Glutathione and modulation of cell apoptosis

Interplay between Mitochondrial Metabolism and Cellular Redox State Dictates Cancer Cell Survival

Mitochondria are the main powerhouse of the cell, generating ATP through the tricarboxylic acid cycle (TCA) and oxidative phosphorylation (OXPHOS), which drives myriad cellular processes. In addition to their role in maintaining bioenergetic homeostasis, changes in mitochondrial metabolism, permeability, and morphology are critical in cell fate decisions and determination. Notably, mitochondrial respiration coupled with the passage of electrons through the electron transport chain (ETC) set up a potential source of reactive oxygen species (ROS). While low to moderate increase in intracellular ROS serves as secondary messenger, an overwhelming increase as a result of either increased production and/or deficient antioxidant defenses is detrimental to biomolecules, cells, and tissues. Since ROS and mitochondria both regulate cell fate, attention has been drawn to their involvement in the various processes of carcinogenesis. To that end, the link between a prooxidant milieu and cell survival and proliferation as well as a switch to mitochondrial OXPHOS associated with recalcitrant cancers provide testimony for the remarkable metabolic plasticity as an important hallmark of cancers. In this review, the regulation of cell redox status by mitochondrial metabolism and its implications for cancer cell fate will be discussed followed by the significance of mitochondria-targeted therapies for cancer.

Glutathione system activity in the blood of overweight postmenopausal women

One of the important components of the antioxidant defense system is the glutathione system, the activity of which, when overweight, changes direction depending on gender and ethnicity. The results of studies involving overweight menopausal women are mixed. The study involved 61 postmenopausal women, who, after clinical and anamnestic examination, were divided into 2 groups: control (BMI = 19-24.9 kg / m2) and overweight group (BMI = 25-29.9 kg/m2). The use of hormone replacement therapy; the use of antioxidant drugs; diseases of endocrine genesis; exacerbation of chronic diseases; premature early menopause; surgical menopause was the exclusion criteria for women from the study. The lipid profile parameters with the calculation of the atherogenic coefficient; reduced and oxidized glutathione levels with the calculation of their ratio, the glutathione S-transferase and glutathione reductase activities were determined in the blood. Overweight women showed an increase in the triacylglycerols (p = 0.041) and cholesterol in very low density lipoproteins levels (p = 0.044). When assessing the glutathione system activity in women of the main group, compared with the control, an increase in the glutathione-S-transferase (p = 0.023) and glutathione reductase (p = 0.022) activities was noted, however, the reduced and oxidized glutathione levels, as well as their ratio did not differ from the control values. The results obtained indicate the activation of the glutathione system enzymatic link in response to changes in lipid status in postmenopausal women with overweight.

Oxidative stress activates the Nrf2-mediated antioxidant response and P38 MAPK pathway: A possible apoptotic mechanism induced by BDE-47 in rainbow trout (Oncorhynchus mykiss) gonadal RTG-2 cells

Our previous study showed that 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), the most biotoxic polybrominated diphenyl ether (PBDE) in the marine environment, induced apoptosis in rainbow trout gonadal RTG-2 cells. This effect occurred via ROS- and Ca²⁺-mediated apoptotic pathways, but the exact mechanism remains unknown. Therefore, in the present study, the possible mechanism was examined from the perspective of ROS-induced oxidative stress. The results showed that BDE-47 exposure significantly elevated the malondialdehyde (MDA) contents and the intracellular GSH/GSSG ratio, and the GSH-related enzymes were greatly altered, indicating alteration of the redox status and occurrence of oxidative stress. The mRNA levels of nuclear factor E2-related factor 2 (Nrf2) and its downstream genes were simultaneously greatly elevated. The p38 mitogen-activated protein kinase (MAPK) signaling pathway was also found to be induced by BDE-47 exposure. The addition of SB203580, a p38 MAPK inhibitor resulted in decreased apoptosis. In addition, supplementation with Ca²⁺ inhibitors BAPTA-AM positively affected p38 MAPK activation. Taken together, BDE-47 exposure resulted in the occurrence of oxidative stress and initiated the Nrf2-mediated antioxidant response. Subsequently, the altered redox status induced p38 MAPK activation, which played a pivotal role in the cellular apoptosis of RTG-2 cells.

Maternal overweight increased sensitivity of mouse preimplantation embryos to oxidative stress in vitro

The aim of this study was to compare the sensitivity of mouse preimplantation embryos obtained from mothers with different body conditions to an environment with increased oxidative stress. An intergenerational dietary model based on mouse overfeeding during the intrauterine and early postnatal period was used to produce females with increased body fat content (≥ 11 %). Three different sources of oxidative stress were applied: 0.01 mM 2,2'-Azobis (2-methylpropionamidine) dihydrochloride (AAPH), free radical-generating compound; 5 mM l-Buthionine-sulfoximine (BSO), glutathione synthesis inhibitor; and 0.01 mM Sodium nitroprusside dihydrate (SNP), nitric oxide donor. Two-cell embryos isolated from controls (with 7 %-8 % body fat content) and overweight mice were cultured in vitro with selected compounds until blastocyst formation. Development of two-cell embryos isolated from overweight dams was negatively affected by the presence of BSO and SNP (P < 0.01). Similar impact was recorded in two-cell embryos obtained from control mothers only after exposure to BSO (P < 0.05). Fluorescence analysis of blastocysts recovered from overweight dams revealed reduced total cell numbers after AAPH and BSO treatment, and increased incidence of cell death after BSO and SNP. In the controls, negative impact on blastocyst quality, represented by reduced cell number, was observed only after BSO. Immunofluorescence evaluation of freshly-recovered zygotes and two-cell embryos showed that those obtained from overweight dams displayed significantly lower fluorescence signal intensity of Glutathione peroxidase 8 than those from control dams. In conclusion, the results suggest that preimplantation embryos originating from overweight mice might be more vulnerable to oxidative stress than those originating from control females.

Sirt1 deficiency upregulates glutathione metabolism to prevent hepatocellular carcinoma initiation in mice

Sirtuin-1 (SIRT1) is involved in various metabolic pathways, including fatty acid synthesis and gluconeogenesis in the liver. However, its role in initiation and progression of liver cancer remains unclear. Studying Sirt1 liver-specific knockout (LKO) mice in combination with diethylnitrosamine (DEN) treatment, we demonstrated that loss of Sirt1 rendered mice resistant to DEN-induced hepatocellular carcinoma (HCC) development. RNA-seq revealed that livers from LKO mice exhibited an enrichment in glutathione metabolism eight months after DEN challenge. Sirt1 deficiency elevated the expression of glutathione-s-transferase family genes by increasing the level of Nrf2, a key regulator of glutathione metabolism. Hence, LKO livers displayed a reductive environment with an increased ratio of GSH to GSSG and an elevated GSH level. Furthermore, using CRISPR knockout techniques, we confirmed that the impairment of HCC formation in LKO mice is mainly dependent on NRF2 signaling. Meanwhile, HCC induced by DEN could be blocked by the administration of N-acetyl cysteine (NAC) when administered one month after DEN challenge. However, NAC treatment starting five months after DEN injection was not able to prevent tumor development. In conclusion, our findings indicate that a reductive environment orchestrated by glutathione metabolism at an early stage can prevent the initiation of HCC.

Temporal correlation of morphological and biochemical changes with the recruitment of different mechanisms of reactive oxygen species formation during human SW872 cell adipogenic differentiation

Human SW872 preadipocyte conversion to mature adipocytes is associated with time-dependent changes in differentiation markers' expression and with morphological changes accompanied by the accumulation of lipid droplets (LDs) as well as by increased mitochondriogenesis and mitochondrial membrane potential. Under identical conditions, the formation of reactive oxygen species (ROS) revealed with a general probe was significant at days 3 and 10 of differentiation and bearly detectable at day 6. NADPH oxidase (NOX)-2 activity determined with an immunocytochemical approach followed a very similar pattern. There was no evidence of mitochondrial ROS (mROS), as detected with a selective fluorescence probe, at days 3 and 6, possibly due to the triggering of the Nrf-2 antioxidant response. mROS were instead clearly detected at day 10, concomitantly with the accumulation of very large LDs, oxidation of both cardiolipin and thioredoxin 2, and decreased mitochondrial glutathione. In conclusion, the morphological and biochemical changes of differentiating SW872 cells are accompanied by the discontinuous formation of ROS derived from NOX-2, increasingly implicated in adipogenesis and adipose tissue dysfunction. In addition, mROS formation was significant only in the late phase of differentiation and was associated with mitochondrial dysfunction.

Stimuli-Responsive Poly(aspartamide) Derivatives and Their Applications as Drug Carriers

Poly(aspartamide) derivatives, one kind of amino acid-based polymers with excellent biocompatibility and biodegradability, meet the key requirements for application in various areas of biomedicine. Poly(aspartamide) derivatives with stimuli-responsiveness can usually respond to external stimuli to change their chemical or physical properties. Using external stimuli such as temperature and pH as switches, these smart poly(aspartamide) derivatives can be used for convenient drug loading and controlled release. Here, we review the synthesis strategies for preparing these stimuli-responsive poly(aspartamide) derivatives and the latest developments in their applications as drug carriers.

Metabolic Reprogramming: A Friend or Foe to Cancer Therapy?

Drug resistance is a major cause of cancer treatment failure, effectively driven by processes that promote escape from therapy-induced cell death. The mechanisms driving evasion of apoptosis have been widely studied across multiple cancer types, and have facilitated new and exciting therapeutic discoveries with the potential to improve cancer patient care. However, an increasing understanding of the crosstalk between cancer hallmarks has highlighted the complexity of the mechanisms of drug resistance, co-opting pathways outside of the canonical "cell death" machinery to facilitate cell survival in the face of cytotoxic stress. Rewiring of cellular metabolism is vital to drive and support increased proliferative demands in cancer cells, and recent discoveries in the field of cancer metabolism have uncovered a novel role for these programs in facilitating drug resistance. As a key organelle in both metabolic and apoptotic homeostasis, the mitochondria are at the forefront of these mechanisms of resistance, coordinating crosstalk in the event of cellular stress, and promoting cellular survival. Importantly, the appreciation of this role metabolism plays in the cytotoxic response to therapy, and the ability to profile metabolic adaptions in response to treatment, has encouraged new avenues of investigation into the potential of exploiting metabolic addictions to improve therapeutic efficacy and overcome drug resistance in cancer. Here, we review the role cancer metabolism can play in mediating drug resistance, and the exciting opportunities presented by imposed metabolic vulnerabilities.

Early closure mechanisms of the ductus arteriosus in immature infants

AIM

According to experimental studies, cardiopulmonary distress decreases after closure of patent ductus arteriosus. However, early closure of the ductus using ibuprofen or indomethacin has failed to increase survival without serious morbidity. We review relevant data aiming to define optimal early management strategies that promote early closure of ductus arteriosus without serious adverse effects.

METHODS

Literature in English was searched selectively focusing on the potential of using acetaminophen for early closure of the ductus.

RESULTS

Prophylactic ibuprofen or indomethacin intended to close the ductus, predisposes infants to ischaemia, bleeding and immune dysfunction. Acetaminophen appears to have a similar efficacy as indomethacin or ibuprofen, and all three dose-dependently constrict the ductus. Ibuprofen and indomethacin cause non-specific inhibition of prostaglandin synthesis, while acetaminophen predominantly inhibits prostaglandin E synthesis. Owing to low CYP450 activity in infancy, acetaminophen toxicity has been rarely evident. However, increasing the dosage increases the oxidative stress. We review prophylactic treatments that may increase the safety and efficacy of acetaminophen. These include vitamin A, cysteine and glutamine, and low-dose corticosteroid supplementation.

CONCLUSION

The current challenge is to define a safe perinatal management practice that promotes cardiorespiratory adaptation in immature infants, particularly the seamless closure of the ductus before significant cardiopulmonary distress develops.

Effects of neoadjuvant therapies on genetic regulation of targeted pathways in ER+ primary ductal breast carcinoma: A meta-analysis of microarray datasets

Breast cancer arises as a result of multiple interactions between environmental and genetic factors. Conventionally, breast cancer is treated based on histopathological and clinical features. DNA technologies like the human genome microarray are now partially integrated into clinical practice and are used for developing new "personalized medicines" and "pharmacogenetics" for improving the efficiency and safety of cancer medications. We investigated the effects of four established therapies-for ER+ ductal breast cancer-on the differential gene expression. The therapies included single agent tamoxifen, two-agent docetaxel and capecitabine, or combined three-agents CAF (cyclophosphamide, doxorubicin, and fluorouracil) and CMF (cyclophosphamide, methotrexate, and fluorouracil). Genevestigator 8.1.0 was used to compare five datasets from patients with infiltrating ductal carcinoma, untreated or treated with selected drugs, to those from the healthy control. We identified 74 differentially expressed genes involved in three pathways, i.e., apoptosis (extrinsic and intrinsic), oxidative signaling, and PI3K/Akt signaling. The treatments affected the expression of apoptotic genes (TNFRSF10B [TRAIL], FAS, CASP3/6/7/8, PMAIP1 [NOXA], BNIP3L, BNIP3, BCL2A1, and BCL2), the oxidative stress-related genes (NOX4, XDH, MAOA, GSR, GPX3, and SOD3), and the PI3K/Akt pathway gene (ERBB2 [HER2]). Breast cancer treatments are complex with varying drug responses and efficacy among patients. This necessitates identifying novel biomarkers for predicting the drug response, using available data and new technologies. GSR, NOX4, CASP3, and ERBB2 are potential biomarkers for predicting the treatment response in primary ER+ ductal breast carcinoma.

Induction of Glutathione Synthesis Provides Cardioprotection Regulating NO, AMPK and PPARa Signaling in Ischemic Rat Hearts

Glutathione (GSH) is essential for antioxidant defence, and its depletion is associated with tissue damage during cardiac ischemia-reperfusion (I/R). GSH is synthesized by the glutamate-cysteine ligase enzyme (GCL) from L-cysteine, which alternatively might be used for hydrogen sulfide production by cystathionine-gamma-lyase (CSE). Here, we have investigated whether in vivo treatment with L-cysteine and an inhibitor of CSE,D,L-propargylglycine (PAG), can modulate cardiac glutathione and whether this treatment can influence heart resistance to I/R in a Langendorff isolated rat hearts model. Pretreatment with PAG + L-cysteine manifested in pronounced cardioprotection, as there was complete recovery of contractile function; preserved constitutive NOS activity; and limited the production of reactive oxygen and nitrogen species in the ischemized myocardium. Cardiac GSH and GSSG levels were increased by 3.5- and 2.1-fold in PAG + L-cysteine hearts and were 3.3- and 3.6-fold higher in PAG + L-cysteine + I/R compared to I/R heart. The cardioprotective effect of PAG + L-cysteine was completely abolished by an inhibitor of GCL, DL-buthionine-(S,R)-sulfoximine. Further analysis indicated diminished fatty acid β-oxidation, increased glucose consumption and anaerobic glycolysis, and promoted OXPHOS proteins and SERCA2 in PAG + L-cysteine + I/R compared to the I/R group. PAG + L-cysteine inhibited PPARα and up-regulated AMPK signalling in the heart. Thus, induction of glutathione synthesis provided cardioprotection regulating NO, AMPK and PPARa signaling in ischemic rat hearts.

Nicotinamide Riboside and Pterostilbene Cooperatively Delay Motor Neuron Failure in ALS SOD1G93A Mice

Oxidative stress-induced damage is a major mechanism in the pathophysiology of amyotrophic lateral sclerosis (ALS). A recent human clinical trial showed that the combination of nicotinamide riboside (NR) and pterostilbene (PT), molecules with potential to interfere in that mechanism, was efficacious in ALS patients. We examined the effect of these molecules in SOD1G93A transgenic mice, a well-stablished model of ALS. Assessment of neuromotor activity and coordination was correlated with histopathology, and measurement of proinflammatory cytokines in the cerebrospinal fluid. Cell death, Nrf2- and redox-dependent enzymes and metabolites, and sirtuin activities were studied in isolated motor neurons. NR and PT increased survival and ameliorated ALS-associated loss of neuromotor functions in SOD1G93A transgenic mice. NR and PT also decreased the microgliosis and astrogliosis associated with ALS progression. Increased levels of proinflammatory cytokines were observed in the cerebrospinal fluid of mice and humans with ALS. NR and PT ameliorated TNFα-induced oxidative stress and motor neuron death in vitro. Our results support the involvement of oxidative stress, specific Nrf2-dependent antioxidant defenses, and sirtuins in the pathophysiology of ALS. NR and PT interfere with the mechanisms leading to the release of proapoptotic molecular signals by mitochondria, and also promote mitophagy.

α-Amino acid N-carboxyanhydride (NCA)-derived synthetic polypeptides for nucleic acids delivery

In recent years, gene therapy has come into the spotlight for the prevention and treatment of a wide range of diseases. Polypeptides have been widely used in mediating nucleic acid delivery, due to their versatilities in chemical structures, desired biodegradability, and low cytotoxicity. Chemistry plays an essential role in the development of innovative polypeptides to address the challenges of producing efficient and safe gene vectors. In this Review, we mainly focused on the latest chemical advances in the design and preparation of polypeptide-based nucleic acid delivery vehicles. We first discussed the synthetic approach of polypeptides via ring-opening polymerization (ROP) of N-carboxyanhydrides (NCAs), and introduced the various types of polypeptide-based gene delivery systems. The extracellular and intracellular barriers against nucleic acid delivery were then outlined, followed by detailed review on the recent advances in polypeptide-based delivery systems that can overcome these barriers to enable in vitro and in vivo gene transfection. Finally, we concluded this review with perspectives in this field.

Biological and Physico-Chemical Characteristics of Arginine-Rich Peptide Gemini Surfactants with Lysine and Cystine Spacers

Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic N-terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants. l-cystine diamide and l-lysine amide linkers were used as spacers. Antimicrobial activity against planktonic and biofilm cultures of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) strains and Candida sp. as well as hemolytic and cytotoxic activities were examined. Moreover, antimicrobial activity in the presence of human serum and the ability to form micelles were evaluated. Membrane permeabilization study, serum stability assay, and molecular dynamics were performed. Generally, critical aggregation concentration was linearly correlated with hydrophobicity. Gemini surfactants were more active than the parent USCLs, and they turned out to be selective antimicrobial agents with relatively low hemolytic and cytotoxic activities. Geminis with the l-cystine diamide spacer seem to be less cytotoxic than their l-lysine amide counterparts, but they exhibited lower antibiofilm and antimicrobial activities in serum. In some cases, geminis with branched fatty acid chains and N-terminal hydrophobic amino acid resides exhibited enhanced selectivity to pathogens over human cells.

Targeting Redox Metabolism in Pancreatic Cancer

Cell metabolism is reprogrammed in cancer cells to meet their high bioenergetics and biosynthetic demands. This metabolic reprogramming is accompanied by alterations in redox metabolism, characterized by accumulation of reactive oxygen species (ROS). Elevated production of ROS, mostly by mitochondrial respiration, is counteracted by higher production of antioxidant defenses (mainly glutathione and antioxidant enzymes). Cancer cells are adapted to a high concentration of ROS, which contributes to tumorigenesis, metastasis formation, resistance to therapy and relapse. Frequent genetic alterations observed in pancreatic ductal adenocarcinoma (PDAC) affect KRAS and p53 proteins, which have a role in ROS production and control, respectively. These observations led to the proposal of the use of antioxidants to prevent PDAC development and relapse. In this review, we focus on the therapeutic strategies to further increase ROS level to induce PDAC cell death. Combining the promotion of ROS production and inhibition of antioxidant capacity is a promising avenue for pancreatic cancer therapy in the clinic.

The Molecular Mechanism of Aluminum Phosphide poisoning in Cardiovascular Disease: Pathophysiology and Diagnostic Approach

Nowadays, poisoning with metal phosphides, especially aluminum phosphide (ALP), is one of the main health threats in human societies. Patients suffer from significant complications due to this type of poisoning, and the heart is one of the main organs targeted by ALP. Therefore, in this study, we discussed the effect of phosphine on cardiac function. This study is based on data obtained from PubMed, between 2002 and 2020. The key keywords included "Aluminum phosphide," "Oxidative Stress," "Mitochondria," "Cardiovascular disease," and "Treatment." The results showed that ALP produced reactive oxygen species (ROS) due to mitochondrial dysfunction. ROS production leads to red blood cell hemolysis, decreased ATP production, and induction of apoptosis in cardiomyocytes, which eventually results in cardiovascular disease. Since ALP has the most significant effect on cardiomyocytes, the use of appropriate treatment strategies to restore cell function can increase patients' survival.

Transcriptome analysis implicates secondary metabolite production, redox reactions, and programmed cell death during allorecognition in Cryphonectria parasitica

The underlying molecular mechanisms of programmed cell death associated with fungal allorecognition, a form of innate immunity, remain largely unknown. In this study, transcriptome analysis was used to infer mechanisms activated during barrage formation in vic3-incompatible strains of Cryphonectria parasitica, the chestnut blight fungus. Pronounced differential expression occurred in barraging strains of genes involved in mating pheromone (mf2-1, mf2-2), secondary metabolite production, detoxification (including oxidative stress), apoptosis-related, RNA interference, and HET-domain genes. Evidence for secondary metabolite production and reactive oxygen species (ROS) accumulation is supported through UPLC-HRMS analysis and cytological staining, respectively. Differential expression of mating-related genes and HET-domain genes was further examined by RT-qPCR of incompatible interactions involving each of the six vegetative incompatibility (vic) loci in C. parasitica and revealed distinct recognition process networks. We infer that vegetative incompatibility in C. parasitica activates defence reactions that involve secondary metabolism, resulting in increased toxicity of the extra- and intracellular environment. Accumulation of ROS (and other potential toxins) may result in detoxification failure and activation of apoptosis, sporulation, and the expression of associated pheromone genes. The incompatible reaction leaves abundant traces of a process-specific metabolome as conidiation is initiated.

Cell Death Induction and Protection by Activation of Ubiquitously Expressed Anion/Cation Channels. Part 1: Roles of VSOR/VRAC in Cell Volume Regulation, Release of Double-Edged Signals and Apoptotic/Necrotic Cell Death

Cell volume regulation (CVR) is essential for survival and functions of animal cells. Actually, normotonic cell shrinkage and swelling are coupled to apoptotic and necrotic cell death and thus called the apoptotic volume decrease (AVD) and the necrotic volume increase (NVI), respectively. A number of ubiquitously expressed anion and cation channels are involved not only in CVD but also in cell death induction. This series of review articles address the question how cell death is induced or protected with using ubiquitously expressed ion channels such as swelling-activated anion channels, acid-activated anion channels and several types of TRP cation channels including TRPM2 and TRPM7. The Part 1 focuses on the roles of the volume-sensitive outwardly rectifying anion channels (VSOR), also called the volume-regulated anion channel (VRAC), which is activated by cell swelling or reactive oxygen species (ROS) in a manner dependent on intracellular ATP. First we describe phenotypical properties, the molecular identity, and physical pore dimensions of VSOR/VRAC. Second, we highlight the roles of VSOR/VRAC in the release of organic signaling molecules, such as glutamate, glutathione, ATP and cGAMP, that play roles as double-edged swords in cell survival. Third, we discuss how VSOR/VRAC is involved in CVR and cell volume dysregulation as well as in the induction of or protection from apoptosis, necrosis and regulated necrosis under pathophysiological conditions.

Thioredoxin Delays Photoreceptor Degeneration, Oxidative and Inflammation Alterations in Retinitis Pigmentosa

Retinitis pigmentosa (RP) is an inherited ocular disorder with no effective treatment. RP onset and progression trigger a cascade of retinal disorders that lead to the death of photoreceptors. After photoreceptors death, neuronal, glial and vascular remodeling can be observed in the retina. The purpose of this study was to study if thioredoxin (TRX) administration is able to decrease photoreceptor death in an animal model of RP (rd1 mouse), but also if it is able to modulate the retinal oxidative stress, glial and vascular changes that can be observed as the disease progresses. Wild type and rd1 mice received several doses of TRX. After treatment, animals were euthanized at postnatals days 11, 17, or 28. Glutathione (GSH) and other thiol compounds were determined by high performance liquid chromatography (HPLC). Glial fibrilary acidic protein (GFAP) and anti-ionized calcium binding adaptor molecule 1 (Iba1) were studied by immunohistochemistry. Vascular endothelial growth factor (VEGF) and hepatic growth factor (HGF) expression were determined by western blot. TRX administration significantly diminished cell death in rd1 mouse retinas and increased GSH retinal concentrations at postnatal day 11 (PN11). TRX was also able to reverse glial alterations at PN11 and PN17. No alterations were observed in retinal VEGF and HGF expression in rd1 mice. In conclusion, TRX treatment decreases photoreceptor death in the first stages of RP and this protective effect may be due in part to the GSH system activation and to a partially decrease in inflammation.

The redox language in neurodegenerative diseases: oxidative post-translational modifications by hydrogen peroxide

Neurodegenerative diseases, a subset of age-driven diseases, have been known to exhibit increased oxidative stress. The resultant increase in reactive oxygen species (ROS) has long been viewed as a detrimental byproduct of many cellular processes. Despite this, therapeutic approaches using antioxidants were deemed unsuccessful in circumventing neurodegenerative diseases. In recent times, it is widely accepted that these toxic by-products could act as secondary messengers, such as hydrogen peroxide (H₂O₂), to drive important signaling pathways. Notably, mitochondria are considered one of the major producers of ROS, especially in the production of mitochondrial H₂O₂. As a secondary messenger, cellular H₂O₂ can initiate redox signaling through oxidative post-translational modifications (oxPTMs) on the thiol group of the amino acid cysteine. With the current consensus that cellular ROS could drive important biological signaling pathways through redox signaling, researchers have started to investigate the role of cellular ROS in the pathogenesis of neurodegenerative diseases. Moreover, mitochondrial dysfunction has been linked to various neurodegenerative diseases, and recent studies have started to focus on the implications of mitochondrial ROS from dysfunctional mitochondria on the dysregulation of redox signaling. Henceforth, in this review, we will focus our attention on the redox signaling of mitochondrial ROS, particularly on mitochondrial H₂O₂, and its potential implications with neurodegenerative diseases.

Amino Acids in Endoplasmic Reticulum Stress and Redox Signaling

Proteins are the chains of amino acids linked via peptide bonds. In cells, newly synthesized proteins are modified and folded in the endoplasmic reticulum (ER) and matured to be functional proteins before they are transported to other tissues or organs. In addition to protein synthesis, the ER is also a stress-sensing organelle for diverse biological functions, such as calcium storage, lipid synthesis, and cellular metabolism. Nutrient deprivation, accumulation of reactive oxygen species, and other intracellular insults can activate ER stress and unfolded protein response (UPR) to restore homeostasis. Dysfunction of the ER influences cellular physiology and metabolism, and contributes to the pathogenesis of various diseases. Amino acids are the building blocks for proteins of eukaryotic organisms. Both in vivo and in vitro studies have found that amino acids can function as signaling molecules to regulate gene expression, cell proliferation and apoptosis, immune response, and antioxidant capacity in numerous biological processes. Importantly, several lines of studies have indicated that amino acids regulate the abundances of proteins implicated in UPR and the redox state, therefore restoring the intracellular homeostasis. Amino acids play an important role in regulating ER stress and redox homeostasis in animal cells for their survival, growth, and development.

An insight into the functional role of antioxidant and detoxification enzymes in adult Rhipicephalus microplus female ticks

Ticks have developed physiological adaptations to transport, store, metabolize and secrete toxic components from the diet and environment. Different classes of enzymes are involved in these processes, however, the role of several of them is not yet characterized in Rhipicephalus microplus. In this context, this work investigated the action of antioxidant and detoxification enzymes, as well as the levels of essential cellular reductants in R. microplus partially engorged females (PEF) and fully engorged females (FEF). Results demonstrated that enzymes transcriptional levels and enzymatic activity from ovary and fat body were higher in PEF than in FEF, except for ovary Glutathione peroxidase (GPx), which was the only enzyme showing highest activity in the FEF stage. These results indicated a higher demand for antioxidant potential in these organs at the initial feeding phase than during egg-laying. In midgut, however, there was more variability in the transcriptional levels and activity of the different enzymes between the PEF and FEF phases. Similar NADPH levels were found in PEF and FEF phases, suggesting a remarkable capacity to maintain a regular supply of reducing power, despite the developmental changes and large intake of heme and iron. However, reduced glutathione (GSH) levels were variable between PEF and FEF when distinct organs were compared. Taken together, our data suggest a higher demand for reducing potential in FEF ticks. The silencing of catalase (CAT) or thioredoxin reductase (TRx) genes in females did not impair feeding, egg-laying capacity, or larvae hatching. CAT-silenced ticks had increased ovary peroxidase activity, a possible compensatory antioxidant mechanism. Altogether, the results shed light on the complexity of the antioxidant and detoxification enzyme system in ticks and its involvement in different physiological mechanisms.

Cathepsin B is an executioner of ferroptosis

Ferroptosis is a necrotic form of cell death caused by inactivation of the glutathione system and uncontrolled iron-mediated lipid peroxidation. Increasing evidence implicates ferroptosis in a wide range of diseases from neurotrauma to cancer, highlighting the importance of identifying an executioner system that can be exploited for clinical applications. In this study, using pharmacological and genetic models of ferroptosis, we observed that lysosomal membrane permeabilization and cytoplasmic leakage of cathepsin B unleashes structural and functional changes in mitochondria and promotes a not previously reported cleavage of histone H3. Inhibition of cathepsin-B robustly rescued cellular membrane integrity and chromatin degradation. We show that these protective effects are independent of glutathione peroxidase-4 and are mediated by preventing lysosomal membrane damage. This was further confirmed when cathepsin B knockout primary fibroblasts remained unaffected in response to various ferroptosis inducers. Our work identifies new and yet-unrecognized aspects of ferroptosis and identifies cathepsin B as a mediator of ferroptotic cell death.

The Impact of Fermented Wheat Germ Extract on Porcine Epithelial Cell Line Exposed to Deoxynivalenol and T-2 Mycotoxins

The effect of fermented wheat germ extract (FWGE) (Immunovet®) was evaluated with cotreatments with deoxynivalenol (DON) and T-2 toxin (T-2). These mycotoxins are produced by Fusarium mold species. The effects of FWGE on IPEC-J2 with DON and T-2 have not been studied until now. The IPEC-J2 porcine, nontumorigenic cell line was selected to investigate the outcome of the individually and simultaneously added compounds, as it has in vivo-like properties. The cells were treated for 24 h with the selected solutions; then, the IPEC-J2 cells were allowed to regenerate in a culture medium for an additional 24 h. In our results, DON and T-2 significantly increased the adverse impacts on cell viability and integrity of the cell monolayer. To elucidate the extent of oxidative stress, extracellular H₂O₂ concentrations and intracellular reactive oxygen species (ROS) were measured. FWGE appeared to be beneficial to IPEC-J2 cells given the separately and significantly decreased ROS levels. 1% and 2% FWGE could significantly reduce mycotoxin-induced oxidative stress. In conclusion, the results demonstrate that FWGE exerted protective effects to counteract the oxidative stress-provoking properties of applied fusariotoxins in the nontumorigenic IPEC-J2 cell line.

Therapeutic potential of sulfur-containing natural products in inflammatory diseases

Owing to the prevalence of chronic inflammation and its related disorders, there is a demand for novel therapeutic agents capable of preventing or suppressing inflammation. Natural products (NPs) are well established as an important resource for drug development and provide an almost infinite array of molecular entities. Sulfur-containing NPs (i.e., NPs containing one or more sulfur atoms) are abundant throughout nature, from bacteria to animals. The aim of this review was to survey the emerging evidence on role of sulfur-containing NPs, such as glutathione, garlic-derived sulfur compounds, Epipolythiodioxopiperazines (EPTs), Isothiocyanates (ITCs), and Ergothioneine (EGT), in the control of inflammation and to determine the possible underlying mechanisms. A discussion of how hydrogen sulfide (H₂S), an endogenous gaseous signaling molecule, links sulfur-containing NPs and their anti-inflammatory action is also performed. This review may help to further the development of sulfur-based compounds by providing a guide for structure-activity relationship-based modification for use in modern medicinal chemistry. However, as this field is still in its infancy, the review is concluded by an overview of the progression of these promising entities as therapeutic agents.

Measurement of Glutathione as a Tool for Oxidative Stress Studies by High Performance Liquid Chromatography

Background: Maintenance of the ratio of glutathione in the reduced (GSH) and oxidised (GSSG) state in cells is important in redox control, signal transduction and gene regulation, factors that are altered in many diseases. The accurate and reliable determination of GSH and GSSG simultaneously is a useful tool for oxidative stress determination. Measurement is limited primarily to the underestimation of GSH and overestimation GSSG as a result of auto-oxidation of GSH. The aim of this study was to overcome this limitation and develop, optimise and validate a reverse-phase high performance liquid chromatographic (HPLC) assay of GSH and GSSG for the determination of oxidant status in cardiac and chronic kidney diseases. Methods: Fluorescence detection of the derivative, glutathione-O-pthaldialdehyde (OPA) adduct was used. The assay was validated by measuring the stability of glutathione and glutathione-OPA adduct under conditions that could affect the reproducibility including reaction time and temperature. Linearity, concentration range, limit of detection (LOD), limit of quantification (LOQ), recovery and extraction efficiency and selectivity of the method were assessed. Results: There was excellent linearity for GSH (r² = 0.998) and GSSG (r² = 0.996) over concentration ranges of 0.1 µM–4 mM and 0.2 µM–0.4 mM respectively. The extraction of GSH from tissues was consistent and precise. The limit of detection for GSH and GSSG were 0.34 µM and 0.26 µM respectively whilst their limits of quantification were 1.14 µM and 0.88 µM respectively. Conclusion: These data validate a method for the simultaneous measurement of GSH and GSSG in samples extracted from biological tissues and offer a simple determination of redox status in clinical samples.

Smart Nanocarriers for the Delivery of Nucleic Acid-Based Therapeutics: A Comprehensive Review

Nucleic acid-based therapies are promising therapeutics for the treatment of several systemic disorders, and they offer an exciting opportunity to address emerging biological challenges. The scope of nucleic acid-based therapeutics in the treatment of multiple disease states including cancers has been widened by recent progress in Ribonucleic acids (RNA) biology. However, cascades of systemic and intracellular barriers, including rapid degradation, renal clearance, and poor cellular uptake, hinder the clinical effectiveness of nucleic acid-based therapies. These barriers can be circumvented by utilizing advanced smart nanocarriers that efficiently deliver and release the encapsulated nucleic acids into the target tissues. This review describes the current status of clinical trials on nucleic acid-based therapeutics and highlights representative examples that provide an overview on the current and emerging trends in nucleic acid-based therapies. A better understanding of the design of advanced nanocarriers is essential to promote the translation of therapeutic nucleic acids into a clinical reality.

Gadolinium Oxide Nanoparticles Induce Toxicity in Human Endothelial HUVECs via Lipid Peroxidation, Mitochondrial Dysfunction and Autophagy Modulation

In spite of the potential preclinical advantage of Gd₂O₃ nanoparticles (designated here as GO NPs) over gadolinium-based compounds in MRI, recent concerns of gadolinium deposits in various tissues undergoing MRI demands a mechanistic investigation. Hence, we chose human to measure umbilical vein endothelial cells (HUVECs) that line the vasculature and relevant biomarkers due to GO NPs exposure in parallel with the NPs of ZnO as a positive control of toxicity. GO NPs, as measured by TEM, had an average length of 54.8 ± 29 nm and a diameter of 13.7 ± 6 nm suggesting a fiber-like appearance. With not as pronounced toxicity associated with a 24-h exposure, GO NPs induced a concentration-dependent cytotoxicity (IC₅₀ = 304 ± 17 µg/mL) in HUVECs when exposed for 48 h. GO NPs emerged as significant inducer of lipid peroxidation (LPO), reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and autophagic vesicles in comparison to that caused by ZnO NPs at its IC₅₀ for the same exposure time (48 h). While ZnO NPs clearly appeared to induce apoptosis, GO NPs revealed both apoptotic as well as necrotic potentials in HUVECs. Intriguingly, the exogenous antioxidant NAC (N-acetylcysteine) co-treatment significantly attenuated the oxidative imbalance due to NPs preventing cytotoxicity significantly.

Dolutegravir derivative inhibits proliferation and induces apoptosis of non-small cell lung cancer cells via calcium signaling pathway

Non-small cell lung cancer (NSCLC) is the most prevalent type of lung cancer. However, there has been little improvement in its cure rate in the last 30 years, due to its intricate heterogeneity and drug resistance. Accumulating evidences have demonstrated that dysregulation of calcium (Ca²⁺) homeostasis contributes to oncogenesis and promotes tumor development. Inhibitors of Ca²⁺ channels/transporters to restore intracellular Ca²⁺ level were found to arrest tumor cell division, induce apoptosis, and suppress tumor growth both in vitro and in vivo. Dolutegravir (DTG), which is a first-line drug for Acquired Immune Deficiency Syndrome (AIDs) treatment, has been shown to increase intracellular Ca²⁺ levels and Reactive oxygen species (ROS) levels in human erythrocytes, leading to suicidal erythrocyte death or eryptosis. To explore the potential of DTG as an antitumor agent, we have designed and synthesized a panel of compounds based on the principle of biologically active substructure splicing of DTG. Our data demonstrated that 7-methoxy-4-methyl-6,8-dioxo-N-(3-(1-(2-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-4-yl)phenyl)-3,4,6,8,12,12a-hexahydro-2H-pyrido[1',2':4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxamide (DTHP), a novel derivative of DTG, strongly inhibited the colony-forming ability and proliferation of NSCLC cells, but displayed no cytotoxicity to normal lung cells. DTHP treatment also induced apoptosis and upregulate intracellular Ca²⁺ level in NSCLC cells significantly. Inhibiting Ca²⁺ signaling alleviated DTHP-induced apoptosis, suggesting the perturbation of intracellular Ca²⁺ is responsible for DTHP-induced apoptosis. We further discovered that DTHP activates AMPK signaling pathway through binding to SERCA, a Ca²⁺-ATPase. On the other hand, DTHP treatment promoted mitochondrial ROS production, causing mitochondrial dysfunction and cell death. Finally, DTHP effectively inhibited tumor growth in the mouse xenograft model of lung cancer with low toxicity to normal organs. Taken together, our work identified DTHP as a superior antitumor agent, which will provide a novel strategy for the treatment of NSCLC with potential clinical application.

Antihypertensive effect of Phragmanthera incana (Schum) Balle on NG-nitro-L-Arginine methyl ester (L-NAME) induced hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Phragmanthera incana (Schum) Balle is a member of the African mistletoes that has been reported to be used in ethnomedicine for the treatment of hypertension.

AIM

The aim of this study was to investigate the antihypertensive effect of Phragmanthera incana leaf ethanol extract (PILEE) in NG-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats.

MATERIALS AND METHODS

Phytochemical analysis of PILEE was determined using the Gas chromatography - Mass spectrophotometry (GC-MS) method. Antihypertensive activity was investigated in rats that received PILEE (50, 100 and 200 mg/kg) or captopril (40 mg/kg) daily for 28 days together with oral administration of L-NAME (40 mg/kg). Blood pressure parameters were measured on day 7, 14, 21 and 28. Blood was obtained for determination of serum nitrite, interleukin-6 (IL-6) and tumor necrosis factor, TNF-α. The heart, liver and kidneys were used to determine oxidative stress indices (malondialdehyde, reduced glutathione and catalase). The cardiac tissue was processed for histopathological changes.

RESULTS

The GC-MS profiling of PILEE identified 20 compounds namely fatty acid esters. Administration of PILEE (50, 100 and 200 mg/kg) dose dependently and significantly reduced systolic blood pressure and mean arterial pressure in hypertensive rats. PILEE administration significantly (p < 0.05) reversed elevated IL-6 and TNF-α in hypertensive rats. PILEE demonstrated antioxidant activity by attenuating L-NAME-induced elevated malondialdehyde and depletion of reduced glutathione and catalase activity in rat tissues. PILEE treatment demonstrated cardioprotective effect in L-NAME-induced cardiac hyperplasia and necrosis in rats.

CONCLUSION

It can be concluded that Phragmanthera incana leaf ethanol extract possess antihypertensive, antioxidant and anti-inflammatory properties, suggesting a protective role in cardiovascular diseases.

Protective effect of quercetin on rat testes against cadmium toxicity by alleviating oxidative stress and autophagy

Cadmium (Cd), a highly toxic heavy metal, adversely affects human and animal health. Quercetin (Que) is a kind of flavonoid that can protect many tissues from the toxic effect of heavy metals. Although many studies have explored the adverse effects of cadmium on rats and other animals, the mechanism of Cd-induced testicular autophagy and the antagonistic effect of Que on cadmium remain unclear. In this study, Sprague-Dawley rats were treated with Cd, Que or Cd, and Que supplements to explore the mechanisms of Que-alleviated testis injury caused by Cd exposure. The rat body weight and relative testicular weight were measured. Morphological changes in testes and indices of oxidative stress were also examined. The expression levels of autophagy-related genes were detected as well. Results showed that Cd decreased the rat body weight and relative testicular weight and induced pathological changes in testes. Conversely, Que alleviated these changes. We also found that Cd increased the malondialdehyde content and decreased the contents of total superoxide dismutase, glutathione peroxidase, catalase, and glutathione. Moreover, the protein expression levels of P62 and LC3-II increased under Cd exposure conditions. Conversely, Que obviously alleviated these toxic activities induced by Cd. Overall, this study showed that Cd accumulated in rat testes, leading to oxidative stress and autophagy. Que can reduce cadmium toxicity by reducing oxidative stress and inhibiting autophagy. The specific mechanism of Que antagonizing Cd toxicity can provide new insights into countering cadmium toxicity.

Yinning Tablet, a hospitalized preparation of Chinese herbal formula for hyperthyroidism, ameliorates thyroid hormone-induced liver injury in rats: Regulation of mitochondria-mediated apoptotic signals

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperthyroidism is closely associated with liver injury. The preliminary clinical observation suggests that Yinning Tablet, a hospitalized preparation of traditional Chinese formula for hyperthyroidism, improves not only hyperthyroidism, but also hyperthyroidism-associated liver injury.

AIM

To evaluate the effect and underlying mechanisms of Yinning Tablet on thyroid hormone-induced liver injury.

MATERIALS AND METHODS

Female rats were orally administered L-thyroxine (1 mg/kg) once daily for 60 days, and co-treated with the carefully identified Yinning Tablet extract (0.6-2.4 g/kg) during the last 30 days. Blood and liver variables were determined enzymatically, histologically, by ELISA, radioimmunoassay, Real-Time PCR or Western blot, respectively.

RESULTS

Co-treatment with the extract attenuated L-thyroxine-induced increases in serum alanine transaminase and aspartate transaminase activities, the ratio of liver weight to body weight, cytoplasmic vacuolization in hepatocytes, infiltrated inflammatory cells and confused structures in liver tissue, accompanied by attenuation of increased serum triiodo-l-thyronine concentration and hepatic deiodinase type I overexpression in rats. Importantly, Yinning Tablet suppressed L-thyroxine-triggered hepatic Bax, cleaved caspases-3, -8 and -9 protein overexpression, and Bcl-2 protein downregulation. Furthermore, the increases in cytochrome c protein expression, Ca²⁺-ATPase activity and malondialdehyde content, and decreases in activities of Na⁺/K⁺-ATPase, catalase, superoxide dismutase and glutathione peroxidase, and total antioxidant capacity in liver tissue were attenuated.

CONCLUSION

The present results suggest that Yinning Tablet ameliorates thyroid hormone-induced liver injury in rats by regulating mitochondria-mediated apoptotic signals. Our findings go insight into the pharmacological basis of the hospitalized preparation for treatment of hyperthyroidism-associated liver injury.

Mitigation of aflatoxin B1- and sodium arsenite-induced cytotoxicities in HUC-PC urinary bladder cells by curcumin and Khaya senegalensis

Background Concomitant exposure to environmental/occupational toxicants such as aflatoxin B1 (AFB1) and arsenic in some regions of the world has been well reported. Therefore, this calls for the assessment of the efficacy of agents such as phytochemicals, which are already known for their ethno-medicinal uses in prophylaxis/remediation. We investigated the possible cytotoxic bio-interactions between AFB1 and sodium arsenite (SA) in urinary bladder cells. We also assessed the cytoprotective effects of curcumin and the ethanol stem bark extract of Khaya senegalensis (K2S). Methods The cells were exposed to graded levels of AFB1, SA, curcumin, and K2S for 24, 48, and 72 h. Subsequently, using optimum toxic concentrations of AFB1 and SA, respectively, the influence of non-toxic levels of curcumin and/or K2S was tested on exposure of the cells to AFB1 and/or SA. Hoechst 33342/propidium iodide staining technique was used to determine the end-points due to cytotoxicity with changes in adenosine triphosphate (ATP) levels determined using Promega's CellTiter-Glo luminescent assay. Results Co-treatment of the cells with AFB1 and SA resulted in synergy in cytotoxic effects. Cytotoxicity was reduced by 3.5- and 2.9-fold by pre-treatment of the cells with curcumin and K2S before treatment with AFB1, while post-treatment resulted in 1.1- and 2.6-fold reduction, respectively. Pre-exposure of the cells with curcumin and K2S before treatment with SA ameliorated cytotoxicity by 3.8- and 3.0-fold, but post-treatment caused a 1.2- and 1.3-fold reduction, respectively. Conclusions Pre-treatment of the cells with either curcumin or K2S exhibited cytoprotective effects by ameliorating AFB1- and SA-induced cytotoxicity with inferred tendencies to prevent carcinogenesis.

Cytotoxic and proapoptotic effect of doxycycline - An in vitro study on the human skin melanoma cells

Doxycycline is a semisynthetic, second generation tetracycline. Currently, it is used, among others, in the treatment of acne and skin infections. Moreover, doxycycline has many valuable nonantibiotic properties, including anti-inflammatory, immunosuppressive and anticancer effects. Recent studies showed that the drug had the ability to inhibit the adhesion and migration of cancer cells, as well as affected their growth and proliferation and induced apoptosis. The purpose of this study was to examine the antimelanoma effect of doxycycline. The obtained results demonstrated that doxycycline decreased the viability and inhibited the proliferation of human melanoma cells, proportionally to the drug concentration and the treatment time. It was stated that doxycycline disturbed the homeostasis of the cells by lowering intracellular level of reduced thiols. In addition, the treatment changed the cell cycle profile and triggered the DNA fragmentation. Mitochondria of melanoma cells exposed to the drug had lowered membrane potential, which indicated cells apoptosis. Finally, doxycycline induced the externalization phosphatidylserine - a well-known hallmark of apoptosis, confirmed by results of annexin V test. The presented study contributes to the increase of knowledge about nonantibacterial action of doxycycline, including the influence on human cancer cells and indicates new potential possibility of effective treatment of malignant melanoma.

TIPE2 suppressed cisplatin resistance by inducing autophagy via mTOR signalling pathway

Tumour necrosis factor-α-induced protein-8-like-2 (TIPE2) has been associated with the progression of numerous cancers. Cisplatin, as a classical chemotherapy strategy for cancers, has been applied in non-small-cell lung cancer (NSCLC) clinical therapy but bears the disadvantage of chemoresistance. The aim of this study was to investigate the role of TIPE2 in cisplatin resistance and illustrate the detailed molecular mechanism. In this study, we proved that TIPE2 was down-regulated in cisplatin (DDP)-resistant NSCLC tissues and DDP-resistant NSCLC cells compared with the sensitive control. The inhibition of TIPE2 contributed to cell cisplatin-resistance, and the overexpression of TIPE2 enhanced cisplatin sensitivity and autophagy. Furthermore, increased TIPE2 elevated apoptosis in DDP-resistant NSCLC cells. In addition, TIPE2 restored the activity of mTOR signalling. Preconditioning with the mTOR activator 3BDO abrogated TIPE2-mediated depression in cisplatin-evoked autophagy. In conclusion, aberrant TIPE2 expression may contribute to the occurrence of chemoresistance by interfering with autophagy in NSCLC in an mTOR-dependent manner. TIPE2 could be used as a novel therapeutic target to overcome cisplatin-resistant NSCLC.

Ternary copper(II) complex of 5-hydroxytryptophan and 1,10-phenanthroline with several pharmacological properties and an adequate safety profile

We report the synthesis and biological evaluation of a ternary copper complex, [Cu(5HTP)(phen)(H₂O)](NO₃).2H₂O, with the antioxidant agent 5-hydroxytryptophan (5-HTP) and phenanthroline (phen, added to improve its lipophilicity and membrane transport). The crystal structure of the complex was determined by X-ray diffraction methods. The complex showed antioxidant, antimicrobial, antitumor and antimetastatic properties with an adequate safety profile. The interaction of the metal with phen promotes cellular copper accumulation and cytotoxicity on human lung A549 cell line (IC₅₀ = 3.6 μM). Furthermore, the viability of the normal human fetal lung fibroblast cell line (MRC-5) is not altered by the complex. An oxidative stress mechanism for the anticancer effect has been determined: cellular increase of reactive oxygen species (ROS), decrease of the glutathione (GSH) and oxidized GSH (GSSG) ratio and alteration of the mitochondrial potential. The complex also displays antimetastatic activities with inhibition of cell adhesion, invasion and migration. It has not mutagenic behavior and no toxicity on Artemia salina indicating its potential to act as an effective and safety antimicrobial and antitumor drug.

N-acetylcysteine and atorvastatin alleviates lung injury due to ischemia-reperfusion injury in rats

BACKGROUND

Acute lung injury is a major cause of death following severe injury and ischemia-reperfusion (IR). We investigated the protective effect of pretreatment with N-acetylcysteine (NAC) and atorvastatin (ATOR) in a mesenteric IR rat model.

METHODS

Male rats were randomly divided into five experimental groups: sham; mesenteric IR; and ATOR, NAC, ATOR + NAC (A + N) pretreatment followed by IR. Blood gas and cytokine levels, biochemistry, and cell count were analyzed. Lung injury was evaluated through histopathology and by using the wet-to-dry lung weight (W/D) ratio.

RESULTS

Following IR, significant changes were noted in biochemistry, cytokine, and lung injury. Compared with those in the IR group, neutrophil-to-lymphocyte ratio, lactate and alanine aminotransferase (ALT) levels were lower in all pretreatment groups, and creatinine and alkaline phosphatase (ALKP) levels were lower only in the A + N group. Blood pH and base excess (BE) were higher, and partial pressure of carbon dioxide in venous blood (PvCO2) lowered significantly in the ATOR and A + N groups than those in the IR group, and bicarbonate (HCO3-) levels increased only in the A + N group. Lung injury scores and W/D indicated significant attenuation in the A + N group. Compared with those in the IR group, tissue tumor necrosis factor-α levels were significantly lower in all the pretreatment groups and interleukin-1β levels were lower in the A + N group.

CONCLUSION

NAC and ATOR decreased inflammation and lung injury following mesenteric IR in rats. NAC and ATOR may alleviate lung injury more efficiently in combination than individually.

The effect of pomegranate on oxidative stress parameters: A systematic review and meta-analysis

OBJECTIVE

Pomegranate contains remarkable amounts of phenolic ingredients and it has been related to the antioxidant capacity of this fruit. Several primary studies show that pomegranate intake can improve antioxidant status. The objective of this systematic review and meta-analysis consisted in investigating the effect of pomegranate on oxidative stress (OS) parameters.

METHODS

A comprehensive electronic database search in Scopus, Web of science, Embase, Cochrane library and Medline was performed to identify eligible randomized controlled trials (RCTs). A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of Cochrane risk of bias assessment tool.

RESULTS

Systematic search yielded 575 references. A total of 11 RCTs reporting data from 484 participants included. Meta-analysis of data from 11 included RCTs did not support convincing evidence as to a significant increasing effect of pomegranate intake in TAC (SMD: 0.43 ; 95 %CI: -0.19, 1.06), Gpx (SMD: 0.18, 95 % CI: -0.25, 0.62, p = 0.4) and paraxonase (SMD: 0.36, 95 % CI: -0.50, 1.22, p= 0.41) as well as not significant decrease in Malondialdehyde (MDA) (SMD: -0.81, 95 % CI: -1.79, 0.09, P = 0.08).

CONCLUSION

Future well-designed clinical trials are needed before definite conclusive claims can be made about the effect of pomegranate on OS parameters.

Effect of cysteine, glutamate and glycine supplementation to in vitro fertilization medium during bovine early embryo development

Glutathione (GSH) is an antioxidant synthesized from three constitutive amino acids (CAA): cysteine (Cys), glycine (Gly) and glutamate (Glu). Glutathione plays an important role in oocyte maturation, fertilization and early embryo development. This study aimed to investigate the effect of Cys (0.6 mM), Gly (0.6 mM) and Glu (0.9 mM) supplementation during in vitro fertilization (IVF) of cattle oocytes. In a Pilot Experiment, de novo synthesis of GSH in bovine zygote was evaluated using a modified TALP medium prepared without MEM-essential and MEM-non-essential amino acids (mTALP): mTALP + CAA (constitutive amino acids); mTALP + CAA+5 mMBSO (buthionine sulfoximide); mTALP + Cys + Gly; mTALP + Cys + Glu and mTALP + Gly + Glu. This evidence led us to investigate the impact of CAA supplementation to TALP medium (with essential and non-essential amino acids) on zygote viability, lipid peroxidation, total intracellular GSH content (include reduced and oxidized form; GSH-GSSG), pronuclear formation in zygotes and subsequent embryo development. IVF media contained a) TALP; b) TALP + Cys + Gly + Glu (TALP + CAA); c) TALP + Cys + Gly; d) TALP + Cys + Glu; e) TALP + Gly + Glu, were used. Total GSH-GSSG concentration was increased in TALP, TALP + CAA, and TALP + Cys + Gly. The viability of zygote was similar among treatments. Lipid peroxidation was increased in zygote fertilized with TALP + Cys + Gly; TALP + Cys + Glu; TALP + Gly + Glu and TALP + CAA. The percentage of penetrated oocytes decreased in TALP + CAA and TALP + Cys + Gly. The cleavage rate was lower in TALP + CAA and TALP + Gly + Glu. The percentage of embryos developing to the blastocyst stage was lower in TALP + Cys + Glu and TALP + CAA. In conclusion, we have demonstrated the synthesis of GSH during IVF. However, Cys, Gly and Glu supplementation to TALP medium had negative effects on embryonic development.

RETRACTED: In vitro and in vivo evaluation of degradation, toxicity, biodistribution, and clearance of silica nanoparticles as a function of size, porosity, density, and composition

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the corresponding author. Subsequent to the publication of the article Journal of Controlled Release 311–312 (2019) 1–15, in follow up studies in 2021, the corresponding author's lab members noticed significant discrepancies in reproducibility of some of the results reported in this manuscript. A detailed investigation in the lab was launched, and by retrieving the raw data available at the core facility pertaining to this manuscript, the following discrepancies were discovered that provide the basis for this retraction. These discrepancies have been reported to the University of Utah Research Integrity and Compliance Office by the corresponding author. The co-authors have been made aware of these discrepancies and of the decision of the corresponding author to retract. The corresponding author believes that the subject matter of this article, detailed analysis of the degradation of silica nanoparticles as a function of their physicochemical properties in relevant biological media in vitro, and in vivo, is significant. For successful utility of these particles in drug delivery applications their detailed biological fate needs to be examined. The significant discrepancies and lack of reproducibility of the reported data however is very unfortunate and the author hopes that this does not cast a doubt on the need for more detailed examination of the biological fate of silica nanoparticles in the future for their successful application in controlled release. In Vitro Data (Fig. 3) • Actual dissolution reaction volume was 2.5mL (confirmed by reviewing the lab notebook of the first author during the investigation) vs 3.5mL reported in the manuscript. • Sample volume was not used in the calculation to convert Inductively Coupled Plasma Mass Spectrometry (ICPMS) data to mg of silicon retrieved which is needed to calculate % degradation (needed to multiply data by 0.1 due to 0.1mL sample volumes). • Our investigation revealed a 20% “matrix effect with fluids” was communicated by ICPMS core facility person to the first author that was not addressed in the manuscript. • All data is different when calculating % degradation, not just by a factor of 10 due to not calculating for the 100ml sample volume. • Raw data during our investigation after publication, obtained from ICPMS facility, and not noted in the lab notebook, for day 28 of simulated lysosomal fluid (SLF) reveals n=1 and no data points for Stober100. In the manuscript however, error bars are shown for all particles at this time point and for the data for Stober100. Intracellular Degradation (Fig. 5) • Extremely high background with control causing negative % degradation for Disulfide Meso 100 from retrieved ICPMS data from core facility after publication, but manuscript shows ~1.25% degradation. • All other calculated % degradation based on retrieved data from ICPMS facility during the investigation after publication, do not match reported data in the paper. • Paper claims n=6, but raw data received from ICPMS facility during investigation (after publication) is clearly n=3. In Vivo Degradation (Fig. 6) ICPMS data retrieved during the investigation after publication for control mice showed extremely high background, and probably were not used in the calculations reported in this manuscript because it would have led to negative silicon contents for a few samples. Urine ICPMS data from the core facility was not available during investigation after publication, and cannot be retrieved from the first author's lab notebook. Hence its validity cannot be ascertained. There may be other discrepancies in the manuscript that have gone unnoticed. However, the Editor-in-Chief agrees that the above is significant enough to warrant retraction of the manuscript.

MIM1 induces COLO829 melanoma cell death through mitochondrial membrane breakdown, GSH depletion, and DNA damage

Malignant melanoma is a high aggressive malignancy in humans and causes 60-80% of deaths from skin cancer. Defect in an intrinsic pathway of apoptosis via overexpression of Mcl-1 is responsible for malignant melanoma development and progression, and also for resistance to chemotherapeutic agents. MIM1 is a specific low molecular Mcl-1 protein inhibitor that is able to induce Mcl-1-dependent cancer cells death. Here, we examined the effect of MIM1 as well as MIM1 and dacarbazine (DTIC) mixture on cell viability, apoptosis, and cell cycle progression in COLO829 melanoma cells. Cell viability was performed by the WST-1 assay. Analysis of apoptosis as well as cell cycle progression was determined by fluorescence image cytometer NucleoCounter NC-3000. The obtained results demonstrated that the MIM1 exhibited high cytotoxicity against melanotic melanoma cells and induced mitochondrial membrane breakdown, GSH depletion, and DNA fragmentation. Additionally, MIM1 enhanced the proapoptotic effect of DTIC toward melanoma cells; furthermore, a mixture of these drugs caused cell cycle arrest at G2/M phase in COLO829 cells. Taken together, these data provide, for the first time, evidence that a low molecular weight Mcl-1 inhibitor-MIM1 may be a promising agent with antitumor and proapoptotic properties toward melanoma cells.