•Dietary copper negatively affected the weight gain of H. malabaricus.•Trophic exposure to copper caused anemia.•Copper accumulated in the blood and promoted erythrocyte DNA damage.•Plasma ionic ...imbalance was indicated by Na+ and Cl−increases and Ca2+ decrease.•The activity of SOD, CAT, and GPx decreased in the gills.
Copper waterborne toxicity is well understood in aquatic organisms. However, the dietary copper effects are much less known, especially in tropical fish. The toxicity of copper via the trophic route could be influenced by the composition of the food, and diets naturally impregnated with copper seem to have greater toxicity at lower concentrations than artificially impregnated ones. Thus, our objective was to investigate the effects of copper on juveniles of the Neotropical fish Hoplias malabaricus fed on live prey (Astyanax altiparanae) previously exposed to the metal (20 µg L − 1) for 96 h. The prey fish were given to H. malabaricus every 96 h, totaling 10 doses at the end of the experiment. Thus, after 40 days fish were killed and tissues were sampled. Blood showed to be the only tissue in which copper accumulated. Anemia was found and there was damage to the DNA of erythrocytes. Furthermore, ionic imbalances were observed in plasma. There was an increase in the concentration of Na+ and Cl− and a decrease in Ca2+, which were associated with increased copper uptake in the gastrointestinal tract of fish fed on copper exposed prey. All the antioxidant enzymes evaluated in the gills showed decreased activity compared to the control group. Copper seems to have interfered in the energy metabolism of H. malabaricus, since a lower condition factor and feed conversion efficiency rate were observed in fish fed with copper diet. The present study confirms the trophic route as an important copper toxicity pathway for H. malabaricus and reinforces the idea that metal toxicity can be increased when it is naturally impregnated in the prey tissues, even if the prey has been exposed to the metal only for a short period of time.
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Melatonin is a natural, multifunctional, nontoxic, regulatory, and ubiquitous biomolecule, having low molecular weight and pleiotropic effects in the plant kingdom. It is a recently discovered plant ...master regulator which has a crucial role under abiotic stress conditions (salinity, drought, heat, cold, alkalinity, acid rain, ozone, and metals stress). In the solanaceous family, the tomato is highly sensitive to abiotic stresses that affect its growth and development, ultimately hampering production and productivity. Melatonin acts as a strong antioxidant, bio-stimulator, and growth regulator, facilitating photosynthesis, delaying leaf senescence, and increasing the antioxidant enzymes system through direct scavenging of reactive oxygen species (ROS) under abiotic stresses. In addition, melatonin also boosts morphological traits such as vegetative growth, leaf photosynthesis, root architecture system, mineral nutrient elements, and antioxidant activities in tomato plants, confirming their tolerances against salinity, drought, heat, cold, alkalinity, acid rain, chemical, pathogen, and metals stress. In this review, an attempt has been made to summarize the potential role of melatonin for tomato plant endurance towards abiotic stresses, along with the known relationship between the two.
•The review presents the role of melatonin in Plant Kingdom.•Multifunctional role of melatonin in tomato is also discussed.•The gene expression due to melatonin in tomato is discussed.•Melatonin and Reactive oxygen species (ROSs) crosstalk in tomato is also presented.
Type 2 diabetes (T2DM) is a persistent metabolic disorder rising rapidly worldwide. It is characterized by pancreatic insulin resistance and β-cell dysfunction. Hyperglycemia induced reactive oxygen ...species (ROS) production and oxidative stress are correlated with the pathogenesis and progression of this metabolic disease. To counteract the harmful effects of ROS, endogenous antioxidants of the body or exogenous antioxidants neutralise it and maintain bodily homeostasis. Under hyperglycemic conditions, the imbalance between the cellular antioxidant system and ROS production results in oxidative stress, which subsequently results in the development of diabetes. These ROS are produced in the endoplasmic reticulum, phagocytic cells and peroxisomes, with the mitochondrial electron transport chain (ETC) playing a pivotal role. The exacerbated ROS production can directly cause structural and functional modifications in proteins, lipids and nucleic acids. It also modulates several intracellular signaling pathways that lead to insulin resistance and impairment of β-cell function. In addition, the hyperglycemia-induced ROS production contributes to micro- and macro-vascular diabetic complications. Various in-vivo and in-vitro studies have demonstrated the anti-oxidative effects of natural products and their derived bioactive compounds. However, there is conflicting clinical evidence on the beneficial effects of these antioxidant therapies in diabetes prevention. This review article focused on the multifaceted role of oxidative stress caused by ROS overproduction in diabetes and related complications and possible antioxidative therapeutic strategies targeting ROS in this disease.
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•Impaired antioxidant system leads to overproduction of free-radicals.•Excess ROS generation causes alteration of cell signaling pathways and homeostasis.•ROS induces disruption of pancreatic β-cell homeostasis and promotes IR.•Targeting the endogenous antioxidant system seems a promising therapeutic approach.
The current study was conducted to demonstrate the possible roles of exogenously applied flavonoid naringenin (Nar) on the efficiency of PSII photochemistry and the responses of chloroplastic ...antioxidant of salt and osmotic-stressed
(
. For this aim, plants were grown in a hydroponic culture and were treated with Nar (0.1 mM and 0.4 mM) alone or in a combination with salt (100 mM NaCl) and/or osmotic (10% Polyethylene glycol, -0.54 MPa). Both caused a reduction in water content (RWC), osmotic potential (Ψ
), chlorophyll fluorescence (F
/F
), and potential photochemical efficiency (F
/F
). Nar reversed the changes on these parameters. The phenomenological fluxes (TR
/CS and ET
/CS) altered by stress were induced by Nar and Nar led to a notable increase in the performance index (PI
) and the capacity of light reaction ΦP
/(1-ΦP
). Besides, Nar-applied plants exhibited higher specific fluxes values ABS/RC, ET
/RC, and ΨE
/(1-ΨE
) and decreasing controlled dissipation of energy (DI
/CS
and DI
/RC). The transcripts levels of psbA and psbD were lowered in stress-treated bean but upregulated in Nar-treated plants after stress exposure. Nar also alleviated the changes on gas exchange parameters carbon assimilation rate (A), stomatal conductance (g
), intercellular CO
concentrations (C
), transpiration rate (E), and stomatal limitation (L
). By regulating the antioxidant metabolism of the isolated chloroplasts, Nar was able to control the toxic levels of hydrogen peroxide (H
O
) and TBARS (lipid peroxidation) produced by stresses. Chloroplastic superoxide dismutase (SOD) activity reduced by stresses was increased by Nar. In response to NaCl, Nar increased the activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR), as well as peroxidase (POX). Nar protected the bean chloroplasts by minimizing disturbances caused by NaCl exposure via the ascorbate (AsA) and glutathione (GSH) redox-based systems. Under Nar plus PEG, Nar maintained the AsA regeneration by the induction of MDHAR and DHAR, but not GSH recycling by virtue of no induction in GR activity and the reduction in GSH/GSSG and GSH redox state. Based on these advances, Nar protected in bean chloroplasts by minimizing disturbances caused by NaCl or PEG exposure via the AsA or GSH redox-based systems and POX activity.
A field study was designed to explore the impacts of foliar-applied chemically and green synthesized titanium dioxide nanoparticles (TiO2 NPs) on cadmium (Cd) uptake in wheat plants. The wheat was ...grown in field which was contaminated with Cd and plants were subjected to foliar episodes of TiO2 NPs during plant growth period. Leaf extracts of two plant species (Trianthema portulacastrum, Chenopodium quinoa) were used for green synthesis while sol-gel method was used for chemical preparation of TiO2 NPs. Results showed that TiO2 NPs significantly enhanced the plant height, length of spikes photosynthesis, and straw and grain yield compared to control. TiO2 NPs minimized the oxidative burst in leaves and improved the enzyme activities than control. Cadmium concentrations of straw, roots and grains decreased after TiO2 NPs treatments than control. The grain Cd contents were below recommended threshold (0.2 mg Cd /kg grain DW) for cereals upon NPs exposure. The health risk index by the dietary use of grains for adults was below threshold upon NPs exposure. Overall, foliar use of TiO2 NPs prepared from plant extracts was appropriate in minimizing Cd contents in wheat grains, thereby reducing risk of Cd to human health via food chain.
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•Foliar exposure of TiO2 NPs resulted in higher yield of wheat grown in Cd-contaminated field•Foliar use of TiO2 NPs resulted in higher chlorophyll contents under Cd stress•TiO2 NPs caused reduction in oxidative stress in plants under Cd stress•TiO2 NPs significantly decreased Cd in wheat straw, roots, and grains•TiO2 NPs decreased the Cd human health risk by use of grains from Cd-contaminated field
Streams are environments susceptible to anthropic impacts that harm aquatic organisms by affecting their homeostasis. This study aimed to determine variations in the response of biochemical and ...genetic biomarkers of fish under the influence of anthropogenic impacts. For this, individuals of the tetra fish Astyanax lacustris were exposed in an impacted stream and one of its non-impacted tributaries (reference) during the dry and rainy seasons. For biochemical analyzes, we evaluated the antioxidant enzymes catalase and glutathione peroxidase and lipid peroxidation in tissue samples of gills and liver. For the genotoxicity test, we evaluated micronuclei and nuclear anomalies in blood samples. The antioxidant enzymes showed seasonal variation, regardless of the stream; lipid peroxidation didn’t differ between seasons or between streams. The frequency of micronuclei and nuclear abnormalities were more frequent in the impacted stream during the rainy season, probably in response to the leaching of toxic compounds that tends to be increased in that season. These results support the use of nuclear biomarkers in biomonitoring programs.
Salinity is one of the major abiotic stresses which affects plant cell metabolism and reduces plant productivity. Variations in the antioxidant defence systems under salinity among two bean genotypes ...were investigated. Our results indicate that the difference between the genotypes in response to salinity is a quantitative trait rather than qualitative since they develop the same strategies with a significant variation in the rate of synthesis and accumulation, with the exemption of the antioxidant defence based on the synthesis of phenolic compounds. For both genotypes, salinity induced a marked reduction in dry matter gain in roots and shoots along with oxidative stress as indicated by the significant increase in malondialdehyde content. In addition, the photosynthetic pigments decreased with the increase of salinity. The only qualitative difference that we found among both genotypes was the decrease of total production of phenolic compounds in leaves that was only detectable in the low-yielding genotype under high salinity. The high-yielding genotype may have a better protection against oxidative damages by increasing the activity of antioxidant enzymes and the amounts of total flavonoids and ascorbic acid under high salinity, which allows maintaining higher yield even upon stress conditions. These results indicate that salt induced oxidative stress in bean is mainly counteracted by enzymatic defence systems, and that the metabolism of phenolic compounds is induced under very extreme conditions. The selection of genotypes for this trait will increase yield under stress conditions.
•Antioxidant defence systems between two bean genotypes are analysed under salinity.•Differences are quantitative rather than qualitative except for phenolic metabolism.•Oxidative stress in bean is counteracted mainly by the enzymatic defence system.•Phenolic compounds decrease in the low-yielding genotype under high salinity.•Phenolic compounds are induced in high-yielding genotype under extreme conditions.
In spinal cord injury (SCI), the initial damage leads to a rapidly escalating cascade of degenerative events, known as secondary injury. Loss of mitochondrial homeostasis after SCI, mediated ...primarily by oxidative stress, is considered to play a crucial role in the proliferation of secondary injury cascade. We hypothesized that effective exogenous delivery of antioxidant enzymes — superoxide dismutase (SOD) and catalase (CAT), encapsulated in biodegradable nanoparticles (nano-SOD/CAT) — at the lesion site would protect mitochondria from oxidative stress, and hence the spinal cord from secondary injury. Previously, in a rat contusion model of severe SCI, we demonstrated extravasation and retention of intravenously administered nanoparticles specifically at the lesion site. To test our hypothesis, a single dose of nano-SOD/CAT in saline was administered intravenously 6 h post-injury, and the spinal cords were analyzed one week post-treatment. Mitochondria isolated from the affected region of the spinal cord of nano-SOD/CAT-treated animals demonstrated significantly reduced mitochondrial reactive oxygen species (ROS) activities, increased mitochondrial membrane potential, reduced calcium levels, and also higher adenosine triphosphate (ATP) production capacity than those isolated from the spinal cords of untreated control or SOD/CAT solution treated animals. Although the treatment did not achieve the same mitochondrial function as in the spinal cords of sham control animals, it significantly attenuated mitochondrial dysfunction following SCI. Further, immunohistochemical analyses of the spinal cords of treated animals showed significantly lower ROS, cleaved caspase-3, and cytochrome c activities, leading to reduced spinal cord neuronal cell apoptosis and smaller lesion area than in untreated animals. These results imply that the treatment significantly attenuated progression of secondary injury that was also reflected from less weight loss and improved locomotive recovery of treated vs. untreated animals. In conclusion, nano-SOD/CAT mitigated activation of cascade of degenerating factors by protecting mitochondria and hence the spinal cord from secondary injury. An effective treatment during the acute phase following SCI could potentially have a positive long-term impact on neurological and functional recovery.
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•Spinal cord injury causes mitochondrial dysfunction.•Dysfunctional mitochondria lead to progression of secondary injury.•Nanoparticles with antioxidant enzymes protected spinal cord from secondary injury.
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