scholarly journals Carotenoids and Markers of Oxidative Stress in Human Observational Studies and Intervention Trials: Implications for Chronic Diseases

Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 179 ◽  
Author(s):  
Bohn

Carotenoids include C30, C40 and C50 terpenoid-based molecules, many of which constitute coloured pigments. However, >1100 of these are known to occur in nature and only about a dozen are known to play a role in our daily diet. Carotenoids have received much attention due to their proposed health benefits, including reducing the incidence of chronic diseases, such as cardiovascular disease and diabetes. Many of these diseases are characterized by chronic inflammation co-occurring with oxidative stress, characterized by, for example, enhanced plasma F2-isoprostane concentrations, malondialdehyde, and 8-hydroxyguanosine. Though carotenoids can act as direct antioxidants, quenching, for example, singlet oxygen and peroxide radicals, an important biological function appears to rest also in the activation of the body’s own antioxidant defence system, related to superoxide-dismutase, catalase, and glutathione-peroxidase expression, likely due to the interaction with transcription factors, such as nuclear-factor erythroid 2-related factor 2 (Nrf-2). Though mostly based on small-scale and observational studies which do not allow for drawing conclusions regarding causality, several supplementation trials with isolated carotenoids or food items suggest positive health effects. However, negative effects have also been reported, especially regarding beta-carotene for smokers. This review is aimed at summarizing the results from human observational studies/intervention trials targeting carotenoids in relation to chronic diseases characterized by oxidative stress and markers thereof.

2014 ◽  
Vol 4 (12) ◽  
pp. 510 ◽  
Author(s):  
Rame Taha ◽  
Gilbert Blaise

Background: Chronic inflammation integrally related to oxidative stress has been increasingly recognized as a contributing factor in various chronic diseases such as neurodegenerative diseases, pulmonary diseases, metabolic syndrome, and cardiovascular diseases as well as premature aging. Thus, inhibiting this vicious circle has the potential to delay, prevent progression, and treat those diseases. However, adverse effects of current anti-inflammatory drugs and the failure of exogenous antioxidant encourage scientists to develop new therapeutic alternatives. The nuclear factor E2-related factor 2 (Nrf2) is the transcription factor that is responsible for the expression of antioxidant response element (ARE)-regulated genes and have been described as having many therapeutic effects. In this review, we have discussed the role of oxidative stress in various chronic diseases. Furthermore, we have also explored various novel ways to activate Nrf2 either directly or indirectly, which may have therapeutic potential in attenuating oxidative stress, inflammation and mitochondrial dysfunction that contributes to chronic diseases.Keywords: Oxidative stress, Mitochondria, Inflammation, Nrf2, Nutrition, Chronic diseases


2001 ◽  
Vol 71 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Monika Eichholzer ◽  
Jürg Lüthy ◽  
Felix Gutzwiller ◽  
Hannes B. Stähelin

Evidence that fruit and vegetables may protect against coronary heart disease is accumulating. It is unclear which constituents of fruit and vegetables are responsible for this protective effect. Folate as a co-substrate in homocysteine metabolism may be important. An intake of about 400 mug folate equivalents/day seems to be required to achieve stable low homocysteine blood levels. Five of eight epidemiologic studies show significant inverse associations between folate and cardiovascular disease. These associations could be confounded by antioxidant vitamins and/or other substances. In trials examining an association between folate and cardiovascular disease such confounding must be excluded, before specific recommendations can be given. Observational studies suggest that vitamin C plays a role in the aetiology of cardiovascular disease, but there are no completed intervention trials of this vitamin alone. With regard to vitamin E two cohort studies point to cardiovascular benefits with the long-term use of supplements of at least 100 IU/day, but the results of controlled trials are inconclusive. There is some evidence from observational studies of an inverse association between beta-carotene and cardiovascular disease, particularly in smokers. Intervention trials do not support this hypothesis, rather, they suggest a possible harmful effect of beta-carotene supplements in smokers. Nevertheless, protective effects of beta-carotene and vitamin E in different dosages, durations of administration, or different combinations, are still possible. The last paragraph of this review discusses limitations of the present and priorities of future research.


2012 ◽  
Vol 82 (5) ◽  
pp. 327-332 ◽  
Author(s):  
Ulrich Moser

Deficiencies of essential nutrients have been responsible for many epidemic outbreaks of deficiency diseases in the past. Large observational studies point at possible links between nutrition and chronic diseases. Low intake of antioxidant vitamins e. g. have been correlated to increased risk of cardiovascular diseases or cancer. The main results of these studies are indications that an intake below the recommendation could be one of the risk factors for chronic diseases. There was hardly any evidence that amounts above the RDA could be of additional benefit. Since observational studies cannot prove causality, the scientific community has been asking for placebo-controlled, randomized intervention trials (RCTs). Thus, the consequences of the epidemiological studies would have been to select volunteers whose baseline vitamin levels were below the recommended values. The hypothesis of the trial should be that correcting this risk factor up to RDA levels lowers the risk of a disease like CVD by 20 - 30 %. However, none of the RCTs of western countries was designed to correct a chronic marginal deficiency, but they rather tested whether an additional supplement on top of the recommended values would be beneficial in reducing a disease risk or its prognosis. It was, therefore, not surprising that the results were disappointing. As a matter of fact, the results confirmed the findings of the observational studies: chronic diseases are the product of several risk factors, among them most probably a chronic vitamin deficiency. Vitamin supplements could only correct the part of the overall risk that is due to the insufficient vitamin intake.


2020 ◽  
Vol 18 (3) ◽  
pp. 260-265
Author(s):  
Xu Lin ◽  
Zheng Xiaojun ◽  
Lv Heng ◽  
Mo Yipeng ◽  
Tong Hong

The purpose of this study was to evaluate the protective effect of swertiamarin on heart failure. To this end, a rat model of heart failure was established via left coronary artery ligation. Infarct size of heart tissues was determined using triphenyl tetrazolium chloride staining. Echocardiography was performed to evaluate cardiac function by the determination of ejection fraction, left ventricular internal dimension in diastole and left ventricular internal dimension in systole. The effect of swertiamarin on oxidative stress was evaluated via enzyme-linked immunosorbent assay. The mechanism was evaluated using western blot. Administration of swertiamarin reduced the infarct size of heart tissues in rat models with heart failure. Moreover, swertiamarin treatment ameliorated the cardiac function, increased ejection fraction and fractional shortening, decreased left ventricular internal dimension in diastole and left ventricular internal dimension in systole. Swertiamarin improved oxidative stress with reduced malondialdehyde, while increased superoxide dismutase, glutathione, and GSH peroxidase. Furthermore, nuclear-factor erythroid 2-related factor 2, heme oxygenase and NAD(P)H dehydrogenase (quinone 1) were elevated by swertiamarin treatment in heart tissues of rat model with heart failure. Swertiamarin alleviated heart failure through suppression of oxidative stress response via nuclear-factor erythroid 2-related factor 2/heme oxygenase-1 pathway providing a novel therapeutic strategy for heart failure.


2020 ◽  
Vol 26 (22) ◽  
pp. 2610-2619 ◽  
Author(s):  
Tarique Hussain ◽  
Ghulam Murtaza ◽  
Huansheng Yang ◽  
Muhammad S. Kalhoro ◽  
Dildar H. Kalhoro

Background: Inflammation is a complex response of the host defense system to different internal and external stimuli. It is believed that persistent inflammation may lead to chronic inflammatory diseases such as, inflammatory bowel disease, neurological and cardiovascular diseases. Oxidative stress is the main factor responsible for the augmentation of inflammation via various molecular pathways. Therefore, alleviating oxidative stress is effective a therapeutic option against chronic inflammatory diseases. Methods: This review article extends the knowledge of the regulatory mechanisms of flavonoids targeting inflammatory pathways in chronic diseases, which would be the best approach for the development of suitable therapeutic agents against chronic diseases. Results: Since the inflammatory response is initiated by numerous signaling molecules like NF-κB, MAPK, and Arachidonic acid pathways, their encountering function can be evaluated with the activation of Nrf2 pathway, a promising approach to inhibit/prevent chronic inflammatory diseases by flavonoids. Over the last few decades, flavonoids drew much attention as a potent alternative therapeutic agent. Recent clinical evidence has shown significant impacts of flavonoids on chronic diseases in different in-vivo and in-vitro models. Conclusion: Flavonoid compounds can interact with chronic inflammatory diseases at the cellular level and modulate the response of protein pathways. A promising approach is needed to overlook suitable alternative compounds providing more therapeutic efficacy and exerting fewer side effects than commercially available antiinflammatory drugs.


2020 ◽  
Vol 10 (5) ◽  
pp. 578-586
Author(s):  
Areeg M. Abdelrazek ◽  
Shimaa A. Haredy

Background: Busulfan (Bu) is an anticancer drug with a variety of adverse effects for cancer patients. Oxidative stress has been considered as a common pathological mechanism and it has a key role in the initiation and progression of liver injury by Bu. Aim: The study aimed to evaluate the antioxidant impact of L-Carnitine and Coenzyme Q10 and their protective role against oxidative stress damage in liver tissues. Methods and Material: Thirty-six albino rats were divided equally into six groups. G1 (con), received I.P. injection of DMSO plus 1 ml of distilled water daily by oral gavages; G2 (Bu), received I.P. injection of Bu plus 1 ml of the distilled water daily; G3 (L-Car), received 1 ml of L-Car orally; G4 (Bu + L-Car) received I.P. injection of Bu plus 1 ml of L-Car, G5 (CoQ10) 1 ml of CoQ10 daily; and G6 (Bu + CoQ10) received I.P. injection of Bu plus 1 ml of CoQ10 daily. Results: The recent data showed that Bu induced significant (P<0.05) elevation in serum ALT, AST, liver GSSG, NO, MDA and 8-OHDG, while showing significant (P<0.05) decrease in liver GSH and ATP. On the other hand, L-Carnitine and Coenzyme Q10 ameliorated the negative effects prompted by Bu. Immunohistochemical expression of caspase-3 in liver tissues reported pathological alterations in Bu group while also showed significant recovery in L-Car more than CoQ10. Conclusion: L-Car, as well as CoQ10, can enhance the hepatotoxic effects of Bu by promoting energy production in oxidative phosphorylation process and by scavenging the free radicals.


2021 ◽  
pp. 1-9
Author(s):  
Hongmei Zhao ◽  
Yun Qiu ◽  
Yichen Wu ◽  
Hong Sun ◽  
Sumin Gao

<b><i>Introduction/Aims:</i></b> Hydrogen sulfide (H<sub>2</sub>S) is considered to be the third most important endogenous gasotransmitter in organisms. GYY4137 is a long-acting donor for H<sub>2</sub>S, a gas transmitter that has been shown to prevent multi-organ damage in animal studies. We previously reported the effect of GYY4137 on cardiac ischaemia reperfusion injury (IRI) in diabetic mice. However, the role and mechanism of GYY4137 in renal IRI are poorly understood. The aims of this study were to determine whether GYY4137 can effectively alleviate the injury induced by renal ischaemia reperfusion and to explore its possible mechanism. <b><i>Methods:</i></b> Mice received right nephrectomy and clipping of the left renal pedicle for 45 min. GYY4137 was administered by intraperitoneal injection for 2 consecutive days before the operation. The model of hypoxia/reoxygenation injury was established in HK-2 cells, which were pre-treated with or without GYY4137. Renal histology, function, apoptosis, and oxidative stress were measured. Western blot was used to measure the target ­protein after renal IRI. <b><i>Results:</i></b> The results indicated that GYY4137 had a clear protective effect on renal IRI as reflected by the attenuation of renal dysfunction, renal tubule injury, and apoptosis. Moreover, GYY4137 remarkably reduced renal IRI-induced oxidative stress. GYY4137 significantly elevated the nuclear translocation of nuclear factor-erythroid-2-related factor 2 (Nrf2) and the expression of antioxidant enzymes regulated by Nrf2, including SOD, HO-1, and NQO-1. <b><i>Conclusions:</i></b> GYY4137 alleviates ischaemia reperfusion-induced renal injury through activating the antioxidant effect mediated by Nrf2 signalling.


Author(s):  
Tom Clifford ◽  
Jarred P. Acton ◽  
Stuart P. Cocksedge ◽  
Kelly A. Bowden Davies ◽  
Stephen J. Bailey

AbstractWe conducted a systematic review of human trials examining the effects of dietary phytochemicals on Nrf2 activation. In accordance with the PRISMA guidelines, Medline, Embase and CAB abstracts were searched for articles from inception until March 2020. Studies in adult humans that measured Nrf2 activation (gene or protein expression changes) following ingestion of a phytochemical, either alone or in combination were included. The study was pre-registered on the Prospero database (Registration Number: CRD42020176121). Twenty-nine full-texts were retrieved and reviewed for analysis; of these, eighteen were included in the systematic review. Most of the included participants were healthy, obese or type 2 diabetics. Study quality was assessed using the Cochrane Collaboration Risk of Bias Assessment tool. Twelve different compounds were examined in the included studies: curcumin, resveratrol and sulforaphane were the most common (n = 3 each). Approximately half of the studies reported increases in Nrf2 activation (n = 10); however, many were of poor quality and had an unclear or high risk of bias. There is currently limited evidence that phytochemicals activate Nrf2 in humans. Well controlled human intervention trials are needed to corroborate the findings from in vitro and animal studies.


2021 ◽  
Vol 22 (11) ◽  
pp. 5995
Author(s):  
Chand Basha Davuljigari ◽  
Frederick Adams Ekuban ◽  
Cai Zong ◽  
Alzahraa A. M. Fergany ◽  
Kota Morikawa ◽  
...  

Acrylamide is a well characterized neurotoxicant known to cause neuropathy and encephalopathy in humans and experimental animals. To investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) in acrylamide-induced neuropathy, male C57Bl/6JJcl adult mice were exposed to acrylamide at 0, 200 or 300 ppm in drinking water and co-administered with subcutaneous injections of sulforaphane, a known activator of the Nrf2 signaling pathway at 0 or 25 mg/kg body weight daily for 4 weeks. Assessments for neurotoxicity, hepatotoxicity, oxidative stress as well as messenger RNA-expression analysis for Nrf2-antioxidant and pro-inflammatory cytokine genes were conducted. Relative to mice exposed only to acrylamide, co-administration of sulforaphane protected against acrylamide-induced neurotoxic effects such as increase in landing foot spread or decrease in density of noradrenergic axons as well as hepatic necrosis and hemorrhage. Moreover, co-administration of sulforaphane enhanced acrylamide-induced mRNA upregulation of Nrf2 and its downstream antioxidant proteins and suppressed acrylamide-induced mRNA upregulation of tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthase (iNOS) in the cerebral cortex. The results demonstrate that activation of the Nrf2 signaling pathway by co-treatment of sulforaphane provides protection against acrylamide-induced neurotoxicity through suppression of oxidative stress and inflammation. Nrf2 remains an important target for the strategic prevention of acrylamide-induced neurotoxicity.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 897
Author(s):  
Wen-Ping Jiang ◽  
Jeng-Shyan Deng ◽  
Shyh-Shyun Huang ◽  
Sheng-Hua Wu ◽  
Chin-Chu Chen ◽  
...  

Liver damage induced by paracetamol overdose is the main cause of acute liver failure worldwide. In order to study the hepatoprotective effect of Sanghuangporus sanghuang mycelium (SS) on paracetamol-induced liver injury, SS was administered orally every day for 6 days in mice before paracetamol treatment. SS decreased serum aminotransferase activities and the lipid profiles, protecting against paracetamol hepatotoxicity in mice. Furthermore, SS inhibited the lipid peroxidation marker malondialdehyde (MDA), hepatic cytochrome P450 2E1 (CYP2E1), and the histopathological changes in the liver and decreased inflammatory activity by inhibiting the production of proinflammatory cytokines in paracetamol-induced acute liver failure. Moreover, SS improved the levels of glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase in the liver. Significantly, SS diminished mitogen-activated protein kinase (MAPK), Toll-like receptor 4 (TLR4), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and the nuclear factor-kappa B (NF-κB) axis, as well as upregulated the Kelch-like ECH-associated protein 1 (Keap1)/erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway, in paracetamol-induced mice. SS mainly inhibited the phosphorylation of the liver kinase B1 (LKB1), Ca2+/calmodulin-dependent kinase kinase β (CaMKKβ), and AMP-activated protein kinase (AMPK) protein expression. Furthermore, the protective effects of SS on paracetamol-induced hepatotoxicity were abolished by compound C, an AMPK inhibitor. In summary, we provide novel molecular evidence that SS protects liver cells from paracetamol-induced hepatotoxicity by inhibiting oxidative stress and inflammation.


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