Cellular Oxidative Stress Markers Research Articles

House sparrows are heavier on organic and integrated-production farms than on conventional farms

The negative impact of conventional farming on avian biodiversity has been increasingly documented. However, the potential effects of different farming practices on bird populations' health remain unclear. We aimed to investigate whether different farming practices (organic, integrated production, conventional/intensive) have differential effects on the body mass - as a proxy for body condition - and biomarkers of oxidative stress in house sparrows (Passer domesticus), a model species strongly associated with human activities and still abundant in Switzerland. We captured a total of 681 birds in 19 organic farms, 20 integrated-production farms (labelled “IP-Suisse”) and 18 conventional farms, and measured bird body mass and tarsus length, as well as levels of malondialdehydes (MDA, a marker of oxidative damage to lipids), superoxide dismutase (SOD, a first-line antioxidant enzyme) activity, and the ratio of oxidized over reduced glutathione (GSSG/GSH, a marker of cellular oxidative stress) in blood and sperm as biomarkers of the systemic oxidative stress endured by birds. Our findings show that house sparrows living in integrated and organic farms were 2.39 % and 4.33 % heavier than birds living in conventional farms, but we did not find any difference in tarsus length, suggesting that birds were of similar size. In addition, we did not find any difference in oxidative stress markers across farming practices. Our results highlight the potential benefits of sustainable farming practices, such as organic and integrated farming, for bird populations and emphasize the need for mitigating the negative impact of agricultural intensification on biodiversity through practices that may enhance the birds’ health and thus lead to positive population dynamics.

Influence of Transportation on Stress Response and Cellular Oxidative Stress Markers in Juvenile Meagre (Argyrosomus regius).

In aquaculture, the transportation of live fish is a crucial but stress-inducing practice, necessitating a thorough understanding of its impact on fish welfare. This study aimed to assess the physiological stress response of meagre (Argyrosomus regius) juveniles during a 24 h commercial transport by quantifying muscle cortisol levels using a specific radioimmunoassay. Additionally, an immunohistochemical approach was used to detect and localize the cellular distribution of oxidative-stress-related biomarkers within various tissues and organs. The results demonstrated a significant increase in muscle cortisol levels following the loading procedure, remaining elevated above basal levels throughout the 24 h transport period. This effect may be attributed to either insufficient time for recovery from the loading stress or prolonged transportation-related stress. Immunostaining for all the antibodies we examined was observed in multiple tissues and organs, but we found no notable variations among the various transport phases. In conclusion, the observed stress response appears to be mainly linked to loading stress and the transport process itself, emphasizing the importance of implementing appropriate operational procedures to safeguard fish well-being during transport. Nonetheless, the unaltered distribution of oxidative stress markers between the control and transported groups suggests that the experienced stress might be within tolerable limits.

High resolution imaging and analysis of extracellular vesicles using mass spectral imaging and machine learning

AbstractExtracellular vesicles (EVs) are potentially useful biomarkers for disease detection and monitoring. Development of a label‐free technique for imaging and distinguishing small volumes of EVs from different cell types and cell states would be of great value. Here, we have designed a method to explore the chemical changes in EVs associated with neuroinflammation using Time‐of‐Flight Secondary Ion Mass spectrometry (ToF‐SIMS) and machine learning (ML). Mass spectral imaging was able to identify and differentiate EVs released by microglia following lipopolysaccharide (LPS) stimulation compared to a control group. This process requires a much smaller sample size (1 µL) than other molecular analysis methods (up to 50 µL). Conspicuously, we saw a reduction in free cysteine thiols (a marker of cellular oxidative stress associated with neuroinflammation) in EVs from microglial cells treated with LPS, consistent with the reduced cellular free thiol levels measured experimentally. This validates the synergistic combination of ToF‐SIMS and ML as a sensitive and valuable technique for collecting and analysing molecular data from EVs at high resolution.

Amelioration of CCl4-induced oxidative stress and hepatotoxicity by Ganoderma lucidum in Long Evans rats

Liver disease is a serious health problem affecting people worldwide at an alarming rate. The present study aimed to investigate the protective effects of Ganoderma lucidum against CCl4-induced liver toxicity in rats. The experimental Long Evans rats were divided into five groups, of which four groups were treated with carbon tetrachloride (CCl4). Among the CCl4 treated groups, one of the groups was treated with silymarin and two of them with ethanolic extract of G. lucidum at 100 and 200 mg/Kg body weight. The oxidative stress parameters and endogenous antioxidant enzyme concentrations were assessed by biochemical tests. Liver enzymes ALT, AST, and ALP were determined spectrophotometrically. Histopathological examinations were carried out to assess hepatic tissue damage and fibrosis. Reverse transcription PCR (RT-PCR) was performed to determine the expression of IL-1β, IL-6, IL-10, TNF-α, and TGF-β genes. Gas Chromatography-Mass Spectroscopy (GC–MS) analysis revealed that G. lucidum is rich in several phytochemicals including 6-Octadecanoic acid (55.81%), l-( +)-Ascorbic acid 2,6-dihexadecanoate (18.72%), Cis-11-Eicosenamide (5.76%), and Octadecanoic acid (5.26%). Treatment with the G. lucidum extract reduced the elevated ALT, AST, ALP levels, and cellular oxidative stress markers and increased the endogenous antioxidant levels. Histopathology observations revealed that the inflammation, infiltration of immune cells, and aberration of collagen fibers in the hepatocytes were altered by the G. lucidum treatment. The increased expression of inflammatory cytokines TNF-α, TGF-β, IL-1 β, and IL-6 were markedly suppressed by G. lucidum extract treatment. G. lucidum also prevented the suppression of protective IL-10 expression by CCl4. This study strongly suggests that G. lucidum extract possesses significant hepatoprotective activity as evidenced by reduced oxidative stress and inflammation mediated by suppression in inflammatory cytokine expression and increased protective IL-10 cytokine expression.

In vitro evaluation of the inhalation toxicity of the cosmetic ingredient aluminum chlorohydrate.

Aluminum chlorohydrate (ACH) is a major aerosol component frequently used as the active ingredient in antiperspirants, and in vivo studies have raised a concern about its inhalation toxicity. Still, few studies have addressed its effects on the human respiratory tract. Therefore, we developed a study on ACH inhalation toxicity using an in vitro human alveolar cell model (A549 cells) with molecular and cellular markers of oxidative stress, immunotoxicity, and epigenetic changes. The chemical characterization of ACH suspensions indicated particle instability and aggregation; however, side-scatter analysis demonstrated significant particle uptake in cells exposed to ACH. Exposure of A549 cells to non-cytotoxic concentrations of ACH (0.25, 0.5, and 1 mg/ml) showed that ACH induced reactive oxygen species. Moreover, ACH upregulated TNF, IL6, IL8, and IL1A genes, but not the lncRNAs NEAT1 and MALAT1. Finally, no alterations on the global DNA methylation pattern (5-methylcytosine and 5-hydroxymethylcytosine) or the phosphorylation of histone H2AX (γ-H2AX) were observed. Our data suggest that ACH may induce oxidative stress and inflammation on alveolar cells, and A549 cells may be useful to identify cellular and molecular events that may be associated with adverse effects on the lungs. Still, further research is needed to ensure the inhalation safety of ACH.

Exercise Augments the Effect of SGLT2 Inhibitor Dapagliflozin on Experimentally Induced Diabetic Cardiomyopathy, Possible Underlying Mechanisms.

One of the most prevalent cardiovascular problems linked with type 2 diabetes mellitus (T2DM) is diabetic cardiomyopathy (DCM). DCM is associated with myocardial oxidative stress, inflammation, apoptosis, suppressed autophagy, extracellular matrix remodeling, and fibrosis. The current study aims to investigate the protective effect of sodium-glucose transport 2 inhibitor (SGLT2i) dapagliflozin and/or exercise on DCM. Thirty adult male Sprague Dawley rats are used. T2DM is induced by a 6-week high-fat diet (HFD) followed by a single intraperitoneal (IP) injection of 35 mg/kg streptozotocin (STZ). Rats are divided into five groups, control, diabetic (DM), DM + swimming, DM + dapagliflozin, and DM + dapagliflozin and swimming. Serum glucose, insulin, insulin resistance (HOMA-IR), and cardiac enzymes (CK-MB and lactate dehydrogenase (LDH) are measured. Heart specimens are used for evaluation of cellular oxidative stress markers malondialdehyde (MDA), antioxidant enzymes, glutathione (GSH), and catalase (CAT), as well as mRNA expression of TGF-β, MMP9, IL-1β, and TNF-α. Stained sections with haematoxylin and eosin (H & E) and Masson trichrome are used for histopathological evaluation and detection of fibrosis, respectively. Immunohistochemical staining for apoptosis (caspase-3), and autophagy (LC3) are also carried out. The combinations of SGLT2i and exercise exhibited the most significant cardioprotective effect. It improved diabetic-induced histopathological alterations in the myocardium and attenuated the elevation of serum blood glucose, CK-MB, LDH, myocardial MDA, and mRNA expression of TNF-α, IL-1β, TGF-β, MMP9, and the immune expression of caspase-3. Moreover, this combination increased the serum insulin, myocardial antioxidants GSH and CAT, and increase the immune expression of the LC-3. In conclusion, a combination of SGLT2i and exercise exerted a better antioxidant, anti-inflammatory, and antifibrotic effect in DCM. Moreover, the combination enhances the autophagic capacity of the heart.

Cathelicidin Mediates an Anti-Inflammatory Role of Active Vitamin D (Calcitriol) During M. paratuberculosis Infection

Vitamin D is a key regulator in calcium and phosphorus metabolism which are essential for maintaining bone health. Recent reports also showed a role for vitamin D in immune regulation which may be linked to vitamin D deficiency in autoimmune disorders including inflammatory diseases and Crohn’s disease (CD). This study examines the role of vitamin D deficiency in the regulation of Cathelicidin Antimicrobial Peptide (CAMP) in CD-like macrophages. The latter includes macrophages infected with Mycobacterium avium subsp. paratuberculosis (MAP) isolated from CD patient. Initially, we measured cathelicidin and calcitriol in ex vivo plasma samples from CD patients with or without MAP infection (N=40 per group). We also measured the expression and production of CAMP/LL-37, TNF-α, IL-1β, IL-10, cellular oxidative stress markers, and bacterial viability following treatment of MAP-infected macrophages with four different forms of vitamin D (D2, D3, calcifediol, and calcitriol). From these studies, we determined that LL-37 and calcitriol were significantly lower in CD samples from MAP-positive patients [155.55 ± 49.77 ng/mL and 51.48 ± 31.04 pg/mL, respectively] compared to MAP-negative patients [193.01 ± 78.95 ng/mL and 272.36 ± 94.77 pg/mL, respectively]. Moreover, calcitriol and calcifediol upregulated CAMP expression by nearly 5-fold and 3-fold, respectively. However, following MAP infection, only calcitriol increased CAMP by 3-folds. Both calcitriol and LL-37 reduced intracellular MAP viability by ~3 folds and inhibited TNF-α and IL-1β expression and production in these cells. Treating co-culture of Caco-2 monolayers and MAP-infected macrophages with LL-37 or calcitriol have shown a reduction in NOX-1 expression and DHE signal, in addition to a higher NADPH/NADPt ratio. Notably, calcitriol’s anti-inflammatory effects were lost upon CAMP knockdown by CAMP-siRNA transfection. Altogether, the data indicate that MAP infection and burden is significant in CD by disrupting the conversion of calcifediol to calcitriol and downregulation of CAMP expression leading to vitamin D deficiency.

Cerebrospinal fluid levels of 8‐isoprostane, a marker of oxidative stress, are elevated in patients with Alzheimer’s disease compared to healthy subjects: Does the malfunction in the cell’s powerhouse lead to Alzheimer’s disease?

AbstractBackgroundOxidative stress may play an important role in the pathology of Alzheimer’s disease (AD). 8‐Isoprostane is a prostaglandin (PG)‐F2‐like compound belonging to the F2 Isoprostane class that is produced in vivo by the free radical‐catalyzed peroxidation of cells membrane arachidonic acid. 8‐Isoprostane is a biomarker of oxidative stress, and could possibly be a surrogate marker of the mitochondrial health in AD.MethodWe measured concentrations of cerebrospinal fluid (CSF) 8‐isoprostane from 113 subjects ranging from healthy subjects (HS, n=25) , to Mild Cognitive Impairment with positive AD biomarkers (MCI+, n=16), AD( n=40), and non‐AD dementia (non‐AD, n=32). Analysis was done using 8‐isoprostane Enzyme‐linked immunosorbent assay from Cayman Chemicals (Cayman Chemicals, MI, USA).ResultPatient characteristics can be seen in Table 1. Analyzing the CSF levels of 8‐isoprostane, a significant difference between 8‐isoprostane concentrations among the groups (ANOVA) was found. Post‐hoc test (t‐test) revealed a difference between the HS and AD groups (Figure 1).ConclusionIn conclusion 8‐isoprostane may be a good surrogate marker of cellular oxidative stress and may be used to evaluate mitochondria’s role in AD pathology in vivo.

Antiproliferative, Antimicrobial and Antiviral Activity of β-Aryl-δ-iodo-γ-lactones, Their Effect on Cellular Oxidative Stress Markers and Biological Membranes.

The aim of this work was the examination of biological activity of three selected racemic cis-β-aryl-δ-iodo-γ-lactones. Tested iodolactones differed in the structure of the aromatic fragment of molecule, bearing isopropyl (1), methyl (2), or no substituent (3) on the para position of the benzene ring. A broad spectrum of biological activity as antimicrobial, antiviral, antitumor, cytotoxic, antioxidant, and hemolytic activity was examined. All iodolactones showed bactericidal activity against Proteus mirabilis, and lactones 1,2 were active against Bacillus cereus. The highest cytotoxic activity towards HeLa and MCF7 cancer cell lines and NHDF normal cell line was found for lactone 1. All assessed lactones significantly disrupted antioxidative/oxidative balance of the NHDF, and the most harmful effect was determined by lactone 1. Contrary to lactone 1, lactones 2 and 3 did not induce the hemolysis of erythrocytes after 48 h of incubation. The differences in activity of iodolactones 1–3 in biological tests may be explained by their different impact on physicochemical properties of membrane as the packing order in the hydrophilic area and fluidity of hydrocarbon chains. This was dependent on the presence and type of alkyl substituent. The highest effect on the membrane organization was observed for lactone 1 due to the presence of bulky isopropyl group on the benzene ring.

Fetal growth restriction is a host specific response to infection with an impaired spiral artery remodeling-inducing strain of Porphyromonas gingivalis

Porphyromonas gingivalis is a periodontal pathogen implicated in a range of pregnancy disorders that involve impaired spiral artery remodeling (ISAR) with or without fetal growth restriction (FGR). Using a rodent periodontitis model, we assessed the ability of P. gingivalis to produce ISAR and FGR in Sprague Dawley (SD) and Wistar (WIS) rats. Both infected SD and WIS rats developed ISAR, but only WIS rats developed FGR despite both rat strains having equivalent microbial loads within the placenta. Neither maternal systemic inflammation nor placental (fetal) inflammation was a feature of FGR in WIS rats. Unique to infected WIS rats, was loss of trophoblast cell density within the junctional zone of the placenta that was not present in SD tissues. In addition, infected WIS rats had a higher proportion of junctional zone trophoblast cells positive for cytoplasmic high temperature requirement A1 (Htra1), a marker of cellular oxidative stress. Our results show a novel phenomenon present in P. gingivalis-induced FGR, with relevance to human disease since dysregulation of placental Htra1 and placental oxidative stress are features of preeclamptic placentas and preeclampsia with FGR.

A new approach on lithium-induced neurotoxicity using rat neuronal cortical culture: Involvement of oxidative stress and lysosomal/mitochondrial toxic Cross-Talk

Abstract Lithium (Li) is a widely-used medication for the treatment of patients with bipolar disorder. Li causes different complications. One of the most important adverse effects of Li is neurotoxicity. Neurotoxicity is usually irreversible which may lead to very important complications. The symptoms of Li-induced neurotoxicity include tremor, delirium, seizures, coma, and death. In this study, we wanted to evaluate the exact sub-cellular mechanisms of Li-induced neurotoxicity. For this purpose, we used primary neuronal cortical culture for investigating lithium-induced neurotoxicity. We applied the postnatal rat pups for isolating the cortical neurons. After that, we evaluated neural viability, neural reactive oxygen specious (ROS), lipid peroxidation, mitochondrial membrane potential (MMP), lysosomal membrane integrity (LMI), and reduced (GSH) and oxidized (GSSG) glutathione. Our results demonstrated that the cytotoxic effect of Li has mediated through lysosomal membrane leakage associated with ROS formation and reduction of MMP. Furthermore, the incubation of isolated neurons with Li caused rapid GSH depletion (as GSSG efflux) as another marker of cellular oxidative stress. We concluded that Li causes neurotoxicity in a dose-dependent manner. Besides, Li-induced neurotoxicity is a result of the generation of ROS and LP, which leads to mitochondrial/lysosomal toxic cross-talk.

Patients with Incompetent Valves in Chronic Venous Insufficiency Show Increased Systematic Lipid Peroxidation and Cellular Oxidative Stress Markers.

Chronic venous insufficiency (CVI) is a disease that impacts cellular homeostasis. CVI may occur with a valvular destruction process known as venous reflux or valvular incompetence. One of the cellular processes that may be triggered as a consequence of these events is the production of reactive oxygen species (ROS), which may trigger the production of different cellular markers and cell damage processes, such as lipid peroxidation. Therefore, the present study performed an observational, analytical, and prospective cohort study by reviewing 110 patients with CVI, and the activities and plasma levels of iNOS, eNOS, NOX1, and NOX2 were determined using immunohistochemistry and RT-qPCR. Lipid peroxidation (MDA) was also measured. Patients were distributed according to the presence or absence of valvular incompetence-venous reflux, which was diagnosed clinically as the absence of venous reflux (NR = 29) or presence of venous reflux (R = 81). Each group was divided according to age, with a cutoff point of fifty years (NR < 50 = 13, NR ≥ 50 = 16, R < 50 = 32, and R ≥ 50 = 49). The results showed that R patients exhibited significantly increased plasma MDA levels, and R < 50 patients exhibited the highest statistically significant increase. iNOS, NOX1, and NOX2 exhibited the highest gene and protein expression in R patients. The increased expression was maintained in the R < 50 patients. Our data suggest that young patients with valvular incompetence (venous reflux) show higher levels of lipid peroxidation and oxidative stress, which reflects the characteristics of an aged patient.

Can acetylcysteine ameliorate cisplatin-induced toxicities and oxidative stress without decreasing antitumor efficacy? A randomized, double-blind, placebo-controlled trial involving patients with head and neck cancer.

The protective antioxidant activity of acetylcysteine (NAC) against toxicity due to cisplatin has been reported in experimental models; however, its efficacy in patients has not been elucidated. The aim of this study was to investigate the possible protective effect of NAC on cisplatin‐induced toxicity and the effect of NAC on clinical response and oxidative stress in patients treated for head and neck cancer. This was a randomized, double‐blind, placebo‐controlled trial conducted in patients receiving high‐dose cisplatin chemotherapy concomitant to radiotherapy. Patients were randomly assigned to groups and received: (a) 600 mg NAC syrup, orally once daily at night for 7 consecutive days or (b) placebo, administered similarly to NAC. Nephro‐, oto‐, hepato‐, myelo‐, and gastrointestinal toxicities, clinical responses, and plasma and cellular markers of oxidative stress were evaluated. Fifty‐seven patients were included (n = 28, NAC arm; and n = 29, placebo arm). A high prevalence of most types of toxicities was observed after cisplatin chemotherapy; however, the parameters were similar between the two groups. There was a predominance of partial response to treatment. In the cellular and plasmatic oxidative stress analyses, minor differences were observed. Overall, there was no statistically significant difference between the groups for all outcomes. These findings show that low‐dose oral NAC does not protect patients with head and neck cancer from cisplatin‐induced toxicities and oxidative stress. The antitumor efficacy of cisplatin was apparently not impaired by NAC.

The anti-proliferative effects of adiponectin on human lung adenocarcinoma A549 cells and oxidative stress involvement

Adiponectin (Acrp30) plays an important role in energy metabolism and inflammation. Recently, in vivo serum Acrp30 levels have been reported to be correlated to risk of developing several types of cancers such as lung cancer, and in vitro studies have demonstrated a role for Acrp30 in the control of cell proliferation and survival. However, the molecular effects of Acrp30 on lung cancer have not yet been clearly defined.In the present study, we investigated the effects of different concentrations of Acrp30 on the A549 human alveolar epithelial cell line, an in vitro model of lung adenocarcinoma. A549 cells were exposed to various concentrations of Acrp30 and successively, proliferation, apoptosis and oxidative stress were evaluated by MTT test, caspase activity assay, flow-cytometry and western blotting analysis. Our results demonstrated that Acrp30 causes, in a time- and dose-dependent manner, a reduction of cell viability and duplication together with an increase in cell apoptosis rate. In addition, we found that Acrp30 induces an increase of lipid peroxidation evaluated by TBARS assay and a concomitant reduction of nitric oxide release, both markers of cellular oxidative stress. Taken together, our data on A549 cells provides new insight into potential involvement of Acrp30 on physio-pathologic mechanisms of lung diseases through interference with proliferation, apoptosis and oxidative status.

Decreased Iron Overload and Oxidative Stress in Transfusion Dependent Patients with Myelodysplastic Syndromes (MDS) with the Oral Iron Chelator Deferiprone

Background: The majority of the patients with low risk myelodysplastic syndrome (MDS) become RBC-transfusion-dependent and thus symptoms resulting from iron overload and oxidative stress may develop. Yet, iron-chelation has not been part of the standard treatment for these patients. The purpose of this study was to assess the effect of deferiprone (L1), an iron chelator, on oxidative stress parameters in iron overloaded and blood dependent patients with low risk MDS.Methods: This work was supported by a grant from Apopharma.Nineteen low risk MDS patients were enrolled. Patients were classified as very low-, low- and intermediate-risk disease, according to the Revised International Prognostic Scoring System (IPSS-R). Inclusion criteria were a cumulative transfusion burden of >20 red blood cells (RBC) units and evidence of iron overload (serum ferritin >1,000 ng/mL). Deferiprone at a dose of up to a maximum dose of 100 mg/kg was administrated for 4 months. Blood samples were taken at baseline, at each monthly visit, and at the end of the study. The samples were tested for oxidative stress parameters: reactive oxygen species (ROS), phosphatidylserine (PS), glutathione (GSH) and membrane lipid peroxidation (LP); iron parameters: serum ferritin and cellular labile iron pool (LIP), and CBC. The primary efficacy variable as a measurement of oxidative stress was ROS. Student's t-test was applied for statistical analyses.Results: Patients (n=19) were treated with deferiprone in a daily dose of 25-100 mg/kg, median of 50 mg/kg/day. Eight patients received treatment for 120 days and completed the study. One of them had mild neutropenia that resolved after short discontinuation of the study drug and finished the study with no more complications. Eleven patients did not finish the study: eight patients due to gastrointestinal (GI) adverse effects, two patients withdrew their consent (one of them after mild neutropenia that resolved) and one patient was killed in a car accident. We thus had measurements of at least two time points for 16 of the patients. The median number of RBC transfusions during study period was 11 (2-20). The primary efficacy variable ROS, as a measurement of oxidative stress, was significantly decreased, in all three lineages: platelet, RBC and neutrophils (decrease of 32%, 33% and 32% respectively, each at P=0.001). Deferiprone administration was also associated with a reduction in other cellular markers of oxidative stress in RBC: PS, GSH, LP and LIP (decrease of 54%, 98%, 300%, and 42% respectively, each at P=0.001). No significant changes were observed in serum ferritin levels, likely due to the short treatment period in patients on repeated transfusion requirements.Conclusions: This is the first prospective study on chelation with Deferiprone in MDS patients. Our data provide preliminary evidence that administration of Deferiprone in a median daily dose of at 50 mg/kg can decrease iron-induced oxidative stress in iron-overloaded MDS patients. Of note, no events of agranulocytosis were observed. The future remains challenge is to prove that reduction in iron toxicity will eventually translate into a clinically meaningful improvement.Prof. Rachmilewitz who unfortunately passed away last year, had a significant contribution to the conception and design of this study. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Exposure of Folsomia candida (Willem 1902) to teflubenzuron over three generations – Increase of toxicity in the third generation

The potential implications of long-term exposure to contaminants are not covered by current standard toxicity guidelines, usually referring to one generation and a fraction of the life cycle of the test species. Hence, in the present study, we aimed to assess the effects of the multigenerational exposure (generation 1–3: F1-F3) of Folsomia candida to an insect growth regulator (IGR) compound: teflubenzuron (TFB). The selected endpoints included both the standard ones as in the OECD and ISO guidelines (survival, reproduction, and avoidance) as well as additional ones (organisms size and cellular oxidative stress markers: acetylcholinesterase, glutathione S-transferase, catalase, glutathione peroxidase, lipid peroxidation). Although no avoidance behaviour was recorded at field-relevant concentrations (PEC (Predicted Environmental Concentration) = 0.06 mg/kg soil dry weigh (dwt)), survival and reproduction were impacted (LC50 = 0.1 mg/kg soil dwt; EC50 = 0.05 mg/kg soil dwt). Multigenerational exposure to TFB caused increased toxicity in F. candida in F3 in terms of survival and reproduction. This could be related to the mode of action of TFB which does not seem to activate some of the general stress mechanisms of response like oxidative stress. In addition, TFB causes a reduction of the organisms’ size, with a reduction of the number of large-sized juveniles, which has potential adverse consequences in terms of organisms’ performance, e.g. change in age structure and hence population dynamics. Hence, both observations may increase the environmental concern and associated risk of this insecticide.

Absence of effect of the antiretrovirals Duovir and Viraday on mitochondrial bioenergetics.

Most toxicity associated with antiretroviral drugs is thought to result from disruption of mitochondrial function. Unfortunately, there are no validated laboratory markers for clinically assessing the onset of mitochondrial toxicity associated with antiretroviral therapy. In a previous study on mitochondrial hepatocytes, the protease inhibitor lopimune was shown to induce mitochondrial toxicity by increasing reactive oxygen species (ROS) production and decreasing respiratory control ratio (RCR) reflecting compromised mitochondrial efficiency in adenosine triphosphate production. Mitochondrial dysfunction and ROS production were directly correlated with the expression of uncoupling protein 2 (UCP2). In the current study we aim to determine the toxicity of nucleoside or nucleotide and nonnucleoside reverse-transcriptase inhibitors, Duovir and Viraday on liver mitochondria isolated from treated mice by monitoring UCP2 expression. Our results showed that both Duovir and Viraday had no effect on mitochondrial respiration states 2, 3, 4, and on RCR. In addition, ROS generation and UCP2 expression were not affected. In conclusion, our results indicate the difference in the mechanism of action of distinct classes of antiretroviral drugs on mitochondrial functions and may associate UCP2 expression with subclinical mitochondrial damage as marker of cellular oxidative stress.

Modulatory Effect of Decalepis hamiltonii on Ethanol-Induced Neurotoxicity in Drosophila melanogaster

Ethanol is known to be an effective inducer of oxidative stress in the brain tissues. Drosophila melanogaster is suitable in vivo model system to study neurotoxic effects of ethanol. The behavioral responses, levels of oxidative markers, and activity of antioxidant enzymes have been investigated in ethanol-exposed Drosophila flies. The results showed that acute ethanol exposure leads to hyperactivity of flies. If alcohol exposure is prolonged then sedation has occurred in the experimental flies. The latter was measured by sensitivity time (ST50) and recovery time (RC50). The levels of ROS and LPO (as cellular markers of oxidative stress) are significantly increased in ethanol-exposed flies while GSH level was declined. Furthermore, higher activities of catalase (CAT) and superoxide dismutase (SOD) were observed in the same group of flies. Ethanol neurotoxicity became more evident when a remarkable decrease of acetylcholine esterase (AChE) activity was seen in ethanol-exposed fruit flies. To battle ethanol neurotoxicity natural antioxidants would be the best choice. According to previously reported studies on the antioxidant capacity of Decalepis hamiltonii (Dh) root extract, its protecting effect in this toxicity model has been investigated. Surprisingly, Dh aqueous extract treatment has increased the time of ST50 and decreased the RC50 values of ethanol-exposed flies. Moreover, we demonstrated that Dh pre-treatment can diminish the ROS and LPO levels. Dh treatment results in augment of GSH level and activity of CAT and SOD enzymes. Antioxidant potential of Dh could restore AChE activity too. This is the first report on protective effects of Dh natural antioxidants in Drosophila melanogaster against oxidative stress induced by ethanol.

Consequences of Cytochrome c Oxidase Assembly Defects for the Yeast Stationary Phase

Functional assembly of cytochrome c oxidase (COX) is essential for an intact mitochondrial respiratory chain, although the consequences of a loss of assembled COX at yeast stationary phase remain largely unexplored. Stationary phase cultures are a good model for terminally differentiated cells in humans, such as neurons. Our goal is to define the physiological changes in mitochondrial respiration and oxidative stress between exponential and stationary phases in a respiratory competent strain and a set of COX assembly mutants with defects in a variety of aspects related to enzyme assembly. These results further our understanding of mitochondrial changes in terminally differentiated cells and aging cells. In this study, we show that a wild‐type respiratory competent yeast strain at stationary phase is characterized by a decreased oxidative capacity, as seen by a reduction in the amount of assembled COX, which is supported by a decrease in protein levels of several COX assembly factors. Wild‐type cells also have a disrupted mitochondrial reticulum during stationary phase. Loss of assembled COX results in the decreased abundance of many mitochondrial proteins at stationary phase, which we show is likely due to decreased membrane potential and changes in mitophagy. In addition to an altered mitochondrial proteome, COX assembly mutants display unexpected changes in markers of cellular oxidative stress at stationary phase. Specifically, differences in distribution of Sod1 between exponential and stationary phases give insight on location of reactive oxygen species (ROS) in the cell. Our results suggest that mitochondria may not be a major source of ROS at stationary phase in cells lacking an intact respiratory chain. Overall, we have identified fundamental differences between exponential and stationary phase mitochondria in respiratory competent yeast and have defined two distinct phenotypes, decreased levels of mitochondrial proteins and less mitochondrial oxidative damage, in cells with a defective respiratory chain. These findings suggest that COX deficiencies are associated with broader cellular phenotypes in terminally differentiated cells in humans.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada (NSERC)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Consequences of cytochrome c oxidase assembly defects for the yeast stationary phase

The assembly of cytochrome c oxidase (COX) is essential for a functional mitochondrial respiratory chain, although the consequences of a loss of assembled COX at yeast stationary phase, an excellent model for terminally differentiated cells in humans, remain largely unexamined. In this study, we show that a wild-type respiratory competent yeast strain at stationary phase is characterized by a decreased oxidative capacity, as seen by a reduction in the amount of assembled COX and by a decrease in protein levels of several COX assembly factors. In contrast, loss of assembled COX results in the decreased abundance of many mitochondrial proteins at stationary phase, which is likely due to decreased membrane potential and changes in mitophagy. In addition to an altered mitochondrial proteome, COX assembly mutants display unexpected changes in markers of cellular oxidative stress at stationary phase. Our results suggest that mitochondria may not be a major source of reactive oxygen species at stationary phase in cells lacking an intact respiratory chain.