Enzymatic antioxidant defence mechanisms of maize and sorghum after exposure to and recovery from pre- and post-flowering dehydration

2009 ◽  
Vol 57 (4) ◽  
pp. 445-459 ◽  
Author(s):  
A. Takele ◽  
J. Farrant
Keyword(s):  
Antioxidant System ◽  
Developmental Stages ◽  
Antioxidant Activities ◽  
Limiting Factor ◽  
Enzymatic Antioxidants ◽  
Antioxidant Protection ◽  
Protection Mechanism ◽  
Enzymatic Antioxidant ◽  
Mda Content ◽  
Sorghum Production

Drought stress is often the most limiting factor for maize and sorghum production in the semi-arid areas. This study evaluates the enzymatic antioxidant protection mechanism response of maize (cv Melkassa-2) and sorghum (cv. Macia) after exposure to and recovery from pre- and post-flowering dehydration.The response of enzymatic antioxidant protection systems revealed that in both test crops dehydration during both the pre- and post-flowering stages resulted in increased activities of enzymatic antioxidant protection mechanisms (SOD, GR, CAT and APX). There were, however, differences between the species in the type and extent of enhanced developmentally-induced and dehydration-induced antioxidant activities. Differences were also noticed in the relative water contents at which changes in enzymatic antioxidant activities occurred. Under dehydration conditions, sorghum was generally found to have relatively higher enzymatic antioxidant activities, providing it better protection against oxidative stress by minimizing the level of lipid peroxidation.Lipid peroxidation, measured as MDA content, was increased in both species during pre- and post-flowering dehydration, but the increase was greater in maize than in sorghum during both developmental stages. Sorghum appeared to be able to reduce MDA on rehydration, but maize contained only 85% less MDA after rehydration as compared to the control following pre-flowering rehydration. During post-flowering rehydration, neither species was able to decrease the MDA content to the control level.The results indicated that tolerance to drought in sorghum is well associated with the consistent enhanced capacity of the enzymatic antioxidant system under both pre- and post-flowering dehydration conditions, and that the sensitivity of maize to drought is linearly correlated to the decreased capacity of the antioxidant system. It may be concluded that, since differences were observed between the species in the response of enzymatic antioxidants to pre- and post-flowering dehydration/rehydration, with sorghum exhibiting comparatively higher overall activities of enzymatic antioxidants and a lower level of MDA than maize during both pre- and post-flowering dehydration, selection based on these criteria may help in the development of genotypes tolerant to dehydration.

scholarly journals Ethylene Induction of Non-Enzymatic Metabolic Antioxidants in Matricaria chamomilla

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5720
Author(s):  
Veronika Petrulova ◽  
Maria Vilkova ◽  
Zuzana Kovalikova ◽  
Matus Sajko ◽  
Miroslav Repcak
Keyword(s):  
Antioxidant System ◽  
Therapeutic Effects ◽  
Enzymatic Antioxidants ◽  
Matricaria Chamomilla ◽  
Chlorogenic Acids ◽  
Isolation And Identification ◽  
Phytochemical Content ◽  
Enzymatic Antioxidant ◽  
Dicaffeoylquinic Acid

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.

scholarly journals Effect of Salt Stress on Growth, Physiological Parameters, and Ionic Concentration of Water Dropwort (Oenanthe javanica) Cultivars

2021 ◽  
Vol 12 ◽  
Author(s):  
Sunjeet Kumar ◽  
Gaojie Li ◽  
Jingjing Yang ◽  
Xinfang Huang ◽  
Qun Ji ◽  
...  
Keyword(s):  
Salt Stress ◽  
Antioxidant Activities ◽  
Soluble Sugars ◽  
Limiting Factor ◽  
Enzymatic Antioxidants ◽  
High Accumulation ◽  
Oenanthe Javanica ◽  
Leaves And Roots ◽  
Water Dropwort ◽  
Number Of Branches

Salt stress is an important environmental limiting factor. Water dropwort (Oenanthe javanica) is an important vegetable in East Asia; however, its phenotypic and physiological response is poorly explored. For this purpose, 48 cultivars of water dropwort were grown hydroponically and treated with 0, 50, 100, and 200 mm NaCl for 14 days. Than their phenotypic responses were evaluated, afterward, physiological studies were carried out in selected sensitive and tolerant cultivars. In the present study, the potential tolerant (V11E0022) and sensitive (V11E0135) cultivars were selected by screening 48 cultivars based on their phenotype under four different levels of salt concentrations (0, 50, 100, and 200 mm). The results depicted that plant height, number of branches and leaves were less effected in V11E0022, and most severe reduction was observed in V11E0135 in comparison with others. Than the changes in biomass, ion contents, accumulation of reactive oxygen species, and activities of antioxidant enzymes and non-enzymatic antioxidants were determined in the leaves and roots of the selected cultivars. The potential tolerant cultivar (V11E0022) showed less reduction of water content and demonstrated low levels of Na+ uptake, malondialdehyde, and hydrogen peroxide (H2O2) in both leaves and roots. Moreover, the tolerant cultivar (V11E0022) showed high antioxidant activities of ascorbate peroxidase (APX), superoxide dismutase, peroxidase, catalase (CAT), reduced glutathione (GSH), and high accumulation of proline and soluble sugars compared to the sensitive cultivar (V11E0135). These results suggest the potential tolerance of V11E0022 cultivar against salt stress with low detrimental effects and a good antioxidant defense system. The observations also suggest good antioxidant capacity of water dropwort against salt stress. The findings of the present study also suggest that the number of branches and leaves, GSH, proline, soluble sugars, APX, and CAT could serve as the efficient markers for understanding the defense mechanisms of water dropwort under the conditions of salt stress.

scholarly journals Antioxidant protection in patients with pulmonary tuberculosis

2021 ◽  
Keyword(s):  
Free Radical ◽  
Pulmonary Tuberculosis ◽  
Antioxidant System ◽  
Cell Membranes ◽  
Antioxidant Defense ◽  
Antioxidant Defense System ◽  
Antioxidant Protection ◽  
Glutathione System ◽  
Defense System ◽  
Enzymatic Antioxidant

The literature review summarizes the data on the classification and characteristics of the antioxidant defense system. This model combines a number of different substances. Each of the components of the antioxidant system acts in close connection with its other structural elements, harmoniously complements, and in many cases – enhances the action of each other. The functional basis of the system of antioxidant protection is formed by the glutathione system, the constituent elements of which are actually glutathione and enzymes that catalyze the reactions of its reverse transformation (oxidation ↔ reduction). Most researchers conventionally divide the system of antioxidant protection into enzymatic and non-enzymatic. The enzyme links of the antioxidant defense system include: catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione transferase and other enzymes. The non-enzymatic system includes fat-soluble vitamins A, E and K, water-soluble vitamins C and PP, biogenic amines, glutathione, carotenoids, ubiquinone, sterols. Both enzymatic and non-enzymatic antioxidant defense systems are present in the bloodstream. The activity of the enzymatic antioxidant system is very well regulated and depends on age, physiological condition, hormone dynamics, intensity of antioxidant enzyme synthesis, pH, presence of coenzymes, inhibitors, activators and other factors. The non-enzymatic part of the antioxidant system does not require as many regulators as the chemical itself - the antioxidant - reacts chemically with the radical. Only the reaction rate can change. The lungs are directly exposed to oxygen and oxidants of polluted air, they are most sensitive to oxidative damage, so they have an increased possibility of free radical reactions. Protection against the damaging effects of reactive oxygen species and free radicals is provided by anti-radical protective systems, especially the glutathione system and its enzymes. Numerous papers have obtained clinical and experimental data on the important role of free radical oxidation of lipids (FROL) and antioxidant systems (AOS) protection in the development of many diseases, including pulmonary tuberculosis (TB). The review presents modern views on the state of the system of lipid peroxidation (LPO) and antioxidant protection in TB. The main topic of the review is information on the generation of free radical compounds by different populations of leukocytes with further enhancement of LPO and secondary deepening of functional disorders. The article substantiates the feasibility of identifying LPO products as non-specific markers of aseptic inflammation in TB and the need to develop new generations of antioxidants. One of the universal mechanisms of damage to cell membranes is LPO, the excessive activation of which is normally prevented by factors of the antioxidant defense system. Membrane-bound enzymes involved in the formation of LPO products include lipoxy and cyclooxygenases. Lipoperoxidation processes change the structure and phospholipid composition of cell membranes, which negatively affects the cellular immune response due to damage to the mechanisms of information transfer from extracellular regulators to intracellular effector systems.

scholarly journals Flight training and dietary antioxidants have mixed effects on the oxidative status of multiple tissues in a female migratory songbird

2021 ◽  
Author(s):  
Abigail E. Frawley ◽  
Kristen J. DeMoranville ◽  
Katherine M. Carbeck ◽  
Lisa Trost ◽  
Amadeusz Bryła ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Oxidative Damage ◽  
Antioxidant Capacity ◽  
Antioxidant System ◽  
Spring Migration ◽  
Flight Training ◽  
Lipid Hydroperoxides ◽  
Enzymatic Antioxidants ◽  
Dietary Antioxidants ◽  
Enzymatic Antioxidant

Birds, like other vertebrates, rely on a robust antioxidant system to protect themselves against oxidative imbalance caused by energy-intensive activities such as flying. Such oxidative challenges may be especially acute for females during spring migration, since they must pay the oxidative costs of flight while preparing for reproduction; however, little previous work has examined how the antioxidant system of female spring migrants responds to dietary antioxidants and the oxidative challenges of regular flying. We fed two diets to female European starlings, one supplemented with a dietary antioxidant and one without, and then flew them daily in a windtunnel for two weeks during the fall and spring migration periods. We measured the activity of enzymatic antioxidants (GPx, SOD, CAT), non-enzymatic antioxidant capacity (ORAC), and markers of oxidative damage (protein carbonyls and lipid hydroperoxides) in four tissues: pectoralis, leg, liver, and heart. Dietary antioxidants affected enzymatic antioxidant activity and lipid damage in the heart, non-enzymatic antioxidant capacity in the pectoralis, and protein damage in leg muscle. In general, birds fed less antioxidants appear to incur increased oxidative damage while upregulating non-enzymatic and enzymatic antioxidant activity, though these effects were strongly tissue-specific. We also found trends for diet x training interactions for enzymatic antioxidant activity in the heart and leg. Flight-training may condition the antioxidant system of females to dynamically respond to oxidative challenges, and females during spring migration may shift antioxidant allocation to reduce oxidative damage.

Cereals frost resistance correlates with an integral indicators of content of low-molecular-weight protective compounds and activity of antioxidant enzymes

2020 ◽  
Vol 2020 (3) ◽  
pp. 71-86
Author(s):  
O. I. Horielova ◽  
◽  
N. I. Ryabchun ◽  
M. A. Shkliarevskyi ◽  
A. M. Reznik ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Antioxidant System ◽  
Frost Resistance ◽  
Low Molecular Weight ◽  
Guaiacol Peroxidase ◽  
Wheat Seedlings ◽  
Enzymatic Antioxidant ◽  
Adult Plants

Along with specific adaptive reactions, universal defense reactions, in particular activation of antioxidant system, are of great importance for plant survival under cold conditions. We have studied a relationship among the content of low-molecular-weight protective compounds with antioxidant properties (proline, soluble carbohydrates, flavonoids), the activity of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase) in seedlings of winter wheat, rye and triticale, and frost resistance of etiolated seedlings and adult plants at tillering stage. It was found that there was a fairly close correlation between the frost resistance of seedlings and adult cereal plants (r = 0,78). It was shown that a pronounced relationship between individual indicators of antioxidant system functioning in unhardened seedlings and their frost resistance was not found. After 6-day hardening of seedlings at 2-4°C, there was a high correlation between the total indicator of the enzymatic antioxidant system (the sum of normalized indicators of superoxide dismutase, peroxidase, and catalase activity) and their frost resistance (r = 0,86), but the correlation coefficient of this index with frost resistance of plants in tillering phase was significantly lower (r = 0,47). At the same time, a high correlation was found between the content of low-molecular-weight protectors in hardened seedlings and frost resistance of tillering adult plants (r = 0.89). The closest correlation was observed between the integral normalized indicator, comprising the sum of normalized values of antioxidant enzymes activity and the content of low-molecular-weight protectors in hardened seedlings, and frost resistance of seedlings (r = 0,94) and plants in tillering phase (r = 0,89). A presence of specific features in the functioning of antioxidant system during cold adaptation of cereal seedlings was established. Rye is characterized by a high content of low-molecular-weight protective compounds; at the same time, increased activity of antioxidant enzymes - superoxide dismutase and catalase - was noted in wheat seedlings. In triticale, depending on the genotype, the values of both enzymatic antioxidant activity and the content of low-molecular-weight protectors varied.

Biological and medical value of antioxidant protection system of the human body

2021 ◽  
Vol 90 (1) ◽  
pp. 21-32
Author(s):  
O.M. Kovalyova ◽  
T.M. Pasiieshvili
Keyword(s):  
Superoxide Dismutase ◽  
Antioxidant System ◽  
Human Body ◽  
Manganese Superoxide Dismutase ◽  
Glutathione Transferase ◽  
Chemical Properties ◽  
Antioxidant Protection ◽  
Glutathione System ◽  
Radical Oxidation ◽  
Manganese Superoxide

The article is devoted to the antioxidant system of the human body in the context of biological and medical significance. The classification of antioxidants in terms of their physical and chemical properties, bioorganic compounds, biochemical effects, mechanisms of implementation of antioxidant protection is presented. The given processes of extreme radical oxidation and mechanisms of antioxidant defense in physiological and pathological conditions. The characteristics of the components of the glutathione system, namely glutathione and enzymes – glutathione peroxidase, glutathione reductase and glutathione transferase are presented. Much attention is paid to manganese superoxide dismutase, an antiradical defense enzyme, as a fundamental regulator of cell proliferation, a mediator of metabolism and apoptosis. Interpretation of changes in the antioxidant enzyme of mitochondrial origin from a prognostic point of view is interpreted on the basis of the results of clinical observations carried out by scientists in various human diseases. The expediency of determining manganese superoxide dismutase in clinical practice for the diagnostic search for the direction of the pathological process, the timely detection of complications and the appointment of adequate therapy is emphasized. Keywords: antioxidant system, classification, glutathione system, manganese superoxide dismutase.

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