment are strongly affected by photochemical transformation of Hg, Hg, and MeHg. Migration of Hg is... (Review)
Review
The fate and transport of Hg species in natural aquatic environment are strongly affected by photochemical transformation of Hg, Hg, and MeHg. Migration of Hg is determined by its complexation with organic and inorganic ligands that are widely present in the water. The presence of dissolved organic matter (DOM) is closely related to photochemical reactions of Hg. DOM can strongly bind to mercury (e.g., Hg and MeHg), thus affecting its speciation, mobility and toxicity, eventually dominating its bioavailability. This review summarizes extensive studies on photochemical behaviors of Hg including: (1) photo-oxidation; (2) photo-reduction; (3) photochemical methylation; and (4) MeHg photo-degradation. Photo-oxidation of Hg is mostly caused by oxidative free radicals (e.g., •OH, CO, O, and O), while photo-reduction of Hg is more complicated and it involves two pathways: (1) primary processes (direct photolysis of Hg or ligand-metal charge transfer of Hg-DOM complex); and (2) secondary processes (reduction of Hg-DOM complex induced by free radicals derived from DOM photolysis). Photochemical methylation of inorganic Hg occurs as follows: (1) Hg complexes with methyl donors (e.g., acetic acid, tert-butyl, alcohols, etc.) to form intermediates, followed by (2) an intramolecular methyl transfer. MeHg photo-degradation is the leading pathway for MeHg demethylation and it primarily proceeds via four different pathways. The information on DOM was also mentioned, but DOM is not the only factor that affects the photochemical behaviors of Hg. Other influencing factors such as: (1) pH value; (2) dissolved oxygen; (3) cations (Fe, K) and anions (NO, HCO, CO, Cl); and (4) suspended substance cannot be ignored.
PubMed: 32143045
DOI: 10.1016/j.scitotenv.2020.137540