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1.
The different physiological responses to heat stress in calli from two ecotypes of common reed ( Phragmites communis Trin.) plants (dune reed (DR) and swamp reed (SR)) were studied. The relative water content, the relative growth rate, cell
viability, membrane permeability (MP), H 2O 2 content, MDA content, proline level, and the activities of enzymes, such as superoxide dismutase (SOD), catalase (CAT), peroxidase
(POD), ascorbate peroxidase (APX), glutathione reductase (GR), and lipoxygenase (LOX) were assayed. Results showed that under
heat stress, DR callus could maintain the higher relative growth rate and cell viability than SR callus, while H 2O 2 content, MDA content, and MP in SR callus increased more than in DR callus. The activities of antioxidant enzymes, such as
SOD, CAT, POD, APX, and GR in two calli were enhanced by high temperature. However, antioxidant enzymes in DR callus showed
the higher thermal stability than those in SR callus. LOX activity increased more in SR callus than in DR callus under heat
stress. High temperature markedly elevated proline content in DR callus whereas had no effect on that in SR callus. Taken
together, DR callus is more thermotolerant than SR callus, which might be due to the higher activity of antioxidant enzymes
and proline level compared with SR callus under heat stress. 相似文献
2.
The aim of the present study is to evaluate the oxidative effects of lead with increased concentrations by the determination
of antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and ascorbate peroxidase
(AP)) and lipid peroxidation levels in the stem and leaves of watercress ( Nasturtium officinale R. Br.) which was exposed to lead acetate, Pb (CH 3COOH) 2 regime with concentrations of 0, 50, 100, 200, 250, and 500 mg/L Pb in a hydroponic culture. After 14 days, accumulation
of lipid peroxidation in stems and leaves and changes in activity of antioxidant enzymes were determined spectrophotometrically.
The maximum accumulation was observed in the highest concentration group. In this group, lipid peroxidation levels were three
times higher than the control group in the stem and leaves. The highest induction in SOD and GR activities were determined
at 200 mg/L Pb group in stem, whereas CAT and AP activities were higher than other groups at the concentration of 250 and
100 mg/L Pb, respectively. The increase in CAT activity was found to be greater than GR, SOD, and AP activities in stems of
watercress under Pb treatment. Both lead accumulation and antioxidant enzyme responses were higher in stems than in leaves.
The results of the present study suggested that the induction in antioxidant responses could be occurring as an adaptive mechanism
to the oxidative potential of lead accumulation. 相似文献
3.
Recent studies from our laboratory have showed that resveratrol, a polyphenol found predominantly in grapes rendered strong cardioprotection in animal models of heart disease. The cardioprotection which was observed was primarily associated with the ability of resveratrol to reduce oxidative stress in these models. The aim of the current study was to corroborate the role of resveratrol as an inhibitor of oxidative stress and explore the underlying mechanisms of its action in heart disease. For this purpose, we used a cell model of oxidative stress, the hydrogen peroxide (H 2O 2) exposed adult rat cardiomyocytes, which was treated with and without resveratrol (30 μM); cardiomyocytes which were not exposed to resveratrol served as controls. Cell injury, cell death and oxidative stress measurements as well as the activities of the major endogenous antioxidants superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were carried out in control and H 2O 2 exposed cardiomyocytes, treated with and without resveratrol. Pharmacological blockade using specific blockers of the antioxidant enzymes were used to confirm their role in mediating resveratrol action in H 2O 2 exposed cardiomyocytes. The status of H 2O 2 and antioxidant enzymes in serum samples from spontaneously hypertensive rats (SHR) treated with and without resveratrol (2.5 mg/kg body weight) was also examined.Our results showed significant cell injury and death in H 2O 2 exposed cardiomyocytes which was prevented upon resveratrol treatment. SOD and CAT activities were decreased in H 2O 2 exposed adult rat cardiomyocytes; treatment with resveratrol significantly prevented this reduction. However, GPx activity was not altered in the H 2O 2 exposed cardiomyocytes in comparison to controls. Pharmacological blockade of SOD and/or CAT prevented the beneficial effect of resveratrol. In SHR, H 2O 2 levels were increased, but CAT activity was decreased, while SOD remained unchanged, when compared to WKY rats; resveratrol treatment significantly prevented the increase in H 2O 2 levels and the decrease in CAT activities in SHR.Based on our results, we conclude that treatment with resveratrol prevents oxidative stress induced cardiomyocyte injury mainly by preserving the activities of critical antioxidant enzymes. This may be a crucial mechanism by which resveratrol confers cardioprotection. 相似文献
4.
The effect of oxygen deprivation (anoxia) on the antioxidant system in suspension culture of anoxia-intolerant Malaysian rice
mutants cells was examined. Abiotic stresses have been reported to adversely affect cell division, damage cellular and organelle
membranes. The signaling defense mechanisms, such as molecular and biochemical aspects responding to stress have been proven
to be very complex, and still largely untapped. The objective of this study was to determine the potential involvement of
activated oxygen species, such as superoxide dismutase, catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase
which occur in cells of rice plants exposed to anoxia stress in two Malaysian rice mutants, MR219-4 and MR219-9, and rice
cultivar FR13A which is known to be tolerant to anoxia stress during 5–30 days of exposure. The antioxidative enzymes were
decreased for MR219-4 and MR219-9 mutants for CAT and APX activities, and increased in FR13A cultivar starting at 20 days
in suspension culture compared to that of control. CAT and APX activities were maintained higher in anoxia condition for all
mutants and cultivar. These findings suggested that anoxia stress in suspension cultures induced the level of H 2O 2 to toxic levels. 相似文献
5.
SummaryReactive oxygen species (ROS) such as hydrogen peroxide (H 2O 2), superoxide anion (O 2?), and hydroxyl radical (OH ?) have been implicated in mediating various pathological events such as cancer, atherosclerosis, diabetes, ischemia, inflammatory diseases, and the aging process. The glutathione (GSH) redox cycle and antioxidant enzymes—superoxide dismutase (SOD) and catalase (CAT)—play an important role in scavenging ROS and preventing cell injury. Pycnogenol has been shown to protect endothelial cells against oxidant-induced injury. The present study determined the effects of pycnogenol on cellular metabolism of H 2O 2 and O 2? and on glutathione-dependent and -independent antioxidant enzymes in bovine pulmonary artery endothelial cells (PAEC). Confluent monolayers of PAEC were incubated with pycnogenol, and oxidative stress was triggered by hypoxanthine and xanthine oxidase or H 2O 2. Pycnogenol caused a concentration-dependent enhancement of H 2O 2 and O 2? clearance. It increased the intracellular GSH content and the activities of GSH peroxidase and GSH disulfide reductase. It also increased the activities of SOD and CAT. The results suggest that pycnogenol promotes a protective antioxidant state by upregulating important enzymatic and nonenzymatic oxidant scavenging systems. 相似文献
6.
Nitraria tangutorum Bobr., a typical desert halophyte, plays an important ecological role because of its superior tolerance to severe drought
and high salinity. Very little is known about the physiological adaptative mechanism of this species to environmental stresses.
The aim of this study was to investigate the changes of antioxidant enzyme activities and the regulatory mechanism of ascorbate
peroxidase (APX) activity in the calli from Nitraria tangutorum Bobr. after treatment with different NaCl concentrations. The activities of superoxide dismutase (SOD) and catalase (CAT)
significantly increased in the calli treated with NaCl, while the peroxidase activity decreased. APX activity was also elevated
significantly in response to NaCl, but the increase was partly abolished by H 2O 2 scavenger dimethylthiourea (DMTU). Furthermore, the excitatory effect of salinity on APX could be alleviated by the addition
of exogenous CAT and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor diphenylene iodonium, indicating
that the modulation of the APX activity in Nitraria tangutorum Bobr. calli might be associated with NADPH oxidase-dependent H 2O 2 generation. Measurement and analysis using fluorescent dye 2′,7′-dichlorodihydrofluorescein diacetate showed the increase
of H 2O 2 content in salinity-treated calli. The investigation of NADPH-dependent O 2− production in plasma membrane (PM) vesicles isolated from Nitraria tangutorum Bobr. calli revealed that salinity treatment stimulated NADPH oxidase activity. In conclusion, these results suggest that
the higher activities of antioxidant enzymes play an important role in the salt tolerance of Nitraria tangutorum Bobr. calli and that the extracellular production of H 2O 2, depending on the excitation of PM NADPH oxidase, is responsible for enhancing the APX activity in Nitraria tangutorum Bobr. calli under salinity stress. 相似文献
7.
Temperature is a critical abiotic factor that causes physiological changes in arthropods. However, little is known about the effect of heat stress on the antioxidant responses of Araneae species. Hylyphantes graminicola is a dominant predator in many cropping systems in China. In the present study, the effect of short-term heat stress (36, 38, 40 or 42 °C) on the reactive oxygen species (ROS) levels, the activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], peroxidases [POD] and glutathione-S-transferases GST]), total antioxidant capacity (TAC), malondialdehyde (MDA) concentrations and survival of H. graminicola spiderlings and adults were investigated. The results showed that H. graminicola adults had a significantly higher survival rate compared to spiderlings at 40 °C. The heat stress increased ROS contents in H. graminicola. The SOD, CAT, POD and GST activities increased in spiderlings and adults under heat stress. These data suggest a defensive function for these enzymes in alleviating oxidative damage. Specifically, SOD plays a key role in reducing the high level of superoxide radicals in spiderlings and adults. Moreover, the POD and CAT capabilities for scavenging H 2O 2 in spiderlings were similar, and CAT may play a more important role than POD in scavenging H 2O 2 in adults at 42 °C. The spiderling TAC increased significantly at 40 and 42 °C, and the adult TAC was stable at 36–40 °C but decreased at 42 °C. These data suggest that TAC was insufficient in H. graminicola adults under more severe stress conditions. These results further our understanding of the physiological response of Araneae species exposed to heat stress. 相似文献
8.
Effect of high-frequency vibration on growth rate, membrane stability and activities of some antioxidant enzymes were studied in callus tissues of Hyoscyamus kurdicus. Calli initiated from leaf (LE), shoot (SE) and root (RE) explants, and sinusoidal vibrations at 0, 50, 100 and 150 Hz for 30 min were applied on the H. kurdicus calli. Results showed that sinusoidal vibration at 50 and 100 Hz promoted the growth rate as compared to control, and the optimum growth was found at 50 Hz. Sinusoidal vibration increased significantly protein and proline contents and activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POX) enzymes, and decreased total carbohydrate, H 2O 2 level and CAT activity as compared to control. Lipid peroxidation also decreased under sinusoidal vibration in all the calli, and the maximum percentage of decrease was observed at 50 Hz. Native polyacrylamide gel electrophoresis indicated different isoform profiles in vibration treated and untreated plants concerning antioxidant enzymes. The responses of different types of calluses were different, and RE callus showed the highest growth, membrane stability and antioxidant enzymes activity as compared to LE and SE calli. These results suggest sinusoidal vibration at optimum frequency could improve callus growth by induction of antioxidative enzymes activity and membrane stability in calli of H. kurdicus. 相似文献
9.
Antioxidant defenses within the lung are pivotal in preventing damage from oxidative toxicants. There have also been several reports with conflicting results on the antioxidant system during aging. In this study, we attempted to investigate age-related alterations in both antioxidant enzyme activities and thiobarbituric acid-reactive substances (TBARS), a product of lipid peroxidation, in the whole lung of control and sulfur dioxide (SO 2) exposed rats of different age groups (3-, 12-, and 24-months-old). Swiss-Albino Male rats were exposed to 10 ppm SO 2 1 hr/day, 7 days/week for 6 weeks. The antioxidant enzymes examined include Cu,Zn-superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST). A mixed pattern of age-associated alterations in antioxidant activities was observed. SOD, GSH-Px and GST activities were increased with age, but CAT activity was decreased. Lung SOD, GSH-Px and GST activities were also increased in response to SO 2. The level of TBARS was increased with age. SO 2 exposure stimulated lipid peroxide formation in the lung as indicated by an increase in the level of TBARS. These findings suggest that both aging and SO 2 exposure may impose an oxidative stress to the body. We conclude that the increase in the activities of the antioxidant enzymes of the lung during aging, could be interpreted as a positive feedback mechanism in response to rising lipid peroxidation. 相似文献
10.
Catalase (CAT) and superoxide dismutase (SOD) are antioxidant enzymes which are important in the metabolism of reactive oxygen species (ROS), and can be induced by environmental stresses including cadmium (Cd), a heavy metal toxic to living organisms. Sugar cane ( Saccharum officinarumL.) in vitro callus cultures were exposed to CdCl 2 and the activities of CAT and SOD were analysed. Lower concentrations of CdCl 2, such as 0.01 and 0.1 mM caused a significant increase in callus growth, whereas 0.5 and 1 mM CdCl 2 strongly inhibited growth of the callus cultures, but only after 9 days of CdCl 2 treatment. Red-brown patches were also observed in calluses exposed to 0.5 and 1 mM CdCl 2. Calluses grown in 0.01 and 0.1 mM CdCl 2 did not exhibit any changes in CAT activity even after 15 days of growth in the presence of CdCl 2. However, for calluses grown in higher concentrations of CdCl 2 (0.5 and 1 mM), a rapid increase in CAT activity was detected, which was 14-fold after 15 days. Furthermore, up to five CAT isoforms were observed in callus tissue. Total SOD activity did not exhibit any major variation. One Mn-SOD and two Cu/Zn-SOD isoenzymes were observed in callus cultures and none exhibited any variation in response to the CdCl 2 treatments. The results suggested that in sugar cane callus cultures, CAT may be the main antioxidant enzyme metabolizing H 2O 2. 相似文献
11.
The essential role of 6-benzylaminopurine (BA) in plant tissue culture has been widely known; however, physiological and biochemical
mechanisms behind BA requirement have not been fully understood yet. BA may have an important role on callus growth by regulating
antioxidant enzyme activities and acting as an effective free radical scavenger. To test this hypothesis, the impact of exogenous
BA concentrations on antioxidative system in Vitis vinifera L. cv. ‘Bogazkere’ callus was investigated under in vitro conditions. Relative fresh weight growth (RFWG) of calli, total
phenolics (TP) content, endogenous hydrogen peroxide (H 2O 2), malondialdehyde (MDA), proline concentrations, percentage of electrolyte leakage (EL), and some of the antioxidant enzyme
activities; such as superoxide dismutase (SOD), and guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)
were measured. Inhibitory effect of high concentrations of BA on antioxidant enzyme activities and RFWG was found. In the
presence of BA at 0.1 mg L −1, SOD, POD, and APX activities decreased, while CAT activity increased in comparison with the controls. Exogenous BA treatments
higher than 0.1 mg L −1 resulted in an increase in cellular TP, H 2O 2, MDA, proline contents, and percentage of EL, while RFWG of calli decreased. Based on the findings, it may be concluded that
only 0.1 mg L −1 BA concentration combined with NAA could play a direct role in reducing the level of free radicals and phenolic production
associated with proliferation capacity of grape cells under in vitro conditions. Furthermore, cytokinin was effective in the
antioxidative enzyme system, lipid peroxidation, and electrolyte leakage. 相似文献
12.
Mountain environmental stresses result in increased formation of hydrogen peroxide (H 2O 2) and accumulation of malondialdehyde (MDA) in leaves of Polygonum viviparum. The activities of several antioxidative system enzymes such as superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC
1.11.1.6), peroxidase (POD, EC 1.11.1.7), glutathione reductase (GR, EC 1.6.4.2), dehydroascorbate reductase (DHAR, EC 1.8.5.1)
and the contents of several non-enzymatic antioxidants such as reduced form of ascorbate (ASC), dehydroascorbate (DHA), reduced
glutathione (GSH), and oxidized glutathione (GSSG) were investigated in leaves of P. viviparum, which were collected from three altitudes (2,200, 3,200, and 3,900 m) of Tianshan Mountain in China. The activities of these
four antioxidative enzymes were accompanied by increases of H 2O 2 levels from 2,200 to 3,200 m. However, the activities of CAT and POD were decreased, whereas the activities of SOD and GR
continually increased at 3,900 m. Analyses of isoforms of SOD, CAT, POD, and GR showed that the leaves of P. viviparum exposed different altitude conditions are capable of differentially altering the intensity. Additionally, two new isoforms
of SOD were detected at 3900 m. A continual increase in the ASC, ASC to DHA ratio, GSH and GSH/[GSH + GSSG] ratio, and the
activity of DHAR were observed in leaves of P. viviparum with the elevation of altitude. These results suggest that the higher contents of ASC, GSH as well as an increase in reduced
redox state may be essential to antioxidation processes in the leaves of P. viviparum, whereas antioxidant enzymes system is a cofactor in the processes. 相似文献
13.
This study was conducted to investigate how the activity and expression of certain paramount antioxidant enzymes respond to grape seed extract (GSE) addition in primary muscle cells of goats. Gluteal primary muscle cells (PMCs) isolated from a 3-week old goat were cultivated as an unstressed cell model, or they were exposed to 100 µM H 2O 2 to establish a H 2O 2-stimulated cell model. The activities of catalase (CAT), superoxide dismutases (SOD) and glutathione peroxidases (GPx) in combination with other relevant antioxidant indexes [i.e., reduced glutathione (GSH) and total antioxidant capacity (TAOC)] in response to GSE addition were tested in the unstressed and H 2O 2-stimulated cell models, and the relative mRNA levels of the CAT, GuZu-SOD, and GPx-1 genes were measured by qPCR. In unstressed PMCs, GSE addition at the dose of 10 µg/ml strikingly attenuated the expression levels of CAT and CuZn-SOD as well as the corresponding enzyme activities. By contrast, in cells pretreated with 100 µM H 2O 2, the expression and activity levels of these two antioxidant enzymes were enhanced by GSE addition at 10 µg/ml. GSE addition promoted GPx activity in both unstressed and stressed PMCs, while the expression of the GPx 1 gene displayed partial divergence with GPx activity, which was mitigated by GSE addition at 10 µg/ml in unstressed PMCs. GSH remained comparatively stable except for GSE addition to H 2O 2-stimulated PMCs at 60 µg/ml, in which a dramatic depletion of GSH occurred. Moreover, GSE addition enhanced TAOC in unstressed (but not H 2O 2-stimulated) PMCs. GSE addition exerted a bidirectional modulating effect on the mRNA levels and activities of CAT and SOD in unstressed and stressed PMCs at a moderate dose, and it only exhibited a unidirectional effect on the promotion of GPx activity, reflecting its potential to improve antioxidant protection in ruminants. 相似文献
14.
Glucose-6-phosphate dehydrogenase (G6PDH) has been implicated in supplying reduced nicotine amide cofactors for biochemical
reactions and in modulating the redox state of cells. In this study, the role of G6PDH in thermotolerance of the calli from
Przewalskia tangutica and tobacco ( Nicotiana tabacum L.) was investigated. Results showed that Przewalskia tangutica callus was more sensitive to heat stress than tobacco callus. The activity of G6PDH and antioxidant enzymes (ascorbate peroxidase,
catalase, peroxidase and superoxide dismutase) in calli from Przewalskia tangutica and tobacco increased after 40 °C treatment, although two calli exhibited a difference in the degree and timing of response
to heat stress. When G6PDH was partially inhibited by glucosamine pretreatment, the antioxidant enzyme activities and thermotolerance
in both calli significantly decreased. Simultaneously, the heat-induced H 2O 2 content and the plasma membrane NADPH oxidase activity were also reduced. Application of H 2O 2 increased the activity of G6PDH and antioxidant enzymes in both calli. Diphenylene iodonium, a NADPH oxidase inhibitor, counteracted
heatinduced H 2O 2 accumulation and reduced the heat-induced activity of G6PDH and antioxidant enzymes. Moreover, exogenous H 2O 2 was effective in restoring the activity of G6PDH and antioxidant enzymes after glucosamine pretreatment. Western blot analysis
showed that G6PDH gene expression in both calli was also stimulated by heat and H 2O 2, and blocked by DPI and glucosamine under heat stress. Taken together, under heat stress G6PDH promoted H 2O 2 accumulation via NADPH oxidase and the elevated H 2O 2 was involved in regulating the activity of antioxidant enzymes, which in turn facilitate to maintain the steady-state H 2O 2 level and protect plants from the oxidative damage. 相似文献
15.
In Camellia japonica callus culture, the effects of light quality on the accumulation of phenolic compounds were examined. To this end, the calli were cultured under three monochrome [white (W), red (R), and blue (B)] and two mixed [red/blue (RB) and red/green/blue (RGB)] light sources. After 4 weeks of culture, fresh and dry callus weights were determined, and phenolic content was analyzed using high-performance liquid chromatography. We also examined the effects of RGB light on calli derived from four origins (leaf: CL; root: CR; petal: CP; and ovary: CO). Total phenolic and flavonoid content and DPPH radical scavenging activity were highest in calli exposed to RB and RGB. Catechin was detected only in calli exposed to mixed light (RB and RGB). Interestingly, red pigmentation development in CL and CR calli after 2 weeks of culture and organogenic calli in CR and CP samples was observed. Furthermore, expression of the phenylalanine ammonia lyase and chalcone synthase genes was found to be higher in the CR line than in other lines, and total phenolic and flavonoid content was also higher in the CR and CP lines. The findings of the present study revealed that the accumulation of phenolics and flavonoids in callus tissue varies depending on light quality, which stimulates cell division, and may thus affect the proliferation and organogenesis of C. japonica callus. We also established that the effects of light on red pigment expression and the accumulation of bioactive compounds are dependent on the tissue origin of callus material. 相似文献
16.
We investigated the interaction between heat shock protein 70 (HSP70) and abscisic acid (ABA)-induced antioxidant response
of maize to the combination of drought and heat stress. First, the increased activities of enzymes, including superoxide dismutase
(SOD), ascorbate peroxidase (APX), glutathione reductase (GR) and catalase (CAT), induced by drought were less than those
by heat or combined drought and heat stress, except some individual cases (e.g. CAT in leaves, GR in roots). Second, both
HSP70 synthesis and H 2O 2 production increased prominently under drought, heat or their combination stress; the increase in leaves induced by drought
and heat combination was the highest, followed by heat and by drought, while the increase in roots had not visible difference.
Third, either in leaves or roots, pretreatment with ABA inhibitor, HSP70 inhibitor and H 2O 2 scavenger, significantly arrested the stress-induced increase of antioxidant enzyme activities, and ABA inhibitor and H 2O 2 scavenger obviously suppressed HSP70 synthesis, while HSP70 inhibitor slightly heightened H 2O 2 accumulation. Finally, 100 μM ABA significantly enhanced the activities of antioxidant enzymes, HSP70 expression and H 2O 2 production under stresses in comparison with ABA-deficient mutant vp5 maize plants without pretreatment. Thus, ABA-induced H 2O 2 production enhances the HSP70 synthesis and up-regulates the activities of antioxidant enzymes, resulting in the suppression
of cellular reactive oxygen species (ROS) levels. Our results suggest that HSP70 may play a crucial role in ABA-induced antioxidant
defense of maize to drought and heat combination. 相似文献
17.
We have investigated the physiological functions of the rapid generation of reactive oxygen species (ROS) and the implication of the antioxidant enzymes in the apoplast and symplast of roots of sunflower ( Helianthus annuus L.) seedlings exposed to methyl jasmonate (MeJA, 50 μM). MeJA-elicited roots showed a fast increase in ROS content, followed by a marked increase in the activity of H 2O 2-scavenging enzymes, guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and catalase (CAT). The mechanisms responsible for MeJA-induced H 2O 2 accumulation was investigated further by studying both the production and scavenging of H 2O 2 in the extracellular matrix. Peroxidases active against (2,2′-azino-bis-[3-ethylbenzthiazoline-6-sulfonic acid], ABTS) and guaiacol were found in the apoplastic fluid, and proved to be ionically and covalently associated with sunflower cell walls, although only the peroxidase activities of the soluble apoplastic fractions and those ionically linked to the cell wall were correlated with the accumulation of the H 2O 2 detected. The results indicated that H 2O 2 accumulation is a complex and highly regulated event requiring the time-dependent stimulation and down-regulation of differently located enzymes, some of which are involved in H 2O 2 generation and degradation. It is concluded that exogenous MeJA may be involved in the oxidative stress processes by regulating antioxidant enzyme activities. 相似文献
18.
Coumarins are a vast group of natural compounds and some of them possess antioxidant activities. The comparison of the antioxidant
activity of some coumarins with various chemical molecular structure has not been investigated in previous studies. Therefore,
this study was aimed to investigate the hepatoprotective effect against carbon tetrachloride (CCl 4) -induced hepatic injury by coumarin (1,2-benzopyrone) and coumarin derivatives, esculetin (6,7-dihydroxycoumarin), scoparone
(6,7-dimethoxycoumarin), and 4-methylumbelliferone (7-hyroxy-4-methyl) in male Sprague–Dawley rats. Product of lipid peroxidation,
malondialdehyde (MDA), activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) were evaluated for oxidative
stress in hepatic injury. Gamma glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH) were detected in plasma as a biomarker
of hepatic injury. Significantly elevated levels of MDA and lowered levels of SOD and CAT activities were observed in liver
of rats exposed to CCl 4, when compared to control values. Similarly, administration of CCl 4 increased LDH and GGT levels in serum. Pre-treatment of rats with esculetin (35 mg kg −1, orally) and scoparone (35 mg kg −1, orally) significantly prevented CCl 4-induced decrease in MDA levels and increase in SOD and CAT, whereas 4-methylumbelliferone (35 mg kg −1) and coumarin (30 mg kg −1) had no effect against CCl 4-induced rise in serum enzymes. Esculetin and scoparone also showed protective properties as was evidenced in reduced LDH
and GGT levels in serum. The results of this study indicate that the chemical structures of coumarins play an important role
in the prevention of oxidative stress. 相似文献
19.
Callus cultures of two parental clones of Populus nigra L., Poli and 58-861, originating from contrasting environments, were exposed to different cadmium concentrations (0, 150
and 250 μM CdSO 4). Clones showed different growth responses to cadmium, evaluated by the tolerance index (Ti), with Poli being more tolerant
to the metal at both concentrations. The cadmium concentration at the end of the treatment was very similar between clones
at 150 μM CdSO 4, while a higher value in 58-861 compared to Poli was detected at 250 μM CdSO 4. The bioconcentration factor evidenced the lowest value in Poli at 250 μM CdSO 4. Unlike 58-861, cadmium provoked a strong induction of thiols and phytochelatins in clone Poli. In both clones, organic acid
concentration differed notably in untreated calli and cadmium treatment induced a general lowering of these compounds. A notably
higher antioxidant enzyme activity (ascorbate peroxidase, APX; catalase, CAT; guaiacol peroxidase, GPX) was measured in control
calli of clone Poli compared to 58-861. Cadmium induced a remarkable enhancement of APX and CAT, but not GPX, activity at
150 μM CdSO 4 in Poli. Conversely, in 58-861 at 150 μM CdSO 4, and in both clones at 250 μM CdSO 4, a decrease in the antioxidant activity occurred. This investigation provided evidence that these two contrasting genotypes
of P. nigra are characterised by a different response to cadmium in callus cultures. In particular, in Poli, the higher tolerance to
cadmium is associated with a higher activity of antioxidative enzymes and the ability to strongly increase thiol and PC concentration
in response to metal exposure. 相似文献
20.
Pigeonpea [ Cajanus cajan (L.) Millsp.] is a waterlogging-sensitive legume crop. We studied the effect of waterlogging stress on hydrogen peroxide
(H 2O 2) content, lipid peroxidation and antioxidant enzyme activities in two pigeonpea genotypes viz., ICPL-84023 (waterlogging
resistant) and MAL-18 (waterlogging susceptible). In a pot experiment, waterlogging stress was imposed for 6 days at early
vegetative stage (20 days after sowing). Waterlogging treatment significantly increased hydrogen peroxide accumulation and
lipid peroxidation, which indicated the extent of oxidative injury posed by stress conditions. Enzyme activities of peroxidase
(POX), catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and polyphenol oxidase (PPO) increased in pigeonpea
roots as a consequence of waterlogged conditions, and all the enzyme activities were significantly higher in waterlogged ICPL-84023
than in MAL-18. POX activity was the maximum immediately after imposing stress, therefore, it was suggested to be involved
in early scavenging of H 2O 2, while rest of the enzymes (CAT, APX, SOD and PPO) were more important in late responses to waterlogging. Present study revealed
that H 2O 2 content is directly related to lipid peroxidation leading to oxidative damage during waterlogging in pigeonpea. Higher antioxidant
potential in ICPL-84023 as evidenced by enhanced POX, CAT, APX, SOD and PPO activities increased capacity for reactive oxygen
species (ROS) scavenging and indicated relationship between waterlogging resistance and antioxidant defense system in pigeonpea. 相似文献
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