34 OVINE SPERM IS HIGHLY SUSCEPTIBLE TO ATTACK BY HYDROGEN PEROXIDE

2010 ◽  
Vol 22 (1) ◽  
pp. 175
Author(s):  
E. G. A. Perez ◽  
M. Nichi ◽  
F. A. Oliveira Neto ◽  
R. O. C. Silva ◽  
A. Dalmazzo ◽  
...  

Ram sperm membrane displays a particular lipid composition, especially regarding the high quantity of polyunsaturated cholesterol. This trait improves membrane fluidity; however, the spermatozoa become more susceptible to the attack of reactive oxygen species (ROS), which may lead to structural and functional damage, impairment or even impeded fecundity. The aim of the present experiment was to study the resistance of ovine spermatozoa to different ROS. Sperm samples from 4 rams were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with four ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analysed using the 3-3′ diamino benzidine (DAB) stain as an index of mitochondrial activity, the eosin nigrosin stain as an index of membrane integrity; the simple stain (fast green/Bengal rose) as an index of acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS) as an index of lipid peroxidation. Results showed that acrosome and membrane integrity as well as mitochondrial potential were highly impaired by hydrogen peroxide, which was not the case for the other ROS (Table 1). Surprisingly, TBARS production was higher in samples incubated with ascorbate and ferrous sulfate (hydroxyl radical). Furthermore, sperm showing impaired mitochondrial potential were negatively correlated with membrane and acrosome integrities (r = -0.83, P < 0.0001 and r = -0.62, P = 0.01, respectively). Results of the present experiment suggest that semen of rams is extremely susceptible to attack by hydrogen peroxide. However, the mechanism by which this substance impairs sperm quality apparently does not involve oxidative stress, because no increase in TBARS was observed. Despite the necessity of further studies to investigate how hydrogen peroxide negatively influences sperm function, the use of catalase and glutathione peroxidase, important hydrogen peroxide scavengers, appears to be an alternative to improve the quality of ram sperm. Table 1.Effect of different reactive oxygen species in semen of rams The authors thank Nutricell for the media used in the experiment and CAPES for financial support.

2010 ◽  
Vol 22 (1) ◽  
pp. 314
Author(s):  
M. Nichi ◽  
E. G. A. Perez ◽  
C. H. C. Viana ◽  
A. C. Teodoro ◽  
P. A. A. Goes ◽  
...  

Oxidative stress is caused by reactive oxygen species (ROS) that may cause structural damage to biomolecules, DNA, lipids, carbohydrates and proteins, as well as other cellular components. Evidence indicates that oxidation products are also deleterious to biological systems. Spermatozoa are particularly susceptible the oxidative stress, mainly due to the reduced cytoplasm and the high content of polyunsaturated fatty acids in its membrane. The mechanisms by which sperm acquire antioxidant capacity are still not completely elucidated. The aim was to study the resistance of sperm derived from different epididymal compartments (caudae and head) to the different ROS and to the lipid peroxidation product malondialdehyde (MDA). Epididymal sperm samples from 4 testicles were collected from the head and caudae epididymides. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical), and MDA. Samples were analyzed for 3-3′ diaminobenzidine stain, as an index of mitochondrial activity; the eosin nigrosin stain, as an index of membrane integrity; the simple stain (fast green/Bengal rose), as an index of acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. Statistical analysis was performed using the SAS System for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Pearson correlation). Results showed that immature sperm (head epididymides) were significantly more susceptible to the MDA and to the hydroxyl radical in all studied variables, especially acrosomes, membranes, and mitochondrial potential. Semen derived from the caudae epididymides was more susceptible to the hydrogen peroxide and to the MDA, especially regarding mitochondrial potential. In semen from the epididymal head, a positive correlation was found between TBARS and sperm showing no mitochondrial potential (r = 0.66, P = 0.01). On the other hand, negative correlations were found between TBARS and sperm with damaged acrosome and membrane (r = -0.63, P = 0.01 and r = -0.58, P = 0.02, respectively) in samples collected from the caudae epididymides. The present results suggest that sperm susceptibility to the attack of ROS is different throughout maturation. Although immature sperm are more susceptible to the hydroxyl radical, mature sperm are more susceptible to the hydrogen peroxide. Furthermore, MDA, a product of lipid peroxidation, is also deleterious to the sperm, indicating that once oxidative stress starts, further damage may be caused by their products. The authors thankNutricell for the media used in the experiment andFAPESP for financial support (process #06/05736-1).


2010 ◽  
Vol 22 (1) ◽  
pp. 316
Author(s):  
R. O. C. Silva ◽  
E. G. A. Perez ◽  
R. P. Cabral ◽  
D. G. Silva ◽  
C. H. C. Viana ◽  
...  

Semen quality is one of the main limiting factors for the success of artificial insemination in goats. It is well known that reactive oxygen species (ROS) lead to structural and functional damages to sperm, impairing or avoiding fecundation. The understanding of sperm oxidative mechanisms in goats may provide information on possible treatments to improve semen quality and fertility rates. The aim of the present study was to verify the resistance of goat spermatozoa to different reactive oxygen species. Sperm samples from 4 goats were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analyzed for mitochondrial activity using the 3,3′ diaminobenzidine stain, for membrane integrity using the eosin/nigrosin staining, for acrosome integrity using the simple stain (fast green/Bengal rose), and for lipid peroxidation by dosing thiobarbituric acid reactive substances (TBARS). Results showed that goat sperm is more sensitive to hydrogen peroxide, when compared to superoxide anion, hydroxyl radical, and MDA, when considering acrosome integrity, membrane integrity, and mitochondrial potential (Table 1). On the other hand, TBARS production was increased in samples submitted to hydroxyl radical incubation. Strong negative correlations were found between sperm samples showing impaired mitochondrial potential and both membrane and acrosome integrity (r = -0.97, P < 0.0001 and r = -0.91, P < 0.0001, respectively). The concentration of TBARS correlated negatively with the percentage of sperm showing intact membranes (r = -0.53, P = 0.06), and the later correlated negatively with sperm showing no mitochondrial activity (r = -0.78, P = 0.0006). Results of the present experiment suggest that goat sperm are extremely susceptible to the attack of hydrogen peroxide, being resistant to other ROS. Therefore, an alternative to improve the use of goat semen in reproductive biotechnologies would be the treatment with catalase or glutathione peroxidase, important hydrogen peroxide scavengers. Table 1.Effect of different ROS on goat sperm The authors thank Nutricell for the media used in this experiment.


2003 ◽  
Vol 9 (5) ◽  
pp. 339-346 ◽  
Author(s):  
Nalin Siriwardhana ◽  
K.-W. Lee ◽  
Y.-J. Jeon ◽  
S.-H. Kim ◽  
J.-W. Haw

Water and organic extracts (diethyl ether, chloroform, ethyl acetate, acetone, ethanol and methanol) obtained from Hizikia fusiformis were screened on reactive oxygen species (ROS) scavenging assays (1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydrogen peroxide and hydroxyl radical) and lipid peroxidation (inhibition of linoleic acid oxidation) inhibitory assays. Water, methanol and ethanol extracts showed significant ROS radical scavenging activities. Water extracts showed high scavenging activities on hydrogen peroxide (around 76%) and DPPH radicals (around 75%) while it presented a moderate scavenging activity on hydroxyl radicals (around 54%). Comparatively higher ROS scavenging activities were recorded in hydroxyl radical and DPPH scavenging assays. DPPH radical scavenging activities were well correlated with the polyphenolic content. ROS scavenging and lipid peroxidation inhibition activities indicated that H. fusiformis might be a valuable natural antioxidative source containing both water and fatsoluble antioxidative components.


2010 ◽  
Vol 22 (1) ◽  
pp. 317
Author(s):  
C. H. C. Viana ◽  
M. Nichi ◽  
R. O. C. Silva ◽  
E. G. A. Perez ◽  
R. N. Garcia ◽  
...  

Boar spermatozoa are sensitive to the attack of reactive oxygen species (ROS) due to the high content of unsaturated fatty acids in its plasma membrane and the relative low antioxidant capacity of boar seminal plasma. The benefical effect of antioxidant supplementation to the semen of boars is still a matter of debate, with different results in the literature, probably due to the empirical methods used to determine the more adequate antioxidant, and to the physiological role or the ROS. The aim of the present experiment was to study which ROS is the most deleterious to the boar sperm. Sperm samples from 4 boars were collected by digital manipulation. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produced hydroxyl radical), and malondialdehyde (lipid peroxidation product). Samples were analyzed for the 3-3′ diaminobenzidine stain, as an index of mitochondrial activity; the eosin/nigrosin staining, as an index of membrane integrity; the simple stain (fast green/Bengal rose), as an index of acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS), as an index of lipid peroxidation. Results showed that the boar sperm is relatively resistant to all ROS studied in the present experiment. Only for the percentage of sperm showing intact membrane, a difference was found between incubation with superoxide anion and hydroxyl radical (Table 1). The TBARS production was higher in samples incubated with hydroxyl radical, indicating that these samples were more susceptible to the attack of this ROS. Surprisingly, a positive correlation was found between TBARS and membrane integrity (r = 0.51, P = 0.04), indicating that samples more susceptible to the oxidative stress showed higher membrane integrity. A hypothesis to explain such conflicting results would be the physiological role of the ROS on several spermatic events, especially in this particular species. It is well known that boar semen, in order to achieve ideal motility, requires aerobic conditions. Further studies are necessary to study the effect of each ROS on each physiological or pathological event on boar sperm function. Table 1.Effect of different ROS in boar semen The authors thank Nutricell for the media used in the present experiment.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Elena Gammella ◽  
Stefania Recalcati ◽  
Gaetano Cairo

Iron is essential for life, while also being potentially harmful. Therefore, its level is strictly monitored and complex pathways have evolved to keep iron safely bound to transport or storage proteins, thereby maintaining homeostasis at the cellular and systemic levels. These sequestration mechanisms ensure that mildly reactive oxygen species like anion superoxide and hydrogen peroxide, which are continuously generated in cells living under aerobic conditions, keep their physiologic role in cell signaling while escaping iron-catalyzed transformation in the highly toxic hydroxyl radical. In this review, we describe the multifaceted systems regulating cellular and body iron homeostasis and discuss how altered iron balance may lead to oxidative damage in some pathophysiological settings.


2021 ◽  
Author(s):  
Qingda Wang ◽  
Zhigang Chen ◽  
Xi Zhang ◽  
Yuping Xin ◽  
Yongzhen Xia ◽  
...  

During aerobic respiration, mitochondria generate superoxide anion (O2&middot−), hydrogen peroxide (H2O2), and hydroxyl radical (HO·), and these reactive oxygen species (ROS) are detrimental to mitochondria. Mitochondrial damage is linked to a broad spectrum of pathologies such as Alzheimer's disease, hemochromatosis, and diabetes. Mitochondria contain several enzymes for rapidly removing superoxide anion and hydrogen peroxide, but how they antagonize HO· is elusive, representing a loophole in the anti-ROS system. Herein, we discovered that Rhodanese 2 (Rdl2) is critical for maintaining the functionality and integrity of mitochondria under sub-lethal ROS stress in Saccharomyces cerevisiae. Rdl2 converts stable sulfur species (thiosulfate and dialkyl polysulfide) to reactive sulfane sulfur including persulfide that protects mitochondrial DNA via scavenging HO·. Surprisingly, hydrogen sulfide (H2S) promotes HO· production through stimulating the Fenton reaction, leading to increased DNA damage. Our study may reveal an ex-ante mean for antagonizing HO·, patching the loophole of the anti-ROS system in mitochondria.


2001 ◽  
Vol 90 (1) ◽  
pp. 45-54 ◽  
Author(s):  
L. A. Callahan ◽  
Z. W. She ◽  
T. M. Nosek

Reactive oxygen species contribute to diaphragm dysfunction in certain pathophysiological conditions (i.e., sepsis and fatigue). However, the precise alterations induced by reactive oxygen species or the specific species that are responsible for the derangements in skeletal muscle function are incompletely understood. In this study, we evaluated the effect of the superoxide anion radical (O2 −·), hydroxyl radical (·OH), and hydrogen peroxide (H2O2) on maximum calcium-activated force (Fmax) and calcium sensitivity of the contractile apparatus in chemically skinned (Triton X-100) single rat diaphragm fibers. O2 −· was generated using the xanthine/xanthine oxidase system; ·OH was generated using 1 mM FeCl2, 1 mM ascorbate, and 1 mM H2O2; and H2O2 was added directly to the bathing medium. Exposure to O2 −· or ·OH significantly decreased Fmax by 14.5% ( P < 0.05) and 43.9% ( P < 0.005), respectively. ·OH had no effect on Ca2+ sensitivity. Neither 10 nor 1,000 μM H2O2 significantly altered Fmax or Ca2+ sensitivity. We conclude that the diaphragm is susceptible to alterations induced by a direct effect of ·OH and O2 −·, but not H2O2, on the contractile proteins, which could, in part, be responsible for prolonged depression in contractility associated with respiratory muscle dysfunction in certain pathophysiological conditions.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Luís Cláudio Nascimento da Silva ◽  
Neyla Maria Pereira Alves ◽  
Maria Carolina Accioly Brelaz de Castro ◽  
Taciana Mirely Maciel Higino ◽  
Cássia Regina Albuquerque da Cunha ◽  
...  

Oxidative stress plays an important role in the induction of cell death and is associated with various pathologic disorders; therefore, the search for natural products that attenuate the effects produced by oxidant agents is greatly increased. Here, the protective effects of native lectin fromCratylia mollisseeds (pCramoll) and recombinant Cramoll 1 (rCramoll) against H2O2-induced oxidative stress in Vero cells were evaluated. Both lectins significantly attenuated the H2O2-induced cytotoxicity in a concentration-dependent way. The maximum protective effects were96.85±15.59%(rCramoll) and59.48±23.44%(pCramoll). The Live/Dead analysis showed a reduction in the percentage of dead cells from65.04±3.29% (H2O2) to39.77±2.93%(pCramoll) and13.90±9.01%(rCramoll). The deleterious effects of H2O2on cell proliferation were reduced to 10.83% (pCramoll) and 24.17% (rCramoll). Lectins treatment attenuated the excessive superoxide production, the collapse of the mitochondrial membrane potential, and the lysosomal and DNA damage in H2O2-treated cells. In conclusion, our results suggest that pCramoll and rCramoll blocked H2O2-induced cytotoxicity through decreasing reactive oxygen species, restoring the mitochondrial potential, preventing the lysosomal damage and DNA fragmentation, and thus promoting cell survival and proliferation.


1995 ◽  
Vol 6 (4) ◽  
pp. 1300-1303
Author(s):  
A Salahudeen ◽  
K Badr ◽  
J Morrow ◽  
J Roberts

F2-isoprostanes are the newly identified reactive oxygen species-catalyzed peroxidation products of arachidonate. The infusion of these prostaglandin F2-like prostanaoids into the rat kidney induces profound parallel reductions in RBF and GFR, suggesting that these metabolites may be partly responsible for the hemodynamic alterations seen in free radical-linked acute renal injury models. The present study examined directly in renal proximal tubular (LLC-PK1) cells whether hydrogen peroxide, a reactive oxygen species implicated in many models of acute renal injury, induces F2-isoprostane production and whether its production can be inhibited by the recently synthesized lipid peroxidation inhibitor 21-aminosteroid (lazaroid U-74389G). The incubation of LLC-PK1 cell layers with hydrogen peroxide for 3 h resulted in a dose-related six-fold increase in F2-isoprostane production, measured by the gas chromatographic-mass spectroscopic method. The preincubation of cells with 21-aminosteroid prevented hydrogen peroxide-induced F2-isoprostane production, a finding also demonstrable with other lipid peroxidation inhibitors, e.g., 2-methyl aminochroman (U-83836E) and diphenyl-p-phenylenediamine. Besides inhibiting isoprostane production, 21-aminosteroid reduced hydrogen peroxide-induced lipid degradation and peroxidation, and protected the cells against hydrogen peroxide-induced cytolysis. The novel finding that hydrogen peroxide induces 21-aminosteroid-inhibitable F2-isoprostane production in renal epithelial cells supports the in vivo report that its levels are elevated in reactive oxygen species-linked renal injury models such as ischemia-reperfusion. Besides direct cell injury, lipid peroxidation by generating F2-isoprostanes may further contribute to renal dysfunction through a vasoconstrictive mechanism. Thus, the inhibition of excess F2-isoprostane production may be one of the additional mechanisms, besides cytoprotection, by which antioxidants ameliorate renal dysfunction in experimental models of acute renal injury.


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