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ALTamimi JZ, AlFaris NA, Alshammari GM, Alagal RI, Aljabryn DH, Aldera H, Alrfaei BM, Alkhateeb MA, Yahya MA. Ellagic acid protects against diabetic nephropathy in rats by regulating the transcription and activity of Nrf2. J Funct Foods 2021. [DOI: 10.1016/j.jff.2021.104397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Mason SA, Keske MA, Wadley GD. Effects of Vitamin C Supplementation on Glycemic Control and Cardiovascular Risk Factors in People With Type 2 Diabetes: A GRADE-Assessed Systematic Review and Meta-analysis of Randomized Controlled Trials. Diabetes Care 2021; 44:618-630. [PMID: 33472962 DOI: 10.2337/dc20-1893] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/30/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Evidence suggests that vitamin C supplementation could be a potential therapy in type 2 diabetes. However, its effectiveness and evidence quality require further evaluation. PURPOSE To investigate the efficacy of oral vitamin C supplementation in improving glycemic control, cardiovascular risk factors, and oxidative stress in people with type 2 diabetes. DATA SOURCES Databases (PubMed, Embase, Scopus, Cochrane Library) and clinical trial registries were searched for randomized controlled trials up to 8 September 2020. STUDY SELECTION Trials in adults with type 2 diabetes were included. Trials were excluded if supplements were not exclusive to vitamin C and if <2 weeks in duration. DATA EXTRACTION Primary outcomes were HbA1c, glucose, cholesterol, triglycerides, and blood pressure (BP). Data were extracted for changes in outcomes between vitamin C and control groups. Evidence certainty was assessed using Grading of Recommendations, Assessment, Development, and Evaluation methods. DATA SYNTHESIS Twenty-eight studies (N = 1,574 participants) were included in the review. Outcomes that changed to a statistically and clinically significant extent with vitamin C were systolic BP (mean difference -6.27 [95% CI -9.60, -2.96] mmHg; P = 0.0002), with moderate evidence certainty, and HbA1c (-0.54% [-0.90, -0.17]; P = 0.004) and diastolic BP (-3.77 [-6.13, -1.42] mmHg; P = 0.002) with very low evidence certainty. LIMITATIONS Studies were predominantly short term (<6 months) with a small number of participants (n < 100). CONCLUSIONS While evidence from short-term studies suggests that vitamin C supplementation may improve glycemic control and BP in people with type 2 diabetes, vitamin C supplementation cannot currently be recommended as a therapy until larger, long-term, and high-quality trials confirm these findings.
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Affiliation(s)
- Shaun A Mason
- School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Victoria, Australia
| | - Michelle A Keske
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Glenn D Wadley
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
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Pham MT, Yang JJ, Balasubramaniam A, Rahim AR, Adi P, Do TTM, Herr DR, Huang CM. Leuconostoc mesenteroides mediates an electrogenic pathway to attenuate the accumulation of abdominal fat mass induced by high fat diet. Sci Rep 2020; 10:21916. [PMID: 33318546 PMCID: PMC7736347 DOI: 10.1038/s41598-020-78835-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/27/2020] [Indexed: 11/26/2022] Open
Abstract
Although several electrogenic bacteria have been identified, the physiological effect of electricity generated by bacteria on host health remains elusive. We found that probiotic Leuconostoc mesenteroides (L. mesenteroides) can metabolize linoleic acid to yield electricity via an intracellular cyclophilin A-dependent pathway. Inhibition of cyclophilin A significantly abolished bacterial electricity and lowered the adhesion of L. mesenteroides to the human gut epithelial cell line. Butyrate from L. mesenteroides in the presence of linoleic acid were detectable and mediated free fatty acid receptor 2 (Ffar2) to reduce the lipid contents in differentiating 3T3-L1 adipocytes. Oral administration of L. mesenteroides plus linoleic acid remarkably reduced high-fat-diet (HFD)-induced formation of 4-hydroxy-2-nonenal (4-HNE), a reactive oxygen species (ROS) biomarker, and decreased abdominal fat mass in mice. The reduction of 4-HNE and abdominal fat mass was reversed when cyclophilin A inhibitor-pretreated bacteria were administered to mice. Our studies present a novel mechanism of reducing abdominal fat mass by electrogenic L. mesenteroides which may yield electrons to enhance colonization and sustain high amounts of butyrate to limit ROS during adipocyte differentiation.
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Affiliation(s)
- Minh Tan Pham
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, 32001, Taiwan
| | - John Jackson Yang
- Department of Life Sciences, National Central University, Taoyuan, Taiwan
| | - Arun Balasubramaniam
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, 32001, Taiwan
| | - Adelia Riezka Rahim
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, 32001, Taiwan
| | - Prakoso Adi
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, 32001, Taiwan
| | - Thi Tra My Do
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, 32001, Taiwan
| | - Deron Raymond Herr
- Department of Pharmacology, National University of Singapore, Singapore, Singapore
| | - Chun-Ming Huang
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, 32001, Taiwan.
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Kaiafa G, Veneti S, Polychronopoulos G, Pilalas D, Daios S, Kanellos I, Didangelos T, Pagoni S, Savopoulos C. Is HbA1c an ideal biomarker of well-controlled diabetes? Postgrad Med J 2020; 97:380-383. [PMID: 32913038 DOI: 10.1136/postgradmedj-2020-138756] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/15/2020] [Indexed: 12/16/2022]
Abstract
HbA1c is a biomarker with a central role in the diagnosis and follow-up of patients with diabetes, although not a perfect one. Common comorbidities encountered in patients with diabetes mellitus, such as renal insufficiency, high output states (iron deficiency anaemia, haemolytic anaemia, haemoglobinopathies and pregnancy) and intake of specific drugs could compromise the sensitivity and specificity of the biomarker. COVID-19 pandemic poses a pressing challenge for the diabetic population, since maintaining optimal blood glucose control is key to reduce morbidity and mortality rates. Alternative methods for diabetes management, such as fructosamine, glycosylated albumin and device-based continuous glucose monitoring, are discussed.
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Affiliation(s)
- Georgia Kaiafa
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
| | - Stavroula Veneti
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
| | - George Polychronopoulos
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
| | - Dimitrios Pilalas
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
| | - Stylianos Daios
- Internal Medicine Department, General Hospital of Serres, Greece
| | - Ilias Kanellos
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
| | - Triantafyllos Didangelos
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
| | - Stamatina Pagoni
- 3rd Department of Internal Medicine, "G. Gennimatas" General Hospital of Athens, Greece.,Hellenic Society of Internal Medicine, Athens, Greece
| | - Christos Savopoulos
- First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Greece
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5
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The Role of Oxidative Stress in Physiopathology and Pharmacological Treatment with Pro- and Antioxidant Properties in Chronic Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2082145. [PMID: 32774665 PMCID: PMC7396016 DOI: 10.1155/2020/2082145] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/08/2020] [Indexed: 01/01/2023]
Abstract
Oxidative stress (OS) has the ability to damage different molecules and cellular structures, altering the correct function of organs and systems. OS accumulates in the body by endogenous and exogenous mechanisms. Increasing evidence points to the involvement of OS in the physiopathology of various chronic diseases that require prolonged periods of pharmacological treatment. Long-term treatments may contribute to changes in systemic OS. In this review, we discuss the involvement of OS in the pathological mechanisms of some chronic diseases, the pro- or antioxidant effects of their pharmacological treatments, and possible adjuvant antioxidant alternatives. Diseases such as high blood pressure, arteriosclerosis, and diabetes mellitus contribute to the increased risk of cardiovascular disease. Antihypertensive, lipid-lowering, and hypoglycemic treatments help reduce the risk with an additional antioxidant benefit. Treatment with methotrexate in autoimmune systemic inflammatory diseases, such as rheumatoid arthritis, has a dual role in stimulating the production of OS and producing mitochondrial dysfunction. However, it can also help indirectly decrease the systemic OS induced by inflammation. Medicaments used to treat neurodegenerative diseases tend to decrease the mechanisms related to the production of reactive oxygen species (ROS) and balance OS. On the other hand, immunosuppressive treatments used in cancer or human immunodeficiency virus infection increase the production of ROS, causing significant oxidative damage in different organs and systems without widely documented exogenous antioxidant administration alternatives.
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6
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A causal link between oxidative stress and inflammation in cardiovascular and renal complications of diabetes. Clin Sci (Lond) 2018; 132:1811-1836. [PMID: 30166499 DOI: 10.1042/cs20171459] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/22/2018] [Accepted: 07/26/2018] [Indexed: 12/14/2022]
Abstract
Chronic renal and vascular oxidative stress in association with an enhanced inflammatory burden are determinant processes in the development and progression of diabetic complications including cardiovascular disease (CVD), atherosclerosis and diabetic kidney disease (DKD). Persistent hyperglycaemia in diabetes mellitus increases the production of reactive oxygen species (ROS) and activates mediators of inflammation as well as suppresses antioxidant defence mechanisms ultimately contributing to oxidative stress which leads to vascular and renal injury in diabetes. Furthermore, there is increasing evidence that ROS, inflammation and fibrosis promote each other and are part of a vicious connection leading to development and progression of CVD and kidney disease in diabetes.
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Goutzourelas N, Orfanou M, Charizanis I, Leon G, Spandidos DA, Kouretas D. GSH levels affect weight loss in individuals with metabolic syndrome and obesity following dietary therapy. Exp Ther Med 2018; 16:635-642. [PMID: 30116319 PMCID: PMC6090313 DOI: 10.3892/etm.2018.6204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/10/2018] [Indexed: 12/19/2022] Open
Abstract
This study examined the effects of redox status markers on metabolic syndrome (MetS) and obesity before and after dietary intervention and exercise for weight loss. A total of 103 adults suffering from MetS and obesity participated in this study and followed a personalized diet plan for 6 months. Body weight, body fat (BF) percentage (BF%), respiratory quotient (RQ) and the redox status markers, reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARS) and protein carbonyls (CARB), were measured twice in each individual, before and after intervention. Dietary intervention resulted in weight loss, a reduction in BF% and a decrease in RQ. The GSH levels were significantly decreased following intervention, while the levels of TBARS and CARB were not affected. Based on the initial GSH levels, the patients were divided into 2 groups as follows: The high GSH group (GSH, >3.5 µmol/g Hb) and the low GSH group (GSH <3.5 µmol/g Hb). Greater weight and BF loss were observed in patients with high GSH levels. It was observed that patients with MetS and obesity with high GSH values responded better to the dietary therapy, exhibiting more significant changes in weight and BF%. This finding underscores the importance of identifying redox status markers, particularly GSH, in obese patients with MetS. Knowing the levels of GSH may aid in developing a better design of an individualized dietary plan for individuals who wish to lose weight.
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Affiliation(s)
- Nikolaos Goutzourelas
- Department of Biochemistry and Biotechnology, University of Thessaly, 41500 Larissa, Greece.,Eatwalk IKE, 15124 Athens, Greece
| | | | | | | | - Demetrios A Spandidos
- Laboratory of Clinical Virology, University of Crete, Medical School, 71409 Heraklion, Greece
| | - Demetrios Kouretas
- Department of Biochemistry and Biotechnology, University of Thessaly, 41500 Larissa, Greece
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8
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Al-Waili N, Al-Waili H, Al-Waili T, Salom K. Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials. Redox Rep 2017; 22:99-118. [PMID: 28276289 PMCID: PMC6837693 DOI: 10.1080/13510002.2017.1297885] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Diabetic nephropathy is the major cause of end-stage renal disease and effective and new therapeutic approaches are needed in diabetic nephropathy and chronic kidney diseases. Oxidative stress and inflammatory process are important factors contributing to kidney damage by increasing production of oxidants. KEAP1/Nrf2/ARE pathway regulates the transcription of many antioxidant genes and modulation of the pathway up regulates antioxidants. NFB controls the expression of genes involved in the inflammatory response. Natural substances have antioxidant and anti-inflammatory activities and have an impact on NFB and KEAP1/Nrf2/ARE pathways. The preclinical studies explored the effectiveness of whole herbs, plants or seeds and their active ingredients in established diabetic nephropathy. They ameliorate oxidative stress induced kidney damage, enhance antioxidant system, and decrease inflammatory process and fibrosis; most likely by activating KEAP1/Nrf2/ARE pathway and by deactivating NFB pathway. Whole natural products contain balanced antioxidants that might work synergistically to induce beneficial therapeutic outcome. In this context, more clinical studies involving whole plants or herbal products or mixtures of different herbs and plants and their active ingredients might change our strategies for the management of diabetic nephropathy. The natural products might be useful as preventive interventions and studies are required in this field.
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Affiliation(s)
- Noori Al-Waili
- New York Medical Care for Nephrology, Al-Waili Foundation for Science, New York, USA
| | - Hamza Al-Waili
- New York Medical Care for Nephrology, Al-Waili Foundation for Science, New York, USA
| | - Thia Al-Waili
- New York Medical Care for Nephrology, Al-Waili Foundation for Science, New York, USA
| | - Khelod Salom
- New York Medical Care for Nephrology, Al-Waili Foundation for Science, New York, USA
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9
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Effects of vitamin C supplementation on glycaemic control: a systematic review and meta-analysis of randomised controlled trials. Eur J Clin Nutr 2017; 71:1371-1380. [PMID: 28294172 DOI: 10.1038/ejcn.2017.24] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 01/11/2017] [Accepted: 02/10/2017] [Indexed: 02/07/2023]
Abstract
Randomised controlled trials (RCTs) have observed contrasting results on the effects of vitamin C on circulating biomarkers of glycaemic and insulin regulation. We conducted a systematic review and meta-analysis of RCTs testing the effect of vitamin C administration on glucose, HbA1c and insulin concentrations. Four databases (PubMed, Embase, Scopus and Cochrane Library) were used to retrieve RCTs published from inception until April 2016 and testing the effects of vitamin C in adult participants. The screening of 2008 articles yielded 22 eligible studies (937 participants). Overall, vitamin C did not modify glucose, HbA1c and insulin concentrations. However, subgroup analyses showed that vitamin C significantly reduced glucose concentrations (-0.44 mmol/l, 95% CI: -0.81, -0.07, P=0.01) in patients with type 2 diabetes and in interventions with a duration greater than 30 days (-0.53%, 95% CI: -0.79, -0.10, P=0.02). Vitamin C administration had greater effects on fasting (-13.63 pmol/l, 95% CI: -22.73, -4.54, P<0.01) compared to postprandial insulin concentration. Meta-regression analyses showed that age was a modifier of the effect of vitamin C on insulin concentration. Furthermore, the effect size was associated with baseline BMI and plasma glucose levels, and with the duration of the intervention. In conclusion, greater reduction in glucose concentrations observed in patients with diabetes, older individuals and with more prolonged supplementation. Personalised interventions with vitamin C may represent a feasible future strategy to enhance benefits and efficacy of interventions. Nevertheless, results need to be interpreted cautiously due to limitations in the primary studies analysed.
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Jha JC, Banal C, Chow BSM, Cooper ME, Jandeleit-Dahm K. Diabetes and Kidney Disease: Role of Oxidative Stress. Antioxid Redox Signal 2016; 25:657-684. [PMID: 26906673 PMCID: PMC5069735 DOI: 10.1089/ars.2016.6664] [Citation(s) in RCA: 385] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Intrarenal oxidative stress plays a critical role in the initiation and progression of diabetic kidney disease (DKD). Enhanced oxidative stress results from overproduction of reactive oxygen species (ROS) in the context of concomitant, insufficient antioxidant pathways. Renal ROS production in diabetes is predominantly mediated by various NADPH oxidases (NOXs), but a defective antioxidant system as well as mitochondrial dysfunction may also contribute. Recent Advances: Effective agents targeting the source of ROS generation hold the promise to rescue the kidney from oxidative damage and prevent subsequent progression of DKD. Critical Issues and Future Directions: In the present review, we summarize and critically analyze molecular and cellular mechanisms that have been demonstrated to be involved in NOX-induced renal injury in diabetes, with particular focus on the role of increased glomerular injury, the development of albuminuria, and tubulointerstitial fibrosis, as well as mitochondrial dysfunction. Furthermore, novel agents targeting NOX isoforms are discussed. Antioxid. Redox Signal. 25, 657-684.
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Affiliation(s)
- Jay C Jha
- 1 Diabetic Complications Division, JDRF Danielle Alberti Memorial Centre for Diabetic Complications, Baker IDI Heart and Diabetes Institute , Melbourne, Australia
| | - Claudine Banal
- 1 Diabetic Complications Division, JDRF Danielle Alberti Memorial Centre for Diabetic Complications, Baker IDI Heart and Diabetes Institute , Melbourne, Australia
| | - Bryna S M Chow
- 1 Diabetic Complications Division, JDRF Danielle Alberti Memorial Centre for Diabetic Complications, Baker IDI Heart and Diabetes Institute , Melbourne, Australia
| | - Mark E Cooper
- 1 Diabetic Complications Division, JDRF Danielle Alberti Memorial Centre for Diabetic Complications, Baker IDI Heart and Diabetes Institute , Melbourne, Australia .,2 Department of Medicine, Monash University , Melbourne, Australia
| | - Karin Jandeleit-Dahm
- 1 Diabetic Complications Division, JDRF Danielle Alberti Memorial Centre for Diabetic Complications, Baker IDI Heart and Diabetes Institute , Melbourne, Australia .,2 Department of Medicine, Monash University , Melbourne, Australia
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11
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Castro JP, Grune T, Speckmann B. The two faces of reactive oxygen species (ROS) in adipocyte function and dysfunction. Biol Chem 2016; 397:709-24. [DOI: 10.1515/hsz-2015-0305] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/08/2016] [Indexed: 12/11/2022]
Abstract
Abstract
White adipose tissue (WAT) is actively involved in the regulation of whole-body energy homeostasis via storage/release of lipids and adipokine secretion. Current research links WAT dysfunction to the development of metabolic syndrome (MetS) and type 2 diabetes (T2D). The expansion of WAT during oversupply of nutrients prevents ectopic fat accumulation and requires proper preadipocyte-to-adipocyte differentiation. An assumed link between excess levels of reactive oxygen species (ROS), WAT dysfunction and T2D has been discussed controversially. While oxidative stress conditions have conclusively been detected in WAT of T2D patients and related animal models, clinical trials with antioxidants failed to prevent T2D or to improve glucose homeostasis. Furthermore, animal studies yielded inconsistent results regarding the role of oxidative stress in the development of diabetes. Here, we discuss the contribution of ROS to the (patho)physiology of adipocyte function and differentiation, with particular emphasis on sources and nutritional modulators of adipocyte ROS and their functions in signaling mechanisms controlling adipogenesis and functions of mature fat cells. We propose a concept of ROS balance that is required for normal functioning of WAT. We explain how both excessive and diminished levels of ROS, e.g. resulting from over supplementation with antioxidants, contribute to WAT dysfunction and subsequently insulin resistance.
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12
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Park SY, Kim YJ, Lee SY, Lee JG, Hwang HR, Jeong DW, Cho YH, Choi EJ, Yi YH, Tak YJ, Jo AR, Lee SH, Jeon JS, Lee BW. Vitamin-Mineral Supplement Use Patterns in Elderly Koreans: Data from the 2007-2008 Korean National Health and Nutrition Examination Survey. Korean J Fam Med 2016; 37:123-9. [PMID: 27073612 PMCID: PMC4826992 DOI: 10.4082/kjfm.2016.37.2.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 08/26/2015] [Accepted: 09/24/2015] [Indexed: 12/17/2022] Open
Abstract
Background Vitamin-mineral supplements are the most popular dietary supplements in Korea. However, few studies have assessed the relationship between vitamin-mineral supplementation and associated factors among the Korean elderly. The purpose of this study was to assess the use of vitamin-mineral supplements among elderly in Korea as well as its association with sociodemographic factors, health-related behaviors, medical conditions, and nutrient intake. Methods This study was based on data from the Korean National Health and Nutrition Examination Survey, conducted by the Korean Ministry of Health and Welfare from 2008 to 2009. Data from 3,294 elderly men and women (65 years of age and older) were analyzed. Multivariable-weighted logistic regression model analysis was used to evaluate the association between vitamin-mineral supplement use and sociodemographic factors, health-related habits, and medical conditions. Results Vitamin-mineral supplementation was reported by 16.3% of the participants. The most common reason for using dietary supplements was recommendations from friends and acquaintances. Highly educated person, female participants had a greater likelihood of taking vitamin-mineral supplements. In addition, analysis of nutrient intake from food sources alone revealed a lower proportion of vitamin-mineral supplement users with nutrient intakes below the estimated average requirements for vitamin A, vitamin C, thiamine, riboflavin, niacin, calcium, iron, and phosphorus, compared to nonusers. However, vitamin-mineral supplementation was not associated with health-related behaviors or medical conditions. Conclusion Highly educated person, elderly Korean women had a greater likelihood of using vitamin-mineral supplements. In addition, nutrient intakes from food sources alone were significantly higher among vitamin-mineral supplement users. Finally, vitamin-mineral supplementation may be an indicator of healthier diet in elderly Koreans.
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Affiliation(s)
- So Young Park
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea
| | - Yun Jin Kim
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea.; Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Sang Yeoup Lee
- Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea.; Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea.; Medical Education Unit and Medical Research Institute, Pusan National University School of Medicine, Yangsan, Korea
| | - Jeong Gyu Lee
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea.; Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Hye Rim Hwang
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea.; Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Dong Wook Jeong
- Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea.; Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Young Hye Cho
- Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea.; Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Eun Jung Choi
- Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea.; Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Yu Hyeon Yi
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea.; Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Young Jin Tak
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea.; Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea
| | - A Ra Jo
- Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea.; Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Seung Hoon Lee
- Department of Family Medicine, Pusan National University Hospital, Busan, Korea.; Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Jeong Suk Jeon
- Department of Family Medicine, Pusan National University School of Medicine, Busan, Korea.; Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Bo Wha Lee
- Department of Family Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
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Nikooyeh B, Neyestani TR. Oxidative stress, type 2 diabetes and vitamin D: past, present and future. Diabetes Metab Res Rev 2016; 32:260-7. [PMID: 26409185 DOI: 10.1002/dmrr.2718] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 07/10/2015] [Accepted: 09/02/2015] [Indexed: 12/28/2022]
Abstract
Oxidative stress refers to an imbalance between potentially harmful free radicals and the body's mechanisms to efficiently detoxify them in favor of the free radicals. Consequently, excess free radicals can attack and damage a wide range of biomolecules including proteins, lipids and nucleic acids. Antioxidant mechanisms of the body are under the influence of genetic and environmental (including dietary) factors. Diabetes is one of the most common metabolic disorders around the world. A huge body of evidence indicates a role for oxidative stress in development of many human diseases including diabetes. In this article, the latest information on the possible links of oxidative stress with diabetes development, control and complications as well as the newest results of antioxidant supplementation trials is reviewed. In addition, the possible role of vitamin D, as a newly recognized antioxidant in diabetes is discussed. Finally, concluding remarks on pivotal issues and future studies are presented.
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Affiliation(s)
- Bahareh Nikooyeh
- Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute (NNFTRI) and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Tirang R Neyestani
- Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute (NNFTRI) and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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14
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Spanidis Y, Mpesios A, Stagos D, Goutzourelas N, Bar-Or D, Karapetsa M, Zakynthinos E, Spandidos DA, Tsatsakis AM, Leon G, Kouretas D. Assessment of the redox status in patients with metabolic syndrome and type 2 diabetes reveals great variations. Exp Ther Med 2016; 11:895-903. [PMID: 26998009 PMCID: PMC4774368 DOI: 10.3892/etm.2016.2968] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/05/2016] [Indexed: 12/23/2022] Open
Abstract
The aim of the present study was to examine the effectiveness of a new redox status marker, the static oxidation reduction potential (sORP), for assessing oxidative stress in 75 patients with metabolic syndrome (MetS) and type 2 diabetes (T2D). A total of 35 normal subjects were used as the controls. Moreover, conventional markers of oxidative stress were assessed, such as thiobarbituric acid reactive substances (TBARS), protein carbonyls, the total antioxidant capacity in plasma, glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. The results revealed that sORP was significantly higher (by 13.4%) in the patients with MetS and T2D compared to the controls, indicating an increase in oxidative stress. This finding was also supported by the significantly lower levels (by 27.7%) of GSH and the higher levels (by 23.3%) of CAT activity in the patients with MetS and T2D compared to the controls. Moreover, our results indicated a great variation in oxidative stress markers between the different patients with MetS and T2D, particarly as regards the GSH levels. Thus, the patients with MetS and T2D were divided into 2 subgroups, one with low GSH levels (n=31; GSH <3 µmol/g Hb) and another with high GSH levels (n=35; GSH >4 µmol/g Hb). The comparison of the markers between the 2 subgroups indicated that in the low GSH group, the GSH levels were significantly lower (by 51.7 and 52.9%) than those in the high GSH group and the controls, respectively. Furthermore, sORP in the low GSH group was significantly higher (by 8.1%) compared to the high GSH group, suggesting its sensitivity for assessing oxidative stress in patients wtih MetS and T2D. Moreover, this variation in oxidative stress levels between the different patients with T2D suggests that the assessment of the redox status may be important in prediabetic conditions, since there is evidence indicating that differences in the redox status in pre-diabetes may result in different outcomes.
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Affiliation(s)
- Ypatios Spanidis
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41221, Greece
| | - Anastasios Mpesios
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41221, Greece
| | - Dimitrios Stagos
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41221, Greece
| | - Nikolaos Goutzourelas
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41221, Greece
| | - David Bar-Or
- Department of Trauma Research, St. Anthony Hospital, Lakewood, CO 80228, USA; Department of Trauma Research, Swedish Medical Center, Englewood, CO 80113, USA; Department of Trauma Research, Medical Center of Plano, Plano, TX 75075, USA; Luoxis Diagnostics, Inc., Englewood, CO 80112, USA
| | - Maria Karapetsa
- Department of Intensive Care, University Hospital of Thessaly Biopolis, Larissa 41110, Greece
| | - Epaminondas Zakynthinos
- Department of Intensive Care, University Hospital of Thessaly Biopolis, Larissa 41110, Greece
| | - Demetrios A Spandidos
- Laboratory of Clinical Virology, University of Crete, Medical School, Heraklion 71409, Greece
| | - Aristides M Tsatsakis
- Department of Forensic Sciences and Toxicology, Medical School, University of Crete, Heraklion 71003, Greece
| | - George Leon
- Standard Centre of Bioassays, 'Hartografoi Hygeias', Athens 15124, Greece
| | - Demetrios Kouretas
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41221, Greece
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15
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Redox Signaling in Diabetic Nephropathy: Hypertrophy versus Death Choices in Mesangial Cells and Podocytes. Mediators Inflamm 2015; 2015:604208. [PMID: 26491232 PMCID: PMC4600552 DOI: 10.1155/2015/604208] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/18/2015] [Indexed: 02/06/2023] Open
Abstract
This review emphasizes the role of oxidative stress in diabetic nephropathy, acting as trigger, modulator, and linker within the complex network of pathologic events. It highlights key molecular pathways and new hypothesis in diabetic nephropathy, related to the interferences of metabolic, oxidative, and inflammatory stresses. Main topics this review is addressing are biomarkers of oxidative stress in diabetic nephropathy, the sources of reactive oxygen species (mitochondria, NADPH-oxidases, hyperglycemia, and inflammation), and the redox-sensitive signaling networks (protein kinases, transcription factors, and epigenetic regulators). Molecular switches deciding on the renal cells fate in diabetic nephropathy are presented, such as hypertrophy versus death choices in mesangial cells and podocytes. Finally, the antioxidant response of renal cells in diabetic nephropathy is tackled, with emphasis on targeted therapy. An integrative approach is needed for identifying key molecular networks which control cellular responses triggered by the array of stressors in diabetic nephropathy. This will foster the discovery of reliable biomarkers for early diagnosis and prognosis, and will guide the discovery of new therapeutic approaches for personalized medicine in diabetic nephropathy.
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16
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Raj PS, Prathapan A, Sebastian J, Antony AK, Riya MP, Rani MRP, Biju H, Priya S, Raghu KG. Parmotrema tinctorum exhibits antioxidant, antiglycation and inhibitory activities against aldose reductase and carbohydrate digestive enzymes: an in vitro study. Nat Prod Res 2014; 28:1480-4. [PMID: 24735436 DOI: 10.1080/14786419.2014.909420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This study evaluated the inhibitory potential of ethyl acetate extract of Parmotrema tinctorum (PTEE), an edible lichen, against aldose reductase (AR) and carbohydrate digestive enzymes such as α-glucosidase and α-amylase. It was also screened for antioxidant activities by using DPPH, ABTS, superoxide and hydroxyl radical-scavenging assays. PTEE exhibited α-glucosidase, α-amylase and AR inhibition along with significant antiglycation potential with an estimated IC50 value of 58.45 ± 1.24, 587.74 ± 3.27, 139.28 ± 2.6 and 285.78 ± 1.287 μg/mL, respectively. Antioxidant activity of PTEE against DPPH (IC50 396.83 ± 2.98 μg/mL), ABTS (151.34 ± 1.79 μg/mL), superoxide (30.29 ± 1.17 μg/mL) and hydroxyl (35.42 ± 1.22 μg/mL) radicals suggests the antioxidant potential of P. tinctorum. Significant antioxidant activity and inhibitory potential against carbohydrate digestive enzymes and AR suggest that P. tinctorum can be developed as functional food/nutraceuticals for diabetes after detailed study.
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Affiliation(s)
- P Salin Raj
- a Agroprocessing and Natural Products Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST) , Pappanamcode, Thiruvananthapuram , Kerala 695019 , India
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17
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Russell WR, Baka A, Björck I, Delzenne N, Gao D, Griffiths HR, Hadjilucas E, Juvonen K, Lahtinen S, Lansink M, Loon LV, Mykkänen H, östman E, Riccardi G, Vinoy S, Weickert MO. Impact of Diet Composition on Blood Glucose Regulation. Crit Rev Food Sci Nutr 2013; 56:541-90. [DOI: 10.1080/10408398.2013.792772] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Wendy R. Russell
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | | | - Inger Björck
- Centre for Chemistry and Chemical Engineering, University of Lund, Lund, Sweden
| | - Nathalie Delzenne
- Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Dan Gao
- Department of Diabetes and Metabolic Diseases, Beckman Research Institute of City of Hope, Duarte, California, USA
| | | | - Ellie Hadjilucas
- Coca-Cola Europe, Scientific and Regulatory Affairs Department, Brussels, Belgium
| | - Kristiina Juvonen
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | | | - Mirian Lansink
- Danone Research, Centre for Specialised Nutrition, Wageningen, The Netherlands
| | - Luc Van Loon
- Department of Movement Sciences, Maastricht University, Maastricht, The Netherlands
| | - Hannu Mykkänen
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Elin östman
- Centre for Chemistry and Chemical Engineering, University of Lund, Lund, Sweden
| | - Gabriele Riccardi
- Department of Clinical and Experimental Medicine, University Federico II, Naples, Italy
| | - Sophie Vinoy
- Kraft Foods, R&D Centre, Nutrition Department, Saclay, France
| | - Martin O. Weickert
- University Hospitals Coventry and Warwickshire and Division of Metabolic and Vascular Health, University of Warwick, Coventry, UK
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18
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Dias IHK, Griffiths HR. Oxidative stress in diabetes - circulating advanced glycation end products, lipid oxidation and vascular disease. Ann Clin Biochem 2013; 51:125-7. [PMID: 24146184 DOI: 10.1177/0004563213508747] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Irundika H K Dias
- Life and Health Sciences, Aston Research Centre for Healthy Ageing, Aston University, Birmingham, UK
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19
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Tiong SH, Looi CY, Hazni H, Arya A, Paydar M, Wong WF, Cheah SC, Mustafa MR, Awang K. Antidiabetic and antioxidant properties of alkaloids from Catharanthus roseus (L.) G. Don. Molecules 2013; 18:9770-84. [PMID: 23955322 PMCID: PMC6270616 DOI: 10.3390/molecules18089770] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/02/2013] [Accepted: 08/09/2013] [Indexed: 11/23/2022] Open
Abstract
Catharanthus roseus (L.) G. Don is a herbal plant traditionally used by local populations in India, South Africa, China and Malaysia to treat diabetes. The present study reports the in vitro antioxidant and antidiabetic activities of the major alkaloids isolated from Catharanthus roseus (L.) G. Don leaves extract. Four alkaloids--vindoline I, vindolidine II, vindolicine III and vindolinine IV--were isolated and identified from the dichloromethane extract (DE) of this plant's leaves. DE and compounds I-III were not cytotoxic towards pancreatic β-TC6 cells at the highest dosage tested (25.0 µg/mL). All four alkaloids induced relatively high glucose uptake in pancreatic β-TC6 or myoblast C2C12 cells, with III showing the highest activity. In addition, compounds II-IV demonstrated good protein tyrosine phosphatase-1B (PTP-1B) inhibition activity, implying their therapeutic potential against type 2 diabetes. III showed the highest antioxidant potential in ORAC and DPPH assays and it also alleviated H₂O₂-induced oxidative damage in β-TC6 cells at 12.5 µg/mL and 25.0 µg/mL.
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Affiliation(s)
- Soon Huat Tiong
- Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (S.H.T.); (H.H.)
| | - Chung Yeng Looi
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (C.Y.L.); (A.A.); (M.P.); (M.R.M.)
| | - Hazrina Hazni
- Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (S.H.T.); (H.H.)
| | - Aditya Arya
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (C.Y.L.); (A.A.); (M.P.); (M.R.M.)
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Mohammadjavad Paydar
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (C.Y.L.); (A.A.); (M.P.); (M.R.M.)
| | - Won Fen Wong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mail:
| | - Shiau-Chuen Cheah
- Faculty of Medicine and Health Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights, Cheras 56000 Kuala Lumpur, Malaysia; E-Mail:
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (C.Y.L.); (A.A.); (M.P.); (M.R.M.)
| | - Khalijah Awang
- Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia; E-Mails: (S.H.T.); (H.H.)
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20
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Lacroix IME, Li-Chan ECY. Overview of food products and dietary constituents with antidiabetic properties and their putative mechanisms of action: a natural approach to complement pharmacotherapy in the management of diabetes. Mol Nutr Food Res 2013; 58:61-78. [PMID: 23943383 DOI: 10.1002/mnfr.201300223] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 06/10/2013] [Accepted: 06/13/2013] [Indexed: 01/05/2023]
Abstract
Diabetes is one of the fastest growing chronic, noncommunicable diseases worldwide. Currently, 11 major classes of pharmacotherapy are available for the management of this metabolic disorder. However, the usage of these drugs is often associated with undesirable side effects, including weight gain and hypoglycemia. There is thus a need for new, safe and effective treatment strategies. Diet is known to play a major role in the prevention and management of diabetes. Numerous studies have reported the putative association of the consumption of specific food products, or their constituents, with the incidence of diabetes, and mounting evidence now suggests that some dietary factors can improve glycemic regulation. Foods and dietary constituents, similar to synthetic drugs, have been shown to modulate hormones, enzymes, and organ systems involved in carbohydrate metabolism. The present article reviews the major classes and modes of action of antidiabetic drugs, and examines the evidence on food products and dietary factors with antidiabetic properties as well as their plausible mechanisms of action. The findings suggest potential use of dietary constituents as a complementary approach to pharmacotherapy in the prevention and/or management of diabetes, but further research is necessary to identify the active components and evaluate their efficacy and safety.
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Affiliation(s)
- Isabelle M E Lacroix
- Faculty of Land & Food Systems, Food Nutrition & Health Program, The University of British Columbia, Vancouver, BC, Canada
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21
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Tavafi M. Diabetic nephropathy and antioxidants. J Nephropathol 2013; 2:20-7. [PMID: 24475422 DOI: 10.5812/nephropathol.9093] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 10/15/2012] [Indexed: 02/07/2023] Open
Abstract
CONTEXT Oxidative stress has crucial role in pathogenesis of diabetic nephropathy (DN). Despite satisfactory results from antioxidant therapy in rodent, antioxidant therapy showed conflicting results in combat with DN in diabetic patients. EVIDENCE ACQUISITIONS Directory of Open Access Journals (DOAJ), Google Scholar,Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched. RESULTS Treatment of DN in human are insufficient with rennin angiotensin system (RAS) blockers, so additional agent ought to combine with this management. Meanwhile based on DN pathogenesis and evidences in experimental and human researches, the antioxidants are the best candidate. New multi-property antioxidants may be improved human DN that show high power antioxidant capacity, long half-life time, high permeability to mitochondrion, improve body antioxidants enzymes activity and anti-inflammatory effects. CONCLUSIONS Based on this review and our studies on diabetic rats, rosmarinic acid a multi-property antioxidant may be useful in DN patients, but of course, needs to be proven in clinical trials studies.
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Affiliation(s)
- Majid Tavafi
- Department of Anatomy, Lorestan University of Medical Sciences, Faculty of Medicine, Khoram Abad, Iran
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22
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Murdolo G, Piroddi M, Luchetti F, Tortoioli C, Canonico B, Zerbinati C, Galli F, Iuliano L. Oxidative stress and lipid peroxidation by-products at the crossroad between adipose organ dysregulation and obesity-linked insulin resistance. Biochimie 2012; 95:585-94. [PMID: 23274128 DOI: 10.1016/j.biochi.2012.12.014] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/13/2012] [Indexed: 12/11/2022]
Abstract
Obesity has been proposed as an energy balance disorder in which the expansion of adipose tissue (AT) leads to unfavorable health outcomes. Even though adiposity represents the most powerful driving force for the development of insulin resistance (IR) and type 2 diabetes, mounting evidence points to "adipose dysregulation", rather than fat mass accrual per se, as a key pathophysiological trigger of the obesity-linked metabolic complications. The dysfunctional fat, besides hypertrophic adipose cells and inflammatory cues, displays a reduced ability to form new adipocytes from the undifferentiated precursor cells (ie, the preadipocytes). The failure of adipogenesis poses a "diabetogenic" milieu either by promoting the ectopic overflow/deposition of lipids in non-adipose targets (lipotoxicity) or by inducing a dysregulated secretion of different adipose-derived hormones (ie, adipokines and lipokines). This novel and provocative paradigm ("expandability hypothesis") further extends current "adipocentric view" implicating a reduced adipogenic capacity as a missing link between "unhealthy" fat expansion and impairment of metabolic homeostasis. Hitherto, reactive oxygen species have been implicated in multiple forms of IR. However, the effects of stress on adipogenesis remain controversial. Compelling circumstantial data indicate that lipid peroxidation by-products (ie, oxysterols and 4-hydrononenal) may detrimentally affect adipose homeostasis partly by impairing (pre)adipocyte differentiation. In this scenario, it is tempting to speculate that a fine tuning of the adipose redox status may provide new mechanistic insights at the interface between fat dysregulation and development of metabolic dysfunctions. Yet, in humans, the molecular "signatures" of oxidative stress in the dysregulated fat as well as the pathophysiological effects of adipose (per)oxidation on glucose homeostasis remain poorly investigated. In this review we will summarize the potential mechanisms by which increased oxidative stress in fat may impair (pre)adipocyte differentiation and promote the adipose dysfunction. We will also attempt to highlight the conundrum with the adipose redox changes and the regulation of glucose homeostasis. Finally, we will briefly discuss the scientific rationale for proposing the adipose redox state as a potential target for novel therapeutic strategies to curb/prevent adiposity-linked insulin resistance.
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Affiliation(s)
- Giuseppe Murdolo
- Department of Internal Medicine, Assisi Hospital, Via Valentin Muller 1, Assisi, Perugia, Italy.
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