Enhanced Antioxidant Defenses Research Articles

A novel therapeutic approach to doxorubicin-induced cardiotoxicity, with a particular emphasis on the potential cardioprotective properties of Vitis gracilis Wall.

Context: Doxorubicin, a potent chemotherapy drug, often leads to cardiotoxicity, limiting its clinical use. This study investigates the potential of Vitis gracilis Wall. nanoherbs (VGN) in mitigating doxorubicin-induced heart damage, aiming to provide insights into its therapeutic efficacy as a cardioprotective agent. Aims: To evaluate the therapeutic potential of VGN in mitigating doxorubicin-induced cardiotoxicity. Methods: The study comprised four treatment groups in male Wistar rats: D0 (negative control), D+ (doxorubicin 0.00038 mg/200 g body weight (BW)/day), DC (doxorubicin + Vitamin C 0.04 mg/200 g BW/d), D25 (doxorubicin + VGN at 25 mg/200 g BW/d), and D30 (doxorubicin + VGN at 30 mg/200 g BW/d). Key cardiac parameters, including LDH, CK-MB, TNF-alpha, IL-10, SOD, and caspase 3, were meticulously measured to assess cardioprotective effects. Statistical analyses were performed to evaluate the significance of observed changes, revealing a dose-dependent reduction in markers of cardiac injury (LDH, CK-MB) and inflammation (TNF-alpha) alongside enhancements in antioxidant defenses (SOD) and inhibition of apoptosis (caspase 3) with VGN administration. Results: The results showed promising reductions in markers of heart injury (LDH, CK-MB) and inflammation (TNF-alpha) specifically at a dose of 30 mg/200 g BW/d significantly (p<0.05). In addition, doses of 30 mg/200 g BW/d of VGN showed potential to increase antioxidant defenses (SOD), IL-10, as well as inhibit apoptosis (caspase 3) (p<0.05), highlighting the best multifaceted cardioprotective effects. Conclusions: The study demonstrates that V. gracilis has the potential to reduce doxorubicin-induced cardiotoxicity through its multifaceted cardioprotective effects. These effects include a reduction in markers of cardiac injury and inflammation at a dose of 30 mg/200 g BW/d, enhancement of antioxidant defenses, and inhibition of apoptosis.

Comprehensive Review of Biological Functions and Therapeutic Potential of Perilla Seed Meal Proteins and Peptides

This comprehensive review explores the biological functions of Perilla frutescens seed proteins and peptides, highlighting their significant potential for health and therapeutic applications. This review delves into the mechanisms through which perilla peptides combat oxidative stress and protect cells from oxidative damage, encompassing free radical scavenging, metal chelating, in vivo antioxidant, and cytoprotective activities. Perilla peptides exhibit robust anti-aging properties by activating the Nrf2 pathway, enhancing cellular antioxidant capacity, and supporting skin health through the promotion of keratinocyte growth, maintenance of collagen integrity, and reduction in senescent cells. Additionally, they demonstrate antidiabetic activity by inhibiting α-amylase and α-glucosidase. The cardioprotective effects of perilla peptides are underscored by ACE-inhibitory activities and combat oxidative stress through enhanced antioxidant defenses. Further, perilla peptides contribute to improved gut health by enhancing beneficial gut flora and reinforcing intestinal barriers. In liver, kidney, and testicular health, they reduce oxidative stress and apoptotic damage while normalizing electrolyte levels and protecting against cyclophosphamide-induced reproductive and endocrine disruptions by restoring hormone synthesis. Promising anticancer potential is also demonstrated by perilla peptides through the inhibition of key cancer cell lines, alongside their anti-inflammatory and immunomodulating activities. Their anti-fatigue effects enhance exercise performance and muscle function, while perilla seed peptide nanoparticles show potential for targeted drug delivery. The diverse applications of perilla peptides support their potential as functional food additives and therapeutic agents.

Glutathione S-Transferase Contributes to the Resistance of Megalurothrips usitatus Against Lambda-Cyhalothrin by Strengthening Its Antioxidant Defense Mechanisms.

The damage caused by Megalurothrips usitatus, a common pest, has significantly affected the Chinese vegetable industry. The inappropriate application of chemical pesticides has caused M. usitatus to become highly resistant to conventional insecticides. Glutathione S-transferase (GST), known for its multifunctional properties, contributes to detoxification and antioxidation. It enhances insects' adaptability to pesticides by facilitating the elimination of lipid peroxidation products resulting from pyrethroid insecticides. This research employed RT-qPCR to identify GST genes that exhibited significant expression in response to lambda-cyhalothrin stress. It also quantified changes in antioxidant and apoptosis markers within the M. usitatus under lambda-cyhalothrin exposure. The functional significance of GST was validated by assessing alterations in the antioxidant defense system and resistance to lambda-cyhalothrin following the inhibition of GST activity. The study's outcomes indicated that MuGSTs1 was markedly upregulated in response to lambda-cyhalothrin stress (p < 0.0001). The GST activity was effectively suppressed by the specific inhibitor, diethyl maleate, achieving an inhibition rate of 64.05%. Following the inhibition of GST, the overall antioxidant capacity was reduced by 3.1-fold compared with the control, and the M. usitatus exhibited a 7.91-fold increase in sensitivity to lambda-cyhalothrin. These findings confirm the pivotal role of GST in the oxidative stress response of the M. usitatus and their contribution to the development of resistance to lambda-cyhalothrin through enhanced antioxidant defenses. This research offers valuable perspectives on the adaptive reactions of insects to chemical stressors, facilitating the management of resistance and the formulation of effective pest control strategies.

Polyphenols as Immunomodulators and Epigenetic Modulators: An Analysis of Their Role in the Treatment and Prevention of Breast Cancer.

Breast cancer poses a substantial health challenge for women globally. Recently, there has been a notable increase in scholarly attention regarding polyphenols, primarily attributed to not only the adverse effects associated with conventional treatments but also their immune-preventive impacts. Polyphenols, nature-derived substances present in vegetation, including fruits and vegetables, have received considerable attention in various fields of science due to their probable wellness merits, particularly in the treatment and hindrance of cancer. This review focuses on the immunomodulatory effects of polyphenols in breast cancer, emphasizing their capacity to influence the reaction of adaptive and innate immune cells within the tumor-associated environment. Polyphenols are implicated in the modulation of inflammation, the enhancement of antioxidant defenses, the promotion of epigenetic modifications, and the support of immune functions. Additionally, these compounds have been shown to influence the activity of critical immune cells, including macrophages and T cells. By targeting pathways involved in immune evasion, polyphenols may augment the capacity of the defensive system to detect and eliminate tumors. The findings suggest that incorporating polyphenol-rich foods into the diet could offer a promising, collaborative (integrative) approach to classical breast cancer remedial procedures by regulating how the defense mechanism interacts with the disease.

Balancing Growth and Defense: Nanoselenium and Melatonin in Tea (Camellia sinensis) Protection against Glufosinate.

Current crop stress resistance research suggests that the prominent stimulants nanoselenium (NSe) and melatonin (MT) might improve tea safety, quality, and stress resistance induced by the widely used nonselective herbicide glufosinate (GLU). Their biofortification effects on tea growth, antioxidant activity, and secondary metabolism pathways response to GLU remain unclear. Here, NSe, MT, and their combination NSe-MT effectively reduced 26.6-50.9% GLU and its metabolites in tea seedlings, balanced the photosystem, enhanced antioxidant defenses, and optimized reactive oxygen species scavenging mechanisms. Further, GLU-induced inhibition of glutamine synthetase (11.2-34.0%), ammonium toxicity (55.0-64.7%), and nitrogen metabolism disorders were alleviated. Stimulants exhibited different preferences in the accumulation of l-theanine (8.4-47%), gamma-aminobutyric acid (10.3-41.7%), and catechins (13.1-73.1%, excluding ECG), thereby influencing tea quality. Transcriptomic and metabolomic analyses validated that NSe-MT had a more pronounced impact on tender tea leaves than individual stimulant treatments. All stimulants reduced GLU-induced excessive jasmonic acid (29.8-50.5%) production and signaling responses, revealing their significance in crop physiological activities under herbicide or nitrogen stress. The reduction in aromatic amino acids helped mitigate GLU's interference with phenylpropanoid biosynthesis, leading to inhibited lignin production but enhanced nutritional flavonoid levels, such as catechins. NSe and NSe-MT demonstrated promising potential as herbicide safeners. These findings provided insights into GLU detoxification mechanisms in other nontarget crops as well.

Pentoxifylline protects memory performance in streptozotocin-induced diabetic rats

Diabetes, characterized by elevated blood glucose levels and associated organ damage, is reportedly correlated with adecline in cognitive functions with a potential involvement of oxidative stress mechanisms. Mitochondria-induced oxidative stress reported to cause hyperglycemia is believed to impair hippocampal neural plasticity, affecting long-term potentiation, and isconsidered crucial for maintaining memory functions. In this study, the neuroprotective effect of Pentoxifylline (PTX) for four weeks, an agent known for antioxidant and anti-inflammatory properties, was examined in an animal model of diabetes. In a streptozotocin (STZ) diabetic model, rats received intraperitoneal PTX (100 mg/kg), and learning and memory functions were tested using the radial arm water maze. STZ-treated diabetic rats exhibited impaired learning and memory functions (short/long-term, P < 0.05), whereas PTX treatment prevented these deficits. PTX treatment normalized diabetes-induced reduction in the protein expression levels of two enzymes of antioxidant defense superoxide dismutase and glutathione peroxidase (P < 0.05) in the hippocampal brain tissues. PTX treatment also mitigated STZ-induced increase in lipid peroxidation (TBARS, P < 0.05). Furthermore, reduced/oxidized glutathione (GSH/GSSG) ratios were enhanced in PTX-treated diabetic rats (P < 0.05), emphasizing the importance of redox balance restoration. However, PTX treatment did not significantly affect theantioxidant defense enzyme catalase activity. In conclusion, STZ-induced diabetes resulted in learning and memory impairment in rats, while PTX treatment prevented these effects, most likely via enhancement of antioxidant defense in the brain. This study highlights PTX’s potential neuroprotective benefits, providing translational insights into the issue of diabetes-related cognitive complications.

Seawater-induced Salinity Enhances Antioxidant Capacity by Modulating Morpho-physiological and Biochemical Responses in Catharanthus roseus

Salt stress impedes plant growth and development due to several factors, including the generation of cellular oxidative stressors. This study aimed to assess the impacts of seawater-induced salinity on the plant development, physio-biochemical responses, and antioxidant capacity of Catharanthus roseus grown in a variety of seawater (4, 8, and 12 dS/m) for varying durations (60, 90, and 120 days). The experiment was laid out in a randomized complete block design with five replications. The results demonstrated that C. roseus successfully endured moderate salinity (8 dS/m) by maintaining plant height, number of leaves, branches, relative water content, and chlorophyll content with a minimum drop in dry biomass (25%) in a time- and dose-dependent approach. Furthermore, greater proline and soluble sugar contents suggested that C. roseus possessed enhanced osmoprotective capabilities to counteract osmotic stress caused by salinity. Conversely, all growth indicators decreased significantly at high salinity (12 dS/m). Increased levels of antioxidant enzyme activity catalase and ascorbate peroxidase, phenol and flavonoid, 2,2-diphenyl-1-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid indicate a coordinated function for antioxidant components in regulating reactive oxygen species (ROS) at low (4 dS/m) and moderate (8 dS/m) salinities. In contrast, excessive salinity (12 dS/m) led to a burst of ROS, as seen by elevated levels of hydrogen peroxide, malondialdehyde, and electrolyte leakage that greatly reduced total dry matter (72%), especially on days 120. The ion studies on plants subjected to salinity revealed that most Na+ remained in the roots. In contrast, most K+, Ca2+, and Mg2+ are deposited more firmly in the leaves than in the roots. The findings imply that C. roseus may tolerate moderate salinity (8 dS/m) owing to its enhanced antioxidant defense system and osmolytes, which trigger antioxidant enzymes and maintain ionic balance.

An Overview of the Mechanisms through Which Plants Regulate ROS Homeostasis under Cadmium Stress.

Cadmium (Cd2+) is a non-essential and highly toxic element to all organic life forms, including plants and humans. In response to Cd stress, plants have evolved multiple protective mechanisms, such as Cd2+ chelation, vesicle sequestration, the regulation of Cd2+ uptake, and enhanced antioxidant defenses. When Cd2+ accumulates in plants to a certain level, it triggers a burst of reactive oxygen species (ROS), leading to chlorosis, growth retardation, and potentially death. To counteract this, plants utilize a complex network of enzymatic and non-enzymatic antioxidant systems to manage ROS and protect cells from oxidative damage. This review systematically summarizes how various elements, including nitrogen, phosphorus, calcium, iron, and zinc, as well as phytohormones such as abscisic acid, auxin, brassinosteroids, and ethylene, and signaling molecules like nitric oxide, hydrogen peroxide, and hydrogen sulfide, regulate the antioxidant system under Cd stress. Furthermore, it explores the mechanisms by which exogenous regulators can enhance the antioxidant capacity and mitigate Cd toxicity.

Rhizofungus Aspergillus terreus Mitigates Heavy Metal Stress-Associated Damage in Triticum aestivum L.

Industrial waste and sewage deposit heavy metals into the soil, where they can remain for long periods. Although there are several methods to manage heavy metals in agricultural soil, microorganisms present a promising and effective solution for their detoxification. We isolated a rhizofungus, Aspergillus terreus (GenBank Acc. No. KT310979.1), from Parthenium hysterophorus L., and investigated its growth-promoting and metal detoxification capabilities. The isolated fungus was evaluated for its ability to mitigate lead (25 and 75 ppm) and copper (100 and 200 ppm) toxicity in Triticum aestivum L. seedlings. The experiment utilized a completely randomized design with three replicates for each treatment. A. terreus successfully colonized the roots of wheat seedlings, even in the presence of heavy metals, and significantly enhanced plant growth. The isolate effectively alleviates lead and copper stress in wheat seedlings, as evidenced by increases in shoot length (142%), root length (98%), fresh weight (24%), dry weight (73%), protein content (31%), and sugar content (40%). It was observed that wheat seedlings possess a basic defense system against stress, but it was insufficient to support normal growth. Fungal inoculation strengthened the host's defense system and reduced its exposure to toxic heavy metals. In treated seedlings, exposure to heavy metals significantly upregulated MT1 gene expression, which aided in metal detoxification, enhanced antioxidant defenses, and maintained metal homeostasis. A reduction in metal exposure was observed in several areas, including normalizing the activities of antioxidant enzymes that had been elevated by up to 67% following exposure to Pb (75 mg/kg) and Cu (200 mg/kg). Heavy metal exposure elevated antioxidant levels but also increased ROS levels by 86%. However, with Aspergillus terreus colonization, ROS levels stayed within normal ranges. This decrease in ROS was associated with reduced malondialdehyde (MDA) levels, enhanced membrane stability, and restored root architecture. In conclusion, rhizofungal colonization improved metal tolerance in seedlings by decreasing metal uptake and increasing the levels of metal-binding metallothionein proteins.

Enhancement of Thermal Tolerance and Growth Performances of Asian Seabass (Lates calcarifer) Fed with Grape Extract Supplemented Feed.

Cold snaps during the winter present a critical challenge for Asian seabass (Lates calcarifer) in Taiwan, as sudden temperature drops significantly affect their growth and survival. This study explores the effects of dietary grape extract (GE) from Vitis vinifera on the growth performance, oxidative stress regulation, and thermal tolerance of this commercially valuable fish. Over a 60-day feeding trial, four dietary groups were tested: a control diet without GE and three diets supplemented with GE at 2% (GE20), 3% (GE30), and 4% (GE40) with commercial feed. The results demonstrated that GE supplementation positively influenced growth, with the GE20 group achieving the best weight gain and feed conversion ratio among all groups. The upregulation of the growth-related gene igf-1 in the liver of the GE20 group further supported its superior growth performance. Additionally, GE-fed groups showed increased expression of antioxidant-related genes sod1 and sod2 in the liver, while gpx1 exhibited a significant increase only in the GE20 group, indicating enhanced antioxidant defenses. Cat gene expression remained unchanged, and higher GE doses reduced the expression of gpx1, cat, and igf-1. Furthermore, GE supplementation improved cold tolerance in all treated groups compared to the control. These findings suggest that dietary GE at 20 g/kg is particularly effective in enhancing growth performance and cold tolerance in Asian seabass, offering a promising strategy for boosting fish health and adaptability in aquaculture.

Physiological and immune responses of largemouth bass (Micropterus salmoides) under the regulation of exercise intensity: An integrated perspective of blood, liver and intestinal analysis

This study examined the effects of different water flow durations on serum biochemical indices, liver antioxidant capacity, and intestinal health of largemouth bass (Micropterus salmoides) in a recirculating aquaculture system (RAS). During a 90-day experiment, 270 largemouth bass (initial weight 96.05 ± 18.87 g) were randomly assigned to three groups: a control group (CG) with a constant flow velocity of 0.3 cm/s, an interval exercise group (IE) with a water flow velocity of 2 bl/s for 8 h/day, and a sustained exercise group (SE) with a continuous flow velocity of 2 bl/s for 24 h/day. The results showed that the IE group had higher total protein (TP) levels than the CG and SE groups (P < 0.05). In contrast, the SE group had lower triglyceride (TG) and cholesterol (CHO) levels (P < 0.05), indicating that exercise intensity significantly affects serum biochemical parameters. The study also evaluated the effects of sustained swimming on liver antioxidant capacity, digestive enzyme activity, intestinal health, and microbial community composition. Antioxidant assays revealed significantly increased activities of superoxide dismutase (T-SOD) and catalase (CAT) in the SE group, along with the lowest malondialdehyde (MDA) levels (P < 0.05), indicating enhanced antioxidant defenses. Enzyme assays showed a significant increase in trypsin and lipase activities due to swimming exercise (P < 0.05). Intestinal morphology analysis showed increased villus height and wall thickness in the SE group, without visible tissue damage, suggesting improved intestinal structural integrity. Gene expression analysis showed a significant upregulation of pro-inflammatory genes in the IE group and an increase in anti-inflammatory gene expression in the SE group. Microbial community analysis showed no significant differences in alpha diversity, species richness, or total diversity among the groups. However, variations in microbial species distribution at the phylum and genus level were observed, which were likely influenced by exercise intensity. In conclusion, sustained swimming exercise significantly improved antioxidant capacity, intestinal health, and modulated the immune response in largemouth bass. This highlights its potential to improve fish health and sustainability in RAS.

Melatonin and copper oxide nanoparticles synergistically mitigate clubroot disease and enhance growth dynamics in Brassica rapa

Clubroot, a devastating soil borne disease affecting 30%∼50% of Brassicaceae crops worldwide, lacks effective control measures. In the present study, we explored the potential of melatonin (MT) and copper oxide nanoparticle (CuO-NPs) in mitigating clubroot severity in the Brassica rapa ssp. pekinensis. Following 18 h priming with MT, CuO-NPs, or both seeds were grown in controlled environment using synthetic potting mix. Inoculated with Plasmodiophora brassicae spores on 5th day, followed by a soil drench phyto-nano treatment with a week interval. Plants were assessed for various health and growth indices including disease, biometrics, photosynthesis, reactive oxygen species (ROS), antioxidant enzyme activity, hormones and genes expression at onset of secondary clubroot infection using established protocols. Statistical analysis employed ANOVA with Fisher's LSD for significance assessment (P < 0.05). Our results revealed that seed priming with both MT (50 μMol/L) and CuO-NPs (200 mg/L), followed by soil drenching significantly reduced clubroot incidence (38%) and disease index (57%), compared to control treatments. This synergistic effect was associated with enhanced plant growth (shoots: 48% and roots: 59%). Plants treated with both MT and CuO-NPs showed robust antioxidant defenses, significantly increased superoxide dismutase (SOD (25/29%)), catalase (CAT (83/55%)), and ascorbate peroxidase (APX (83/46%)) activity in both shoots/roots, respectively, compared to infected control. Notably, salicylic acid and jasmonic acid levels doubled in treated plants, while stress hormone abscisic acid (ABA) decreased by 80% in roots and 21% in shoots. Gene expression analysis corroborated these findings, showing that the combined treatment activated antioxidant defense genes (SOD, APX and CAT) by 1.9–7.2-fold and upregulated hormone signaling genes JAZ1 (7.8-fold), MYC2 (3.9-fold) and SABP2 (36-fold). Conversely, ABA biosynthesis genes (ABA1 and NCED1) were downregulated up to 7.2-fold, while plant resistance genes NPR1, PRB1 and PDF1.2 were dramatically increased by up to 6.3-fold compared to infected plants. Overall, our combined treatment approach significantly reduces clubroot severity in B. rapa via enhanced antioxidant defenses, improved ROS scavenging, coordinated hormonal regulation and increased pathogen response genes. This study offers promising strategy for developing effective control measures against clubroot in susceptible cruciferous crops.

The Important Role of Protein Kinases in the p53 Sestrin Signaling Pathway.

p53, a crucial tumor suppressor and transcription factor, plays a central role in the maintenance of genomic stability and the orchestration of cellular responses such as apoptosis, cell cycle arrest, and DNA repair in the face of various stresses. Sestrins, a group of evolutionarily conserved proteins, serve as pivotal mediators connecting p53 to kinase-regulated anti-stress responses, with Sestrin 2 being the most extensively studied member of this protein family. These responses involve the downregulation of cell proliferation, adaptation to shifts in nutrient availability, enhancement of antioxidant defenses, promotion of autophagy/mitophagy, and the clearing of misfolded proteins. Inhibition of the mTORC1 complex by Sestrins reduces cellular proliferation, while Sestrin-dependent activation of AMP-activated kinase (AMPK) and mTORC2 supports metabolic adaptation. Furthermore, Sestrin-induced AMPK and Unc-51-like protein kinase 1 (ULK1) activation regulates autophagy/mitophagy, facilitating the removal of damaged organelles. Moreover, AMPK and ULK1 are involved in adaptation to changing metabolic conditions. ULK1 stabilizes nuclear factor erythroid 2-related factor 2 (Nrf2), thereby activating antioxidative defenses. An understanding of the intricate network involving p53, Sestrins, and kinases holds significant potential for targeted therapeutic interventions, particularly in pathologies like cancer, where the regulatory pathways governed by p53 are often disrupted.

Exogenous TiO2 Nanoparticles Alleviate Cd Toxicity by Reducing Cd Uptake and Regulating Plant Physiological Activity and Antioxidant Defense Systems in Rice (Oryza sativa L.)

Cadmium (Cd) is a potentially hazardous element with significant biological toxicity, negatively affecting plant growth and physio-biochemical metabolism. Thus, it is necessary to examine practical and eco-friendly approaches to reduce Cd toxicity. Titanium dioxide nanoparticles (TiO2-NPs) are growth regulators that help in nutrient uptake and improve plant defense systems against abiotic and biological stress. A pot experiment was performed in the late rice-growing season (July—November) 2022 to explore the role of TiO2-NPs in relieving Cd toxicity on leaf physiological activity, biochemical attributes, and plant antioxidant defense systems of two different fragrant rice cultivars, i.e., Xiangyaxiangzhan (XGZ) and Meixiangzhan-2 (MXZ-2). Both cultivars were cultivated under normal and Cd-stress conditions. Different doses of TiO2-NPs with and without Cd-stress conditions were studied. The treatment combinations were: Cd−, 0 mg/kg CdCl2·2.5 H2O; Cd+, 50 mg/kg CdCl2·2.5 H2O; Cd + NP1, 50 mg/kg Cd + 50 TiO2-NPs mg/L; Cd + NP2, 50 mg/kg Cd + 100 TiO2-NPs mg/L; Cd + NP3, 50 mg/kg Cd + 200 TiO2-NPs mg/L; Cd + NP4, 50 mg/kg Cd + 400 TiO2-NPs mg/L. Our results showed that the Cd stress significantly (p &lt; 0.05) decreased leaf photosynthetic efficiency, stomatal traits, antioxidant enzyme activities, and the expression of their encoding genes and protein content. Moreover, Cd toxicity destabilized plant metabolism owing to greater accretion of hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels at vegetative and reproductive stages. However, TiO2-NPs application improved leaf photosynthetic efficacy, stomatal traits, and protein and antioxidant enzyme activities under Cd toxicity. Application of TiO2-NPs decreased the uptake and accumulation of Cd in plants and levels of H2O2 and MDA, thereby helping to relieve Cd-induced peroxidation damage of leaf membrane lipids by enhancing the activities of different enzymes like ascorbate peroxidase (APX), catalase (CAT), peroxidase (POS), and superoxide dismutase (SOD). Average increases in SOD, APX, CAT, and POS activities of 120.5 and 110.4%, 116.2 and 123.4%, 41.4 and 43.8%, and 36.6 and 34.2% in MXZ-2 and XGZ, respectively, were noted in Cd + NP3 treatment across the growth stages as compared with Cd-stressed plants without NPs. Moreover, the correlation analysis revealed that the leaf net photosynthetic rate is strongly associated with leaf proline and soluble protein content, suggesting that a higher net photosynthetic rate results in higher leaf proline and soluble protein content. Of the treatments, the Cd + NP3 (50 mg/kg Cd + 200 mg/L TiO2-NPs) performed the best for both fragrant rice cultivars under Cd toxicity. Our results showed that TiO2-NPs strengthened rice metabolism through an enhanced antioxidant defense system across the growth stages, thereby improving plant physiological activity and biochemical characteristics under Cd toxicity.

Melatonin Decreases Negative Effects of Combined Drought and High Temperature Stresses through Enhanced Antioxidant Defense System in Tomato Leaves

In tomato (Lycopersicon esculentum L.), the effects of combined drought (D) and high temperature (HT) stress during the flowering stage had not been studied in detail. Therefore, this study was conducted with an objective of quantifying the effects of foliar spray of melatonin under individual and combined drought and HT stress. At flowering stage, D stress was imposed through withholding irrigation, while HT stress was imposed through exposing the plants to ambient temperature (AT) along with an increase of +5 °C. Under D + HT, plants were first subjected to drought followed by a + 5 °C increase in AT. The duration of individual or combined stress was ten days. At 80% available soil moisture, 100 µM melatonin was sprayed on D, HT, or D + HT treated plants. Among the stresses, D + HT stress increased the thylakoid membrane damage and decreased the photosynthetic rate and fruit yield more than D or HT stress. Foliar spray of 100 µM melatonin produced decreased thylakoid membrane damage [D: 31%, HT: 26%, and D + HT: 18%] and increased antioxidant enzyme, viz., superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase, activity over stress-control plants. The photosynthetic rate [D: 24%, HT: 22%, and D + HT: 19%] and fruit yield [D: 32%, HT: 23%, and D + HT: 16%] were increased over stress-control plants. Hence, it is evident that the increased photosynthetic rate and fruit yield in D + HT and 100 µM melatonin-sprayed plants may be associated with an increased antioxidant defense system. Melatonin as a novel biostimulator has a great potential in scavenging free radicals through increased antioxidant activity, which shields the photosynthetic membrane from damage and therefore helps in stress mitigation.

Alleviation of Meloidogyne incognita induced biotic stress in Daucus carota by nitrogen: Insights into cellular viability and reactive oxygen species of the host

Developing innovative nematode management solutions is becoming more important since ecologically hazardous nematicides are being phased out of the global markets. As a result, alternative measures that are less harmful to the environment are preferred for dealing with the root-knot nematodes which cause huge economic losses to farmers. This investigation was therefore, entailed to find the optimum nitrogen fertilizer rate to maximize plant growth promotion and upsurge nematicidal activity, while minimizing the harmful effects on environment. Among the various nitrogen fertilizer treatments from 50 kg/ha to 200 kg/ha, the most effective concentration was found to be 150 kg/ha N (U150Mi) at which significant (P ≤ 0.05) improvements in growth, yield, photosynthetic pigments, nitrate reductase activity (NRA), protein, and carbohydrate content of carrot were observed as compared to the nematode inoculated untreated plants. Scanning electron microscopy showed that compared to the untreated inoculated control, the stomatal characteristics of carrot improved significantly at U150Mi (150 kg/ha N). Laser confocal microscopy illustrated that nitrogen fertilizer markedly improved the cellular viability of carrot at U150Mi (150 kg/ha N) in comparison to nematode infected plants. Histochemical analysis revealed that the reactive oxygen species (ROS) marker, superoxide anion radicals were significantly scavenged by the enhanced antioxidant defense system of carrot at U150Mi (150 kg/ha N). In vitro studies demonstrate that nitrogen fertilizer has nematicidal properties that were dose dependent. Gall/egg mass indices and reproduction factor were dramatically reduced when U150Mi (150 kg/ha N) was applied to carrot plants inoculated with Meloidogyne incognita.

KSHV hijacks FoxO1 to promote cell proliferation and cellular transformation by antagonizing oxidative stress.

Reactive oxygen species (ROS) are a group of a highly short-lived molecules that control diverse behaviors of cells. Normal cells maintain ROS balance to ensure their functions. Because of oncogenic stress, cancer cells often have excessive ROS, also known as oxidative stress, which are often counteracted by enhanced antioxidant systems to maintain redox homeostasis. Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus associated with Kaposi's sarcoma (KS), which manifests hyper inflammation and oxidative stress as the hallmarks. We have previously shown that excessive ROS can disrupt KSHV latency by inducing viral lytic replication, leading to cell death. Paradoxically, most KS tumor cells are latently infected by KSHV in a highly inflammatory and oxidative stress tumor microenvironment, which is in part due to the activation of alternative complement and TLR4 pathways, indicating the existence of an enhanced antioxidant defense system in KS tumor cells. In this study, we show that KSHV upregulates antioxidant genes, including SOD2 and CAT by hijacking the forkhead box protein O1 (FoxO1), to maintain intracellular ROS level. Moreover, the fine-tuned balance of ROS level in KSHV-transformed cells is essential for cell survival. Consequently, KSHV-transformed cells are extremely sensitive to exogenous ROS insult such as treatment with a low level of hydrogen peroxide (H2 O2 ). Either chemical inhibition or knockdown of FoxO1 by short interfering RNAs decreases the expression of antioxidant genes and subsequently increases the intracellular ROS level in KSHV-transformed cells, resulting in the inhibition of cell proliferation and colony formation in soft agar. Mechanistically, KSHV-encoded microRNAs and vFLIP upregulate FoxO1 by activating the NF-κB pathway. These results reveal a novel mechanism by which an oncogenic virus counteracts oxidative stress by upregulating FoxO1, which is essential for KSHV-induced cell proliferation and cellular transformation. Therefore, FoxO1 might be a potential therapeutic target for KSHV-related malignancies.

Occlusion preconditioned mice are resilient to hypobaric hypoxia-induced myocarditis and arrhythmias due to enhanced immunomodulation, metabolic homeostasis, and antioxidants defense.

Sea-level residents experience altitude sickness when they hike or visit altitudes above ~2,500 m due to the hypobaric hypoxia (HH) conditions at such places. HH has been shown to drive cardiac inflammation in both ventricles by inducing maladaptive metabolic reprogramming of macrophages, which evokes aggravated proinflammatory responses, promoting myocarditis, fibrotic remodeling, arrhythmias, heart failure, and sudden deaths. The use of salidroside or altitude preconditioning (AP) before visiting high altitudes has been extensively shown to exert cardioprotective effects. Even so, both therapeutic interventions have geographical limitations and/or are inaccessible/unavailable to the majority of the population as drawbacks. Meanwhile, occlusion preconditioning (OP) has been extensively demonstrated to prevent hypoxia-induced cardiomyocyte damage by triggering endogenous cardioprotective cascades to mitigate myocardial damage. Herein, with the notion that OP can be conveniently applied anywhere, we sought to explore it as an alternative therapeutic intervention for preventing HH-induced myocarditis, remodeling, and arrhythmias. OP intervention (6 cycles of 5 min occlusion with 200 mmHg for 5 min and 5 min reperfusion at 0 mmHg - applying to alternate hindlimb daily for 7 consecutive days) was performed, and its impact on cardiac electric activity, immunoregulation, myocardial remodeling, metabolic homeostasis, oxidative stress responses, and behavioral outcomes were assessed before and after exposure to HH in mice. In humans, before and after the application of OP intervention (6 cycles of 5 min occlusion with 130% of systolic pressure and 5 min reperfusion at 0 mmHg - applying to alternate upper limb daily for 6 consecutive days), all subjects were assessed by cardiopulmonary exercise testing (CPET). Comparing the outcomes of OP to AP intervention, we observed that similar to the latter, OP preserved cardiac electric activity, mitigated maladaptive myocardial remodeling, induced adaptive immunomodulation and metabolic homeostasis in the heart, enhanced antioxidant defenses, and conferred resistance against HH-induce anxiety-related behavior. Additionally, OP enhanced respiratory and oxygen-carrying capacity, metabolic homeostasis, and endurance in humans. Overall, these findings demonstrate that OP is a potent alternative therapeutic intervention for preventing hypoxia-induced myocarditis, cardiac remodeling, arrhythmias, and cardiometabolic disorders and could potentially ameliorate the progression of other inflammatory, metabolic, and oxidative stress-related diseases.

Seed Priming and Foliar Supplementation with β-aminobutyric Acid Alleviates Drought Stress through Mitigation of Oxidative Stress and Enhancement of Antioxidant Defense in Linseed (Linum usitatissimum L.)

Seed Priming and Foliar Supplementation with β-aminobutyric Acid Alleviates Drought Stress through Mitigation of Oxidative Stress and Enhancement of Antioxidant Defense in Linseed (Linum usitatissimum L.)

Effect of supplemental methyl sulfonyl methane on performance, carcass and meat quality and oxidative status in chronic cyclic heat-stressed finishing broilers

Methyl sulfonyl methane (MSM) is available as a dietary supplement for human and has been associated with multiple health benefits such as reduction of oxidative stress. Heat stress (HS) is an environmental stressor challenging poultry production and known to inflict oxidative stress. We hypothesized that dietary MSM could attenuate HS-induced detrimental effects in broilers mediated by enhancement of antioxidant defenses. Hence, seven hundred ninety-two 1-day-old male Ross 308 broilers were allocated to 3 dietary treatments composed of corn-soybean meal diets with 0 (Ctrl), 1, or 2 g/kg MSM, with 12 replicates (22 birds each) per treatment for 39 d and subjected to a chronic cyclic HS model (temperature of 34°C and 52-58% relative humidity for 6 h daily) from d 24 to 39. MSM at 1 and 2 g/kg linearly increased daily gain and decreased feed-to-gain ratio compared with Ctrl in the grower phase (d 10-21, both P < 0.05). In the finisher phase (d 21-39) none of the performance and carcass indices were affected by treatment (P > 0.05). Nonetheless, data suggest reduced mortality by feeding MSM during HS. Also, during HS the diets with graded levels of MSM resulted in reduced rectal temperatures (P < 0.05) along with linearly decreased panting frequency on d 24 (P < 0.05). MSM supplemented birds showed a trend for linearly decreased thiobarbituric acid reactive substances of breast meat upon simulated retail display (P=0.078). In addition, MSM administration linearly decreased lipid oxidation in plasma (d 25 and 39, P < 0.05) and breast muscle at d 23 (P < 0.05), concomitantly with linearly increased glutathione levels in erythrocytes (d 23 and 39, P < 0.05; d 25, P < 0.1) and breast muscle (d 23, P < 0.05; d 39, P < 0.1). In conclusion, MSM increased growth performance of broilers during grower phase, and exhibited positive effects on heat tolerance mediated by improved antioxidant capacity in broilers resulting in lower mortality in finisher phase.