Antioxidant defense systems: the role of carotenoids, tocopherols, and thiols

1991 ◽  
Vol 53 (1) ◽  
pp. 194S-200S ◽  
Author(s):  
P Di Mascio ◽  
M E Murphy ◽  
H Sies
2020 ◽  
Vol 2020 ◽  
pp. 1-29 ◽  
Author(s):  
Rossella D’Oria ◽  
Rossella Schipani ◽  
Anna Leonardini ◽  
Annalisa Natalicchio ◽  
Sebastio Perrini ◽  
...  

Reactive oxygen species (ROS) are highly reactive chemical species containing oxygen, controlled by both enzymatic and nonenzymatic antioxidant defense systems. In the heart, ROS play an important role in cell homeostasis, by modulating cell proliferation, differentiation, and excitation-contraction coupling. Oxidative stress occurs when ROS production exceeds the buffering capacity of the antioxidant defense systems, leading to cellular and molecular abnormalities, ultimately resulting in cardiac dysfunction. In this review, we will discuss the physiological sources of ROS in the heart, the mechanisms of oxidative stress-related myocardial injury, and the implications of experimental studies and clinical trials with antioxidant therapies in cardiovascular diseases.


2007 ◽  
Vol 57 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Mamdouh Ali ◽  
Eman Noaman ◽  
Sherien Kamal ◽  
Saaed Soliman ◽  
Dina Ismail

Role of germanium L-cysteine α-tocopherol complex as stimulator of some antioxidant defense systems in gamma-irradiated rats This study was conducted to evaluate the potency of the newly prepared germanium L-cysteine α-tocopherol complex [germanium dichloro tetrakis (L-cysteinyl-α-tocopherol amide) dichloride] as a protective agent against γ-irradiation-induced free radicals production and liver toxicity. Male Swiss albino rats were injected intraperitoneally with the germanium complex in a concentration of 75 mg kg-1 body mass per dose, for 6 successive doses, last dose administered twenty minutes pre-exposure to a single dose of whole body γ-irradiation of 6.5 Gy. Lipid peroxidation (LPx), nitric oxide (NO), glutathione (GSH) levels, and activity of the antioxidant enzymes glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were estimated in blood and liver. Blood total protein, cholesterol, triglyceride and α-tocopherol content were estimated as well. The results revealed that administration of germanium complex pre-irradiation resulted in significant (p < 0.001) improvement compared to the irradiated group in the level of hepatic and blood LPx. Hepatic GSH revealed a significant increase (p < 0.001), while its level showed no significant variation in blood. Also, the level of NO in blood and liver increased significantly (p < 0.001). On the other hand, pretreatment with the germanium complex normalized the activities of SOD, GPx and CAT in blood and liver when compared to the irradiated group. The study also documents a marked decrease in a blood triglyceride and cholesterol (p < 0.001) and a significant increase (p < 0.001) of α-tocopherol and total protein contents in blood. These biochemical changes were associated with marked improvement of histological status. Therefore, the germanium L-cysteine α-tocopherol complex may be a good candidate for ameliorating the changes induced by irradiation, which indicates the beneficial radio-protective role of this antioxidant agent.


2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Vladimir Mihailovic ◽  
Jelena S. Katanic Stankovic ◽  
Dragica Selakovic ◽  
Gvozden Rosic

Nanoparticles (NPs) are used in many products and materials for humans such as electronics, in medicine for drug delivery, as biosensors, in biotechnology, and in agriculture, as ingredients in cosmetics and food supplements. Besides that, NPs may display potentially hazardous properties on human health and the environment as a consequence of their abundant use in life nowadays. Hence, there is increased interest of researchers to provide possible therapeutic agents or dietary supplements for the amelioration of NP-induced toxicity. This review summarizes the new findings in the research of the use of antioxidants as supplements for the prevention and alleviation of harmful effects caused by exposure of organisms to NPs. Also, mechanisms involved in the formation of NP-induced oxidative stress and protective mechanisms using different antioxidant substances have also been elaborated. This review also highlights the potential of naturally occurring antioxidants for the enhancement of the antioxidant defense systems in the prevention and mitigation of organism damage caused by NP-induced oxidative stress. Based on the presented results of the most recent studies, it may be concluded that the role of antioxidants in the prevention and treatment of nanoparticle-induced toxicity is unimpeachable. This is particularly important in terms of oxidative stress suppression.


2000 ◽  
Vol 73 (1-2) ◽  
pp. 71-78 ◽  
Author(s):  
Tetsuya Suwa ◽  
Tomoatsu Mune ◽  
Hiroyuki Morita ◽  
Hisashi Daido ◽  
Masanao Saio ◽  
...  

Author(s):  
Alicja Kowalczyk

AbstractMolecular studies of the causes of male infertility revealed a significant contribution of oxidative stress. When excessive amounts of reactive oxygen species (ROS) are produced or antioxidant activity fails, the equilibrium between oxidation and reduction is disrupted, causing oxidative stress (OS). High levels of ROS can have an adverse effect on sperm function through the initiation of DNA damage, lipid peroxidation, loss of membrane integrity and increased permeability, inactivation of cellular enzymes, and cell apoptosis. In addition to endogenous factors such as immature sperm, leukocytes, and varicocele, potential causes of excessive ROS can also be found exogenously in males with testicular hyperthermia or exposed to environmental toxicity. To maintain the optimal functioning of sperm cells, it is, therefore, necessary to balance the redox potential, i.e., to balance ROS by antioxidants. The purpose of this review is to present the antioxidant defense systems in semen.


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