Aspects of the structure, function, and applications of superoxide dismutase

Natural phytochemicals reverting M2 to M1 macrophages: A novel alternative leishmaniasis therapy

INTRODUCTION

Leishmaniasis is a tropical parasitic disease caused by the protozoan Leishmania which remains a significant global health concern with diverse clinical manifestations. Transmitted through the bite of an infected sandfly, its progression depends on the interplay between the host immune response and the parasite. The disease outcome is linked to macrophage polarisation into M1 and M2 phenotypes. M1 macrophages are pro-inflammatory and promote parasite clearance, while M2 macrophages support tissue repair and parasite survival by facilitating promastigote entry and intracellular amastigote proliferation.

PURPOSE

The review focuses on discovering novel phytochemicals that exploit the immunomodulatory properties of macrophages, which can serve as an alternative antileishmanial treatments due to their diverse chemical structures and ability to modulate immune responses. It examines the immunomodulatory effects of phytochemicals that directly or indirectly promote antileishmanial activity by influencing macrophage polarisation and cytokine secretion. They can induce M1 macrophage polarisation to directly combat leishmaniasis or suppress M2 macrophages, thereby exerting indirect antileishmanial activity by influencing the release of M1-and M2-related cytokines.

RESULTS & DISCUSSION

Phytochemicals demonstrate antileishmanial effects through ROS production, M1 activation, and cytokine modulation. They regulate M1/M2-related cytokines and macrophage activity, influencing immune responses. Although their effects may be non-specific, targeted delivery strategies could overcome current therapeutic limitations, positioning phytochemicals as promising candidates for leishmaniasis treatment to counter the limitations of current medications.

Angiotensin-converting enzyme 2 activation attenuates inflammation and oxidative stress in brain death donor followed by rat lung transplantation

Brain death (BD) provides most of the donor organs destined for lung transplantation (LTx). However, the organs may be affected by inflammatory and oxidative processes. Based on this, we hypothesize that the angiotensin-converting enzyme 2 (ACE2) activation can reduce the lung injury associated with LTx. 3 h after BD induction, rats were injected with saline (BD group) or an ACE2 activator (ACE2a group; 15 mg/kg-1) and kept on mechanical ventilation for additional 3 h. A third group included a control ventilation (Control group) prior to transplant. After BD protocol, left LTx were performed, followed by 2 h-reperfusion. ACE2 activation was associated with better oxygenation after BD management (p = 0.01), attenuating edema (p = 0.05) followed by the reduction in tissue resistance (p = 0.01) and increase of respiratory compliance (p = 0.02). Nrf2 expression was also upregulated in the ACE2a group (p = 0.03). After transplantation, ACE2a group showed lower levels of TNF-α (p = 0.02), IL-6 (p = 0.001), IL-1β (p = 0.01), ROS (p = 0.004) and MDA (p = 0.002), in addition to higher CAT activity (p = 0.04). In conclusion, our study suggests that ACE2 activation improves anti-inflammatory and antioxidant activity in a model of LTx.

Hematological changes, oxidative stress assessment, and dysregulation of aquaporin-3 channel, prolactin, and oxytocin receptors in kidneys of lactating Wistar rats treated with monosodium glutamate

High consumption of locally produced delicacies could expose nursing mothers to high monosodium glutamate (MSG) levels, frequently used as a necessary condiment in low-income countries. Thus, this study evaluated some novel preliminary changes in renal hormonal receptors, the aquaporin-3 channel, oxidative stress markers, and hematological indices induced by monosodium glutamate in lactating rats. Post-parturition, twenty-four (24) lactating Wistar rats were divided into four (4) groups of six rats each (n = 6). Oral administration of distilled water and MSG started three (3) days postpartum as follows: group 1: distilled water (1 ml/kg BW), group 2: MSG (925 mg/kg BW), group 3: MSG (1850 mg/kg BW), and group 4: MSG (3700 mg/kg BW). At the end of the experiment, which lasted fourteen (14) days, animals were sacrificed and samples of blood and tissues were obtained for biochemical analysis. MSG administration significantly (p < 0.05) increased ROS and MDA, with a significant (p < 0.05) decrease in kidney antioxidants. Serum creatinine, total, conjugated, and unconjugated bilirubin significantly (p < 0.05) increased with MSG administration. The prolactin receptor was significantly reduced (p < 0.05), while the oxytocin receptor and aquaporin-3 channel were significantly (p < 0.05) increased in the MSG-administered groups. There were significant (p < 0.05) changes in the hematological indices of the MSG-administered animals. Thus, the findings of this study suggest that high MSG consumption causes hematological alterations and may alter renal function via increased ROS production and dysregulation of the AQP-3 channel, prolactin, and oxytocin receptors in the kidneys of lactating Wistar rats.

The hard life of an octopus embryo is seen through gene expression, energy metabolism, and its ability to neutralize radical oxygen species

The reproductive process in Octopus maya was analyzed to establish the amount of reactive oxygen species that the embryos inherit from females, during yolk synthesis. At the same time, respiratory metabolism, ROS production, and the expression of some genes of the antioxidant system were monitored to understand the ability of embryos to neutralize maternal ROS and those produced during development. The results indicate that carbonylated proteins and peroxidized lipids (LPO) were transferred from females to the embryos, presumably derived from the metabolic processes carried out during yolk synthesis in the ovary. Along with ROS, females also transferred to embryos glutathione (GSH), a key element of the antioxidant defense system, thus facilitating the neutralization of inherited ROS and those produced during development. Embryos are capable of neutralizing ROS thanks to the early expression of genes such as catalase (CAT) and superoxide dismutase (SOD), which give rise to the synthesis of enzymes when the circulatory system is activated. Also, it was observed that the levels of the routine metabolic rate of embryos are almost as high as those of the maximum activity metabolism, which leads, on the one hand, to the elevated production of ROS and suggests that, at this stage of the life cycle in octopuses, energy production is maximum and is physically limited by the biological properties inherent to the structure of embryonic life (oxygen transfer through the chorion, gill surface, pumping capacity, etc.). Due to its role in regulating vascularization, a high expression of HIf-1A during organogenesis suggests that circulatory system development has begun in this phase of embryo development. The results indicate that the routine metabolic rate and the ability of O. maya embryos to neutralize the ROS are probably the maximum possible. Under such circumstances, embryos cannot generate more energy to combat the free radicals produced by their metabolism, even when environmental factors such as high temperatures or contaminants could demand excess energy.

Exploring the Link between Oxidative Stress, Selenium Levels, and Obesity in Youth

Obesity is a worldwide increasing concern. Although in adults this is easily estimated with the body mass index, in children, who are constantly growing and whose bodies are changing, the reference points to assess weight status are age and gender, and need corroboration with complementary data, making their quantification highly difficult. The present review explores the interaction spectrum of oxidative stress, selenium status, and obesity in children and adolescents. Any factor related to oxidative stress that triggers obesity and, conversely, obesity that induces oxidative stress are part of a vicious circle, a complex chain of mechanisms that derive from each other and reinforce each other with serious health consequences. Selenium and its compounds exhibit key antioxidant activity and also have a significant role in the nutritional evaluation of obese children. The balance of selenium intake, retention, and metabolism emerges as a vital aspect of health, reflecting the complex interactions between diet, oxidative stress, and obesity. Understanding whether selenium status is a contributor to or a consequence of obesity could inform nutritional interventions and public health strategies aimed at preventing and managing obesity from an early age.

Effects of Reactive Oxygen and Nitrogen Species on Male Fertility

Significance: In recent decades, male fertility has been severely reduced worldwide. The causes underlying this decline are multifactorial, and include, among others, genetic alterations, changes in the microbiome, and the impact of environmental pollutants. Such factors can dysregulate the physiological levels of reactive species of oxygen (ROS) and nitrogen (RNS) in the patient, generating oxidative and nitrosative stress that impairs fertility. Recent Advances: Recent studies have delved into other factors involved in the dysregulation of ROS and RNS levels, such as diet, obesity, persistent infections, environmental pollutants, and gut microbiota, thus leading to new strategies to solve male fertility problems, such as consuming prebiotics to regulate gut flora or treating psychological conditions. Critical Issues: The pathways where ROS or RNS may be involved as modulators are still under investigation. Moreover, the extent to which treatments can rescue male infertility as well as whether they may have side effects remains, in most cases, to be elucidated. For example, it is known that prescription of antioxidants to treat nitrosative stress can alter sperm chromatin condensation, which makes DNA more exposed to ROS and RNS, and may thus affect fertilization and early embryo development. Future Directions: The involvement of extracellular vesicles, which might play a crucial role in cell communication during spermatogenesis and epididymal maturation, and the relevance of other factors such as sperm epigenetic signatures should be envisaged in the future.

Anti-inflammatory effect of thalidomide in an experimental lung donor model of brain death

Lung transplantation stands as a vital treatment for severe lung diseases, primarily sourcing organs from donors with brain death (BD). This research delved into the potential anti-inflammatory effects of thalidomide in rats with BD-induced lung complications. In this study twenty-four Wistar rats were divided into three groups: the control (CTR), brain death (BD) and brain death + thalidomide (TLD) groups. Post specific procedures, a 360 min monitoring period ensued. Comprehensive analyses of blood and heart-lung samples were conducted. Elevated IL-6 levels characterized both BD and TLD groups relative to the CTR (p = 0.0067 and p = 0.0137). Furthermore, TNF-α levels were notably higher in the BD group than both CTR and TLD (p = 0.0152 and p = 0.0495). Additionally, IL-1β concentrations were significantly pronounced in both BD and TLD compared to CTR, with the BD group surpassing TLD (p = 0.0256). Immunohistochemical assessments revealed augmented NF-ĸB expression in the BD group in comparison to both CTR and TLD (p = 0.0006 and p = 0.0005). With this study we can conclude that BD induced acute pulmonary inflammation, whereas thalidomide manifested a notable capability in diminishing key inflammatory markers, indicating its prospective therapeutic significance in lung transplantation scenarios.

Beyond NPK: Mineral Nutrient-Mediated Modulation in Orchestrating Flowering Time

Flowering time in plants is a complex process regulated by environmental conditions such as photoperiod and temperature, as well as nutrient conditions. While the impact of major nutrients like nitrogen, phosphorus, and potassium on flowering time has been well recognized, the significance of micronutrient imbalances and their deficiencies should not be neglected because they affect the floral transition from the vegetative stage to the reproductive stage. The secondary major nutrients such as calcium, magnesium, and sulfur participate in various aspects of flowering. Micronutrients such as boron, zinc, iron, and copper play crucial roles in enzymatic reactions and hormone biosynthesis, affecting flower development and reproduction as well. The current review comprehensively explores the interplay between microelements and flowering time, and summarizes the underlying mechanism in plants. Consequently, a better understanding of the interplay between microelements and flowering time will provide clues to reveal the roles of microelements in regulating flowering time and to improve crop reproduction in plant industries.

Reactive Oxygen Species: A Crosslink between Plant and Human Eukaryotic Cell Systems

Reactive oxygen species (ROS) are important regulating factors that play a dual role in plant and human cells. As the first messenger response in organisms, ROS coordinate signals in growth, development, and metabolic activity pathways. They also can act as an alarm mechanism, triggering cellular responses to harmful stimuli. However, excess ROS cause oxidative stress-related damage and oxidize organic substances, leading to cellular malfunctions. This review summarizes the current research status and mechanisms of ROS in plant and human eukaryotic cells, highlighting the differences and similarities between the two and elucidating their interactions with other reactive substances and ROS. Based on the similar regulatory and metabolic ROS pathways in the two kingdoms, this review proposes future developments that can provide opportunities to develop novel strategies for treating human diseases or creating greater agricultural value.

Broad spectrum bioactivity of a novel β-glucan rich heteropolysaccharide, Pestalopine isolated from endophytic fungi Pestalotiopsis chamaeropsis CEL6

A biologically potent exopolysaccharide (EPS), Pestalopine was produced by Pestalotiopsis chamaeropsis CEL6, an endophytic fungal isolate of Chloranthus elatior Sw. Pestalopine is composed of glucose, arabinose, fucose, rhamnose, and galactose in a molar ratio of nearly 10:1:2:2:4 having an Mw ∼ 3.29 × 105 Da. Pestalopine exhibited a radical scavenging effect and significantly increased antioxidant parameters (malondialdehyde, superoxide dismutase, glutathione peroxidase, reduced glutathione oxidized glutathione) in peritoneal macrophage cells in a concentration-dependent manner, with a maximum effect at 500 mg mL-1. Pestalopine is hepatoprotective in nature and improves the liver function profiles-total bilirubin, direct bilirubin, hepatic enzymes: alkaline phosphatase, gamma-glutamyl transferase, aspartate aminotransferase, alanine transaminase of liver fibrosis induced (through thioacetamide) male Wistar rats in comparison to control. Pestalopine-fed rats are reported to have higher counts of beneficial Lactobacillus sp. Present findings suggest that Pestalopine, a novel compound may have promise as a non-toxic exogenous antioxidant with hepatoprotective and probiotic efficacies.

Modulation of Alveolar Macrophage Activity by Eugenol Attenuates Cigarette-Smoke-Induced Acute Lung Injury in Mice

This study investigates the role of eugenol (EUG) on CS-induced acute lung injury (ALI) and how this compound is able to modulate macrophage activity. C57BL/6 mice were exposed to 12 cigarettes/day/5days and treated 15 min/day/5days with EUG. Rat alveolar macrophages (RAMs) were exposed to CSE (5%) and treated with EUG. In vivo, EUG reduced morphological changes inflammatory cells, oxidative stress markers, while, in vitro, it induced balance in the oxidative stress and reduced the pro-inflammatory cytokine release while increasing the anti-inflammatory one. These results suggest that eugenol reduced CS-induced ALI and acted as a modulator of macrophage activity.

Oral delivery of a highly stable superoxide dismutase as a skin aging inhibitor

As an effective antioxidant enzyme, superoxide dismutase (SOD) has been widely used as a food supplement, cosmetic additive, and therapeutic agent. However, oral delivery of SOD is challenging due to its relative instability, limited bioavailability, and low absorption efficiency in the gastrointestinal (GI) tract. We addressed these issues using a highly stable superoxide dismutase (hsSOD) generated from a hot spring microbial sample. This SOD exhibited a specific activity of 5000 IU/mg while retaining its enzymatic activity under low pH environments of an artificial GI system and in the presence of surfactants and various proteolytic enzymes. The inhibitory effects of hsSOD against skin-aging was evaluated under both in vitro and in vivo experiments using fibroblast cell and D-galactose induced aging-mouse models, respectively. Effective oral delivery of hsSOD promises wide applicability in pharmaceutical and food industries.

Effects of functional modules and bacterial clusters response on transmission performance of antibiotic resistance genes under antibiotic stress during anaerobic digestion of livestock wastewater

The formation and transmission of antibiotic resistance genes (ARGs) have attracted increasing attention. It is unclear whether the internal mechanisms by which antibiotics affect horizontal gene transfer (HGT) of ARGs during anaerobic digestion (AD) were influenced by dose and type. We investigated the effects of two major antibiotics (oxytetracycline, OTC, and sulfamethoxazole, SMX) on ARGs during AD according to antibiotic concentration in livestock wastewater influent. The low-dose antibiotic (0.5 mg/L) increased ROS and SOS responses, promoting the formation of ARGs. Meanwhile, low-dose antibiotics could also promote the spread of ARGs by promoting pili, communication responses, and the type IV secretion system (T4SS). However, different types and doses of antibiotics would lead to changes in the above functional modules and then affect the enrichment of ARGs. With the increasing dose of SMX, the advantages of pili and communication responses would gradually change. In the OTC system, low-dose has the strongest promoting ability in both pili and communication responses. Similarly, an increase in the dose of SMX would change T4SS from facilitation to inhibition, while OTC completely inhibits T4SS. Microbial and network analysis also revealed that low-dose antibiotics were more favorable for the growth of host bacteria.

Higher Concentration of Dietary Selenium, Zinc, and Copper Complex Reduces Heat Stress-Associated Oxidative Stress and Metabolic Alteration in the Blood of Holstein and Jersey Steers

This study investigated the influence of high concentrations of dietary minerals on reducing heat stress (HS)-associated oxidative stress and metabolic alterations in the blood of Holstein and Jersey steers. Holstein steers and Jersey steers were separately maintained under a 3 × 3 Latin square design during the summer conditions. For each trial, the treatments included Control (Con; fed basal TMR without additional mineral supplementation), NM (NRC recommended mineral supplementation group; [basal TMR + (Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm) as DM basis]), and HM (higher than NRC recommended mineral supplementation group; [basal TMR + (Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm) as DM basis]). Blood samples were collected at the end of each 20-day feeding trial. In both breeds, a higher superoxide dismutase concentration (U/mL) along with lower HSP27 (μg/L) and HSP70 (μg/L) concentrations were observed in both mineral-supplemented groups compared to the Con group (p < 0.05). The HM group had significantly higher lactic acid levels in Jersey steers (p < 0.05), and tended to have higher alanine levels in Holstein steers (p = 0.051). Based on star pattern recognition analysis, the levels of succinic acid, malic acid, γ-linolenic acid, 13-methyltetradecanoic acid, and tyrosine decreased, whereas palmitoleic acid increased with increasing mineral concentrations in both breeds. Different treatment groups of both breeds were separated according to the VIP scores of the top 15 metabolites through PLS−DA analysis; however, their metabolic trend was mostly associated with the glucose homeostasis. Overall, the results suggested that supplementation with a higher-than-recommended concentration of dietary minerals rich in organic Se, as was the case in the HM group, would help to prevent HS-associated oxidative stress and metabolic alterations in Holstein and Jersey steers.

Dextran sodium sulfate alters antioxidant status in the gut affecting the survival of Drosophila melanogaster

Inflammatory bowel disease (IBD) is a group of disorders characterized by chronic inflammation in the intestine. Several studies confirmed that oxidative stress induced by an enormous amount of reactive free radicals triggers the onset of IBD. Currently, there is an increasing trend in the global incidence of IBD and it is coupled with a lack of adequate long-term therapeutic options. At the same time, progress in research to understand the pathogenesis of IBD has been hampered due to the absence of adequate animal models. Currently, the toxic chemical Dextran Sulfate Sodium (DSS) induced gut inflammation in rodents is widely perceived as a good model of experimental colitis or IBD. Drosophila melanogaster, a genetic animal model, shares ~ 75% sequence similarity to genes causing different diseases in humans and also has conserved digestion and absorption features. Therefore, in the current study, we used Drosophila as a model system to induce and investigate DSS-induced colitis. Anatomical, biochemical, and molecular analyses were performed to measure the levels of inflammation and cellular disturbances in the gastrointestinal (GI) tract of Drosophila. Our study shows that DSS-induced inflammation lowers the levels of antioxidant molecules, affects the life span, reduces physiological activity and induces cellular damage in the GI tract mimicking pathophysiological features of IBD in Drosophila. Such a DSS-induced Drosophila colitis model can be further used for understanding the molecular pathology of IBD and screening novel drugs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03349-2.

Copper Chaperone for Superoxide Dismutase FoCCS1 in Frankliniella occidentalis May Be Associated with Feeding Adaptation after Host Shifting

Western flower thrips (Frankliniella occidentalis) pose a serious threat to the global vegetable and flower crop production. The regulatory mechanism for superoxide dismutase (SOD) in the feeding adaptation of F. occidentalis after host shifting remains unclear. In this study, the copper chaperone for SOD (CCS) and manganese SOD (MnSOD) genes in F. occidentalis were cloned, and their expression levels at different developmental stages was determined. The mRNA expression of FoCCS1 and FoMnSOD2 in F. occidentalis second-instar larvae and adult females of F₁, F₂, and F₃ generations was analyzed after shifting the thrips to kidney bean and broad bean plants, respectively. The F₂ and F₃ second-instar larvae and F₂ adult females showed significantly upregulated FoCCS1 mRNA expression after shifting to kidney bean plants. The F₁ second-instar larvae and F₂ adult females showed significantly upregulated FoCCS1 mRNA expression after shifting to broad bean plants. The RNA interference significantly downregulated the FoCCS1 mRNA expression levels and adult females showed significantly inhibited SOD activity after shifting to kidney bean and broad bean plants. F. occidentalis adult females subjected to RNA interference and released on kidney bean and broad bean leaves for rearing, respectively, significantly reduced the survival rate and fecundity. These findings suggest that FoCCS1 plays an active role in regulating the feeding adaptation ability of F. occidentalis after host shifting.

Global distribution of treatment resistance gene markers for leishmaniasis

BACKGROUND

Pentavalent antimonials (Sb(V)) such as meglumine antimoniate (Glucantime®) and sodium stibogluconate (Pentostam®) are used as first-line treatments for leishmaniasis, either alone or in combination with second-line drugs such as amphotericin B (Amp B), miltefosine (MIL), methotrexate (MTX), or cryotherapy. Therapeutic aspects of these drugs are now challenged because of clinical resistance worldwide.

METHODS

We reviewedthe recent original studies were assessed by searching in electronic databases such as Scopus, Pubmed, Embase, and Web of Science.

RESULTS

Studies on molecular biomarkers involved in drug resistance are essential for monitoring the disease. We reviewed genes and mechanisms of resistance to leishmaniasis, and the geographical distribution of these biomarkers in each country has also been thoroughly investigated.

CONCLUSION

Due to the emergence of resistant genes mainly in anthroponotic Leishmania species such as L. donovani and L. tropica, as the causative agents of ACL and AVL, respectively, selection of an appropriate treatment modality is essential. Physicians should be aware of the presence of such resistance for the selection of proper treatment modalities in endemic countries.

Biogenic Synthesis of Silver Nanoparticles Using Rhazya stricta Extracts and Evaluation of Its Biological Activities

Rhazya stricta is a well-known medicinal plant and source of numerous potential secondary metabolites including steroids, alkaloids, and tannins. R. stricta possesses multimedical applications and used for curing of various diseases such as inflammation, diabetes, sore throat, infectious, helminthiasis, arthritis, and cancer. The current investigation deals with synthesizing AgNPs using aqueous and ethanol extracts of R. stricta. The synthesized R. stricta-AgNPs were characterized through UV-visible, Fourier transform infrared (FTIR), and atomic force microscopy (AFM) methods. The UV-visible analysis exhibited a characteristic absorption ${\lambda }_{\max }$ at 475 nm in R. stricta ethanol AgNPs while this peak was absent in R. stricta aqueous crude extract. The thermal stability of R. stricta-AgNPs demonstrated that by increasing the reduction time and temperature, the absorption of AgNPs also increased, leading to more stable NPs formation. The FTIR spectra showed a broad peak at 450-550 cm-1 that confirmed the occurrence of AgNPs of R. stricta. The AFM study of the synthesized AgNPs revealed the spherical shape and size ranging from 30 nm to 90 nm. In antioxidant and antibacterial study, the R. stricta-AgNPs exhibited good antioxidant activity (87.94% and 88.37%) than the ethanol crude extract (50.00% and 56.81%) at 100 μg/mL using DPPH assay. Maximum antibacterial activity was recorded against Gram-positive bacteria (Staphylococcus aureus), which was 15 and 0 mm, while against Gram-negative bacteria (Klebsiella pneumonia) was found to be 16 and 14 mm, respectively, whereas against Bacillus subtills, a poor activity was recorded as 14 for extract and 0 mm for AgNPs, respectively. In the acetic acid-induced writhing model, the percent effect of extract (100 mg/kg) and AgNPs (15 mg/kg) was 79.98 and 83.23, respectively. The maximum muscle coordination effect of extracts in the inclined plan and traction test was 44% and 38% at higher doses. A mild sedative effect was also recorded against extract and AgNPs. The significant ( $p<0.05$ ) effect of extract was noted at 100 mg/kg while AgNPs was more significant ( $p<0.01$ ) at the tested dose of 15 mg/kg. These findings have concluded that R. stricta-AgNPs is an effective bioreductant of AgNPs synthesis and exhibit several applications in distinctive biomedical and pharmaceutical industries.

Moderate acidification mitigates the toxic effects of phenanthrene on the mitten crab Eriocheir sinensis

Freshwater acidification and phenanthrene may result in complex adverse effects on aquatic animals. Juvenile Chinese mitten crabs (Eriocheir sinensis) were exposed to different pH levels (7.8, 6.5, and 5.5) under phenanthrene (PHE) (0 (control) and 50 μg/L) conditions for 14 days. Antioxidant and transcriptomic responses were determined under stress conditions to evaluate the physiological adaptation of crabs. Under the control pH 7.8, PHE led to significantly reduced activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione S-transferase (GST), but increased glutathione peroxidase (GSH-Px), 7-ethoxyresorufin-o-deethylase (EROD) activities, and malondialdehyde (MDA) levels. However, moderate acidification (pH 6.5) changed PHE effects by increasing antioxidant enzymes. Acidification generally reduced SOD, GPx, GST and EROD activities, but increased CAT, GR, MDA. Compared with pH7.8 group, pH7.8 × PHE and pH6.5 × PHE groups had 1148 and 1498 differentially expressed genes, respectively, with "Biological process" being the main category in the two experimental groups. pH7.8 × PHE treatment caused significant enrichment of disease and immune-related pathways, while under pH6.5 × PHE, more pathways related to metabolism, detoxification, environmental information processing, and energy supply were significantly enriched. Thus, PHE had a significant inhibitory effect on antioxidant performance in crabs, while moderate acidification (pH6.5) mitigated the toxic effects of PHE. Overall, moderate acidification has a positive effect on the defense against the negative effects of PHE in Chinese mitten crabs, and this study provides insights into the defense mechanism of crustaceans in response to combined stress of acidification and PHE.

Ecotoxicity assessment of triphenyl phosphate (TPhP) exposure in Hoplobatrachus rugulosus tadpoles

Triphenyl phosphate (TPhP), a widely used aromatic organophosphate flame retardant, is known to accumulate in organisms through water, air, and soil, consequently, causing toxicity. This study is the first to evaluate the acute and sub-chronic toxicities of TPhP to amphibians. In the acute toxicity analysis, the 96-h median lethal concentration (LC₅₀) for GS35 Hoplobatrachus rugulosus tadpoles was 2.893 mg/L, and the 10% effect concentration (EC₁₀) was 289 μg/L. After two weeks of exposure to low TPhP concentrations, the survival and metamorphosis rates of H. rugulosus tadpoles decreased, and the metamorphosis time was prolonged as the TPhP concentration increased. The threshold concentration that affected tadpole survival and metamorphosis time was 50 μg/L and 100 μg/L, respectively. No significant differences were observed in the condition factor and hepatic somatic index of the tadpole after metamorphosis; however, tadpole body mass and TPhP concentration were negatively correlated. Further, TPhP inhibited the expressions of Cu-Zn sod and cat, thereby reducing the activities of superoxide dismutase and catalase in the tadpole liver. The threshold for affecting gene expression and enzymatic activity was 100 μg/L. These findings provide significant insights on the stress ecology of aquatic organisms.

Four alternative splicing transcripts of intracellular copper/zinc superoxide dismutase 1 in Oxya chinensis

In this study, we obtained four alternative splicing transcripts of intracellular copper/zinc superoxide dismutase 1 (icCuZnSOD1) in Oxya chinensis. OcicCuZnSOD1a has all common characteristics of CuZnSOD family and is a canonical CuZnSOD. OcicCuZnSOD1b is missing a Zn binding site. OcicCuZnSOD1c lacks Zn ion and is a Cu-only SOD. OcicCuZnSOD1d is missing a CuZnSOD conserved sequence and lacks the E-loop, a conserved disulfide bond, and an active site arginine. OcicCuZnSOD1a was the most heat-resistant and OcicCuZnSOD1c was the most unstable at high temperatures above 55 °C. They were stable at a wide pH range, especially in alkaline conditions. The four variants expressed at the throughout developmental stages and had various tissue expression patterns. OcicCuZnSOD1a and OcicCuZnSOD1d were significantly induced by 8.79 mM CuCl₂ and OcicCuZnSOD1b was significantly up-regulated by 14.67 mM CuCl₂. OcicCuZnSOD1a was significantly inhibited by 19.13 mM ZnSO₄ while OcicCuZnSOD1d were significantly induced by 22.61 mM ZnSO₄. Disc diffusion assay showed that the four isoforms of OcicCuZnSOD1 made the killing zones smaller surrounding the CdCl₂-soaked filter discs. However, the reduction ratios of OcicCuZnSOD1a were the highest. These results implied that the four transcripts played roles in defense against CdCl₂-induced oxidative stress while OcicCuZnSOD1a had stronger antioxidant capacity.

Deciphering the transfers of antibiotic resistance genes under antibiotic exposure conditions: Driven by functional modules and bacterial community

Antibiotics can exert selective pressures on sludge as well as affect the emergence and spread of antibiotic resistance genes (ARGs). However, the underlying mechanisms of ARGs transfers are still controversial and not fully understood in sludge system. In present study, two anaerobic sequence batch reactors (ASBR) were constructed to investigate the development of ARGs exposed to two sulfonamide antibiotics (SMs, sulfadiazine SDZ and sulfamethoxazole SMX) with increasing concentrations. The abundance of corresponding ARGs and total ARGs obviously increased with presence of SMs. Functional analyses indicated that oxidative stress response, signal transduction and type IV secretion systems were triggered by SMs, which would promote ARGs transfers. Network analysis revealed 18 genera were possible hosts of ARGs, and their abundances increased with SMs. Partial least-squares path modeling suggested functional modules directly influenced mobile genetic elements (MGEs) as well as the ARGs might be driven by both functional modules and bacteria community, while bacteria community composition played a more key role. Sludge with refractory antibiotics (SDZ) may stimulate the relevant functions and shift the microbial composition to a greater extent, causing more ARGs to emerge and spread. The mechanisms of ARGs transfers are revealed from the perspective of functional modules and bacterial community in sludge system for the first time, and it could provide beneficial directions, such as oxidative stress reduction, cellular communication control, bacterial composition directional regulation, for ARGs spread controlling in the future.

The macronuclear genome of the Antarctic psychrophilic marine ciliate Euplotes focardii reveals new insights on molecular cold adaptation

The macronuclear (MAC) genomes of ciliates belonging to the genus Euplotes species are comprised of numerous small DNA molecules, nanochromosomes, each typically encoding a single gene. These genomes are responsible for all gene expression during vegetative cell growth. Here, we report the analysis of the MAC genome from the Antarctic psychrophile Euplotes focardii. Nanochromosomes containing bacterial sequences were not found, suggesting that phenomena of horizontal gene transfer did not occur recently, even though this ciliate species has a substantial associated bacterial consortium. As in other euplotid species, E. focardii MAC genes are characterized by a high frequency of translational frameshifting. Furthermore, in order to characterize differences that may be consequent to cold adaptation and defense to oxidative stress, the main constraints of the Antarctic marine microorganisms, we compared E. focardii MAC genome with those available from mesophilic Euplotes species. We focussed mainly on the comparison of tubulin, antioxidant enzymes and heat shock protein (HSP) 70 families, molecules which possess peculiar characteristic correlated with cold adaptation in E. focardii. We found that α-tubulin genes and those encoding SODs and CATs antioxidant enzymes are more numerous than in the mesophilic Euplotes species. Furthermore, the phylogenetic trees showed that these molecules are divergent in the Antarctic species. In contrast, there are fewer hsp70 genes in E. focardii compared to mesophilic Euplotes and these genes do not respond to thermal stress but only to oxidative stress. Our results suggest that molecular adaptation to cold and oxidative stress in the Antarctic environment may not only be due to particular amino acid substitutions but also due to duplication and divergence of paralogous genes.

Health Beneficial Properties of Grapevine Seed Extract and Its Influence on Selected Biochemical Markers in the Blood, Liver and Kidneys of Rattus norvegicus

Cadmium (Cd) is a heavy metal that occurs in all areas of the environment, including the food chain. In the body, it causes oxidative stress by producing free radicals that are harmful to the cells. Grape seed extract (GSE) contains a wide range of biologically active components that help to neutralize the adverse effects of free radicals. In this study, the effects of GSE prepared form semi-resistant grapevine cultivar Cerason, which is rich in phenolics, on biochemical markers of brown rats exposed to the effects of cadmium were monitored. GSE increased the plasma antioxidant activity and, in the kidneys and the liver, Cd content was significantly lowered by GSE co-administration. Accordingly, the increase in creatinine content and alanine aminotransferase activity and the decrease of catalase and superoxide dismutase activities caused by cadmium were slowed down by GSE co-administration. The results of this work reveal that grape seed extract offers a protective effect against the intake of heavy metals into the organism.

Response of the critically endangered Przewalski's gazelle (Procapra przewalskii) to selenium deprived environment

Selenium (Se) is an essential mineral nutrient for animals. Se deprivation can lead to many disorders and even death. This study investigated the response of Przewalski's gazelle (P. przewalskii) to Se-deprived environment. We found that Se deprivation in soil and forage not only influenced the mineral contents of the blood and hair in P. przewalskii, but also severely disrupted their blood parameters. We identified significant changes in the abundance of 146 proteins and 25 metabolites (P < 0.05) in serum, including the selenoproteins L8IG93 (glutathione peroxidase) and F4YD09 (Cu/Zn superoxide dismutase). Furthermore, the major known proteins and metabolites associated with the Se stress response in P. przewalskii were Cu/Zn superoxide dismutase, the vitamin K-dependent protein C, the C4b-binding protein alpha chain, complement component C7, lipase linoleic acid, peptidase D, thymidine, pseudo-uridine, L-phenylalanine, L-glutamine, PGA1, and 15-deoxy-delta-12,14-PGJ2. The main signaling pathways involved included complement and coagulation cascades, metabolic pathways, and stress granule formation. Our results indicate that the intake of Se-deficient forage elicited an oxidative stress response in P. przewalskii. These findings provide insights into the response mechanisms of this threatened gazelle to Se stress, and enable the development of conservation strategies to protect populations on the Qinghai-Tibetan Plateau. SIGNIFICANCE: This study is the first to point out the presence of oxidative stress in P. przewalskii in selenium-deficient areas through proteomics and metabolomics studies. These findings should prove helpful for conservation efforts aimed at P. przewalskii populations and maintenance of the integrity of their ecological environment.

Crystal structure of a Cu,Zn superoxide dismutase from the thermophilic fungus Chaetomium thermophilum

BACKGROUND

Thermophilic fungi have recently emerged as a promising source of thermostable enzymes. Superoxide dismutases are key antioxidant metalloenzymes with promising therapeutic effects in various diseases, both acute and chronic. However, structural heterogeneity and low thermostability limit their therapeutic efficacy.

OBJECTIVE

Although several studies from hypethermophilic superoxide dismutases (SODs) have been reported, information about Cu,Zn-SODs from thermophilic fungi is scarce. Chaetomium thermophilum is a thermophilic fungus that could provide proteins with thermophilic properties.

METHOD

The enzyme was expressed in Pichia pastoris cells and crystallized using the vapor-diffusion method. X-ray data were collected, and the structure was determined and refined to 1.56 Å resolution. Structural analysis and comparisons were carried out.

RESULTS

The presence of 8 molecules (A through H) in the asymmetric unit resulted in four different interfaces. Molecules A and F form the typical homodimer which is also found in other Cu,Zn-SODs. Zinc was present in all subunits of the structure while copper was found in only four subunits with reduced occupancy (C, D, E and F).

CONCLUSION

The ability of the enzyme to form oligomers and the elevated Thr:Ser ratio may be contributing factors to its thermal stability. Two hydrophobic residues that participate in interface formation and are not present in other CuZn-SODs may play a role in the formation of new interfaces and the oligomerization process. The CtSOD crystal structure reported here is the first Cu,Zn-SOD structure from a thermophilic fungus.

Mycoremediation of heavy metals: processes, mechanisms, and affecting factors

Industrial processes and mining of coal and metal ores are generating a number of threats by polluting natural water bodies. Contamination of heavy metals (HMs) in water and soil is the most serious problem caused by industrial and mining processes and other anthropogenic activities. The available literature suggests that existing conventional technologies are costly and generated hazardous waste that necessitates disposal. So, there is a need for cheap and green approaches for the treatment of such contaminated wastewater. Bioremediation is considered a sustainable way where fungi seem to be good bioremediation agents to treat HM-polluted wastewater. Fungi have high adsorption and accumulation capacity of HMs and can be potentially utilized. The most important biomechanisms which are involved in HM tolerance and removal by fungi are bioaccumulation, bioadsorption, biosynthesis, biomineralisation, bioreduction, bio-oxidation, extracellular precipitation, intracellular precipitation, surface sorption, etc. which vary from species to species. However, the time, pH, temperature, concentration of HMs, the dose of fungal biomass, and shaking rate are the most influencing factors that affect the bioremediation of HMs and vary with characteristics of the fungi and nature of the HMs. In this review, we have discussed the application of fungi, involved tolerance and removal strategies in fungi, and factors affecting the removal of HMs.

Garlic Alleviates the Injurious Impact of Cyclosporine-A in Male Rats through Modulation of Fibrogenic and Steroidogenic Genes

This work aimed to study the hepato-testicular protective effect of garlic in rats treated with cyclosporine A (CsA). Forty male Westar albino rats were randomly distributed in five groups (8 rats each): control, olive oil, garlic, CsA, and CsA co-treated with garlic. CsA induced an upsurge in the alanine transaminase, aspartate transaminase, and alkaline phosphatase levels and decreased albumin and total protein levels, expression of superoxide dismutase (SOD) gene, serum testosterone, triiodothyronine, and thyroxine levels compared to the control group. Additionally, there was an increase in the cholesterol, triglyceride, and low-density lipoprotein levels and a substantial reduction in the high-density lipoprotein levels compared to the control groups. Histopathological investigation of the liver showed abnormalities like hepatic cell degeneration, congestion of blood vessels, and highly active Kupffer cells in the CsA group. Histopathological examination of testes showed damaged seminiferous tubules, stoppage of the maturation of spermatogonia, and the presence of cells with irregular dense nuclei in the lumina of some tubules. For the groups treated with garlic, mitigation of the damage caused by CsA in the liver and testes, liver function tests, lipid profiles, and hormones was seen along with improved gene expression of SOD and steroidogenesis genes, and decreased gene expression of collagen I-α1 and transforming growth factor-1β. Conclusively, garlic had a positive impact on CsA-induced hepatic and sperm toxicity. It is recommended that garlic should be supplemented in transplant treatments using CsA to alleviate the cyclosporin-induced oxidative injuries and other harmful effects.

Accelerated senescence as a cost of reproduction: Testing associations between oxidative stress and reproductive effort in rural and urban women

OBJECTIVES

Oxidative stress is hypothesized to contribute to age-related somatic deterioration. Both reproductive and ecological context may necessitate tradeoffs that influence this outcome. We examined whether measures of lifetime reproductive effort were related to levels of oxidative stress biomarkers in peri- and post-menopausal women and whether associations were moderated by rural or urban residence.

METHODS

We surveyed 263 healthy women (age 62.1 ± 10.0 SD) from rural (N = 161) and urban Poland (N = 102), collecting sociodemographic data and urine samples to analyze biomarkers of oxidative stress (8-oxo-2'-deoxyguanosine, 8-OHdG) and antioxidative defense (copper-zinc superoxide dismutase, Cu-Zn SOD). Linear regression models, adjusted for residence, were used to test for associations between reproductive effort and 8-OHdG and Cu-Zn SOD.

RESULTS

Univariate models demonstrated significant associations between gravidity and the biomarkers of oxidative stress (8-OHdG: R² = 0.042, P ≤ .001; Cu-Zn SOD: R² = 0.123, P ≤ .001). Multivariate models incorporating potential confounding variables, as well as cross-product interaction terms, indicated that gravidity was associated with 8-OHdG (P < .01, R² _adj = 0.067) and Cu-Zn SOD (P = .01, R² _adj = 0.159). Residence (ie, urban vs rural) did not significantly moderate the associations between the biomarkers and reproductive effort.

CONCLUSIONS

Higher lifetime reproductive effort contributes to increases in oxidative stress and antioxidative defenses. Our results provide evidence of potential mechanisms underlying the physiological tradeoffs influencing senescence for women with high reproductive effort. We illustrate the value of applying an evolutionary perspective to elucidate variation in human health and senescence.

Dietary reduced glutathione supplementation can improve growth, antioxidant capacity, and immunity on Chinese mitten crab, Eriocheir sinensis

Eriocheir sinensis is an important aquaculture species in China, and its yield and quality are threatened by oxidative stress caused by deteriorating water conditions. Reduced glutathione (GSH) is an endogenous antioxidant, but whether dietary GSH can increase the resistance of E. sinensis to environmental stress remains unclear. Therefore, in this study, crabs were fed with dietary GSH (0, 300, 600, 900, and 1200 mg/kg diet weight) for up to 10 weeks to determine the effects of different dietary GSH concentrations on growth, antioxidant capacity, and immunity of E. sinensis. The results showed that the weight gain rate and survival rate increased significantly as dietary GSH levels increased from 0 to 900 mg/kg, but decreased at 1200 mg/kg. Compared with the control group, the diet supplemented with 900 mg/kg GSH not only increased the concentration of GSH in the haemolymph and hepatopancreas, but also enhanced the activity of glutathione peroxidase (GSH-Px) (p < 0.05). Diets supplemented with 600 or 900 mg/kg GSH significantly increased the enzymes activities of superoxide dismutase (SOD), lysozyme (LZM), alkaline phosphatase, and acid phosphatase, and significantly decreased the content of malondialdehyde. To understand the changes in the activity of these enzymes further, the expression of related genes was detected. Diets supplemented with 600 or 900 mg/kg GSH significantly upregulated the genes expressions of cytosolic manganese SOD, mitochondrial manganese SOD, copper, zinc-SOD, GSH-Px, LZM, and prophenoloxidase activating factor, and significantly down regulated the expression of Toll-like receptor 1, Toll-like receptor 2, Dorsal, and the myeloid differentiation factor 88. However, a diet supplemented with 1200 mg/kg GSH decreased those positive indicators. Overall, our results demonstrated that an appropriate diet supplemented with 600 or 900 mg/kg GSH enhances antioxidant capacity and immunity, which will enhance the general health of E. sinensis.

Stress-mediated generation of deleterious ROS in healthy individuals - role of cytochrome c oxidase

Psychosocial stress is known to cause an increased incidence of coronary heart disease. In addition, multiple other diseases like cancer and diabetes mellitus have been related to stress and are mainly based on excessive formation of reactive oxygen species (ROS) in mitochondria. The molecular interactions between stress and ROS, however, are still unknown. Here we describe the missing molecular link between stress and an increased cellular ROS, based on the regulation of cytochrome c oxidase (COX). In normal healthy cells, the "allosteric ATP inhibition of COX" decreases the oxygen uptake of mitochondria at high ATP/ADP ratios and keeps the mitochondrial membrane potential (ΔΨm) low. Above ΔΨm values of 140 mV, the production of ROS in mitochondria increases exponentially. Stress signals like hypoxia, stress hormones, and high glutamate or glucose in neurons increase the cytosolic Ca2+ concentration which activates a mitochondrial phosphatase that dephosphorylates COX. This dephosphorylated COX exhibits no allosteric ATP inhibition; consequently, an increase of ΔΨm and ROS formation takes place. The excess production of mitochondrial ROS causes apoptosis or multiple diseases.

Ferric nitrosylated myoglobin catalyzes peroxynitrite scavenging

Myoglobin (Mb), generally taken as the molecular model of monomeric globular heme-proteins, is devoted: (i) to act as an intracellular oxygen reservoir, (ii) to transport oxygen from the sarcolemma to the mitochondria of vertebrate heart and red muscle cells, and (iii) to act as a scavenger of nitrogen and oxygen reactive species protecting mitochondrial respiration. Here, the first evidence of ^·NO inhibition of ferric Mb- (Mb(III)) mediated detoxification of peroxynitrite is reported, at pH 7.2 and 20.0 °C. ^·NO binds to Mb(III) with a simple equilibrium; the value of the second-order rate constant for Mb(III) nitrosylation (i.e., ^·NOk_on) is (6.8 ± 0.7) × 10⁴ M^-1 s^-1 and the value of the first-order rate constant for Mb(III)-NO denitrosylation (i.e., ^·NOk_off) is 3.1 ± 0.3 s^-1. The calculated value of the dissociation equilibrium constant for Mb(III)-NO complex formation (i.e., ^·NOk_off/^·NOk_on = (4.6 ± 0.7) × 10^-5 M) is virtually the same as that directly measured (i.e., ^·NOK = (3.8 ± 0.5) × 10^-5 M). In the absence of ^·NO, Mb(III) catalyzes the conversion of peroxynitrite to NO₃^-, the value of the second-order rate constant (i.e., ^Pk_on) being (1.9 ± 0.2) × 10⁴ M^-1 s^-1. However, in the presence of ^·NO, Mb(III)-mediated detoxification of peroxynitrite is only partially inhibited, underlying the possibility that also Mb(III)-NO is able to catalyze the peroxynitrite isomerization, though with a reduced rate (^Pk_on* = (2.8 ± 0.3) × 10³ M^-1 s^-1). These data expand the multiple roles of ^·NO in modulating heme-protein actions, envisaging a delicate balancing between peroxynitrite and ^·NO, which is modulated through the relative amount of Mb(III) and Mb(III)-NO.

Formation, nutritional value, and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans

Black garlic (BG) is essentially a processed food and obtained through the transformation of fresh garlic (FG) (Allium sativum L.) via a range of chemical reactions (including the Maillard reaction) and microbial fermentation. This review provides the up-to-date knowledge of the dynamic and complicated changes in major components during the conversion of FG to BG, including moisture, lipids, carbohydrates (such as sugars), proteins, organic acids, organic sulfur compounds, alkaloids, polyphenols, melanoidins, 5-hydroxymethylfurfural, vitamins, minerals, enzymes, and garlic endophytes. The obtained evidence confirms that BG has several advantages over FG in certain product attributes and biological properties (especially antioxidant activity), and the factors affecting the quality of BG include the type and characteristics of FG and processing technologies and methods (especially pretreatments, and processing temperature and humidity). The interactions among garlic components, and between garlic nutrients and microbes, as well as the interplay between pretreatment and main manufacturing process, all determine the sensory and nutritional qualities of BG. Before BG is marketed as a novel snack or functional food, more research is required to fill the knowledge gaps related to quantitative monitoring of the changes in metabolites (especially those taste-active and/or biological-active substances) during BG manufacturing to maximize BG's antioxidant, anticancer, antiobesity, anti-inflammatory, immunostimulatory, anti-allergic, hepatoprotective, cardioprotective and oxidative stress-/hangover syndrome-reducing functions, and beneficial effects on memory/nervous systems. Assessments of the quality, efficacy, and safety of BG should be performed considering the impacts of BG production conditions, postproduction handling, and intake methods.

The Significance of Reactive Oxygen Species and Antioxidant Defense System in Plants: A Concise Overview

In plants, there is a complex and multilevel network of the antioxidative system (AOS) operating to counteract harmful reactive species (RS), the foremost important of which are reactive oxygen species (ROS), and maintain homeostasis within the cell. Specific AOSs for plant cells are, first and foremost, enzymes of the glutathione-ascorbate cycle (Asc-GSH), followed by phenolic compounds and lipophilic antioxidants like carotenoids and tocopherols. Evidence that plant cells have excellent antioxidative defense systems is their ability to survive at H₂O₂ concentrations incompatible with animal cell life. For the survival of stressed plants, it is of particular importance that AOS cooperate and participate in redox reactions, therefore, providing better protection and regeneration of the active reduced forms. Considering that plants abound in antioxidant compounds, and humans are not predisposed to synthesize the majority of them, new fields of research have emerged. Antioxidant potential of plant compounds has been exploited for anti-aging formulations preparation, food fortification and preservation but also in designing new therapies for diseases with oxidative stress implicated in etiology.

The first report of a tetra-azide bound mononuclear cobalt(iii) complex and its comparative biomimetic catalytic activity with tri-azide bound cobalt(iii) compounds

Three new azide-bound cobalt(iii) complexes derived from three different triamines with extensive hydrogen bonded supramolecular chain structures and the role of their structural factors in oxidative coupling of o-aminophenols have been reported.

Understanding of ROS-Inducing Strategy in Anticancer Therapy

Redox homeostasis is essential for the maintenance of diverse cellular processes. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells as a result of hypermetabolism, but the redox balance is maintained in cancer cells due to their marked antioxidant capacity. Recently, anticancer therapies that induce oxidative stress by increasing ROS and/or inhibiting antioxidant processes have received significant attention. The acceleration of accumulative ROS disrupts redox homeostasis and causes severe damage in cancer cells. In this review, we describe ROS-inducing cancer therapy and the anticancer mechanism employed by prooxidative agents. To understand the comprehensive biological response to certain prooxidative anticancer drugs such as 2-methoxyestradiol, buthionine sulfoximine, cisplatin, doxorubicin, imexon, and motexafin gadolinium, we propose and visualize the drug-gene, drug-cell process, and drug-disease interactions involved in oxidative stress induction and antioxidant process inhibition as well as specific side effects of these drugs using pathway analysis with a big data-based text-mining approach. Our review will be helpful to improve the therapeutic effects of anticancer drugs by providing information about biological changes that occur in response to prooxidants. For future directions, there is still a need for pharmacogenomic studies on prooxidative agents as well as the molecular mechanisms underlying the effects of the prooxidants and/or antioxidant-inhibitor agents for effective anticancer therapy through selective killing of cancer cells.

Anticonvulsant and Neuroprotective Effects of Paeonol in Epileptic Rats

Paeonol is the main active compound in the root bark extract of the peony tree, and it has antioxidative and anti-inflammatory effects. Recent studies have reported the neuroprotective effects of paeonol including its capacity in improving impaired memory. However, the effect of paeonol on epilepsy is yet to be demystified. We aimed to investigate the therapeutic effect of paeonol in epilepsy and its relationship with oxidative stress damage and neuronal loss in the rat brain to reveal the underlying mechanisms of epileptic seizures. A rat model for chronic epilepsy was established, and the seizure scores of the rats in different groups were recorded. The seizure duration and the seizure onset latency were used to evaluate the anticonvulsant effects of paeonol. Terminal deoxynucleotidyl transferase dUTP nick end-labeling staining, Nissl staining and H/E staining were used to evaluate the effects of paeonol on neuronal loss and apoptosis in epileptic rats. The colorimetric assessment of malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, catalase activity and total antioxidant capacity of paeonol were used in assessing paeonol's effect on oxidative stress in epileptic rats. Evaluation of Caspase-3 mRNA and protein expression levels were determined using western blot and quantitative real-time (RT-q)PCR. In this study, we found that paeonol reduced the seizure scores of epileptic rats and attenuated the duration and onset latency of seizures. Paeonol can also increase the activities of total antioxidant capacity, SOD and catalase activity and reduce MDA content as well. This suggests that paeonol can improve the level of oxidative stress in rats. More significantly, paeonol can improve neuronal loss and apoptosis in epileptic rats. These results indicate that paeonol has anticonvulsant and neuroprotective effects in epileptic rats. This effect may be caused by reducing oxidative stress.

Chronomics of Circulating Plasma Lipid Peroxides and Antioxidant Enzymes in Renal Stone Formers

The chronome of lipid peroxidation and anti-oxidant defense mechanisms may relate to the efficacy and management of time qualified preventive therapeutic and dietary interventions. One hundred renal stone patients, 20-60 years of age, and 50 clinically healthy volunteers, 21-45 years, were synchronized for 1 week with diurnal activity from 06:00 to 22:00 and nocturnal rest. All subjects took their usual meals three times daily (breakfast around 08:30, lunch around 13:00, and dinner around 20:30) with usual fluid intake. Drugs known to affect free radical system were not taken. Blood samples were collected at 6-h intervals for 24-h under standardized, presumably 24-h synchronized conditions. Determinations included plasma lipid peroxides, in terms of malondialdehyde (MDA) and blood superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase (CAT) activities. A marked circadian variation was demonstrated for each studied variable by population-mean cosinor in renal stone patients and healthy participants (p < 0.001). By comparison to healthy subjects, parameter tests indicate that the stone formers had a higher MESOR of MDA, but a lower MESOR of SOD, GPx, GR and CAT. Furthermore, the patients also differed from the healthy controls in terms of their circadian amplitude and acrophase (tested jointly) of all variables (p < 0.001). Mapping the broader time structure with multifrequency circadian characteristics of oxidants and anti-oxidants is needed for exploring their role as marker in the treatment and management of urolithiasis.

Molecular characterization of manganese superoxide dismutase (MnSOD) from sterlet Acipenser ruthenus and its responses to Aeromonas hydrophila challenge and hypoxia stress

A novel gene encoding the mitochondrial manganese superoxide dismutase from sterlet Acipenser ruthenus (Ar-MnSOD) was cloned. The full-length cDNA of MnSOD was of 1040 bp with a 672 bp open reading frame encoding 224 amino acids and the deduced amino acid sequence was located in mitochondria. Sequence comparison analysis showed that Ar-MnSOD was highly similar to MnSODs of invertebrates and vertebrates, especially those of freshwater Cyprinidae fishes and mammals. Phylogenetic analysis revealed that Ar-MnSOD was distant from MnSODs of other fishes and belonged to the family of mitochondrial MnSODs (mMnSOD). Consistently, Ar-MnSOD was located in mitochondria. The 3D structure of Ar-MnSOD was predicted and the overall structure was similar to that of MnSODs of humans and the bay scallop Argopecten irradians. In addition, mRNA of Ar-MnSOD was detected to extensively express in all tissues, with the highest level in brain and liver. Spleen and head kidney inoculation of Aeromonas hydrophila led to a significant up-regulation of Ar-MnSOD transcript levels. Also, hypoxia induced a transient increase in transcription of Ar-MnSOD in the gills, but not in the heart and brain, suggesting metabolic depression in these vital organs. The results also implied the anti-hypoxia properties of Ar-MnSOD in the related tissues and proved that Ar-MnSOD was involved in the stress response and (anti) oxidative processes triggered by hypoxia. The results indicated that Ar-MnSOD is induced upon A. hydrophila infection and hypoxia, consistent with its role in host immune and stress-induced anti-oxidative responses.

Effects of UV-B radiation on the survival, egg hatchability and transcript expression of antioxidant enzymes in a high-temperature adapted strain of Neoseiulus barkeri

Biological control of spider mites in hot and dry weather is a serious technical issue. A high-temperature adapted strain (HTAS) of the predatory mite Neoseiulus barkeri Hughes was selected from its conventional strain (CS), via long-term heat acclimation and frequent heat hardenings in our previous studies. However, the environment of high temperature is usually associated with enhanced ultraviolet (UV) radiation. In the present study, the physiological effects of UV-B radiation on survival rate and egg damage of N. barkeri were investigated, as well as the activities and expression profiles of antioxidant enzymes to UV-B radiation stress. UV-B radiation had deleterious effects on egg hatchability and survival of N. barkeri. Adults of the HTAS strain were less UV-B resistant than those of the CS strain; they also had lower levels of enzymatic activity of superoxide dismutase (SOD) and catalase against oxidative damage and weaker upregulation of SOD genes. The mRNA expression of three SOD genes of CS adult females immediately increased whereas that of HTAS showed almost no difference under UV-B stress for 1 h. The results showed the HTAS of N. barkeri had lower fitness under UV-B stress compared with the CS of N. barkeri. These results suggested that long-term heat acclimation may exert a profound impact on the developmental physiology of N. barkeri.

Steered molecular dynamic simulations of conformational lock of Cu, Zn-superoxide dismutase

The conformational lock was a bio-thermodynamic theory to explain the characteristics of interfaces in oligomeric enzymes and their effects on catalytic activity. The previous studies on superoxide dismutases (Cu, Zn-SODs) showed that the dimeric structure contributed to the high catalytic efficiency and the stability. In this study, steered molecular dynamics simulations were used firstly to study the main interactions between two subunits of Cu, Zn-SODs. The decomposition process study showed that there were not only four pairs of hydrogen bonds but also twenty-five residue pairs participating hydrophobic interactions between A and B chains of SOD, and van der Waals interactions occupied a dominant position among these residue pairs. Moreover, the residue pairs of hydrogen bonds played a major role in maintaining the protein conformation. The analysis of the energy and conformational changes in the SMD simulation showed that there were two groups (two conformational locks) between A and B chains of SOD. The first group consisted of one hydrogen-bond residues pair and seven hydrophobic interactions residues pairs with a total average energy of −30.10 KJ/mol, and the second group of three hydrogen-bond residues pair and eighteen hydrophobic interactions residues pairs formed with a total average energy of −115.23 KJ/mol.

Therapeutic effects of the rhSOD2-Hirudin fusion protein on bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis and high mortality, posing a major threat to human health. Increased levels of inflammatory cytokines, reactive oxygen species and coagulation cascade have been extensively reported in IPF. We previously fused Hirudin and human manganese superoxide dismutase (hSOD2) to generate a dual-feature fusion protein, denoted as rhSOD2-Hirudin fusion protein. In this study, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) and Hydroxyproline (HYP) assays were used to investigate the effects of rhSOD2-Hirudin protein on thrombin-induced fibroblast proliferation and collagen accumulation in vitro. Subsequently, the mice model of pulmonary fibrosis induced by bleomycin was used for evaluating the anti-inflammatory and anti-fibrotic effects of rhSOD2-Hirudin protein in vivo. Results showed that rhSOD2-Hirudin protein could inhibit the proliferation of fibroblasts and reduce the HYP production in vitro by inhibiting the activity of thrombin. In vivo experiments showed that lung inflammation and fibrosis were significantly decreased in rhSOD2-Hirudin protein-treated mice. Furthermore, rhSOD2-Hirudin protein treatment reduced profibrotic protein and gene expression while reducing the number of inflammatory cells in the lung. In conclusion, rhSOD2-Hirudin protein can effectively attenuate pulmonary fibrosis in vitro and in vivo, mainly by inhibiting the activity of thrombin meanwhile increasing SOD2 levels prevent cells from being damaged by reactive oxygen species, thereby mitigating IPF progression. This study provided important information on the feasibility and efficacy of rhSOD2-Hirudin protein as a novel therapeutic agent for IPF.

Eucalyptol promotes lung repair in mice following cigarette smoke-induced emphysema

BACKGROUND

Eucalyptol is a monoterpenoid oil present in many plants, principally the Eucalyptus species, and has been reported to have anti-inflammatory and antioxidative effects.

HYPOTHESIS/PURPOSE

Since the potential effect of eucalyptol on mouse lung repair has not yet been studied, and considering that chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide, the aim of this study was to investigate eucalyptol treatment in emphysematous mice.

STUDY DESIGN

Male mice (C57BL/6) were divided into the following groups: control (sham-exposed), cigarette smoke (CS) (mice exposed to 12 cigarettes a day for 60 days), CS + 1 mg/ml (CS mice treated with 1 mg/ml eucalyptol for 60 days), and CS + 10 mg/ml (CS mice treated with 10 mg/ml eucalyptol for 60 days). Mice in the CS and control groups received vehicle for 60 days. Eucalyptol (or the vehicle) was administered via inhalation (15 min/daily). Mice were sacrificed 24 h after the completion of the 120-day experimental procedure.

METHODS

Histology and additional lung morphometric analyses, including analysis of mean linear intercept (Lm) and volume density of alveolar septa (Vv[alveolar septa]) were performed. Biochemical analyses were also performed using colorimetric assays for myeloperoxidase (MPO), malondialdehyde (MDA), and superoxide dismutase (SOD) activity, in addition to using ELISA kits for the determination of inflammatory marker levels (tumor necrosis factor alpha [TNF-α], interleukin-1 beta [IL-1β], interleukin 6 [IL-6], keratinocyte chemoattractant [KC], and tumor growth factor beta 1 [TGF-β1]). Finally, we investigated protein levels by western blotting (nuclear factor (erythroid-derived 2)-like 2 [Nrf2], nuclear factor kappa B [NF-κB], matrix metalloproteinase 12 [MMP-12], tissue inhibitor of matrix metalloproteinase 1 [TIMP-1], neutrophil elastase [NE], and elastin).

RESULTS

Eucalyptol promoted lung repair at the higher dose (10 mg/ml), with de novo formation of alveoli, when compared to the CS group. This result was confirmed with Lm and Vv[alveolar septa] morphometric analyses. Moreover, collagen deposit around the peribronchiolar area was reduced with eucalyptol treatment when compared to the CS group. Eucalyptol also reduced all inflammatory (MPO, TNF-α, IL-1β, IL-6, KC, and TGF-β1) and redox marker levels (MDA) when compared to the CS group (at least p < 0.05). In general, 10 mg/ml eucalyptol was more effective than 1 mg/ml and, at both doses, we observed an upregulation of SOD activity when compared to the CS group (p < 0.001). Eucalyptol upregulated elastin and TIMP-1 levels, and reduced neutrophil elastase (NE) levels, when compared to the CS group.

CONCLUSION

In summary, eucalyptol promoted lung repair in emphysematous mice and represents a potential therapeutic phytomedicine in the treatment of COPD.

Alfalfa polysaccharide prevents H2O2-induced oxidative damage in MEFs by activating MAPK/Nrf2 signaling pathways and suppressing NF-κB signaling pathways

Alfalfa polysaccharide (APS) is a bioactive component extracted from alfalfa that exhibits potent antioxidant properties. However, the cellular and molecular mechanisms underlying these properties remain unclear. To explore the molecular mechanism by which APS exerts antioxidant effects, an H2O2-induced oxidative stress mouse embryonic fibroblast (MEF) model was established. Cell proliferation, antioxidant enzyme activity, immune cytokine expression, and related protein expression were examined in APS-supplemented or non-supplemented conditions. The results suggested that APS strengthened the antioxidative capacity of MEFs, increasing cell proliferation, superoxide dismutase activity (SOD), and the total antioxidant capacity (T-AOC). In addition, APS reduced the secretion of interleukin (IL)-6 and IL-8 as well as expression of the proinflammatory gene retinoic acid-inducible gene I (RIG-I). APS was also able to activate the mitogen-activated protein kinase (MAPK) pathway, which promoted the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus. However, expression of nuclear factor-κB (NF-κB) was decreased after APS treatment. Overall, these results suggest that APS relieves H2O2-induced oxidative stress in MEFs by activating MAPK/Nrf2 signaling and suppressing NF-κB signaling. To the best of our knowledge, this is the first study to link APS with MAPK/Nrf2, NF-κB and RIG-I, thus providing new perspectives regarding the mechanisms of the antioxidant activity of APS.

The Double Life of Group B Streptococcus: Asymptomatic Colonizer and Potent Pathogen

Group B streptococcus (GBS) is a β-hemolytic gram-positive bacterium that colonizes the lower genital tract of approximately 18% of women globally as an asymptomatic member of the gastrointestinal and/or vaginal flora. If established in other host niches, however, GBS is highly pathogenic. During pregnancy, ascending GBS infection from the vagina to the intrauterine space is associated with preterm birth, stillbirth, and fetal injury. In addition, vertical transmission of GBS during or after birth results in life-threatening neonatal infections, including pneumonia, sepsis, and meningitis. Although the mechanisms by which GBS traffics from the lower genital tract to vulnerable host niches are not well understood, recent advances have revealed that many of the same bacterial factors that promote asymptomatic vaginal carriage also facilitate dissemination and virulence. Furthermore, highly pathogenic GBS strains have acquired unique factors that enhance survival in invasive niches. Several host factors also exist that either subdue GBS upon vaginal colonization or alternatively permit invasive infection. This review summarizes the GBS and host factors involved in GBS's state as both an asymptomatic colonizer and an invasive pathogen. Gaining a better understanding of these mechanisms is key to overcoming the challenges associated with vaccine development and identification of novel strategies to mitigate GBS virulence.

Molecular characterization and expression analysis of iron superoxide dismutase gene from Pseudochlorella pringsheimii (Trebouxiophyceae, Chlorophyta)

The FeSOD isoforms of Pseudochlorella pringsheimii were identified, a preliminary characterization of the enzyme was conducted, and the relationship among the FeSOD gene from P. pringsheimii and that of other organisms was examined. The FeSOD has an open reading frame of 612 bp that encodes 203 deduced amino acids with a molecular mass of 23 kDa. Expression of the recombinant FeSOD gene was done successfully in Escherichia coli. The purified FeSOD has a specific enzyme activity that reached 688 U mg^-1 protein (in vitro assay). Alkaline conditions showed the highest activity for the recombinant FeSOD. Moreover, it showed a relative thermostability up to 50 °C, while at 50 and 70 °C, the activity was reduced by 32 and 68%, respectively, after 1 h as compared to the maximum. Phylogenetic analysis revealed three main clusters i.e., the prokaryotic Cyanophyta, bacteria, and the eukaryotic Chlorophyta intermingled with plant species and a dinoflagellate. P. pringsheimii was closely grouped with Chlorella pyrenoidosa, however, other species showed a relative disparity. Alignment of FeSOD gene sequences of the different species showed many conserved regions which could be used for FeSOD sequences among unexplored species and may be useful for the taxonomy of the revised coccoid Chlorella species.