Reactive Oxygen Species: the Dual Role in Physiological and Pathological Conditions of the Human Body

Supplementation of Plant-Based Cryopreservation Medium with Folic Acid Conserves the Quality of Bulk Post-Thawed Spermatozoa

The current study evaluated the effects of cryopreservation medium supplementation with folic acid as an antioxidant on post-thawed semen quality in bulk. Semen samples were collected from four proved Iranian Mahabadi bulls and diluted in extender containing 1.5% soybean lecithin. The diluted semen was assigned into six parts and supplemented with different doses of folic acid as follows: FA0 (extender without folic acid), FA0.05, FA0.1, FA0.2, FA0.4, and FA0.8 (extenders containing 0.05, 0.1, 0.2, 0.4, and 0.8 mM folic acid, respectively). Then, the semen samples were cryopreserved in liquid nitrogen. Sperm motility and velocity parameters, membrane integrity, abnormal morphology, viability, and lipid peroxidation were evaluated after thawing. In the results, FA0.05 presented higher (p≤0.05) total motility, progressive motility, membrane integrity, and viability and lower lipid peroxidation compared to other groups. Abnormal morphology was not affected (p>0.05) by treatments. In conclusion, supplementation of cryopreservation medium with 0.05 mM folic acid is a helpful method to conserve the quality of post-thawed semen in bulk.

Dopaminergic Receptors as Neuroimmune Mediators in Experimental Autoimmune Encephalomyelitis

The dopaminergic system plays an essential role in maintaining homeostasis between the central nervous system (CNS) and the immune system. Previous studies have associated imbalances in the dopaminergic system to the pathogenesis of multiple sclerosis (MS). Here, we examined the protein levels of dopaminergic receptors (D1R and D2R) in different phases of the experimental autoimmune encephalomyelitis (EAE) model. We also investigated if the treatment with pramipexole (PPX)-a dopamine D2/D3 receptor-preferring agonist-would be able to prevent EAE-induced motor and mood dysfunction, as well as its underlying mechanisms of action. We report that D2R immunocontent is upregulated in the spinal cord of EAE mice 14 days post-induction. Moreover, D1R and D2R immunocontents in lymph nodes and the oxidative damage in the spinal cord and striatum of EAE animals were significantly increased during the chronic phase. Also, during the pre-symptomatic phase, axonal damage in the spinal cord of EAE mice could already be found. Surprisingly, therapeutic treatment with PPX failed to inhibit the progression of EAE. Of note, PPX treatment inhibited EAE-induced depressive-like while failed to inhibit anhedonic-like behaviors. We observed that PPX treatment downregulated IL-1β levels and increased BNDF content in the spinal cord after EAE induction. Herein, we show that a D2/D3 receptor-preferred agonist mitigated EAE-induced depressive-like behavior, which could serve as a new possibility for further clinical trials on treating depressive symptoms in MS patients. Thus, we infer that D2R participates in the crosstalk between CNS and immune system during autoimmune and neuroinflammatory response induced by EAE, mainly in the acute and chronic phase of the disease.

The Antioxidant Effect of Small Extracellular Vesicles Derived from Aloe vera Peels for Wound Healing

BACKGROUND

Extracellular vesicles (EVs) derived from plants have emerged as potential candidates for cosmetic and therapeutic applications. In this study, we isolated EVs from Aloe vera peels (A-EVs) and investigated the antioxidant and wound healing potential of A-EVs.

METHODS

A-EVs were isolated by ultracentrifugation and tangential flow filtration and were characterized using transmission electron microscopy, nanoparticle tracking analysis. The cytotoxicity and cellular uptake of A-EVs were investigated by WST-1 assay and flow cytometry. The antioxidant effect of A-EVs was evaluated by superoxide dismutase (SOD) activity assay and cellular antioxidant activity (CAA) assay. The wound healing potential was assessed by in vitro scratch assay using human keratinocytes (HaCaT) and fibroblasts (HDF). The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and their associated genes was analyzed by quantitative RT-PCR.

RESULTS

A-EVs displayed a round shape and had diameters from 50 to 200 nm. A-EVs showed good cytocompatibility on human skin cells and were internalized into HaCaT cells via clathrin-, caveolae-mediated endocytosis, and membrane fusion. The SOD activity and CAA assays exhibited that A-EVs had antioxidant activity and reduced intracellular ROS levels in H2O2-treated HaCaT cells in a dose-dependent manner. A scratch assay showed that A-EVs enhanced the migration ability of HaCaT and HDF. Moreover, A-EVs significantly upregulated the mRNA expression of Nrf2, HO-1, CAT, and SOD genes in H2O2-treated HaCaT cells. Our findings reveal that A-EVs could activate the antioxidant defense mechanisms and wound healing process via the Nrf2 activation.

CONCLUSION

Overall results suggest that the A-EVs are promising as a potential agent for skin regeneration.

Assessment and Establishment of Correlation between Reactive Oxidation Species, Citric Acid, and Fructose Level in Infertile Male Individuals: A Machine-Learning Approach

Background:

Biochemical complexity of seminal plasma and obesity has an important role in male infertility (MI); so far, it has not been possible to provide evidence of clinical significance for all of them.

Aims:

Our goal here is to evaluate the correlation between biochemical markers with semen parameters, which might play a role in MI.

Study Setting and Design:

We enlisted 100 infertile men as patients and 50 fertile men as controls to evaluate the sperm parameters and biochemical markers in ascertaining MI.

Materials and Methods:

Semen analyses, seminal fructose, citric acid, and reactive oxidation species (ROS) were measured in 100 patients and 50 controls.

Statistical Analysis:

Descriptive statistics, an independent t-test, Pearson correlation, and machine-learning approaches were used to integrate the various biochemical and seminal parameters measured to quantify the inter-relatedness between these measurements.

Results:

Pearson correlation results showed a significant positive correlation between body mass index (BMI) and fructose levels. Citric acid had a positive correlation with sperm count, morphology, motility, and volume but displayed a negative correlation with BMI and basal metabolic rate (BMR). However, BMI and BMR had a positive correlation with ROS. Sperm count, morphology, and motility were negative correlations with ROS. The machine-learning approach detected that pH was the most critical parameter with an inverse effect on citric acid, and BMI and motility were the most critical parameter for ROS.

Conclusion:

We recommend that evaluation of biochemical markers of seminal fluid may benefit in understanding the etiology of MI based on the functionality of accessory glands and ROS levels.

A homozygous nonsense mutation in DCBLD2 is a candidate cause of developmental delay, dysmorphic features and restrictive cardiomyopathy

DCBLD2 encodes discodin, CUB and LCCL domain-containing protein 2, a type-I transmembrane receptor that is involved in intracellular receptor signalling pathways and the regulation of cell growth. In this report, we describe a 5-year-old female who presented severe clinical features, including restrictive cardiomyopathy, developmental delay, spasticity and dysmorphic features. Trio-whole-exome sequencing and segregation analysis were performed to identify the genetic cause of the disease within the family. A novel homozygous nonsense variant in the DCBLD2 gene (c.80G > A, p.W27*) was identified as the most likely cause of the patient's phenotype. This nonsense variant falls in the extracellular N-terminus of DCBLD2 and thus might affect proper protein function of the transmembrane receptor. A number of in vitro investigations were performed on the proband's skin fibroblasts compared to normal fibroblasts, which allowed a comprehensive assessment resulting in the functional characterization of the identified DCBLD2 nonsense variant in different cellular processes. Our data propose a significant association between the identified variant and the observed reduction in cell proliferation, cell cycle progression, intracellular ROS, and Ca2 + levels, which would likely explain the phenotypic presentation of the patient as associated with lethal restrictive cardiomyopathy.

Dipeptidyl Peptidase (DPP)-IV Inhibitors with Antioxidant Potential Isolated from Natural Sources: A Novel Approach for the Management of Diabetes

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia that is predominantly caused by insulin resistance or impaired insulin secretion, along with disturbances in carbohydrate, fat and protein metabolism. Various therapeutic approaches have been used to treat diabetes, including improvement of insulin sensitivity, inhibition of gluconeogenesis, and decreasing glucose absorption from the intestines. Recently, a novel approach has emerged using dipeptidyl peptidase-IV (DPP-IV) inhibitors as a possible agent for the treatment of T2DM without producing any side effects, such as hypoglycemia and exhaustion of pancreatic β-cells. DPP-IV inhibitors improve hyperglycemic conditions by stabilizing the postprandial level of gut hormones such as glucagon-like peptide-1, and glucose-dependent insulinotropic polypeptides, which function as incretins to help upregulate insulin secretion and β-cell mass. In this review, we summarized DPP-IV inhibitors and their mechanism of inhibition, activities of those isolated from various natural sources, and their capacity to overcome oxidative stress in disease conditions.

Poly adenosine diphosphate-ribosylation, a promising target for colorectal cancer treatment

The development of colorectal cancer (CRC) can result from changes in a variety of cellular systems within the tumor microenvironment. Particularly, it is primarily associated with genomic instability that is the gradual accumulation of genetic and epigenetic changes consisting of a characteristic set of mutations crucial for pathways in CRC progression. Based on this background, the potential to focus on poly [adenosine diphosphate (ADP)-ribose] polymerase (PARP)-1 and poly-ADP ribosylation (PARylation) as the main causes of malignant formation of CRC may be considered. One of the important functions of PARP-1 and PARylation is its deoxyribonucleic acid (DNA) repair function, which plays a pivotal role in the DNA damage response and prevention of DNA damage maintaining the redox homeostasis involved in the regulation of oxidation and superoxide. PARP-1 and PARylation can also alter epigenetic markers and chromatin structure involved in transcriptional regulation for the oncogenes or tumor suppressor genes by remodeling histone and chromatin enzymes. Given the high importance of these processes in CRC, it can be considered that PARP-1 and PARylation are at the forefront of the pathological changes required for CRC progression. Therefore, this review addresses the current molecular biological features for understanding the multifactorial function of PARP-1 and PARylation in CRC related to the aforementioned roles; furthermore, it presents a summary of recent approaches with PARP-1 inhibition in non-clinical and clinical studies targeting CRC. This understanding could help embrace the importance of targeting PARP-1 and PARylation in the treatment of CRC, which may present the potential to identify various research topics that can be challenged both non-clinically and clinically.

Poly adenosine diphosphate-ribosylation, a promising target for colorectal cancer treatment

The development of colorectal cancer (CRC) can result from changes in a variety of cellular systems within the tumor microenvironment. Particularly, it is primarily associated with genomic instability that is the gradual accumulation of genetic and epigenetic changes consisting of a characteristic set of mutations crucial for pathways in CRC progression. Based on this background, the potential to focus on poly [adenosine diphosphate (ADP)-ribose] polymerase (PARP)-1 and poly-ADP ribosylation (PARylation) as the main causes of malignant formation of CRC may be considered. One of the important functions of PARP-1 and PARylation is its deoxyribonucleic acid (DNA) repair function, which plays a pivotal role in the DNA damage response and prevention of DNA damage maintaining the redox homeostasis involved in the regulation of oxidation and superoxide. PARP-1 and PARylation can also alter epigenetic markers and chromatin structure involved in transcriptional regulation for the oncogenes or tumor suppressor genes by remodeling histone and chromatin enzymes. Given the high importance of these processes in CRC, it can be considered that PARP-1 and PARylation are at the forefront of the pathological changes required for CRC progression. Therefore, this review addresses the current molecular biological features for understanding the multifactorial function of PARP-1 and PARylation in CRC related to the aforementioned roles; furthermore, it presents a summary of recent approaches with PARP-1 inhibition in non-clinical and clinical studies targeting CRC. This understanding could help embrace the importance of targeting PARP-1 and PARylation in the treatment of CRC, which may present the potential to identify various research topics that can be challenged both non-clinically and clinically.

Review on Bee Products as Potential Protective and Therapeutic Agents in Male Reproductive Impairment

Bee products are sources of functional food that have been used in complementary medicine to treat a variety of acute and chronic illnesses in many parts of the world. The products vary from location to location as well as country to country. Therefore, the aim of this review was to identify various bee products with potential preventive and therapeutic values used in the treatment of male reproductive impairment. We undertook a vigorous search for bee products with preventive and therapeutic values for the male reproductive system. These products included honey, royal jelly, bee pollen, bee brood, apilarnil, bee bread, bee wax, and bee venom. We also explained the mechanisms involved in testicular steroidogenesis, reactive oxygen species, oxidative stress, inflammation, and apoptosis, which may cumulatively lead to male reproductive impairment. The effects of bee pollen, bee venom, honey, propolis, royal jelly, and bee bread on male reproductive parameters were examined. Conclusively, these bee products showed positive effects on the steroidogenic, spermatogenic, oxidative stress, inflammatory, and apoptotic parameters, thereby making them a promising possible preventive and therapeutic treatment of male sub/infertility.

Rice bran, an off-shoot to newer therapeutics in neurological disorders

Normal brain functioning involves the interaction of interconnected molecular and cellular activities, which appear to alter normal to abnormal brain functioning when worsened, contributing to the emergence of neurological disorders. There are currently millions of people who are living with brain disorders globally and this will rise if suitable prevention strategies are not explored. Nutraceutical intended to treat numerous health goals with little adverse effect possible together can be more beneficial than pharmaceutical monotherapy for fostering balanced brain functioning. Nutraceutical provides a specific composition of effective macronutrients and micronutrients that are difficult to synthesize in the laboratory. Numerous elements of rice fibers in rice bran are characterized as natural anti-oxidant and having potential anti-inflammatory activity. The rice bran captures interest among the researchers as it is widespread, affordable, and rich in nutrients including protein, fat, carbohydrates, bioactive components, and dietary fiber. This review covers the neuroprotective multiplicity of rice bran and its constituents to deter pathological conditions of the brain and to facilitate balanced brain functioning at the same time.

Tannic acid alleviates lipopolysaccharide‑induced H9C2 cell apoptosis by suppressing reactive oxygen species‑mediated endoplasmic reticulum stress

Sepsis-induced myocardial dysfunction is one of the features of multiple organ dysfunction in sepsis, which is associated with extremely high mortality and is characterized by impaired myocardial compliance. To date, there are few effective treatment options available to cure sepsis. Tannic acid (TA) is reportedly protective during sepsis; however, the underlying mechanisms by which TA protects against septic heart injury remain elusive. The present study investigated the potential effects and underlying mechanisms of TA in alleviating lipopolysaccharide (LPS)-induced H9C2 cardiomyocyte cell apoptosis. H9C2 cells were treated with LPS (15 µg/ml), TA (10 µM) and TA + LPS; control cells were treated with medium only. Apoptosis was measured using flow cytometry, reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis. Additionally, the levels of cellular reactive oxygen species (ROS), malondialdehyde and nicotinamide adenine dinucleotide phosphate were evaluated. Western blotting and RT-qPCR were also employed to detect the expression levels of endoplasmic reticulum (ER) stress-associated functional proteins. The present findings demonstrated that TA reduced the degree of LPS-induced H9C2 cell injury, including inhibition of ROS production and ER stress (ERS)-associated apoptosis. ERS-associated functional proteins, including activating transcription factor 6, protein kinase-like ER kinase, inositol-requiring enzyme 1, spliced X box-binding protein 1 and C/EBP-homologous protein were suppressed in response to TA treatment. Furthermore, the expression levels of ERS-associated apoptotic proteins, including c-Jun N-terminal kinase, Bax, cytochrome c, caspase-3, caspase-12 and caspase-9 were reduced following treatment with TA. Additionally, the protective effects of TA on LPS-induced H9C2 cells were partially inhibited following treatment with the ROS inhibitor N-acetylcysteine, which demonstrated that ROS mediated ERS-associated apoptosis and TA was able to decrease ROS-mediated ERS-associated apoptosis. Collectively, the present findings demonstrated that the protective effects of TA against LPS-induced H9C2 cell apoptosis may be associated with the amelioration of ROS-mediated ERS. These findings may assist the development of potential novel therapeutic methods to inhibit the progression of myocardial cell injury.

6-benzylaminopurine exposure induced development toxicity and behaviour alteration in zebrafish (Danio rerio)

6-benzylaminopurine (6-BA) is one of the first synthetic hormones and has been widely used in fruit cultivation, gardening and agriculture. However, excessive use of 6-BA will cause potential harm to the environment and humans. Therefore, our research focused on assessing the impact of 6-BA on the development and neurobehavior of zebrafish. The results showed that 6-BA had little effect on the embryos from 2 hpf to 10 hpf. However, delayed development, decreased survival and hatchability were observed under 30 and 40 mg/L 6-BA from 24 hpf. 6-BA also reduced surface tension of embryonic chorions at 24 hpf. In addition, 6-BA caused abnormal morphology and promoted the accumulation of oxidative stress. Transcription of genes in connection with development and oxidative stress was also strikingly altered. Results of movement assay showed that zebrafish were less active and their behavior was significantly inhibited under the 20 and 30 mg/L 6-BA treatments. Locomotion-related genes th and mao were down-regulated by gradient, while the transcription of dbh was upregulated at a low concentration (2 mg/L) but decreased as the concentration increased. Moreover, 6-BA exposure caused increased arousal and decreased sleep. Sleep/wake related genes hcrt and hcrtr2 were upregulated, but decreased at 30 mg/L, while the mRNA level of aanat2 was reduced in a concentration-dependent manner. To sum up, our results showed that 6-BA induced developmental toxicity, promoted the accumulation of oxidative stress, and damaged locomotion and sleep/wake behavior.

Antioxidant effect of ethanolic onion (Allium cepa) husk extract in ageing rats

The role of natural antioxidants in preventing of age-relating diseases is evident. The vegetable industry generates a large amount of waste, which is a good source of antioxidants.

The aim of the study was the investigation of the antioxidant effect of long-term consumption of ethanolic yellow onion husk extract in ageing laboratory rodents.

Twenty male Wistar albino rats were divided randomly into two groups (n = 10): a control group and an experimental group that received ethanolic yellow onion husk extract (2 mL/rat diluted with distilled water; activity of 4.44 µmol-equiv. quercetin) for 188 days. Oxygen radical absorbance capacity and ferric reducing antioxidant power assays were used to determine the total antioxidant capacity of the extract, which amounted to 941.4 ± 32.7 µmol equiv. Trolox/g raw material and 167.4 ± 16.4 µmol-equiv. quercetin/g raw material, respectively. Oral intake of the onion husk extract affected the indicators of the antioxidant system of the liver and the brain but not of the blood and plasma, mainly due to elevations in the activity of catalase and superoxide dismutase in the liver by 44.4% and 79.1%, respectively, and in the brain by three-fold and 79.1%, respectively.

The availability, cheapness and high antioxidant potential of onion waste qualifies it a good source of functional ingredients and bioactive substances applicable in the food and pharmaceutical industries.

L-carnitine extenuates endocrine disruption, inflammatory burst and oxidative stress in carbendazim-challenged male rats via upregulation of testicular StAR and FABP9, and downregulation of P38-MAPK pathways

We have addressed in the current study the potential of L-carnitine (LC) to extenuate the reproductive toxic insults of carbendazim (CBZ) in male rats, and the molecular mechanisms whereby carnitine would modify the spermatogenic and steroidogenic derangements invoked by the endocrine disruptor. Herein, animals received daily doses of carbendazim (100 mg/kg) by gavage for 8 weeks. Another CBZ-challenged group was co-supplemented with LC (500 mg/kg, IP) twice weekly for 8 weeks. Sperm quantity and quality (morphology, motility and viability), serum testosterone and gonadotropins, and thyroid hormone levels were assessed. Serum tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations were determined by ELISA. Oxidant/antioxidant status in rat testis was investigated via measuring testicular contents of malondialdehyde (MDA) and reduced glutathione (GSH), as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Immunohistochemical localizations of the junctional protein; occludin, and inflammatory markers; inducible nitric oxide synthase (iNOS) and nuclear factor kappa beta (NF-κB) were further analyzed. A host of transduction genes that regulate spermatogenic and steroidogenic pathways, and their encoded proteins namely, Steroidogenic Acute Regulatory Protein (StAR), Fatty acid binding protein 9 (FABP9) and P38-mitogen activated protein kinase (P38-MAPK) were assessed by real time quantitative (RT-qPCR) and Western blot. LC improved rat spermiogram, testicular histological alterations and endocrine perturbances, and modulated genes' expressions and their respective proteins. In conclusion, LC effects appear to reside for the most part on its endocrine-preserving, anti-oxidant and anti-inflammatory properties through a myriad of interlaced signal transductions that ultimately recapitulated its beneficial effects on spermatogenesis and steroidogenesis.

Oxidative stress and regulated cell death in Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Motor deficits usually associated with PD correlate with dopaminergic axonal neurodegeneration starting at the striatum, which is then followed by dopaminergic neuronal death in the substantia nigra pars compacta (SN), with both events occurring already at the prodromal stage. We will overview the main physiological characteristics responsible for the higher susceptibility of the nigrostriatal circuit to mitochondrial dysfunction and oxidative stress, as hinted by the acting mechanisms of the PD-causing neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Then, we will present multiple lines of evidence linking several cell death mechanisms involving mitochondria and production of reactive oxygen species to neuronal loss in PD, namely intrinsic and extrinsic apoptosis, necroptosis, ferroptosis, parthanatos and mitochondrial permeability transition-driven necrosis. We will focus on gathered data from postmortem PD samples and relevant in vivo models, especially MPTP-based models.

Antioxidants for the Treatment of Retinal Disease: Summary of Recent Evidence

Retinal tissue is prone to oxidant burden and oxidative stress secondary to the generation of reactive oxygen species from high metabolic demand. The formation of reactive oxygen species occurs primarily from the mitochondrial respiratory chain as well as several enzymatic and oxidation reactions that occur in the neurosensory retina and retinal pigment epithelium. This oxidative stress has been implicated in the pathogenesis of several retinal diseases and the role of antioxidants as a therapeutic treatment shows promise in slowing the progression of certain diseases. The aim of this narrative review is to describe the mechanisms of retinal oxidative stress and summarize the current available evidence for antioxidants as a treatment for vitreoretinal disorders.

"Urate and NOX5 Control Blood Digestion in the Hematophagous Insect Rhodnius prolixus"

Low levels of reactive oxygen species (ROS) are now recognized as essential players in cell signaling. Here, we studied the role of two conserved enzymes involved in redox regulation that play a critical role in the control of ROS in the digestive physiology of a blood-sucking insect, the kissing bug Rhodnius prolixus. RNAi-mediated silencing of RpNOX5 and RpXDH induced early mortality in adult females after a blood meal. Recently, a role for RpNOX5 in gut motility was reported, and here, we show that midgut peristalsis is also under the control of RpXDH. Together with impaired peristalsis, silencing either genes impaired egg production and hemoglobin digestion, and decreased hemolymph urate titers. Ultrastructurally, the silencing of RpNOX5 or RpXDH affected midgut cells, changing the cells of blood-fed insects to a phenotype resembling the cells of unfed insects, suggesting that these genes work together in the control of blood digestion. Injection of either allopurinol (an XDH inhibitor) or uricase recapitulated the gene silencing effects, suggesting that urate itself is involved in the control of blood digestion. The silencing of each of these genes influenced the expression of the other gene in a complex way both in the unfed state and after a blood meal, revealing signaling crosstalk between them that influences redox metabolism and nitrogen excretion and plays a central role in the control of digestive physiology.

Fate of β-Carotene within Loaded Delivery Systems in Food: State of Knowledge

Nanotechnology has opened new opportunities for delivering bioactive agents. Their physiochemical characteristics, i.e., small size, high surface area, unique composition, biocompatibility and biodegradability, make these nanomaterials an attractive tool for β-carotene delivery. Delivering β-carotene through nanoparticles does not only improve its bioavailability/bioaccumulation in target tissues, but also lessens its sensitivity against environmental factors during processing. Regardless of these benefits, nanocarriers have some limitations, such as variations in sensory quality, modification of the food matrix, increasing costs, as well as limited consumer acceptance and regulatory challenges. This research area has rapidly evolved, with a plethora of innovative nanoengineered materials now being in use, including micelles, nano/microemulsions, liposomes, niosomes, solidlipid nanoparticles, nanostructured lipids and nanostructured carriers. These nanodelivery systems make conventional delivery systems appear archaic and promise better solubilization, protection during processing, improved shelf-life, higher bioavailability as well as controlled and targeted release. This review provides information on the state of knowledge on β-carotene nanodelivery systems adopted for developing functional foods, depicting their classifications, compositions, preparation methods, challenges, release and absorption of β-carotene in the gastrointestinal tract (GIT) and possible risks and future prospects.

Moringa oleifera Extract Extenuates Echis ocellatus Venom-Induced Toxicities, Histopathological Impairments and Inflammation via Enhancement of Nrf2 Expression in Rats

Echis ocellatus snakebite causes more fatalities than all other African snake species combined. Moringa oleifera reportedly possesses an antivenom property. Therefore, we evaluated the effectiveness of M. oleifera ethanol extract (MOE) against E. ocellatus venom (EOV) toxicities. Thirty male rats were grouped as follows (n = 5): Group 1 (normal control received saline), groups 2 to 6 were administered intraperitoneally, 0.22 mg/kg (LD50) of EOV. Group 2 was left untreated while group 3 to 6 were treated post-envenoming with 0.2 mL of polyvalent antivenom, 200, 400, and 600 mg/kg of MOE respectively. MOE significantly (p < 0.05) normalized the altered haematological indices and blood electrolytes profiles. MOE attenuated venom-induced cellular dysfunctions, characterized by a significant increase in NRF2, and concomitant downregulation of increased antioxidant enzymes (SOD and CAT) activities in the serum and heart of the treated rats. MOE normalized the elevated TNF-α and IL-1β in serum and heart tissues. Furthermore, the IgG titre value was significantly (p < 0.5) higher in the envenomed untreated group compared to the MOE-treated groups. Hemorrhagic, hemolytic and coagulant activities of the venom were strongly inhibited by the MOE dose, dependently. Lesions noticed on tissues of vital organs of untreated rats were abolished by MOE. Our findings substantiate the effectiveness of MOE as a potential remedy against EOV toxicities.

Toxic effect of titanium dioxide nanoparticles on corneas in vitro and in vivo

Titanium dioxide nanoparticles (TiO₂ NPs) are widely used in a variety of areas. However, TiO₂ NPs possess cytotoxicity which involves oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key molecule preventing cells from oxidative stress damage. In the current study, we explored the effect of Nrf2 signaling pathway in TiO₂ NPs-induced corneal endothelial cell injury. Firstly, we found TiO₂ NPs inhibited proliferation and damaged morphology and mitochondria of mouse primary corneal endothelial cells. Moreover, TiO₂ NPs-induced oxidative damage of mouse primary corneal endothelial cells was inhibited by antioxidant NAC by evaluating production of reactive oxygen species (ROS), malondialdehyde (MDA), and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Next, flow cytometry analysis showed TiO₂ NPs promoted apoptosis and cell cycle G2/M phase arrest of mouse primary corneal endothelial cells. Further investigation suggested that Nrf2 signaling pathway activation and the downregulation of ZO-1, β-catenin and Na-K-ATPase were involved in TiO₂ NPs-induced mouse primary corneal endothelial cell injury. Our research highlighted the toxic effect of TiO₂ NPs on corneas in vitro and in vivo, providing an alternative insight into TiO₂ NPs-induced corneal endothelial cell injury.

Naphthoquinone derivatives exhibit apoptosis-like effect and anti-trypanosomal activity against Trypanosoma evansi

Trypanosoma evansi is an extracellular flagellate blood protozoan parasite and an etiological agent of animal trypanosomosis. Presently, only a few drugs are registered and have been used for the treatment of animal trypanosomosis, but they show severe toxic effects and also face the problem of drug resistance. Naphthoquinones (NTQ) are considered as fortunate structures in the field of medicinal chemistry as they have been reported for their antitrypanosomal potential against other trypanosomes-T. brucei and T. cruzi. In the present study, six naphthoquinones (NTQ1-NTQ6) derivatives were evaluated for anti-trypanosomal activity by demonstrating their growth inhibitory effect against T. evansi. All NTQs significantly (p < 0.001) exhibited activity against parasite growth and multiplication with IC₅₀ values of 11.48 μM, 373.6 μM, 12.97 μM, 21.97 μM, 18.19 μM and 5.758 μM but NTQ1, NTQ3 and NTQ6 were selected based on their IC₅₀ value for further studies. The dose-and time-dependent morphological effect on parasite was evaluated including the measurement of reactive oxygen species (ROS) by spectrofluorometery and measurement of apoptosis by flow cytometry. The selected NTQs exhibited a significant production of ROS and displayed a significant AV⁺ and PI⁺ labelled cells in the axenic culture of T. evansi than quinapyramine methyl sulphate (QPS), as reference control. NTQs also showed more cytotoxic effect on horse peripheral blood mononuclear cells as compare to QPS. Therefore, we confirmed the antitrypanosomal activity and apoptotic-like mechanism of NTQs in an axenic culture of T. evansi.

Dual-Cross-Linked Network Hydrogels with Multiresponsive, Self-Healing, and Shear Strengthening Properties

Dual-cross-linked network (DCN) hydrogels with multiresponsive and self-healing properties are attracting intensive interests due to their enhanced mechanical strength for a wide range of applications. Herein, we developed a DCN hydrogel that combines a dynamic imine and a benzoxaboronic ester with a neutral pK_a value (∼7.2) as dual linkages and contains biocompatible zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) [poly(MPC)] as the backbone. Oscillatory rheology result indicated shear strengthening mechanical properties compared to the single-cross-linked network (SCN) hydrogels, which use either imine bond or benzoxaboronic ester as the linkage alone. Due to the coexistence of stimuli-responsive imine and benzoxaboronic ester, the DCN hydrogels show sensitive multiple responsiveness to pH, sugar, and hydrogen peroxide. The dynamic nature of the dual linkages endows the DCN hydrogels with excellent self-healing ability after fracture. More importantly, the excellent biocompatibility and performance in three-dimensional (3D) cell encapsulation were established by a cytotoxicity Live/Dead assay, indicating DCN hydrogel's great potential as a cell culture scaffold. The biocompatible poly(MPC)-based backbone and the rapid formation of the cross-linking network make the DCN hydrogels promising candidates for future biomedical applications.

Reactive Oxygen Species: Drivers of Physiological and Pathological Processes

Since the Great Oxidation Event, about 2.4 billion years ago, the Earth is immersed in an oxidizing atmosphere. Thus, it has been proposed that excess oxygen, originally a waste product of photosynthetic cyanobacteria, induced oxidative stress and the production of reactive oxygen species (ROS), which have since acted as fundamental drivers of biologic evolution and eukaryogenesis. Indeed, throughout an organism’s lifespan, ROS affect directly (as mutagens) or indirectly (as messengers and regulators) all structural and functional components of cells, and many aspects of cell biology. Whether left unchecked by protective antioxidant systems, excess ROS not only cause genomic mutations but also induce irreversible oxidative modification of proteins (protein oxidation and peroxidation), lipids and glycans (advanced lipoxidation and glycation end products), impairing their function and promoting disease or cell death. Conversely, low-level local ROS play an important role both as redox-signaling molecules in a wide spectrum of pathways involved in the maintenance of cellular homeostasis (MAPK/ERK, PTK/PTP, PI3K-AKT-mTOR), and regulating key transcription factors (NFκB/IκB, Nrf2/KEAP1, AP-1, p53, HIF-1). Consequently, ROS can shape a variety of cellular functions, including proliferation, differentiation, migration and apoptosis. In this review, we will give a brief overview of the relevance of ROS in both physiological and pathological processes, particularly inflammation and aging. In-depth knowledge of the molecular mechanisms of ROS actuation and their influence under steady-state and stressful conditions will pave the way for the development of novel therapeutic interventions. This will mitigate the harmful outcomes of ROS in the onset and progression of a variety of chronic inflammatory and age-related diseases.

Strategies to expand the therapeutic potential of superoxide dismutase by exploiting delivery approaches

The overproduction of free radicals can cause oxidative-stress damage to a range of biomolecules, and thus potentially contribute to several pathologies, from neurodegenerative disorders to cardiovascular diseases and metabolic disorders. Endogenous antioxidant enzymes, such as superoxide dismutase (SOD), play an important role in diminishing oxidative stress. SOD supplementation could therefore be an effective preventive strategy to reduce the risk of free-radical overproduction. However, the efficacy of SOD administration is hampered by its rapid clearance. Several different approaches to improve the bioavailability of SOD have been explored in recent decades. This review intends to describe the rationale that underlie the various approaches and chemical strategies that have led to the most recent advances in SOD delivery. This critical description includes SOD conjugates, SOD loaded into particulate carriers (micelles, liposomes, nanoparticles, microparticles) and the most promising and suitable formulations for oral delivery, with a particular emphasis on reports of preclinical/clinical results. Likely future directions are also considered and reported.

Antioxidant activity and hepatoprotective effect of 10 medicinal herbs on CCl4-induced liver injury in mice

BACKGROUND

Many natural products confer health benefits against diverse diseases through their antioxidant activities. Carbon tetrachloride (CCl₄) is often used in animal experiments to study the effects of substances on liver injury and the related mechanisms of action, among which oxidative stress is a major pathogenic factor.

AIM

To compare antioxidant and hepatoprotective activities of ten herbs and identify and quantify phytochemicals for the one with strongest hepatoprotection.

METHODS

The antioxidant activity of ten medicinal herbs was determined by both ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays. The total phenolic and flavonoid contents were determined by Folin–Ciocalteu method and aluminum chloride colorimetry, respectively. Their effects on CCl₄-induced oxidative liver injury were evaluated and compared in a mouse model by administrating each water extract (0.15 g/mL, 10 mL/kg) once per day for seven consecutive days and a dose of CCl₄ solution in olive oil (8%, v/v, 10 mL/kg). The herb with the strongest hepatoprotective performance was analyzed for the detailed bioactive components by using high-performance liquid chromatography-electrospray ionization source-ion trap tandem mass spectrometry.

RESULTS

The results revealed that all tested herbs attenuated CCl₄-induced oxidative liver injury; each resulted in significant decreases in levels of serum alanine transaminase, aspartate transaminase, alkaline phosphatase, and triacylglycerols. In addition, most herbs restored hepatic superoxide dismutase and catalase activities, glutathione levels, and reduced malondialdehyde levels. Sanguisorba officinalis (S. officinalis) L., Coptis chinensis Franch., and Pueraria lobata (Willd.) Ohwi root were the three most effective herbs, and S. officinalis L. exhibited the strongest hepatoprotective effect. Nine active components were identified in S. officinalis L. Gallic acid and (+)-catechin were quantified (7.86 ± 0.45 mg/g and 8.19 ± 0.57 mg/g dried weight, respectively). Furthermore, the tested herbs displayed a range of in vitro antioxidant activities proportional to their phenolic content; the strongest activities were also found for S. officinalis L.

CONCLUSION

This study is of value to assist the selection of more effective natural products for direct consumption and the development of nutraceuticals or therapeutics to manage oxidative stress-related diseases.

TRPM2 channel-mediated cell death: An important mechanism linking oxidative stress-inducing pathological factors to associated pathological conditions

Oxidative stress resulting from the accumulation of high levels of reactive oxygen species is a salient feature of, and a well-recognised pathological factor for, diverse pathologies. One common mechanism for oxidative stress damage is via the disruption of intracellular ion homeostasis to induce cell death. TRPM2 is a non-selective Ca2+-permeable cation channel with a wide distribution throughout the body and is highly sensitive to activation by oxidative stress. Recent studies have collected abundant evidence to show its important role in mediating cell death induced by miscellaneous oxidative stress-inducing pathological factors, both endogenous and exogenous, including ischemia/reperfusion and the neurotoxicants amyloid-β peptides and MPTP/MPP+ that cause neuronal demise in the brain, myocardial ischemia/reperfusion, proinflammatory mediators that disrupt endothelial function, diabetogenic agent streptozotocin and diabetes risk factor free fatty acids that induce loss of pancreatic β-cells, bile acids that damage pancreatic acinar cells, renal ischemia/reperfusion and albuminuria that are detrimental to kidney cells, acetaminophen that triggers hepatocyte death, and nanoparticles that injure pericytes. Studies have also shed light on the signalling mechanisms by which these pathological factors activate the TRPM2 channel to alter intracellular ion homeostasis leading to aberrant initiation of various cell death pathways. TRPM2-mediated cell death thus emerges as an important mechanism in the pathogenesis of conditions including ischemic stroke, neurodegenerative diseases, cardiovascular diseases, diabetes, pancreatitis, chronic kidney disease, liver damage and neurovascular injury. These findings raise the exciting perspective of targeting the TRPM2 channel as a novel therapeutic strategy to treat such oxidative stress-associated diseases.

The correlation of IRE1α oxidation with Nox4 activation in aging-associated vascular dysfunction

Oxidative stress attributable to the activation of a Nox4-containing NADPH oxidase is involved in aging-associated vascular dysfunction. However, the Nox4-induced signaling mechanism for the vascular alteration in aging remains unclear. In an aged aorta, the expression of Nox4 mRNA and protein by Nox family of genes was markedly increased compared with a young aorta. Nox4 localization mainly to ER was also established. In the aorta of Nox4 WT mice aged 23–24 months (aged), reactive oxygen species (ROS) and endoplasmic reticulum (ER)/oxidative stress were markedly increased compared with the counter KO mice. Furthermore, endothelial functions including eNOS coupling process and acetylcholine-induced vasodilation were significantly disturbed in the aged WT, slightly affected in the counter KO aorta. Consistently, in d-galactose-induced in vitro aging condition, ER-ROS and its associated ER Nox4 expression and activity were highly increased. Also, in chronic d-galactose-treated condition, IRE1α phosphorylation and XBP-1 splicing and were transiently increased, but IRE1α sulfonation was robustly increased in the aging Nox4 WT condition when compared to the counter KO condition. In vitro D-gal-induced aging study, the phenomenon were abrogated with Nox4 knock-down condition and was significantly decreased in GKT, Nox4 inhibitor and 4-PBA, ER chemical chaperone-treated human umbilical vein endothelial cells. The state of Nox4-based ER redox imbalance/ROS accumulation is suggested to determine the pathway “the UPR; IRE1α phosphorylation and XBP-1 splicing and the UPR failure; IRE1α cysteine-based oxidation, especially sulfonation, finally controlling aging-associated vascular dysfunction.

Utility of Reactive Species Generation in Plasma Medicine for Neuronal Development

Reactive oxygen species (ROS) are critical signaling molecules for neuronal physiology that stimulate growth and development and play vital roles in several pathways when in a balanced state, but they cause neurodegeneration when unbalanced. As ROS levels above a certain threshold cause the activation of the autophagy system, moderate levels of ROS can be used as treatment strategies. Currently, such treatments are used together with low-level laser or photodynamic therapies, photo-bio modulation, or infrared treatments, in different chronic diseases but not in the treatment of neurodegeneration. Recently, non-thermal plasma has been successfully used in biomedical applications and treatments, and beneficial effects such as differentiation, cell growth, and proliferation, stimulation of ROS based pathways have been observed. Besides the activation of a wide range of biological signaling pathways by generating ROS, plasma application can be an effective treatment in neuronal regeneration, as well as in neuronal diseases. In this review, we summarize the generation and role of ROS in neurons and provide critical insights into their potential benefits on neurons. We also discuss the underlying mechanisms of ROS on neuronal development. Regarding clinical applications, we focus on ROS-based neuronal growth and regeneration strategies and in the usage of non-thermal plasma in neuronal and CNS injury treatments.

The Presence of D-Penicillamine during the In Vitro Capacitation of Stallion Spermatozoa Prolongs Hyperactive-Like Motility and Allows for Sperm Selection by Thermotaxis

Assisted reproductive technologies (ARTs) in the horse still yield suboptimal results in terms of pregnancy rates. One of the reasons for this is the lack of optimal conditions for the sperm capacitation in vitro. This study assesses the use of synthetic human tubal fluid (HTF) supplemented with D-penicillamine (HTF + PEN) for the in vitro capacitation of frozen/thawed stallion spermatozoa by examining capacitation-related events over 180 min of incubation. Besides these events, we explored the in vitro capacity of the spermatozoa to migrate by thermotaxis and give rise to a population of high-quality spermatozoa. We found that HTF induced higher levels of hyperactive-like motility and protein tyrosine phosphorylation (PTP) compared to the use of a medium commonly used in this species (Whitten's). Also, HTF + PEN was able to maintain this hyperactive-like motility, otherwise lost in the absence of PEN, for 180 min, and also allowed for sperm selection by thermotaxis in vitro. Remarkably, the selected fraction was enriched in spermatozoa showing PTP along the whole flagellum and lower levels of DNA fragmentation when compared to the unselected fraction (38% ± 11% vs 4.4% ± 1.1% and 4.2% ± 0.4% vs 11% ± 2% respectively, t-test p < 0.003, n = 6). This procedure of in vitro capacitation of frozen/thawed stallion spermatozoa in HTF + PEN followed by in vitro sperm selection by thermotaxis represents a promising sperm preparation strategy for in vitro fertilization and intracytoplasmic sperm injection in this species.

Scientific landscape of oxidative stress in male reproductive research: A scientometric study

Unraveling the role of reactive oxygen species and associated oxidative stress (OS) in male reproduction is one of the key areas of male reproductive research. This article illustrates the scientific landscape of OS in male reproductive research over the past several decades (1941-2018) using a scientometric approach. Scientometric data (articles per year, authors, affiliations, journals, and countries) on OS related to male reproduction were retrieved from the Scopus database and analyzed for each decade. Our analysis revealed an increasing trend in OS-based male reproductive research from 1941 to 2018 with a steep raise in publications and research collaborations starting from the period 1991-2000 (R² = 0.81). Semen abnormalities and varicocele were the major areas investigated in relation to OS with the highest positive trend in publications from the time interval 1981-1990 to 2011-2018. Analysis of publications based on OS assessment techniques revealed chemiluminescence (n = 180) and evaluation of antioxidants (n = 300) as the most widely used direct and indirect tests, respectively. Furthermore, prognostic/diagnostic studies on OS evaluation increased significantly over the time. Our analysis highlights the evolution of OS in male reproductive research and its emergence as an important prognostic and diagnostic tool in the evaluation of male infertility.

Investigating the potential use of an oleaginous bacterium, Rhodococcus opacus PD630, for nano-TiO2 remediation

The occurrence of titanium dioxide nanoparticles (nTiO₂), in the effluents released from wastewater treatment plants, has raised concerns. The fate of nTiO₂ and their potential impact on organisms from different ecosystems are widely investigated. For the first time, in this work, we report the responses of an oleaginous bacteria Rhodococcus opacus PD630, belonging to an ecologically important genus Rhodococcus to environmentally relevant concentrations of nTiO_2, under dark and UV light conditions. We observed a dose-dependent increase in nTiO₂ uptake by the bacteria that reached a maximum of 1.4 mg nTiO₂ (g cell)^-1 under mid-log UV exposure, corresponding to 97% uptake. The nTiO₂ induced oxidative stress in bacteria that increased from 25.1 to a maximum of 100.3, 44.1, and 51.7 μmol ^.OH (g cell)^-1 under dark, continuous, and mid-log UV, respectively. However, nTiO₂ did not affect bacterial viability. Further, due to oxidative stress, the triacylglycerol (biodiesel) content from bacteria increased from 30% to a maximum of 54% CDW. Based on our findings, we propose an application of R. opacus PD 630 in nTiO₂ remediation due to their high nTiO₂ uptake and resistance.

Evaluation of bioactive compounds, free radical scavenging and anticancer activities of bulb extracts of Boophone disticha from Eastern Cape Province, South Africa

Boophone disticha (B. disticha) is a bulbous tropical and subtropical flowering plant widespread in Africa, which is frequently used to treat several human ailments. Until the present, there is no scientific validation on the biological activity of this plant from the Eastern Cape Province of South Africa and as a result, this study aimed to assess the bioactive compounds, free radicals scavenging and anticancer potentials of crude bulb extracts (chloroform, acetone, and ethanol) of Boophone disticha obtained from this geographical location. Standard biochemical techniques and Gas-chromatography mass spectrometry (GCMS) analysis were used to pinpoint the bioactive compounds in the crude extracts sequel to their antioxidant potentials against radicals such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), hydrogen peroxide and nitric oxide as well as their ferric ion reducing power. In addition, their cytotoxicity effects against Human cervix adenocarcinoma (HeLa) cells were assessed as an in vitro model for anticancer. The phytochemical evaluation of the crude extracts showed the presence of phenolics, flavonoids, and alkaloids. GCMS profiles confirmed the presence of some bioactive compounds in the crude extracts of B. disticha that could be responsible for their biological activities. The plant extracts possessed considerable antioxidant activity and exhibited dose-dependent radicals’ inhibition from all assays carried out. Furthermore, the cytotoxicity effects against HeLa cells recorded inhibition concentration (IC₅₀) of 1.5, 1.6, and 1.9 µg/mL for acetone, chloroform, and ethanolic extracts of B. disticha, respectively. Findings from the present study suggest that B. disticha could be a good prospective source of antioxidant and anticancer agents. Therefore, further research on the isolation and purification of compounds from these extracts are indispensable.

Bioactive Compounds and Bioactivities of Brassica oleracea L. var. Italica Sprouts and Microgreens: An Updated Overview from a Nutraceutical Perspective

Sprouts and microgreens, the edible seedlings of vegetables and herbs, have received increasing attention in recent years and are considered as functional foods or superfoods owing to their valuable health-promoting properties. In particular, the seedlings of broccoli (Brassica oleracea L. var. Italica) have been highly prized for their substantial amount of bioactive constituents, including glucosinolates, phenolic compounds, vitamins, and essential minerals. These secondary metabolites are positively associated with potential health benefits. Numerous in vitro and in vivo studies demonstrated that broccoli seedlings possess various biological properties, including antioxidant, anticancer, anticancer, antimicrobial, anti-inflammatory, anti-obesity and antidiabetic activities. The present review summarizes the updated knowledge about bioactive compounds and bioactivities of these broccoli products and discusses the relevant mechanisms of action. This review will serve as a potential reference for food selections of consumers and applications in functional food and nutraceutical industries.

Alterations in the Antioxidant Enzyme Activities in the Neurodevelopmental Rat Model of Schizophrenia Induced by Glutathione Deficiency during Early Postnatal Life

The aim of the present study was to assess the effects of l-buthionine-(S,R)-sulfoximine (BSO), a glutathione (GSH) synthesis inhibitor, and GBR 12909, a dopamine reuptake inhibitor, administered alone or in combination to Sprague-Dawley rats during early postnatal development (p5-p16), on the levels of reactive oxygen species (ROS), lipid peroxidation (LP) and the activities of antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione disulfide reductase (GR) in peripheral tissues (liver, kidney) and selected brain structures (prefrontal cortex, PFC; hippocampus, HIP; and striatum, STR) of 16-day-old rats. The studied parameters were analyzed with reference to the content of GSH and sulfur amino acids, methionine (Met) and cysteine (Cys) described in our previous study. This analysis showed that treatment with a BSO + GBR 12909 combination caused significant decreases in the lipid peroxidation levels in the PFC and HIP, in spite of there being no changes in ROS. The reduction of lipid peroxidation indicates a weakening of the oxidative power of the cells, and a shift in balance in favor of reducing processes. Such changes in cellular redox signaling in the PFC and HIP during early postnatal development may result in functional changes in adulthood.

FtH-Mediated ROS Dysregulation Promotes CXCL12/CXCR4 Axis Activation and EMT-Like Trans-Differentiation in Erythroleukemia K562 Cells

The cell-microenvironment communication is essential for homing of hematopoietic stem cells in stromal niches. Recent evidences support the involvement of epithelial-to-mesenchymal (EMT) process in hematopoietic stem cell homeostasis as well as in leukemia cells invasiveness and migration capability. Here, we demonstrate that the alteration of iron homeostasis and the consequent increase of redox metabolism, mediated by the stable knock down of ferritin heavy chain (FtH), enhances the expression of CXCR4 in K562 erythroleukemia cells, thus promoting CXCL12-mediated motility. Indeed, addition of the CXCR4 receptor antagonist AMD3100 reverts this effect. Upon FtH knock down K562 cells also acquire an “EMT-like” phenotype, characterized by the increase of Snail, Slug and Vimentin with the parallel loss of E-cadherin. By using fibronectin as substrate, the cell adhesion assay further shows a reduction of cell adhesion capability in FtH-silenced K562 cells. Accordingly, confocal microscopy shows that adherent K562 control cells display a variety of protrusions while FtH-silenced K562 cells remain roundish. These phenomena are largely due to the reactive oxygen species (ROS)-mediated up-regulation of HIF-1α/CXCR4 axis which, in turn, promotes the activation of NF-κB and the enhancement of EMT features. These data are confirmed by treatments with either N-acetylcysteine (NAC) or AMD3100 or NF-κB inhibitor IκB-alpha which revert the FtH-silenced K562 invasive phenotype. Overall, our findings demonstrate the existence of a direct relationship among iron metabolism, redox homeostasis and EMT in the hematological malignancies. The effects of FtH dysregulation on CXCR4/CXCL12-mediated K562 cell motility extend the meaning of iron homeostasis in the leukemia cell microenvironment.

Reactive oxygen species in male reproduction: A boon or a bane?

Reactive oxygen species (ROS) are free radicals derived from oxygen during normal cellular metabolism. ROS play a crucial role in the physiological processes and signalling pathways associated with male fertility. At physiological concentrations, ROS act as molecular mediators of signal transduction pathways involved in the regulation of the hypothalamic-pituitary-gonadal axis, spermatogenesis and steroidogenesis. They also trigger the morphological changes required for sperm maturation, such as DNA compaction and flagellar modification. Furthermore, ROS modulate crucial processes involved in the attainment of sperm fertilising ability such as capacitation, hyperactivation, acrosome reaction and sperm-oocyte fusion. Conversely, oxidative stress prevails when the concentration of ROS overwhelms the body's antioxidant defence. Various endogenous and exogenous factors enhance the synthesis of ROS resulting in the disruption of structural and functional integrity of spermatozoa through the induction of apoptotic pathway and oxidation of molecules, such as lipids, proteins and DNA. Therefore, maintenance of a balanced redox state is critical for normal male reproductive functions. This article discusses the dual role of ROS in male reproduction, highlighting the physiological role as well as their pathological implications on male fertility.

Oxidative Damage in Sporadic Colorectal Cancer: Molecular Mapping of Base Excision Repair Glycosylases in Colorectal Cancer Patients

Oxidative stress with subsequent premutagenic oxidative DNA damage has been implicated in colorectal carcinogenesis. The repair of oxidative DNA damage is initiated by lesion-specific DNA glycosylases (hOGG1, NTH1, MUTYH). The direct evidence of the role of oxidative DNA damage and its repair is proven by hereditary syndromes (MUTYH-associated polyposis, NTHL1-associated tumor syndrome), where germline mutations cause loss-of-function in glycosylases of base excision repair, thus enabling the accumulation of oxidative DNA damage and leading to the adenoma-colorectal cancer transition. Unrepaired oxidative DNA damage often results in G:C>T:A mutations in tumor suppressor genes and proto-oncogenes and widespread occurrence of chromosomal copy-neutral loss of heterozygosity. However, the situation is more complicated in complex and heterogeneous disease, such as sporadic colorectal cancer. Here we summarized our current knowledge of the role of oxidative DNA damage and its repair on the onset, prognosis and treatment of sporadic colorectal cancer. Molecular and histological tumor heterogeneity was considered. Our study has also suggested an additional important source of oxidative DNA damage due to intestinal dysbiosis. The roles of base excision repair glycosylases (hOGG1, MUTYH) in tumor and adjacent mucosa tissues of colorectal cancer patients, particularly in the interplay with other factors (especially microenvironment), deserve further attention. Base excision repair characteristics determined in colorectal cancer tissues reflect, rather, a disease prognosis. Finally, we discuss the role of DNA repair in the treatment of colon cancer, since acquired or inherited defects in DNA repair pathways can be effectively used in therapy.

Efficacy of Antioxidant Supplementation on Conventional and Advanced Sperm Function Tests in Patients with Idiopathic Male Infertility

Antioxidants are used in the empirical treatment of infertile men. The aim of this study was to evaluate the effects of antioxidant therapy on conventional semen parameters and advanced sperm function tests in men seeking fertility treatment. A total of 148 infertile men of unknown etiology were divided into idiopathic (n = 119) and unexplained male infertility (UMI; n = 29). All participants were treated with the antioxidant supplement 'FH PRO for Men' for a period of three months. Compared with pretreatment results, there was a significant improvement in conventional semen parameters including sperm concentration, total and progressive motility and normal morphology, and seminal oxidation reduction potential (ORP), and sperm DNA fragmentation (SDF) in idiopathic infertile men. The changes were more prominent in idiopathic infertile men positive for ORP and SDF. UMI patients showed an improvement in progressive motility, ORP, and SDF after antioxidant treatment. Statistical analysis revealed that the efficacy of FH PRO for Men was significant in idiopathic male infertility compared with UMI. Treatment of idiopathic male infertility patients with the FH PRO for Men antioxidant regimen for three months resulted in a significant improvement in conventional semen parameters and sperm function. Therefore, FH PRO for Men offers promise for the medical treatment of idiopathic male infertility.

Adverse effect of cylindrospermopsin on embryonic development in zebrafish (Danio rerio)

Eutrophication of freshwater bodies increases the occurrence of toxic cyanobacterial blooms. The cyanobacterial toxin cylindrospermopsin (CYN) is receiving great interest due to its increasing presence in waterbodies. However, the toxic effects of CYN on zebrafish development are poorly understood, especially the toxicological mechanism, which is still unclear. In this study, we examined the adverse effects of CYN on embryonic development in zebrafish. CYN (2-2000 nM) exposure decreased embryos survival rate, hatching rate, body length and eye size in a concentration-dependent manner and caused abnormalities in embryo morphology, including pericardial edema, spinal curvature, tail deformity, uninflated swim bladder, cardiac and vascular defects. CYN at concentrations of 20 nM or higher significantly increased ROS level and promoted cell apoptosis in zebrafish embryos. To preliminarily elucidate the potential mechanism of zebrafish developmental toxicity caused by CYN, we examined the expression of oxidative stress- and apoptotic-related genes. CYN could promote the expression of oxidative stress-related genes (SOD1, CAT and GPx1) and induce changes in transcriptional levels of apoptotic-related genes (p53, Bax and Bcl-2). Taken together, CYN induced adverse effects on zebrafish embryos development, which may associate with oxidative stress and apoptosis. These outcomes will advance our understanding of CYN toxicity, environmental problems and health hazards caused by climate changes and eutrophication.

Rapid screening and characterization of natural antioxidants in Polygonum viviparum by an on-line system integrating the pressurised liquid micro-extraction, HPLC-DAD-QTOF-MS/MS analysis and antioxidant assay

Rapid discovery of active ingredients from complex matrices is one of great challenges for modern drug development. Traditional methods often require many sample treatment steps, including an extraction step with exclusively dedicated solvents followed by repeated separation and activities assessment. This present work described an integrated analytical setup for natural antioxidants discovery in which the online extraction (OLE) of a solid sample is directly coupled to its analysis by high performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry and 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) antioxidant assay (OLE-HPLC-DAD-QTOF-MS/MS-ABTS). This developed approach makes sample extraction, chromatographic separation and chemical detection, and antioxidant assay integrated into a single HPLC injection and was successfully applied for the rapid discovery of natural antioxidant bioactives from Polygonum viviparum. A total of 21 secondary metabolites were characterized according to their retention times, ultraviolet (UV) spectra, exact mass and fragmentation ions in MS/MS spectra, and 18 of them displayed antioxidant activity (response as negative peaks in antioxidant assay). This work describes a simple, green and efficient approach to minimize the sample consumption (only 0.4 mg was required) and eliminate complex sample treatment procedures. The developed OLE-HPLC-DAD-QTOF-MS/MS-ABTS system offers new perspectives for rapid chemical profiling of natural products and their antioxidants discovery.

Nanodelivery of Natural Antioxidants: An Anti-aging Perspective

The aging process is known to be associated with heightened oxidative stress and related systemic inflammation. Therefore, antioxidant supplementation is regarded as a promising strategy to combat aging and associated pathological conditions. Food-grade antioxidants from plant-derived extracts are the most common ingredients of these supplements. Phyto-bioactive compounds such as curcumin, resveratrol, catechins, quercetin are among the most commonly applied natural compounds used as potential modulators of the free radical-induced cellular damages. The therapeutic potential of these compounds is, however, restricted by their low bioavailability related to poor solubility, stability, and absorbance in gastrointestinal tract. Recently, novel nanotechnology-based systems were developed for therapeutic delivery of natural antioxidants with improved bioavailability and, consequently, efficacy in clinical practice. Such systems have provided many benefits in preclinical research over the conventional preparations, including superior solubility and stability, extended half-life, improved epithelium permeability and bioavailability, enhanced tissue targeting, and minimized side effects. The present review summarizes recent developments in nanodelivery of natural antioxidants and its application to combat pathological conditions associated with oxidative stress.

PM2.5, Fine Particulate Matter: A Novel Player in the Epithelial-Mesenchymal Transition?

Epithelial-mesenchymal transition (EMT) refers to the conversion of epithelial cells to mesenchymal phenotype, which endows the epithelial cells with enhanced migration, invasion, and extracellular matrix production abilities. These characteristics link EMT with the pathogenesis of organ fibrosis and cancer progression. Recent studies have preliminarily established that fine particulate matter with an aerodynamic diameter of less than 2.5 μm (PM_2.5) is correlated with EMT initiation. In this pathological process, PM_2.5 particles, excessive reactive oxygen species (ROS) derived from PM_2.5, and certain components in PM_2.5, such as ions and polyaromatic hydrocarbons (PAHs), have been implicated as potential EMT mediators that are linked to the activation of transforming growth factor β (TGF-β)/SMADs, NF-κB, growth factor (GF)/extracellular signal-regulated protein kinase (ERK), GF/phosphatidylinositol 3-kinase (PI3K)/Akt, wingless/integrated (Wnt)/β-catenin, Notch, Hedgehog, high mobility group box B1 (HMGB1)-receptor for advanced glycation end-products (RAGE), and aryl hydrocarbon receptor (AHR) signaling cascades and to cytoskeleton rearrangement. These pathways directly and indirectly transduce pro-EMT signals that regulate EMT-related gene expression in epithelial cells, finally inducing the characteristic alterations in morphology and functions of epithelia. In addition, novel associations between autophagy, ATP citrate lyase (ACLY), and exosomes with PM_2.5-induced EMT have also been summarized. However, some debates and paradoxes remain to be consolidated. This review discusses the potential molecular mechanisms underlying PM_2.5-induced EMT, which might account for the latent role of PM_2.5 in cancer progression and fibrogenesis.

The β2-adrenergic receptor-ROS signaling axis: An overlooked component of β2AR function?

β2-Adrenergic receptor (β2AR) agonists are clinically used to elicit rapid bronchodilation for the treatment of bronchospasms in pulmonary diseases such as asthma and COPD, both of which exhibit characteristically high levels of reactive oxygen species (ROS); likely secondary to over-expression of ROS generating enzymes and chronically heightened inflammation. Interestingly, β2AR has long-been linked to ROS, yet the involvement of ROS in β2AR function has not been as vigorously studied as other aspects of β2AR signaling. Herein, we discuss the existing body of evidence linking β2AR activation to intracellular ROS generation and importantly, the role of ROS in regulating β2AR function. The reciprocal interplay of the β2AR and ROS appear to endow this receptor with the ability to self-regulate signaling efficacy and ligand binding, hereby unveiling a redox-axis that may be unfavorably altered in pathological states contributing to both disease progression and therapeutic drug responses.

Analysis of the Mechanisms of Action of Naphthoquinone-Based Anti-Acute Myeloid Leukemia Chemotherapeutics

Acute myeloid leukemia (AML) is a neoplastic disorder resulting from clonal proliferation of poorly differentiated immature myeloid cells. Distinct genetic and epigenetic aberrations are key features of AML that account for its variable response to standard therapy. Irrespective of their oncogenic mutations, AML cells produce elevated levels of reactive oxygen species (ROS). They also alter expression and activity of antioxidant enzymes to promote cell proliferation and survival. Subsequently, selective targeting of redox homeostasis in a molecularly heterogeneous disease, such as AML, has been an appealing approach in the development of novel anti-leukemic chemotherapeutics. Naphthoquinones are able to undergo redox cycling and generate ROS in cancer cells, which have made them excellent candidates for testing against AML cells. In addition to inducing oxidative imbalance in AML cells, depending on their structure, naphthoquinones negatively affect other cellular apparatus causing neoplastic cell death. Here we provide an overview of the anti-AML activities of naphthoquinone derivatives, as well as analysis of their mechanism of action, including induction of reduction-oxidation imbalance, alteration in mitochondrial transmembrane potential, Bcl-2 modulation, initiation of DNA damage, and modulation of MAPK and STAT3 activity, alterations in the unfolded protein response and translocation of FOX-related transcription factors to the nucleus.

Mechanism of isoniazid-induced hepatotoxicity in zebrafish larvae: Activation of ROS-mediated ERS, apoptosis and the Nrf2 pathway

Isoniazid (INH) is a first-line anti-tuberculosis drug. INH has been detected in surface waters which may create a risk to aquatic organisms. In this study, the hepatotoxicity of INH was elucidated using zebrafish. The liver morphology, transaminase level, redox-related enzyme activity, reactive oxygen species (ROS) content and mRNA levels of liver injury-related genes were measured. The results showed that INH (4, 6 mM) significantly caused liver atrophy and increased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in zebrafish. INH (6 mM) led to decreased catalase (CAT) activity, glutathione peroxidase (GPx) activity and glutathione (GSH) content but increased ROS and malondialdehyde (MDA) levels. Moreover, INH (6 mM) decreased expression levels of miR-122 and pparα but increased mRNA levels of ap-1 and c-jun. Furthermore, mRNA levels of factors related to endoplasmic reticulum stress (ERS) (grp78, atf6, perk, ire1, xbp1s and chop), apoptosis (bax, cyt, caspase-3, caspase-8 and caspase-9) and the Nrf2 signalling pathway (nrf2, ho-1, nqo1, gclm and gclc) were significantly upregulated. INH may act on hepatotoxicity in zebrafish by increasing ROS content, which weakens the antioxidant capacity, leading to ERS, cell apoptosis and liver injury. In addition, the Nrf2 signalling pathway is activated as a stress compensation mechanism during INH-induced liver injury, but it is not sufficient to counteract INH-induced hepatotoxicity.

Oxidative stress before and after surgery in benign prostatic hyperplasia patients

The aim was to assess oxidative stress in benign prostatic hyperplasia patients and also to evaluate the effect of operation in late (60 days) post-operative period. This study was conducted with 16 patients with benign prostatic hyperplasia and 16 healthy subjects. Serum malondialdehyde, blood 8-hydroxy-2'-deoxyguanosine/deoxyguanosine, erythrocyte superoxide dismutase, serum total coenzyme Q₁₀ and coenzyme Q₁₀ levels were measured. Independent samples t test was used to analyse the differences between control group and patients, while paired t test was used to analyse the differences between pre-operative and post-operative periods. Malondialdehyde and total coenzyme Q₁₀ levels were lower in patients, while 8-hydroxy-2'-deoxyguanosine/deoxyguanosine level was increased. However, superoxide dismutase activity and coenzyme Q₁₀ levels did not differ. After 60 days of operation, 8-hydroxy-2'-deoxyguanosine/deoxyguanosine and superoxide dismutase activity decreased, while total coenzyme Q₁₀ level increased. However, malondialdehyde and coenzyme Q₁₀ levels were not affected. The international prostate symptom scores of the patients were also decreased after the operation. The results suggest that blood 8-hydroxy-2'-deoxyguanosine/deoxyguanosine level may reflect the oxidative stress better than the malondialdehyde level, and surgical operation attenuates the oxidative stress in late post-operative period in benign prostatic hyperplasia patients.

Water- and Fat-Soluble Antioxidants in Human Seminal Plasma and Serum of Fertile Males

Reactive oxygen species (ROS) are physiologically involved in functions like sperm maturation, capacitation and acrosome reaction, but their excess is involved in male infertility. Antioxidants in seminal plasma (SP) are an important factor balancing physiologic and harmful ROS activities. In this study, we determined and compared the full profiles of the water- and fat-soluble antioxidants in SP and serum of 15 healthy fertile subjects (ranging between the ages of 35 and 42 years). Ejaculates were obtained after 2⁻5 days of sexual abstinence. After liquefaction and withdrawal of an aliquot for the sperm count, samples were centrifuged to obtain SP. Thirty min after semen donation, a venous blood sample was collected from each subject. Donors with lower SP concentrations of ascorbic acid (n = 5) or α-tocopherol (n = 5) received a 4 week oral administration of either vitamin C (100 mg/day) or vitamin E (30 mg/day). They were then re-assayed to determine the SP and serum levels of ascorbic acid and α-tocopherol. SP and serum samples were properly processed and analyzed by HPLC methods suitable to determine water (ascorbic acid, glutathione (GSH) and uric acid) and fat-soluble (all-trans-retinoic acid, all-trans-retinol, α-tocopherol, carotenoids and coenzyme Q10) antioxidants. Data demonstrate that only ascorbic acid is higher in SP than in serum (SP/serum ratio = 4.97 ± 0.88). The other water-soluble antioxidants are equally distributed in the two fluids (GSH SP/serum ratio = 1.14 ± 0.34; uric acid SP/serum ratio = 0.82 ± 0.12). All fat-soluble antioxidants are about 10 times less concentrated in SP than in serum. In donors treated with vitamin C or vitamin E, ascorbic acid and α-tocopherol significantly increased in both fluids. However, the SP/serum ratio of ascorbic acid was 4.15 ± 0.45 before and 3.27 ± 0.39 after treatment, whilst those of α-tocopherol were 0.11 ± 0.03 before and 0.10 ± 0.02 after treatment. The results of this study, by showing the peculiar composition in water- and fat-soluble antioxidants SP, indicate that it is likely that still-unknown mechanisms allow ascorbic acid accumulation in SP against a concentration gradient. SP mainly relies its defenses on water- rather than fat-soluble antioxidants and on the mechanisms ensuring their transfer from serum.

Evaluation of the antioxidant effects of acid hydrolysates from Auricularia auricular polysaccharides using a Caenorhabditis elegans model

Caenorhabditis elegans is an important model organism for studying stress response mechanisms. In this paper, C. elegans was used to evaluate the antioxidant effects of acid hydrolysates from Auricularia auricular polysaccharides.