Impact of Polyphenols on Inflammatory and Oxidative Stress Factors in Diabetes Mellitus: Nutritional Antioxidants and Their Application in Improving Antidiabetic Therapy

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia and oxidative stress. Oxidative stress plays a crucial role in the development and progression of diabetes and its complications. Nutritional antioxidants derived from dietary sources have gained significant attention due to their potential to improve antidiabetic therapy. This review will delve into the world of polyphenols, investigating their origins in plants, metabolism in the human body, and relevance to the antioxidant mechanism in the context of improving antidiabetic therapy by attenuating oxidative stress, improving insulin sensitivity, and preserving β-cell function. The potential mechanisms of, clinical evidence for, and future perspectives on nutritional antioxidants as adjuvant therapy in diabetes management are discussed.

The effect of diet on oxidative stress and metabolic diseases-Clinically controlled trials

Oxidative stress is associated with several chronic diseases. It is acknowledged that molecules damaged by reactive oxygen species activate the inflammatory process and that this response increases the production of free radicals. Modifications in a diet can improve or decrease redox state markers. The aim of this revision was to provide an update of clinical controlled trials, to assess changes in diet and markers of oxidative stress in subjects with metabolic diseases. They were investigated randomized controlled intervention studies (RCTs) published in MEDLINE (U.S. National Library of Medicine, National Institutes of Health) that were conducted in subjects with obesity, hypertension, diabetes, or dyslipidemia; with dietary intervention; where markers of oxidative stress have been evaluated and published in the last 5 years. Food antioxidants, hypocaloric diets with loss of adipose tissue, substitution of animal protein by vegetable, and changes in the microbiota improve antioxidant status in people with chronic disease. PRACTICAL APPLICATIONS: Hyperglycemia in diabetes mellitus and adipose tissue in obesity are known to trigger oxidative stress. Oxidative stress, in turn, decreases insulin sensitivity and favors an inflammatory state producing adhesion molecules. Oxidative stress and adhesion molecules, can increase blood pressure and oxidation of lipoproteins, that ultimately could lead to a cerebrovascular event. Consumption of high-antioxidant and polyphenol foods increases plasma antioxidant capacity and decreases oxidative stress markers in people with diabetes, obesity, hypertension, and hypertriglyceridemia. In addition, weight loss caused by caloric restriction with or without exercise increases the endogenous antioxidant capacity. Therefore, it is likely that the combination of a hypocaloric diet with a high content of antioxidants and polyphenols will have a greater effect. Other dietary changes with antioxidant effect, such as the substitution of animal for vegetable protein or the addition of fiber, might be mediated by changes in the microbiota. However, this aspect requires further study.

Mechanism of Generation of Oxidative Stress and Pathophysiology of Type 2 Diabetes Mellitus: How Are They Interlinked?

Oxidative stress has been considered as a major hallmark for the pathogenesis and development of type 2 diabetes mellitus (T2DM), but still it is debatable whether it is a mere aggregation of inflammatory-induced responses or clinical entity that underlies with various pathophysiological factors. In this regard, the latest studies have shown the increasing trends for the involvement of reactive oxygen species (ROS) and oxidative stress in the pathogenesis and development of T2DM. ROS are highly reactive species and almost all cellular components are chemically changed due to the influence of ROS that ultimately results in the production of lipid peroxidation. Lipid peroxidation is a major causative factor for the development of oxidative stress that leads to overt T2DM and its associated micro- and macro-vascular complications. In this article, we have briefly described the role of various causative factors, transcriptional and metabolic pathways which are responsible to increase the production of oxidative stress, a most pivotal factor for the pathogenesis and development of T2DM. Therefore, we conclude that measurement of oxidative stress biomarkers may be one of the optional tool for the diagnosis and prediction of T2DM. Moreover, the key findings described in this article also provides a new conceptual framework for forthcoming investigations on the role of oxidative stress in pathogenesis of T2DM and drug discovery. J. Cell. Biochem. 118: 3577-3585, 2017. © 2017 Wiley Periodicals, Inc.

Feasibility of assessing health state by detecting redox state of human body based on Chinese medicine constitution

This article discussed the feasibility of assessing health state by detecting redox state of human body. Firstly, the balance of redox state is the basis of homeostasis, and the balance ability of redox can reflflect health state of human body. Secondly, the redox state of human body is a sensitive index of multiple risk factors of health such as age, external environment and psychological factors. It participates in the occurrence and development of multiple diseases involving metabolic diseases and nervous system diseases, and can serve as a cut-in point for treatment of these diseases. Detecting the redox state of high risk people is signifificantly important for early detection and treatment of disease. The blood plasma and urine could be selected to detect, which is convenient. It is pointed that the indexes not only involve oxidation product and antioxidant enzyme but also redox couple. Chinese medicine constitution reflflects the state of body itself and the ability of adapting to external environment, which is consistent with the connotation of health. It is found that there are nine basic types of constitution in Chinese population, which provides a theoretical basis of health preservation, preventive treatment of disease and personalized treatment. With the combination of redox state detection and the Chinese medicine constitution theory, the heath state can be systemically assessed by conducting large-scale epidemiological survey with classifified detection on redox state of human body.

Oxidative stress induced in nurses by exposure to preparation and handling of antineoplastic drugs in Mexican hospitals: a multicentric study

The impact of involuntary exposure to antineoplastic drugs (AD) was studied in a group of nurses in diverse hospitals in Mexico. The results were compared with a group of unexposed nurses. Anthropometric characteristics and the biochemical analysis were analyzed in both groups. Also, lipid peroxidation level (LPX), protein carbonyl content (PCC), and activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were evaluated in blood of study participants as oxidative stress (OS) biomarkers. The group of occupationally exposed (OE) nurses consisted of 30 individuals ranging in age from 25 to 35 years. The control group included 30 nurses who were not occupationally exposed to the preparation and handling of AD and whose anthropometric and biochemical characteristics were similar to those of the OE group. All biomarkers evaluated were significantly increased (P < 0.5) in OE nurses compared to the control group. Results show that the assessment of OS biomarkers is advisable in order to evaluate exposure to AD in nurses.

Different impacts of cardiovascular risk factors on oxidative stress

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it.

A novel component of the metabolic syndrome: the oxidative stress

The metabolic syndrome (MS) represents a cluster of cardiovascular (CV) risk factors associated to CV disease and type 2 diabetes. It is still under debate whether MS is a mere aggregation of risk factors or it represents a clinical entity with visceral obesity as underlying pathophysiological trigger. The publication of several diagnostic criteria of MS by scientific associations or experts panels reflects this uncertainty in understanding the real nature of MS. Besides the metabolic disturbances of MS, as visceral obesity, hypertriglyceridemia, low HDL cholesterol, hypertension and hyperglycemia, novel mechanisms of arterial damage have been identified. This paper reviews the evidence showing that MS and MS factors are characterized by increased oxidative stress, a relevant factor contributing to the development of metabolic and cardiovascular complications. In the next future, the measure of plasma oxidative stress may contribute to identify a subset of MS patients at increased CV risk, candidates to more intensive therapies.