High Reactive Oxygen Species Scavenging Research Articles

Hyaluronic acid methacrylate/Pluronic F127 hydrogel enhanced with spermidine-modified mesoporous polydopamine nanoparticles for efficient synergistic periodontitis treatment

Bacterial infection, reactive oxygen species (ROS) accumulation, and persistent inflammation pose significant challenges in the treatment of periodontitis. However, the current single-modal strategy makes achieving the best treatment effect difficult. Herein, we developed a double-network hydrogel composed of Pluronic F127 (PF-127) and hyaluronic acid methacrylate (HAMA) loaded with spermidine-modified mesoporous polydopamine nanoparticles (M@S NPs). The PF-127/HAMA/M@S (PH/M@S) hydrogel was injectable and exhibited thermosensitivity and photocrosslinking capabilities, which enable it to adapt to the irregular shape of periodontal pockets. In vitro, the PH/M@S displayed multiple therapeutic effects, such as photothermal antibacterial activity, a high ROS scavenging capacity, and anti-inflammatory effects, which are beneficial for the multimodal treatment of periodontitis. The underlying anti-inflammatory mechanism of this hydrogel involves suppression of the extracellular regulated protein kinase 1/2 and nuclear factor kappa-B signalling pathways. Furthermore, in lipopolysaccharide-stimulated macrophage conditioned media, the PH/M@S effectively restored the osteogenic differentiation potential. In a rat model of periodontitis, the PH/M@S effectively reduced the bacterial load, relieved local inflammation and inhibited alveolar bone resorption. Collectively, these findings highlight the versatile functions of the PH/M@S, including photothermal antibacterial activity, ROS scavenging, and anti-inflammatory effects, indicating that this hydrogel is a promising multifunctional filling material for the treatment of periodontitis.

The OsWRKY72-OsAAT30/OsGSTU26 module mediates reactive oxygen species scavenging to drive heterosis for salt tolerance in hybrid rice.

Hybrid rice (Oryza sativa) generally outperforms its inbred parents in yield and stress tolerance, a phenomenon termed heterosis, but the underlying mechanism is not completely understood. Here, we combined transcriptome, proteome, physiological, and heterosis analyses to examine the salt response of super hybrid rice Chaoyou1000 (CY1000). In addition to surpassing the mean values for its two parents (mid-parent heterosis), CY1000 exhibited a higher reactive oxygen species scavenging ability than both its parents (over-parent heterosis or heterobeltiosis). Nonadditive expression and allele-specific gene expression assays showed that the glutathione S-transferase gene OsGSTU26 and the amino acid transporter gene OsAAT30 may have major roles in heterosis for salt tolerance, acting in an overdominant fashion in CY1000. Furthermore, we identified OsWRKY72 as a common transcription factor that binds and regulates OsGSTU26 and OsAAT30. The salt-sensitive phenotypes were associated with the OsWRKY72paternal genotype or the OsAAT30maternal genotype in core rice germplasm varieties. OsWRKY72paternal specifically repressed the expression of OsGSTU26 under salt stress, leading to salinity sensitivity, while OsWRKY72maternal specifically repressed OsAAT30, resulting in salinity tolerance. These results suggest that the OsWRKY72-OsAAT30/OsGSTU26 module may play an important role in heterosis for salt tolerance in an overdominant fashion in CY1000 hybrid rice, providing valuable clues to elucidate the mechanism of heterosis for salinity tolerance in hybrid rice.

Zn-MOF hydrogel: regulation of ROS-mediated inflammatory microenvironment for treatment of atopic dermatitis

Atopic dermatitis (AD) is a chronic and recurrent inflammation disease associated with immune dysfunction. The high level of reactive oxygen species (ROS) causes high oxidative stress and further results in the deterioration of AD. At the same time, the ROS produced by bacterial infection can further aggravate AD. Here, the prepared PVA-based hydrogel (Gel) has a high ROS scavenging ability, and the antibacterial agent Zn-MOF(ZIF-8) loaded into the hydrogel shows a lasting and effective antibacterial activity. Thus, a Zn-MOF hydrogel (Gel@ZIF-8) is prepared to regulate ROS-mediated inflammatory microenvironment. In vitro experiments show that Gel@ZIF-8 has good antibacterial effect and cell biocompatibility. In the AD-induced mouse model, Gel@ZIF-8 can significantly enhance the therapeutic effect, such as reduce the thickness of epidermis, the number of mast cells and IgE antibodies. The results indicate that the ROS-scavenging hydrogel could treat the AD by regulating the inflammatory microenvironment, providing a promising treatment for managing AD.

Length‐Controlled Construction of Ceria Nanowires with Ultrafine Diameter and Stable Morphology for Targeted Acute Lung Injury Therapy

AbstractThe overproduction of reactive oxygen species (ROS) is one of the major reasons for the aggravation of acute lung injury (ALI). Smaller‐sized ceria nanoparticles featured with higher ROS scavenging capability than their bigger‐sized counterparts are potential candidates for ALI therapy. However, smaller‐sized ceria nanoparticles are more easily accumulated in spleen and liver rather than lung. Herein, it is reported that this obstacle can be addressed by constructing ceria into ultrafine nanowires, through which the ultrafine diameter ensures the high ROS scavenging activity and the high aspect ratio promotes the lung targeted accumulation. To demonstrate the feasibility of this conception, a platform is developed to realize length‐controlled ceria nanowires (diameter of ≈1.5 nm) synthesis. These nanowires are PEGylated using a carefully optimized procedure that can preserve their fragile crystal structures. The PEGylated nanowires exhibit higher ROS scavenging capabilities than the ≈3.9 nm sized nanoparticles. Most importantly, lung targeted accumulation can be realized through modulating the length of the nanowires, where the longer nanowires (>100 nm) show much higher lung accumulation. Due to these properties, the longer ceria nanowires can effectively scavenge the overproduced ROS during the progression of ALI, and thereby inhibit the edema and inflammation in the lung tissue.

Nanoceria-GO-intercalated multicellular spheroids revascularize and salvage critical ischemic limbs through anti-apoptotic and pro-angiogenic functions

Critical limb ischemia (CLI) is a serious form of peripheral arterial disease that involves severe blockage of blood flow in lower extremities, often leading to foot necrosis and limb loss. Lack of blood flow and high pro-inflammation with overproduced reactive oxygen species (ROS) in CLI aggravate the degenerative events. Among other therapies, cell delivery is considered potential for restoring regenerative capacity, and preservation of cell survival under high oxidative stress has been challenging and prerequisite to harness cellular functions. Here, we introduce a multicellular delivery system that is intercalated with nanoceria-decorated graphene oxide (CeGO), which is considered to have high ROS scavenging ability while providing cell-matrix interaction signals. The CeGO nano-microsheets (8-nm-nanoceria/0.9-μm-GO) incorporated in HUVEC/MSC (7/3) could form cell-material hybrid spheroids mediated by cellular contraction. Under in vitro oxidative-stress-challenge with H2O2, the CeGO-intercalation enhanced the survival and anti-apoptotic capacity of cellular spheroids. Pro-angiogenic events of cellular spheroids, including cell sprouting and expression of angiogenic markers (HIF1α, VEGF, FGF2, eNOS) were significantly enhanced by the CeGO-intercalation. Proteomics analysis also confirmed substantial up-regulation of a series of angiogenesis-related secretome molecules. Such pro-angiogenic events with CeGO-intercalation were proven to be mediated by the APE/Ref-1 signaling pathway. When delivered to ischemic hindlimb in mice, the CeGO-cell spheroids could inhibit the accumulation of in vivo ROS rapidly, preserving high cell survival rate (cells were more proliferative and less apoptotic vs. those in cell-only spheroids), and up-regulated angiogenic molecular expressions. Monitoring over 28 days revealed significantly enhanced blood reperfusion and tissue recovery, and an ultimate limb salvage with the CeGO-cell delivery (∼60% salvaged vs. ∼29% in cell-only delivery vs. 0% in ischemia control). Together, the CeGO intercalated in HUVEC/MSC delivery is considered a potential nano-microplatform for CLI treatment, by scavenging excessive ROS and enhancing transplanted cell survival, while stimulating angiogenic events, which collectively help revascularization and tissue recovery, salvaging critical ischemic limbs.

Reactive Oxygen Species Suppressive Kraft Lignin-Gelatin Antioxidant Hydrogels for Chronic Wound Repair.

Chronic wound is difficult to repair because the normal wound healing mechanism is inhibited by the continuous inflammatory response. The delayed inflammatory responses generate high level of reactive oxygen species (ROS) at the wound sites, which leads to a longer inflammatory phase and induces a vicious cycle that interferes with the normal wound healing process. Therefore, ROS scavenging is an important factor for chronic wound healing. In this study, antioxidant hydrogel is developed by cross-linking kraft lignin, an antioxidant agent, and gelatin (Klig-Gel). Klig-Gel hydrogel is fabricated via ring opening reaction with epichlorohydrin as a cross-linker. High ROS scavenging activities are confirmed by various antioxidant evaluations, and in vitro natural antioxidant expression tests show reduction of oxidative stress. Mechanical properties of Klig-Gel hydrogel are tailorable by introducing different amount of kraft lignin to the hydrogel system. Biocompatibility is confirmed regardless of the kraft lignin content. Klig-Gel hydrogel is a promising ROS scavenging material that can be applied in various chronic wound healing applications.

Polydopamine coated Au-Pt nanorods: Enhanced photothermal properties and efficient reactive oxygen scavengers

As an emerging cancer treatment strategy, photothermal therapy (PTT) is precise, controllable, minimally invasive, low cost and less toxic side effects, thus photothermal transduction agents have been extensively investigated in recent years. Noble metal nanomaterials with unique localized surface plasmon resonance (LSPR) effects are particularly suitable as photothermal transduction agent, but the currently developed precious noble metal nano photothermal transduction agents face serious problems such as complex synthesis process, poor photothermal performance and high biotoxicity. Moreover, the large amount of reactive oxygen species (ROS) produced during PTT treatment could cause irreversible damage to the healthy tissues surrounding the tumor. In this work, we deposited platinum (Pt) on the tips of gold nanorods (AuNRs) to form dumbbell-shaped Au-Pt bimetallic nanorods (AuPtNRs), and functionalized AuPtNRs with biocompatible polydopamine (PDA) to obtain AuPt@PDA. With 808 nm laser irradiation, the prepared AuPt@PDA exhibited excellent photothermal stability, and its photothermal conversion efficiency (PCE) reached 81.78%, which was significantly higher than that of AuNRs (52.32%) and AuPtNRs (78.76%). With low cytotoxicity, AuPt@PDA decreased cell viability from 91.12% to 39.36% after PTT on cancer cells in vitro, while significantly reducing intracellular ROS levels generated by heat stress. Therefore, the excellent photothermal properties, high cancer cell killing and ROS scavenging activity of AuPt@PDA in PTT could be an ideal candidate for improving therapeutic efficacy while reducing the risk of toxic side effects due to heat stress-induced ROS formation.

Biocatalytic and Antioxidant Nanostructures for ROS Scavenging and Biotherapeutics

AbstractIn human systems, reactive oxygen species (ROS) significantly affect different physiological activities and play critical roles in diverse living processes. It is widely known that excessive ROS generation in inflammatory tissues can further deteriorate the localized tissue injury and cause chronic diseases. Though promising for reducing ROS levels, many antioxidant molecules and natural enzymes suffer from abundant intrinsic limitations. Recently, a series of biocatalytic or antioxidant nanostructures have been designed with distinctive ROS scavenging capabilities, which show promising activities to overcome these kernel challenges. In this timely review, the most recent advances in engineering biocatalytic and antioxidant nanostructures for ROS scavenging are summarized. First, the ROS scavenging principles and corresponding methods for testing various enzymatic activities are carefully concluded. Subsequently, the rationally designed nanostructures with high ROS scavenging efficiencies are comprehensively discussed, especially on the catalytic activities, mechanisms, and structure‐function relationships. After that, the representative applications of these ROS scavenging nanostructures for diverse biotherapeutics are summarized in detail. At last, the primary challenges and future perspectives in this emerging research frontier have also been outlined. It is believed that this progress review will offer a cutting‐edge understanding and guidance to engineering future high‐performance ROS scavenging nanostructures for broad biotherapeutic applications.

Overexpression of MdIAA24 improves apple drought resistance by positively regulating strigolactone biosynthesis and mycorrhization.

Most land plant species have the ability to establish a symbiosis with arbuscular mycorrhizal (AM) fungi. These fungi penetrate into root cortical cells and form branched structures (known as arbuscules) for nutrient exchange. We cloned the MdIAA24 from apple (Malus domestica) following its up-regulation during AM symbiosis. Results demonstrate the positive impact of the overexpression (OE) of MdIAA24 in apple on AM colonization. We observed the strigolactone (SL) synthesis genes, including MdD27, MdCCD7, MdCCD8a, MdCCD8b and MdMAXa, to be up-regulated in the OE lines. Thus, the OE lines exhibited both a higher SL content and colonization rate. Furthermore, we observed that the OE lines were able to maintain better growth parameters under AM inoculation conditions. Under drought stress with the AM inoculation, the OE lines were less damaged, which was demonstrated by a higher relative water content, a lower relative electrolytic leakage, a greater osmotic adjustment, a higher reactive oxygen species scavenging ability, an improved gas exchange capacity and an increased chlorophyll fluorescence performance. Our findings demonstrate that the OE of MdIAA24 in apple positively regulates the synthesis of SL and the formation of arbuscules as a drought stress coping mechanism.

Ceria-based nanotheranostic agent for rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease that affects 1-2% of the human population worldwide, and effective therapies with targeted delivery for local immune suppression have not been described. We address this problem by developing a novel theranostic nanoparticle for RA and assessed its therapeutic and targeting effects under image-guidance.Methods: Albumin-cerium oxide nanoparticles were synthesized by the biomineralization process and further conjugated with near-infrared, indocyanine green (ICG) dye. Enzymatic-like properties and reactive oxygen species (ROS) scavenging activities, as well as the ability to reprogram macrophages, were determined on a monocyte cell line in culture. The therapeutic effect and systemic targeting potential were evaluated in collagen-induced arthritis (CIA) mouse model using optical/optoacoustic tomographic imaging.Results: Small nanotheranostics with narrow size distribution and high colloidal stability were fabricated and displayed high ROS scavenging and enzymatic-like activity, as well as advanced efficacy in a converting pro-inflammatory macrophage phenotype into anti-inflammatory phenotype. When administrated into affected animals, these nanoparticles accumulated in inflamed joints and revealed a therapeutic effect similar to the gold-standard therapy for RA, methotrexate.Conclusions: The inflammation-targeting, inherent contrast and therapeutic activity of this new albumin-cerium oxide nanoparticle may make it a relevant agent for assessing severity in RA, and other inflammatory diseases, and controlling inflammation with image-guidance. The design of these nanotheranostics will enable potential clinical translation as systemic therapy for RA.

Physiological adaptations of Elymus dahuricus to high altitude on the Qinghai–Tibetan Plateau

The harsh natural environment on the Qinghai–Tibetan Plateau has a detrimental effect on the growth of vegetation. Elymus dahuricus, a widely distributed perennial herb on the Qinghai–Tibetan Plateau, is highly adapted to alpine regions. To unveil the mechanism of E. dahuricus adaptation to high altitude on the Qinghai–Tibetan Plateau, the relative photosynthetic characteristics and physiological indexes of wild E. dahuricus collected from different elevations in Huangzhong County and Minhe County of Qinghai Province were investigated. Increases in the maximum photochemical efficiency (Fv/Fm), potential activity (Fv/Fo), non-photochemical quenching (NPQ), total carotenoids content (Car), chlorophyll a to chlorophyll b ratio (Chl a/b) and total carotenoids to chlorophyll ratio (Car/Chl) were accompanied by decreases in photochemical quenching coefficient (qP), effective photochemical quantum yield of PSII (Y(II)) and chlorophyll a (Chl a) and chlorophyll b (Chl b) contents. Increases in Fv/Fm and Fv/F0 with altitude indicate that the photosynthetic capacity can be maintained with increases in altitude. As a photoprotective mechanism, decreases in chlorophyll content could lead to a reduction in the absorption of high energy light by leaves; therefore, the photosynthetic capacity of E. dahuricus was maintained on the Qinghai–Tibetan Plateau. Furthermore, the increasing malondialdehyde content along altitudinal gradients indicated that the alpine environments had an adverse effect on E. dahuricus growth. The increase in superoxide dismutase, peroxidase and catalase activities reflected a higher reactive oxygen species scavenging capacity, and the increases in soluble sugar and proline contents increased the osmotic adjustment substance contents, suggesting that the reactive oxygen species scavenging ability and osmotic pressure regulation play roles in maintaining the normal growth of E. dahuricus. In conclusion, the high altitude on the Qinghai–Tibetan Plateau negatively affected E. dahuricus growth, and the adaptation mechanism and survival strategies of E. dahuricus were ascribed to the comprehensive effects of photosynthetic capacity, reactive oxygen species scavenging and osmotic adjustments.

Discussions with Leaders: A Conversation Between Richard Wahl and Johannes Czernin.

3 Objectives: As a common reactive oxygen species (ROS)-related renal disease, acute kidney injury (AKI) causes numerous deaths annually, and only supportive treatment is currently available in the clinics. The detrimental reactive oxygen species (ROS) that trigger oxidative stress and inflammation are believed to induce the AKI. Recent progress in nanomedicine has enabled the dramatic treatment of ROS-related diseases using the nano-antioxidants, which, however, are subject to uptake by the kidney due to the renal glomerular filtration barrier. Our goal is to exploit the nano-antioxidants with high renal accumulation and presenting therapeutic effect for AKI. Methods: The blue Mo-based polyoxometalate (POM) nanoclusters were found to exhibit broad antioxidative activities against multiple toxic ROS including H2O2, O2•−, and •OH, where the readily variable valence of Mo5+ and Mo6+ in POM plays an important role in scavenging ROS. The murine model of AKI was built through intramuscular injection of 50% glycerol into dehydrated normal mice. Two hours after induction of AKI,POM radiolabeled with 89Zr was intravenously injected into AKI mice. Longitudinal PET imaging was then performed at various time points to monitor the renal accumulation in vivo. The therapeutic efficacy against AKI in living animals was evaluated by a dynamic PET with 68Ga-EDTA, blood urea nitrogen and creatinine measurements, H&E staining of kidney tissues, and biomarkers detection (e.g., kidney injury molecule-1, heme oxygenase-1, level of superoxide dismutase, DNA damage, etc.) in the kidneys. Results: These ultra-small POM nanoclusters containing elements of Mo, O, and P were uniform with an average diameter of ca. 1 nm. The hydrated size of POM is below 10 nm, which meets the threshold for kidney filtration and thus are able to pass through. They exhibited high ROS (i.e., H2O2, O2•- and •OH) scavenging activity, which were confirmed both in solutions and on cells. PET imaging of AKI mice showed that these nanoclusters presented high and gradual accumulation in the injured kidneys at all examined time points after injection, and the renal uptake of 89Zr-POM at 24 h post-injection (p.i.) was 17.7 ± 3.1 %ID/g. Furthermore, the dynamic PET with 68Ga-EDTA, blood urea nitrogen and creatinine measurements, and H&E staining of kidney tissues revealed that these ultra-small nanoclusters could recover renal function in the AKI mice. The detection of ROS-related biomarkers in renal tissues revealed the anti-oxidative roles of POM nanoclusters in AKI mice, which were reduced to the levels observed in healthy mice. CONCLUSION: In summary, a novel multi-antioxidant in the form of POM nanoclusters for antioxidative therapy of AKI in living animals was presented. Our findings revealed that POM nanoclusters exhibited broad antioxidative activities against multiple toxic ROS including H2O2, O2•−, and •OH.With high renal uptake, these ultra-small nanoclusters displayed excellent therapeutic efficacy of AKI induced by ROS, which has been demonstrated by dynamic PET imaging with 68Ga-EDTA, blood urea nitrogen and creatinine measurements, H&E staining, and biomarkers detection of kidney tissues. The protective effect of POM nanoclusters against AKI in living animals suggests exploring their use for the treatment of AKI patients, as well as patients with other ROS-related diseases.

PvNAC1 increases biomass and enhances salt tolerance by decreasing Na+ accumulation and promoting ROS scavenging in switchgrass (Panicum virgatum L.)

Switchgrass (Panicum virgatum L.) is a bioenergy crop; thus, it is important to improve biomass to effectively produce bioethanol, particularly under adverse stress conditions. NAC transcription factors are involved in the abiotic stress response. PvNAC1 was isolated in the nucleus of switchgrass, with its C-terminal region containing a transcriptional activation domain. PvNAC1 expression was induced by dehydration, salt, H2O2, and abscisic acid treatments. Overexpressing (OE) PvNAC1 improved growth performance, leading to significantly taller and heavier (dry weight) plants. Moreover, cellulose content was significantly higher in OE plants, indicating that PvNAC1 plays an important role regulating growth and bioethanol production. PvNAC1 RNA interference (RNAi) switchgrass plants exhibited reduced dry weight and cellulose content. OE PvNAC1 enhanced tolerance to salt stress, through higher reactive oxygen species scavenging ability and less Na+ and more K+ accumulation in roots and shoots. RNAi plants were more sensitive to salt stress. The quantitative polymerase chain reaction results revealed that some stress responsive genes, three antioxidant enzymatic genes, and an ion homeostasis-related gene were upregulated in OE plants and downregulated in RNAi plants. These results show that PvNAC1 functions as a transcriptional activator in response to salt stress and growth.

Photodamage attenuating potential of Nectandra hihua against UVB-induced oxidative stress in L929 fibroblasts

The total phenolic content (TP) and antioxidant activity of the ethanolic extract and fractions that were obtained from the leaves of Nectandra hihua were assessed using different methods. The ethanolic extract (EE) and ethyl acetate fraction (EAF) had the best antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (ABTS+ 2.55 ± 0.06, 3.54 ± 0.03 mmol TE/g; DPPH IC50 10.27 ± 0.05, 9.88 ± 0.02 μg/mL; FRAP 2.17 ± 0.08, 2.38 ± 0.04 mmol TE/g; ORAC 5.16 ± 0.08, 5.35 ± 0.07 mmol TE/g; TP 568.05 ± 18.15, 397.20 ± 17.88 mg GAE/g, respectively). The cytoprotective effect, reactive oxygen species (ROS) and lipid peroxidation inhibitions on L929 fibroblasts irradiated with UVB (600 mJ/cm2) in pre- and post-treatments with EE and EAF were determined. These plant materials demonstrated high ROS scavenging activity and lipid peroxidation inhibition on L929 fibroblasts in both treatments, especially with pre-treatment (EE 38.47 ± 1.95% and EAF 40.20 ± 4.5% inhibition of ROS production, and EE 39.03 ± 3.33% and EAF 41.67 ± 7.6% of lipid peroxidation inhibition), indicating the best cytoprotection with pre-treatment (13.52 ± 1.66% and 13.34 ± 2.61% increases in cell viability). The antioxidant flavonoids quercitrin, avicularin, juglalin, afzelin and astragalin were isolated from EAF. The results obtained indicate that EE and EAF present photodamage attenuating potential against UVB-induced oxidative stress and can be useful as a starting point for developing dermatological products to prevent oxidative skin damage.

Insight into the role of grafting and arbuscular mycorrhiza on cadmium stress tolerance in tomato.

Physiological, biochemical, metabolite changes, and gene expression analysis of greenhouse tomato (Solanum lycopersicum L.) were investigated in two grafting combinations (self-grafted ‘Ikram’ and ‘Ikram’ grafted onto interspecific hybrid rootstock `Maxifort'), with and without arbuscular mycorrhizal (AM), exposed to 0 and 25 μM Cd. Tomato plants responded to moderate Cadmium (Cd) concentration by decreasing yield and crop growth parameters due to the accumulation of Cd in leaf tissue, inhibition of the PS II activity, reduced nutrients translocation, and also to the oxidative stress as evidenced by enhanced hydrogen peroxide (H2O2) generation, ion leakage, and lipid peroxidation. AM inoculation significantly enhanced the metal concentration in shoots and reduced growth and yield. The Ikram/Maxifort combination induced higher antioxidant enzymes, higher accumulation of proline and reduction of lipid peroxidation products. This suggests that the use of Maxifort rootstock in tomato has a high reactive oxygen species scavenging activity since lower H2O2 concentrations were observed in the presence of Cd. The higher crop performance of Ikram/Maxifort in comparison to Ikram/Ikram combination was also due to the improved nutritional status (higher P, K, Ca, Fe, Mn, and Zn) and increased availability of metabolites involved in cadmium tolerance (phytochelatin PC2, fructans, and inulins). The up-regulation of LeNRAMP3 gene in leaf of Ikram/Maxifort could explain the better nutritional status of interspecific grafting combination (higher Fe, Mn, and Zn).

The calcium-ROS-pH triangle and mitochondrial permeability transition: challenges to mimic cardiac ischemia-reperfusion.

The calcium-ROS-pH triangle and mitochondrial permeability transition: challenges to mimic cardiac ischemia-reperfusion.

Antioxidant nanozyme: a facile synthesis and evaluation of the reactive oxygen species scavenging potential of nanoceria encapsulated albumin nanoparticles.

Several diseases and disorders, including cancer are endorsed by excessive oxidative stress caused due to the incomplete removal of reactive oxygen species (ROS) by the antioxidant defense system of the body. Therefore, present interest among the scientific community lies in the development of a highly stable, biocompatible artificial enzymatic system that possesses a high ROS scavenging activity over a period of time. In recent years, catalytic nanoparticles emerged as a potential candidate in the field of nanomedicine. Due to their inherent catalytic properties, they are exploited as an artificial enzyme (nanozyme), to reinstate or correct aberrant enzymatic activities in patients. Among them, cerium oxide nanoparticles/nanoceria (CNPs) emerged as a potent artificial redox enzyme, mimicking the activity of superoxide dismutase (SOD) and catalase and endure a tremendous ROS scavenging potential as depicted in a surfeit of human cell lines and animal models. In the present article, a facile synthesis of biocompatible nanoceria encapsulated albumin nanoparticles (BCNPs) via desolvation technique that lead to the abatement of intracellular ROS is reported. Physico-chemical characterizations of as-prepared BCNPs corroborate the formation of a highly monodispersed, spherical and stable aqueous delivery system. Interestingly, such entrapment does not affect the enzyme mimetic activity of CNPs, as demonstrated by SOD assay. The biocompatibility and ROS scavenging potential of BCNPs were further assessed in vitro against human lung epithelial cells by cell viability assay and flow cytometric analysis, respectively. The quantitative and qualitative assessments of cellular uptake of BCNPs were done by inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) analysis. Furthermore, the BCNPs preserve the cell's antioxidant defense system and protect them from oxidant-mediated apoptosis as confirmed by semi-quantitative RT-PCR analysis. Thus, the as-prepared BCNPs could provide an opportunity to be utilized as a potential candidate against ROS induced diseases and disorders.

Selenium Promotes the Growth and Photosynthesis of Tomato Seedlings Under Salt Stress by Enhancing Chloroplast Antioxidant Defense System

Tomato (Lycopersicon esculentum Miller) cv. Jiahe No. 9 (a salinity-resistant cultivar) and cv. Shuangfeng 87-5 (a salinity-sensitive cultivar) were used as experimental materials to investigate the effects of exogenous selenium (Na2SeO3 0.05 mM) on plant growth, chlorophyll fluorescence, photosynthetic rate, and antioxidative metabolism of chloroplasts in tomato seedlings under NaCl (100 mM) stress. Salt stress significantly inhibited plant growth, net photosynthetic rate (Pn), maximum quantum yield of PSII (Fv/Fm), actual photochemical efficiency of PSII (ΦPSII), photochemical quenching coefficient (qP), and non-photochemical quenching coefficient (qN) of both cultivars, whereas application of Se reversed the negative effects of salt stress. Furthermore, application of Se significantly decreased the levels of hydrogen peroxide (H2O2) and malondialdehyde. Application of Se increased the activities of superoxidase dismutase, glutathione reductase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione peroxidase, and thioredoxin reductase, and the contents of ascorbate, glutathione (GSH) and NADPH, and the ratios of GSH/GSSH, AsA/DHA, and NADPH/ NADP+ in the salt-stressed chloroplasts of both cultivars. These results suggest that Se alleviates salt-induced oxidative stress through regulating the antioxidant defense systems in the chloroplasts of tomato seedlings, which is associated with the improvement of the photochemical efficiency of PSII, thereby maintaining higher photosynthetic rates. In addition, the salt tolerance of Jiahe No. 9 is closely related with high reactive oxygen species scavenging activity and reducing power levels in the chloroplasts.

Comparative physiological and proteomic response to abrupt low temperature stress between two winter wheat cultivars differing in low temperature tolerance

Abrupt temperature reduction in winter wheat at either autumn seedling stage prior to vernalisation or early spring crown stage can cause severe crop damage and reduce production. Many studies have reported the physiological and molecular mechanisms underlying cold acclimation in winter wheat by comparing it with spring wheat. However, processes associated with abrupt temperature reduction in autumn seedling stage prior to vernalisation in winter wheat are less understood. In this study, physiological and molecular responses of winter wheat seedlings to abrupt low temperature (LT) stress were characterised in the relatively LT-tolerant winter wheat cultivar Shixin 828 by comparing it with the relatively LT-sensitive cultivar Shiluan 02-1 using a combination of physiological, proteomics and biochemical approaches. Shixin 828 was tolerant to abrupt LT stress, while Shiluan 02-1 exhibited high levels of reactive oxygen species (ROS) and leaf cell death. Significant increases in relative abundance of antioxidant-related proteins were found in Shixin 828 leaves, which correlate with observed higher antioxidant enzyme activity in Shixin 828 compared to Shiluan 02-1. Proteomics analysis also indicated that carbohydrate metabolism-related proteins were more abundant in Shiluan 02-1, correlating with observed accumulation of soluble sugars in Shiluan 02-1 leaves. Amino acid analysis revealed a strong response to LT stress in wheat leaves. A negative effect of exogenous sucrose on LT tolerance was also found. This study indicates that high ROS scavenging capacity and high abundance of photosynthesis-related proteins might play a role in winter wheat response to abrupt LT stress. In contrast, excess accumulation of soluble sugars might be disadvantageous for LT tolerance in the wheat cultivar Shiluan 02-1.

Different response on drought tolerance and post-drought recovery between the small-leafed and the large-leafed white clover (Trifolium repens L.) associated with antioxidative enzyme protection and lignin metabolism

The objective of this present investigation was to study the different response on drought tolerance and post-drought recovery for two different genotypes of white clover (a drought-tolerant small-leafed white clover and a drought-sensitive large-leafed white clover) associating with antioxidative enzyme and lignin metabolism. Two materials were exposed to 12 days of drought stress and 6 days of rewatering in a greenhouse. Significantly higher activities of superoxide dismutase, ascorbate peroxidase, catalase, guaiacol peroxidase and root activity as well as lower electrolyte leakage and malondialdehyde levels of the small-leafed in leaves and roots were observed as compared to the large-leafed under drought stress and rewatering. Lignification-related enzymes (polyphenol oxidase, cinnamyl alcohol dehydrogenase) activities of two materials in leaves gradually increased from 0 to 9 days of drought stress; then declined at 12 days of drought stress and after rewatering. After 12 days of drought stress, lignin content of two materials in roots was significantly higher relative to the well-watered. Lignin content of leaves in the small-leafed also increased significantly after 6 days of rewatering, but not in the large-leafed. The small-leafed exhibited more sensitive lignin metabolism and faster lignification in leaves and roots than the large-leafed regarding the response of drought stress. These results indicated that antioxidant efficiency and lignin metabolism played important roles in response to drought stress and rewatering for different white clovers. Comparatively higher reactive oxygen species scavenging system and more sensitive lignin metabolism could be associated with better drought tolerance and post-drought recovery in white clover.