Resveratrol and fish oil reduce catecholamine-induced mortality in obese rats: role of oxidative stress in the myocardium and aorta

Pien-tze-huang promotes wound healing in streptozotocin-induced diabetes models associated with improving oxidative stress via the Nrf2/ARE pathway

Diabetic foot ulcers are a serious complication of diabetes, with high mortality and a lack of effective clinical treatment, which leads to a considerable financial burden. Pien-Tze-Huang (PZH) is a Chinese traditional medicine with a long history that has been found to be an effective and convenient treatment for inflammatory diseases such as skin abscesses and ulcers. In this study, we assessed the effects of PZH on diabetic wounds and the underlying mechanisms. The wounds were established on the backs of streptozotocin-induced type 1 diabetic rats and type 2 diabetic mouse models. We found that PZH treatment used locally or by gavage significantly promoted wound healing, accelerated re-epithelialization and vasculature in the wound tissue, upregulated the expression of the growth factors VEGF-A, PDGF, and EGF, and activated the Nrf2/ARE pathway in the wound tissue. In vitro assays showed that PZH improved the proliferation, migration and angiogenic function of human umbilical vein endothelial cells (HUVECs) cultured in palmitic acid, reduced the expression of the apoptotic proteins p53, Bax, and cleaved-caspase3, and activated Nrf2/ARE signaling; however, these protective effects were abrogated after Nrf2 was knocked down by specific siRNA. In addition, the levels of the serum inflammatory cytokines IL-1β, TNF-α, and IL-6 were reduced after PZH gavage treatment. In conclusion, the positive role of PZH in diabetic wound healing might be related to the activation of the Nrf2/ARE pathway to regulate the level of oxidative stress in vivo and increase the expression of growth factors to improve angiogenesis.

Solubility and physicochemical properties of resveratrol in peanut oil

The solubility and physicochemical properties of resveratrol in peanut oil were systematically studied following ultrasonic and magnetic stirring-assisted dissolution. The highest resveratrol solubility in peanut oil observed was 95.91%. The optimal dissolution process was determined to be the addition of 183.00 mg/kg resveratrol, a magnetic temperature of 40.00℃, and a magnetic duration of 3.50 h, which yielded a resveratrol content of 175.51 mg/kg oil. Under this standardized process, the oil composition remained unchanged. Resveratrol promoted the conversion of saturated triglycerides into unsaturated triglycerides, increased the linolenic acid content, and did not facilitate the formation of trans fatty acids. In addition, resveratrol preservedthe lightcolor, decreased the peroxide and acid values by 30%, prolonged the shelf life by more than 2 folds, and improved the thermal stability. In this sense, peanut oil with resveratrol can serve as anti-isomerism and antioxidant additive.

Effects of Zingiber officinale extract supplementation on metabolic and genotoxic parameters in diet-induced obesity in mice

Obesity is an epidemic associated with many diseases. The nutraceutical Zingiber officinale (ZO) is a potential treatment for obesity; however, the molecular effects are unknown. Swiss male mice were fed a high-fat diet (59 % energy from fat) for 16 weeks to generate a diet-induced obesity (DIO) model and then divided into the following groups: standard diet + vehicle; standard diet + ZO; DIO + vehicle and DIO + ZO. Those in the ZO groups were supplemented with 400 mg/kg per d of ZO extract (oral administration) for 35 d. The animals were euthanised, and blood, quadriceps, epididymal fat pad and hepatic tissue were collected. DIO induced insulin resistance, proinflammatory cytokines, oxidative stress and DNA damage in different tissues. Treatment with ZO improved insulin sensitivity as well as decreased serum TAG, without changes in body weight or adiposity index. TNF-α and IL-1β levels were lower in the liver and quadriceps in the DIO + ZO group compared with the DIO group. ZO treatment reduced the reactive species and oxidative damage to proteins, lipids and DNA in blood and liver in obese animals. The endogenous antioxidant activity was higher in the quadriceps of DIO + ZO. These results in the rat model of DIO may indicate ZO as an adjuvant on obesity treatment.

Polyphenols and Fish Oils for Improving Metabolic Health: A Revision of the Recent Evidence for Their Combined Nutraceutical Effects

Polyphenols and omega-3 polyunsaturated fatty acids from fish oils, i.e., eicosapentaenoic and docosahexaenoic acids, are well-recognized nutraceuticals, and their single antioxidant and anti-inflammatory properties have been demonstrated in several studies found in the literature. It has been reported that the combination of these nutraceuticals can lead to three-fold increases in glutathione peroxidase activity, two-fold increases in plasma antioxidant capacity, decreases of 50-100% in lipid peroxidation, protein carbonylation, and urinary 8-isoprotanes, as well as 50-200% attenuation of common inflammation biomarkers, among other effects, as compared to their individual capacities. Therefore, the adequate combination of those bioactive food compounds and their single properties should offer a powerful tool for the design of successfully nutritional interventions for the prevention and palliation of a plethora of human metabolic diseases, frequently diet-induced, whose etiology and progression are characterized by redox homeostasis disturbances and a low-grade of chronic inflammation. However, the certain mechanisms behind their biological activities, in vivo interaction (both between them and other food compounds), and their optimal doses and consumption are not well-known yet. Therefore, we review here the recent evidence accumulated during the last decade about the cooperative action between polyphenols and fish oils against diet-related metabolic alterations, focusing on the mechanisms and pathways described and the effects reported. The final objective is to provide useful information for strategies for personalized nutrition based on these nutraceuticals.

The therapeutic effect of resveratrol: Focusing on the Nrf2 signaling pathway

Resveratrol is a natural polyphenol derived from grapes, berries, red wine, peanuts amongst other fruits and nuts. Beneficial effects such as anti-inflammatory, antioxidant, hepatoprotective, neuroprotective, cardioprotective, renoprotective, anti-obesity, anti-diabetic, and anti-cancer of resveratrol have been demonstrated by preclinical and clinical research. A possibility is that these therapeutical effects are associated with modulation of the Nrf2 signaling pathway in the following way: resveratrol may potentiate Nrf2 signaling through blockage of Keap1, by means of changing the Nrf2 mediators, its expression and its nuclear translocation. This article reviews the evidence of the Nrf2 modulating hypothesis as a possible molecular mechanism underlying the medicinal properties of resveratrol.

Omega-3 polyunsaturated fatty acids have beneficial effects on visceral fat in diet-induced obesity model

This study evaluated the effects of omega-3 polyunsaturated fatty acids (PUFAs) on oxidative stress and energy metabolism parameters in the visceral fat of a high-fat-diet induced obesity model. Energy intake, body mass, and visceral fat mass were also evaluated. Male Swiss mice received either a control diet (control group) or a high-fat diet (obese group) for 6 weeks. After this period, the groups were divided into control + saline, control + omega-3, obese + saline, and obese + omega-3, and to these groups 400 mg·(kg body mass)-1·day-1 of fish oil (or saline) was administered orally, for 4 weeks. Energy intake and body mass were monitored throughout the experiment. In the 10th week, the animals were euthanized and the visceral fat (mesenteric) was removed. Treatment with omega-3 PUFAs did not affect energy intake or body mass, but it did reduced visceral fat mass. In visceral fat, omega-3 PUFAs reduced oxidative damage and alleviated changes to the antioxidant defense system and the Krebs cycle. The mitochondrial respiratory chain was neither altered by obesity nor by omega-3 PUFAs. In conclusion, omega-3 PUFAs have beneficial effects on the visceral fat of obese mice because they mitigate changes caused by the consumption of a high-fat diet.

Resveratrol and Its Effects on the Vascular System

Resveratrol, the phenolic substance isolated initially from Veratrum grandiflorum and richly present in grapes, wine, peanuts, soy, and berries, has been attracting attention of scientists and medical doctors for many decades. Herein, we review its effects on the vascular system. Studies utilizing cell cultures and pre-clinical models showed that resveratrol alleviates oxidative stress and inflammation. Furthermore, resveratrol suppresses vascular smooth muscle cell proliferation, promotes autophagy, and has been investigated in the context of vascular senescence. Pre-clinical models unambiguously demonstrated numerous vasculoprotective effects of resveratrol. In clinical trials, resveratrol moderately diminished systolic blood pressure in hypertensive patients, as well as blood glucose in patients with diabetes mellitus. Yet, open questions remain, as exemplified by a recent report which states that the intake of resveratrol might blunt certain positive effects of exercise in older persons, and further research addressing the framework for long-term use of resveratrol as a food supplement, will stay in demand.

Dietary resveratrol impairs body weight gain due to reduction of feed intake without affecting fatty acid composition in Atlantic salmon

Recent studies suggest that the use of vegetable oils at expense of fish oil in aquaculture feeds might have potential negative effects on fish redox homeostasis and adiposity. Resveratrol (RESV) is a lipid-soluble phytoalexin present in fruits and vegetables with proven in vivo antioxidant function in animals. The present study aims to assess the potential use of RESV in Atlantic salmon feeds. To this end, post-smolt salmons with an initial BW of 148±3 g were fed four experimental diets for 15 weeks. A diet low in fish oil served as a control and was supplemented with 0, 0.5, 1.5 and 2.5 g/kg of RESV, respectively. The effect of the experimental diets on animal performance, tissue fatty acid composition, and the expression of genes encoding proteins involved in antioxidant signalling, lipid peroxidation, and metabolism were studied. Resveratrol significantly reduced feed intake and final BW of the salmon. Feeding RESV did not affect the sum of saturated and monounsaturated fatty acids or total lipids in the fillet. While the content of total polyunsaturated fatty acids was not affected, the percentages of some fatty acids in the liver and fillet were changed by RESV. Furthermore, in liver, the relative expression of glutathione peroxidase 4b, nuclear factor-like 2, and arachidonate 5-lipoxygenase remained unchanged across treatment groups. In conclusion, the negative impact of dietary RESV on FI and hence reduction of the BW discourages its inclusion in low fish oil diets for Atlantic salmon.

n-3 PUFA and obesity: from peripheral tissues to the central nervous system

The current paradigms of prevention and treatment are unable to curb obesity rates, which indicates the need to explore alternative therapeutic approaches. Obesity leads to several damages to the body and is an important risk factor for a number of other chronic diseases. Furthermore, despite the first alterations in obesity being observed and reported in peripheral tissues, studies indicate that obesity can also cause brain damage. Obesity leads to a chronic low-grade inflammatory state, and the therapeutic manipulation of inflammation can be explored. In this context, the use of n-3 PUFA (especially in the form of fish oil, rich in EPA and DHA) may be an interesting strategy, as this substance is known by its anti-inflammatory effect and numerous benefits to the body, such as reduction of TAG, cardiac arrhythmias, blood pressure and platelet aggregation, and has shown potential to help treat obesity. Thereby, the aim of this narrative review was to summarise the literature related to n-3 PUFA use in obesity treatment. First, the review provides a brief description of the obesity pathophysiology, including alterations that occur in peripheral tissues and at the central nervous system. In the sequence, we describe what are n-3 PUFA, their sources and their general effects. Finally, we explore the main topic linking obesity and n-3 PUFA. Animal and human studies were included and alterations on the whole organism were described (peripheral tissues and brain).

Finding Ponce de Leon's Pill: Challenges in Screening for Anti-Aging Molecules

Aging is characterized by the progressive accumulation of degenerative changes, culminating in impaired function and increased probability of death. It is the major risk factor for many human pathologies - including cancer, type 2 diabetes, and cardiovascular and neurodegenerative diseases - and consequently exerts an enormous social and economic toll. The major goal of aging research is to develop interventions that can delay the onset of multiple age-related diseases and prolong healthy lifespan (healthspan). The observation that enhanced longevity and health can be achieved in model organisms by dietary restriction or simple genetic manipulations has prompted the hunt for chemical compounds that can increase lifespan. Most of the pathways that modulate the rate of aging in mammals have homologs in yeast, flies, and worms, suggesting that initial screening to identify such pharmacological interventions may be possible using invertebrate models. In recent years, several compounds have been identified that can extend lifespan in invertebrates, and even in rodents. Here, we summarize the strategies employed, and the progress made, in identifying compounds capable of extending lifespan in organisms ranging from invertebrates to mice and discuss the formidable challenges in translating this work to human therapies.

Sulforaphane improves dysregulated metabolic profile and inhibits leptin-induced VSMC proliferation: Implications toward suppression of neointima formation after arterial injury in western diet-fed obese mice

Sulforaphane (SFN), a dietary phase-2 enzyme inducer that mitigates cellular oxidative stress through nuclear factor erythroid 2-related factor 2 (Nrf2) activation, is known to exhibit beneficial effects in the vessel wall. For instance, it inhibits vascular smooth muscle cell (VSMC) proliferation, a major event in atherosclerosis and restenosis after angioplasty. In particular, SFN attenuates the mitogenic and pro-inflammatory actions of platelet-derived growth factor (PDGF) and tumor necrosis factor-α (TNFα), respectively, in VSMCs. Nevertheless, the vasoprotective role of SFN has not been examined in the setting of obesity characterized by hyperleptinemia and insulin resistance. Using the mouse model of western diet-induced obesity, the present study demonstrates for the first time that subcutaneous delivery of SFN (0.5mg/Kg/day) for~3weeks significantly attenuates neointima formation in the injured femoral artery [↓ (decrease) neointima/media ratio by~60%; n=5-8]. This was associated with significant improvements in metabolic parameters, including ↓ weight gain by~52%, ↓ plasma leptin by~42%, ↓ plasma insulin by~63%, insulin resistance [↓ homeostasis model assessment of insulin resistance (HOMA-IR) index by~73%], glucose tolerance (↓ AUCGTT by~24%), and plasma lipid profile (e.g., ↓ triglycerides). Under in vitro conditions, SFN significantly decreased leptin-induced VSMC proliferation by~23% (n=5) with associated diminutions in leptin-induced cyclin D1 expression and the phosphorylation of p70S6kinase and ribosomal S6 protein (n=3-4). The present findings reveal that, in addition to improving systemic metabolic parameters, SFN inhibits leptin-induced VSMC proliferative signaling that may contribute in part to the suppression of injury-induced neointima formation in diet-induced obesity.

The role of Nrf2 in oxidative stress-induced endothelial injuries

Endothelial dysfunction is an important risk factor for cardiovascular disease, and it represents the initial step in the pathogenesis of atherosclerosis. Failure to protect against oxidative stress-induced cellular damage accounts for endothelial dysfunction in the majority of pathophysiological conditions. Numerous antioxidant pathways are involved in cellular redox homeostasis, among which the nuclear factor-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway is perhaps the most prominent. Nrf2, a transcription factor with a high sensitivity to oxidative stress, binds to AREs in the nucleus and promotes the transcription of a wide variety of antioxidant genes. Nrf2 is located in the cytoskeleton, adjacent to Keap1. Keap1 acts as an adapter for cullin 3/ring-box 1-mediated ubiquitination and degradation of Nrf2, which decreases the activity of Nrf2 under physiological conditions. Oxidative stress causes Nrf2 to dissociate from Keap1 and to subsequently translocate into the nucleus, which results in its binding to ARE and the transcription of downstream target genes. Experimental evidence has established that Nrf2-driven free radical detoxification pathways are important endogenous homeostatic mechanisms that are associated with vasoprotection in the setting of aging, atherosclerosis, hypertension, ischemia, and cardiovascular diseases. The aim of the present review is to briefly summarize the mechanisms that regulate the Nrf2/Keap1-ARE signaling pathway and the latest advances in understanding how Nrf2 protects against oxidative stress-induced endothelial injuries. Further studies regarding the precise mechanisms by which Nrf2-regulated endothelial protection occurs are necessary for determining whether Nrf2 can serve as a therapeutic target in the treatment of cardiovascular diseases.

Lifespan and healthspan extension by resveratrol

A number of small molecules with the ability to extend the lifespan of multiple organisms have recently been discovered. Resveratrol, amongst the most prominent of these, has gained widespread attention due to its ability to extend the lifespan of yeast, worms, and flies, and its ability to protect against age-related diseases such as cancer, Alzheimer's, and diabetes in mammals. In this review, we discuss the origins and molecular targets of resveratrol and provide an overview of its effects on the lifespan of simple model organisms and mammals. We also examine the unique ability of resveratrol to extend the healthy years, or healthspan, of mammals and its potential to counteract the symptoms of age-related disease. Finally, we explore the many scientific, medical, and economic challenges faced when translating these findings to the clinic, and examine potential approaches for realizing the possibility of human lifespan extension. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.

Resveratrol reduces chronic inflammation and improves insulin action in the myocardium of high-fat diet-induced obeserats

OBJECTIVE: To evaluate the effects of resveratrol on insulin signaling and inflammation pathway in the myocardium of high-fat diet-induced obese rats. METHODS: Thirty Wistar rats were divided into a control group (n=10, standard diet), obese group (n=10, high-fat diet), and obese supplemented with resveratrol group (n=10, 20 mg/kg/day) for eight weeks. An insulin tolerance test was performed at the end of the study period "0" (without insulin), 5, 10, 15, 20, 25, and 30 minutes after an intraperitoneal injection of insulin (2 U/kg). Body and epididymal adipose tissue were weighed. Fragments of the myocardium were extracted for Western blot analyses of insulin pathway and proinflammatory molecules. RESULTS: Resveratrol increased the rate of glucose disappearance, phosphorylation of the insulin receptor, insulin receptor substrate 1, and protein kinase B; and reduced expression of tumor necrosis factor alpha and of the molecules involved in proinflammatory signal transduction, namely Ikappa B kinase and nuclear factor kappa B complex. The results also suggest that higher insulin sensitivity and lower levels of proinflammatory molecules occurred regardless of weight and epididymal adipose tissue loss. CONCLUSION: Resveratrol increases insulin action and reduces inflammatory molecules in the myocardium.

Sulforaphane attenuation of type 2 diabetes-induced aortic damage was associated with the upregulation of Nrf2 expression and function

Type 2 diabetes mellitus (T2DM) significantly increases risk for vascular complications. Diabetes-induced aorta pathological changes are predominantly attributed to oxidative stress. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor orchestrating antioxidant and cytoprotective responses to oxidative stress. Sulforaphane protects against oxidative damage by increasing Nrf2 expression and its downstream target genes. Here we explored the protective effect of sulforaphane on T2DM-induced aortic pathogenic changes in C57BL/6J mice which were fed with high-fat diet for 3 months, followed by a treatment with streptozotocin at 100 mg/kg body weight. Diabetic and nondiabetic mice were randomly divided into groups with and without 4-month sulforaphane treatment. Aorta of T2DM mice exhibited significant increases in the wall thickness and structural derangement, along with significant increases in fibrosis (connective tissue growth factor and transforming growth factor), inflammation (tumor necrosis factor-α and vascular cell adhesion molecule 1), oxidative/nitrative stress (3-nitrotyrosine and 4-hydroxy-2-nonenal), apoptosis, and cell proliferation. However, these pathological changes were significantly attenuated by sulforaphane treatment that was associated with a significant upregulation of Nrf2 expression and function. These results suggest that sulforaphane is able to upregulate aortic Nrf2 expression and function and to protect the aorta from T2DM-induced pathological changes.

Carbonyl stress in aging process: role of vitamins and phytochemicals as redox regulators

There is a growing scientific agreement that the cellular redox regulators such as antioxidants, particularly the natural polyphenolic forms, may help lower the incidence of some pathologies, including metabolic diseases like diabetes and diabesity, cardiovascular and neurodegenerative abnormalities, and certain cancers or even have anti-aging properties. The recent researches indicate that the degree of metabolic modulation and adaptation response of cells to reductants as well as oxidants establish their survival and homeostasis, which is linked with very critical balance in imbalances in cellular redox capacity and signaling, and that might be an answer the questions why some antioxidants or phytochemicals potentially could do more harm than good, or why some proteins lose their function by increase interactions with glyco- and lipo-oxidation mediates in the cells (carbonyl stress). Nonetheless, pursue of healthy aging has led the use of antioxidants as a means to disrupt age-associated physiological dysfunctions, dysregulated metabolic processes or prevention of many age-related diseases. Although it is still early to define their exact clinical benefits for treating age-related disease, a diet rich in polyphenolic or other forms of antioxidants does seem to offer hope in delaying the onset of age-related disorders. It is now clear that any deficiency in antioxidant vitamins, inadequate enzymatic antioxidant defenses can distinctive for many age-related disease, and protein carbonylation can used as an indicator of oxidative stress associated diseases and aging status. This review examines antioxidant compounds and plant polyphenols as redox regulators in health, disease and aging processes with hope that a better understanding of the many mechanisms involved with these distinct compounds, which may lead to better health and novel treatment approaches for age-related diseases.