scholarly journals The Enzymatic Antioxidant System of Human Spermatozoa

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Cristian O’Flaherty

The ejaculated spermatozoon, as an aerobic cell, must fight against toxic levels of reactive oxygen species (ROS) generated by its own metabolism but also by other sources such as abnormal spermatozoa, chemicals and toxicants, or the presence of leukocytes in semen. Mammalian spermatozoa are extremely sensitive to oxidative stress, a condition occurring when there is a net increase in ROS levels within the cell. Opportunely, this specialized cell has a battery of antioxidant enzymes (superoxide dismutase, peroxiredoxins, thioredoxins, thioredoxins reductases, and glutathione s-transferases) working in concert to assure normal sperm function. Any impairment of the antioxidant enzymatic activities will promote severe oxidative damage which is observed as plasma membrane lipid peroxidation, oxidation of structural proteins and enzymes, and oxidation of DNA bases that lead to abnormal sperm function. Altogether, these damages occurring in spermatozoa are associated with male infertility. The present review contains a description of the enzymatic antioxidant system of the human spermatozoon and a reevaluation of the role of its different components and highlights the necessity of sufficient supply of reducing agents (NADPH and reduced glutathione) to guarantee normal sperm function.

1995 ◽  
Vol 7 (4) ◽  
pp. 659 ◽  
Author(s):  
RJ Aitken

The cellular generation of reactive oxygen species was first observed in mammalian spermatozoa in the late 1940s. The field then remained dormant for 30 years until Thaddeus Mann and Roy Jones published a series of landmark papers in the 1970s in which the importance of lipid peroxidation as a mechanism for damaging mammalian spermatozoa was first intimated. The subsequent demonstration that human spermatozoa produce reactive oxygen species and are susceptible to peroxidative damage has triggered intense interest in the role of oxidative stress in the aetiology of male infertility. Moreover, data have recently been obtained to indicate that, although excessive exposure to reactive oxygen species may be harmful to spermatozoa, in physiological amounts these molecules are of importance in the control of normal sperm function. This review considers the dualistic role of reactive oxygen species and sets out the current understanding of the importance of oxidative processes in both the physiology and the pathology of the human spermatozoon. Extra keywords: human spermatozoa, reactive oxygen species.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5720
Author(s):  
Veronika Petrulova ◽  
Maria Vilkova ◽  
Zuzana Kovalikova ◽  
Matus Sajko ◽  
Miroslav Repcak

Phytochemical investigations of Matricaria chamomilla L. (Asteraceae) stated the presence of several compounds with an established therapeutic and antioxidant potential. The chamomile non-enzymatic antioxidant system includes low molecular mass compounds, mainly polyphenols such as cinnamic, hydroxybenzoic and chlorogenic acids, flavonoids and coumarins. The objective of this work was to evaluate the role of the non-enzymatic antioxidant system after stimulation by ethylene in tetraploid chamomile plants. Seven days of ethylene treatment significantly increased the activity of phenylalanine ammonia-lyase, which influenced the biosynthesis of protective polyphenols in the first step of their biosynthetic pathway. Subsequently, considerable enhanced levels of phenolic metabolites with a substantial antioxidant effect (syringic, vanillic and caffeic acid, 1,5-dicaffeoylquinic acid, quercetin, luteolin, daphnin, and herniarin) were determined by HPLC-DAD-MS. The minimal information on the chlorogenic acids function in chamomile led to the isolation and identification of 5-O-feruloylquinic acid. It is accumulated during normal conditions, but after the excessive effect of abiotic stress, its level significantly decreases and levels of other caffeoylquinic acids enhance. Our results suggest that ethephon may act as a stimulant of the production of pharmaceutically important non-enzymatic antioxidants in chamomile leaves and thus, lead to an overall change in phytochemical content and therapeutic effects of chamomile plants, as well.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1061
Author(s):  
Fabrizia Bonacina ◽  
Angela Pirillo ◽  
Alberico L. Catapano ◽  
Giuseppe D. Norata

High density lipoproteins (HDL) are heterogeneous particles composed by a vast array of proteins and lipids, mostly recognized for their cardiovascular (CV) protective effects. However, evidences from basic to clinical research have contributed to depict a role of HDL in the modulation of immune-inflammatory response thus paving the road to investigate their involvement in other diseases beyond those related to the CV system. HDL-C levels and HDL composition are indeed altered in patients with autoimmune diseases and usually associated to disease severity. At molecular levels, HDL have been shown to modulate the anti-inflammatory potential of endothelial cells and, by controlling the amount of cellular cholesterol, to interfere with the signaling through plasma membrane lipid rafts in immune cells. These findings, coupled to observations acquired from subjects carrying mutations in genes related to HDL system, have helped to elucidate the contribution of HDL beyond cholesterol efflux thus posing HDL-based therapies as a compelling interventional approach to limit the inflammatory burden of immune-inflammatory diseases.


2015 ◽  
Vol 29 (5) ◽  
pp. 926-932 ◽  
Author(s):  
Barbara Poniedziałek ◽  
Piotr Rzymski ◽  
Jacek Karczewski

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 562 ◽  
Author(s):  
Mona Soliman ◽  
Haifa A. Alhaithloul ◽  
Khalid Rehman Hakeem ◽  
Basmah M. Alharbi ◽  
Mohamed El-Esawi ◽  
...  

Nitric oxide (NO) at optimal levels is considered beneficial to plant functioning. The present study was carried out to investigate the role of exogenously applied NO (100 and 150 µM sodium nitropurusside, SNP) in amelioration of nickel (Ni)-mediated oxidative effects in eggplant. Ni stress declined growth and biomass production, relative water content (RWC), and chlorophyll pigment synthesis, thereby affecting the photosynthetic efficiency. Exogenously applied SNP proved beneficial in mitigating the Ni-mediated growth restrictions. NO-treated seedlings exhibited improved photosynthesis, stomatal conductance, and chlorophyll content with the effect of being apparent at lower concentration (100 µM SNP). SNP upregulated the antioxidant system mitigating the oxidative damage on membranes due to Ni stress. The activity of superoxide dismutase, catalase, glutathione S-transferase, ascorbate peroxidase, and glutathione reductase was upregulated due to SNP which also increased the ascorbate and reduced glutathione content. SNP-supplied seedlings also showed higher proline and glycine betaine accumulation, thereby improving RWC and antioxidant system. Glyoxalase I activity was induced due to SNP application declining the accumulation of methylglyoxal. NO-mediated mitigation of Ni toxicity was confirmed using NO scavenger (PTIO, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), which reversed the influence of SNP almost entirely on the parameters studied. Uptake of nitrogen (N), potassium (K), and calcium (Ca) was increased due to SNP application and Ni was reduced significantly. Therefore, this study revealed the efficiency of exogenous SNP in enhancing Ni stress tolerance through upregulating antioxidant and glyoxalase systems.


2018 ◽  
Vol 99 (6) ◽  
pp. 919-923
Author(s):  
N G Elmanova

Aim. Study of the features of changes of antioxidant protection in patients with mechanical jaundice of benign and malignant origin in dynamics. Methods. The author studied the role of antioxidant system in the progression of mechanical jaundice of various origins in 104 patients. Groups of patients with a syndrome of mechanical jaundice of benign (62 patients) and malignant origin (42 patients) were isolated. The material of the study was blood from the ulnar vein, which was taken in the morning on an empty stomach before surgery. In the dynamics (on the 7th day after the operation), 53 patients were examined. To assess the state of antioxidant protection, a spectrophotometric method of investigation was used. Results. A high level of malonic dialdehyde, the product of lipid peroxidation, was determined in all patients regardless of origin. There was also a depression of the enzymatic link of antioxidant protection (a decrease in the activity of superoxide dismutase and catalase). After surgical intervention in patients with mechanical jaundice of benign origin, correction of the level of reduced glutathione was observed. In patients with mechanical jaundice of malignant origin in dynamics, the activity of antioxidant enzymes did not differ significantly from the norm (p1-3 = 0,23; p1-3 = 311). Conclusion. After surgical intervention, partial improvement of the condition of patients with mechanical jaundice of benign origin was observed, and dysfunction of antioxidant protection persisted in patients with mechanical jaundice of malignant origin.


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