Altered Redox Status Research Articles

The role of biochar in heavy metal-contaminated wastewater and soil treatment: A Comprehensive review

As a result of water shortages, farmers are forced to use wastewater as an irrigation source for agricultural land, primarily for vegetables. Although wastewater contains abundant plant nutrients and are always readily available, it also contains hazardous contaminants, including heavy metals. Wastewater contains dangerous levels of heavy metals, particularly lead (Pb). Vegetables irrigated with Pb-contaminated wastewater create growth and yield problems and pose serious health risks to those who consume them. Thus, increased global demand for soil remediation is driven by concerns about heavy metal contamination. Toxic metals are prevented from entering food crops by using biochar as a low-cost biosorbent, which can immobilize heavy metals in wastewater-irrigated soil. Sorption, redox state alteration of heavy metals, soil pH modification, and precipitation are just some of the many mechanisms by which biochar can immobilize metals in soil. This can boost crop development and yield while also lowering human health risks. Soil heavy metals can be immobilized by several methods using biochar's features, like its high surface area and wide pH range, as well as its long-term stability and the presence of oxygen-containing functional groups. This review focuses on using biochar to reclaim soil and water that have been contaminated by heavy metals as well as to fertilize plants.

Alteration of redox status and fatty acid profile in gills from the green crab (Carcinus aestuarii) following dimethoate exposure

Dimethoate is a broad-spectrum organophosphate insecticide and acaricide. Through various pathways, such as runoff and drift, dimethoate can reach marine environment, and easily impact common organisms in coastal areas, close to agriculture lands, namely crustaceans. The purpose of this study was to investigate the potential effects of dimethoate exposure (50, 100, and 200 μg/l), for 1 day, on a wide range of markers of oxidative stress and neurotransmission impairment, as well as fatty acids composition and histopathological aspect in the gills of the green crab Carcinus aestuarii. A significant increase in n-3 polyunsaturated fatty acids series, namely the eicosapentaenoic acid (C20: 5n3) and its precursor alpha-linolenic acid (C 18: 3n3) in dimethoate-treated crabs was recorded. Concerning n-6 polyunsaturated fatty acids, we noted a high reduction in arachidonic acid (C20:4n-6) levels. Dimethoate exposure increased the levels of hydrogen peroxide, malondialdehyde, lipid hydroperoxides, protein carbonyl, and caused the advanced oxidation of protein products along with enzymatic and non-enzymatic antioxidant-related markers. Acetylcholinesterase activity was highly inhibited following exposure to dimethoate in a concentration-dependent manner. Finally, deleterious histopathological changes with several abnormalities were noted in exposed animals confirming our biochemical findings. The present study offered unique insights to establish a relationship between redox status and alterations in fatty acid composition, allowing a better understanding of dimethoate-triggered toxicity.

Dysregulation of intracellular redox homeostasis by the SARS-CoV-2 ORF6 protein

SARS-CoV-2 has evolved several strategies to overcome host cell defenses by inducing cell injury to favour its replication. Many viruses have been reported to modulate the intracellular redox balance, affecting the Nuclear factor erythroid 2-Related Factor 2 (NRF2) signaling pathway. Although antioxidant modulation by SARS-CoV-2 infection has already been described, the viral factors involved in modulating the NRF2 pathway are still elusive. Given the antagonistic activity of ORF6 on several cellular pathways, we investigated the role of the viral protein towards NRF2-mediated antioxidant response. The ectopic expression of the wt-ORF6 protein negatively impacts redox cell homeostasis, leading to an increase in ROS production, along with a decrease in NRF2 protein and its downstream controlled genes. Moreover, when investigating the Δ61 mutant, previously described as an inactive nucleopore proteins binding mutant, we prove that the oxidative stress induced by ORF6 is substantially related to its C-terminal domain, speculating that ORF6 mechanism of action is associated with the inhibition of nuclear mRNA export processes. In addition, activation by phosphorylation of the serine residue at position 40 of NRF2 is increased in the cytoplasm of wt-ORF6-expressing cells, supporting the presence of an altered redox state, although NRF2 nuclear translocation is hindered by the viral protein to fully antagonize the cell response. Furthermore, wt-ORF6 leads to phosphorylation of a stress-activated serine/threonine protein kinase, p38 MAPK, suggesting a role of the viral protein in regulating p38 activation. These findings strengthen the important role of oxidative stress in the pathogenesis of SARS-CoV-2 and identify ORF6 as an important viral accessory protein hypothetically involved in modulating the antioxidant response during viral infection.

Redox-Mediated Rewiring of Signalling Pathways: The Role of a Cellular Clock in Brain Health and Disease.

Metazoan signalling pathways can be rewired to dampen or amplify the rate of events, such as those that occur in development and aging. Given that a linear network topology restricts the capacity to rewire signalling pathways, such scalability of the pace of biological events suggests the existence of programmable non-linear elements in the underlying signalling pathways. Here, we review the network topology of key signalling pathways with a focus on redox-sensitive proteins, including PTEN and Ras GTPase, that reshape the connectivity profile of signalling pathways in response to an altered redox state. While this network-level impact of redox is achieved by the modulation of individual redox-sensitive proteins, it is the population by these proteins of critical nodes in a network topology of signal transduction pathways that amplifies the impact of redox-mediated reprogramming. We propose that redox-mediated rewiring is essential to regulate the rate of transmission of biological signals, giving rise to a programmable cellular clock that orchestrates the pace of biological phenomena such as development and aging. We further review the evidence that an aberrant redox-mediated modulation of output of the cellular clock contributes to the emergence of pathological conditions affecting the human brain.

The Role of the Oxidative State and Innate Immunity Mediated by TLR7 and TLR9 in Lupus Nephritis.

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE) and is considered one of the leading causes of mortality. Multiple immunological pathways are involved in the pathogenesis of SLE, which makes it imperative to deepen our knowledge about this disease's immune-pathological complexity and explore new therapeutic targets. Since an altered redox state contributes to immune system dysregulation, this document briefly addresses the roles of oxidative stress (OS), oxidative DNA damage, antioxidant enzymes, mitochondrial function, and mitophagy in SLE and LN. Although adaptive immunity's participation in the development of autoimmunity is undeniable, increasing data emphasize the importance of innate immunity elements, particularly the Toll-like receptors (TLRs) that recognize nucleic acid ligands, in inflammatory and autoimmune diseases. Here, we discuss the intriguing roles of TLR7 and TLR9 in developing SLE and LN. Also included are the essential characteristics of conventional treatments and some other novel and little-explored alternatives that offer options to improve renal function in LN.

Redox state and altered pyruvate metabolism contribute to a dose-dependent metformin-induced lactate production of human myotubes.

Metformin-induced glycolysis and lactate production can lead to acidosis as a life-threatening side effect, but slight increases in blood lactate levels in a physiological range were also reported in metformin-treated patients. However, how metformin increases systemic lactate concentrations is only partly understood. Because human skeletal muscle has a high capacity to produce lactate, the aim was to elucidate the dose-dependent regulation of metformin-induced lactate production and the potential contribution of skeletal muscle to blood lactate levels under metformin treatment. This was examined by using metformin treatment (16-776 μM) of primary human myotubes and by 17 days of metformin treatment in humans. As from 78 µM, metformin induced lactate production and secretion and glucose consumption. Investigating the cellular redox state by mitochondrial respirometry, we found metformin to inhibit the respiratory chain complex I (776 µM, p < 0.01) along with decreasing the [NAD+]:[NADH] ratio (776 µM, p < 0.001). RNA sequencing and phospho-immunoblot data indicate inhibition of pyruvate oxidation mediated through phosphorylation of the pyruvate dehydrogenase (PDH) complex (39 µM, p < 0.01). On the other hand, in human skeletal muscle, phosphorylation of PDH was not altered by metformin. Nonetheless, blood lactate levels were increased under metformin treatment (p < 0.05). In conclusion, the findings suggest that metformin-induced inhibition of pyruvate oxidation combined with altered cellular redox state, shifts the equilibrium of the lactate dehydrogenase (LDH) reaction leading to a dose-dependent lactate production in primary human myotubes.

Impact of azithromycin, doxycycline and redox-active small molecules on amoxicillin-induced Chlamydia pneumoniae persistence

Amoxicillin is recommended as primary treatment for community-acquired bacterial pneumonia (CABP). 5–10% of CABP cases are caused by Chlamydia pneumoniae, an obligate intracellular bacterium which responds to beta-lactam antibiotics by converting to a persistent phenotype. To support rational pharmacotherapy of C. pneumoniae infections, we investigated how clinically relevant concentrations of azithromycin and doxycycline affect amoxicillin induced C. pneumoniae persistence. Given the known role of redox state alterations in the action of bactericidal antibiotics and widespread use of redox-active dietary supplements when experiencing respiratory symptoms, we also studied how redox active compounds affect the studied antibiotic treatments. Our data demonstrate that clinically applied amoxicillin concentrations (10 and 25 mg/l) fail to eradicate C. pneumoniae infection in respiratory epithelial cells. Transmission electron microscopy (TEM) of amoxicillin-treated C. pneumoniae infected cells reveal aberrant bacterial morphology characteristic of chlamydial stress response. Amoxicillin was also found to significantly limit the antichlamydial effect of azithromycin or doxycycline. However, based on quantitative culture and quantitative PCR data, azithromycin was superior to doxycycline in C. pneumoniae eradication either as monotherapy or in combination with amoxicillin. Amoxicillin was also found to decrease respiratory epithelial cell glutathione (GSH) levels, whereas redox-active dibenzocyclooctadiene lignans increased C. pneumoniae load in amoxicillin-treated cultures up to two-fold. These data highlight the impact of relative administration time on the efficacy of antichlamydial antibiotics and indicate unfavorable interactions between amoxicillin and redox-active small molecules.

Maternal hepatic adaptations during obese pregnancy encompass lobe-specific mitochondrial alterations and oxidative stress.

Maternal obesity(MO) is rising worldwide, affecting half of all gestations, constituting a risk-factor for pregnancy-associated liver diseases (PALD) and hepatic diseases. PALD occur in approximately 3% of pregnancies and are characterized by maternal hepatic oxidative stress(OS) and mitochondrial dysfunction. Understanding the role of MO on liver function and pathophysiology could be crucial for understanding the altered pathways leading to PALD and liver disease. We investigated specific hepatic metabolic alterations in mitochondria and oxidative stress during MO at late-gestation. Maternal hepatic tissue was collected at 90% gestation in Control and MO ewes. Maternal hepatic redox state, mitochondrial Respiratory Chain(MRC) and OS markers were investigated. MO decreased MRC complex-II activity and SDHA and SDHB protein, increased complex-I and complex-IV activities despite reduced mtCO1 protein, and increased ATP5a protein. Hepatic MO-metabolic remodeling was characterized by decreased ANT-1/2 and VDAC protein expression and PKA activity, and augmented NAD+/NADH ratio due to reduced NADH levels. MO showed an altered redox state with increased OS, increased lipid peroxidation, decreased GSH/GSSG ratio, increased SOD and decreased catalase antioxidant enzymatic activities, lower catalase, glutathione peroxidase (Gpx)-4 and glutathione reductase protein expression, and increased Gpx-1 abundance. MO-related hepatic changes were more evident in the right lobe, corroborated by the integrative data analysis. Hepatic tissue from obese pregnant ewes showed alterations in the redox state, consistent with OS and MRC and metabolism remodeling. These are hallmarks of PALD and hepatic disease, supporting MO as a risk-factor and highlighting OS and mitochondrial dysfunction as mechanisms responsible for liver disease predisposition.

Exercise-induced changes to the fiber type-specific redox state in human skeletal muscle are associated with aerobic capacity.

The benefits of exercise involve skeletal muscle redox state alterations of nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD). We determined the fiber-specific effects of acute exercise on the skeletal muscle redox state in healthy adults. Muscle biopsies were obtained from 19 participants (11 M, 8 F; 26 ± 4 yr) at baseline (fasted) and 30 min and 3 h after treadmill exercise at 80% maximal oxygen consumption (V̇o2max). Muscle samples were probed for autofluorescence of NADH (excitation at 340-360 nm) and oxidized flavoproteins (Fp; excitation at 440-470 nm) and subsequently, fiber typed to quantify the redox signatures of individual muscle fibers. Redox state was calculated as the oxidation-to-reduction redox ratio: Fp/(Fp + NADH). At baseline, pair-wise comparisons revealed that the redox ratio of myosin heavy chain (MHC) I fibers was 7.2% higher than MHC IIa (P = 0.023, 95% CI: 5.2, 9.2%) and the redox ratio of MHC IIa was 8.0% higher than MHC IIx (P = 0.035, 95% CI: 6.8, 9.2%). MHC I fibers also displayed greater NADH intensity than MHC IIx (P = 0.007) and greater Fp intensity than both MHC IIa (P = 0.019) and MHC IIx (P < 0.0001). Fp intensities increased in all fiber types (main effect, P = 0.039) but redox ratios did not change (main effect, P = 0.483) 30 min after exercise. The change in redox ratio was positively correlated with capillary density in MHC I (rho = 0.762, P = 0.037), MHC IIa fibers (rho = 0.881, P = 0.007), and modestly in MHC IIx fibers (rho = 0. 771, P = 0.103). These findings support the use of redox autofluorescence to interrogate skeletal muscle metabolism.NEW & NOTEWORTHY This study is the first to use autofluorescent imaging to describe differential redox states within human skeletal muscle fiber types with exercise. Our findings highlight an easy and efficacious technique for assessing skeletal muscle redox in humans.

Fluorescent Probes for Mammalian Thioredoxin Reductase: Mechanistic Analysis, Construction Strategies, and Future Perspectives.

The modulation of numerous signaling pathways is orchestrated by redox regulation of cellular environments. Maintaining dynamic redox homeostasis is of utmost importance for human health, given the common occurrence of altered redox status in various pathological conditions. The cardinal component of the thioredoxin system, mammalian thioredoxin reductase (TrxR) plays a vital role in supporting various physiological functions; however, its malfunction, disrupting redox balance, is intimately associated with the pathogenesis of multiple diseases. Accordingly, the dynamic monitoring of TrxR of live organisms represents a powerful direction to facilitate the comprehensive understanding and exploration of the profound significance of redox biology in cellular processes. A number of classic assays have been developed for the determination of TrxR activity in biological samples, yet their application is constrained when exploring the real-time dynamics of TrxR activity in live organisms. Fluorescent probes offer several advantages for in situ imaging and the quantification of biological targets, such as non-destructiveness, real-time analysis, and high spatiotemporal resolution. These benefits facilitate the transition from a poise to a flux understanding of cellular targets, further advancing scientific studies in related fields. This review aims to introduce the progress in the development and application of TrxR fluorescent probes in the past years, and it mainly focuses on analyzing their reaction mechanisms, construction strategies, and potential drawbacks. Finally, this study discusses the critical challenges and issues encountered during the development of selective TrxR probes and proposes future directions for their advancement. We anticipate the comprehensive analysis of the present TrxR probes will offer some glitters of enlightenment, and we also expect that this review may shed light on the design and development of novel TrxR probes.

Ginsenoside Re blocks Bay k-8644-induced neurotoxicity via attenuating mitochondrial dysfunction and PKCδ activation in the hippocampus of mice: Involvement of antioxidant potential.

Although the anticonvulsant effects of ginsenosides are recognized, little is known about their effects on the convulsive behaviors induced by the activation of L-type Ca2+ channels. Here, we investigated whether ginsenoside Re (GRe) modulates excitotoxicity induced by the L-type Ca2+ channel activator Bay k-8644. GRe significantly attenuated Bay k-8644-induced convulsive behaviors and hippocampal oxidative stress in mice. GRe-mediated antioxidant potential was more pronounced in the mitochondrial fraction than cytosolic fraction. As L-type Ca2+ channels are thought to be targets of protein kinase C (PKC), we investigated the role of PKC under excitotoxic conditions. GRe attenuated Bay k-8644-induced mitochondrial dysfunction, PKCδ activation, and neuronal loss. The PKCδ inhibition and neuroprotection mediated by GRe were comparable to those by the ROS inhibitor N-acetylcysteine, the mitochondrial protectant cyclosporin A, the microglial inhibitor minocycline, or the PKCδ inhibitor rottlerin. Consistently, the GRe-mediated PKCδ inhibition and neuroprotection were counteracted by the mitochondrial toxin 3-nitropropionic acid or the PKC activator bryostatin-1. GRe treatment did not have additional effects on PKCδ gene knockout-mediated neuroprotection, suggesting that PKCδ is a molecular target of GRe. Collectively, our results suggest that GRe-mediated anticonvulsive/neuroprotective effects require the attenuation of mitochondrial dysfunction and altered redox status and inactivation of PKCδ.

Detailed mechanistic investigation of stress-induced lipogenesis in oleaginous yeast for value-added metabolites

In the present study, a marine red yeast Rhodotorula glutinis ISO A1 cultivated under combinations of artificial seawater (ASW) and sewage wastewater (SWW) has been subjected to detailed mechanistic investigations via physiological and biochemical analysis to dissect the pathway of halotolerance behavior and carbon flux channelization towards enhanced lipid synthesis. Amid all tested groups (25–100% ASW), cells grown in 25% ASW yielded ∼ 1.4-fold higher lipid yield than glucose synthetic medium (GSM) and revealed metabolic rewiring of cells to channelize carbon pools for producing neutral lipids of vehicular quality. Detailed carbohydrate profiling showed enhanced glycerol, trehalose, mannose, and xylitol/arabitol under saline stress, suggesting the interplay of these metabolites to impart tolerance against osmotic imbalance. Further, the strengthened enzymatic activity (glutathione reductase, superoxide dismutase, ascorbate peroxidase) and non-enzymatic metabolites (betaine, proline) highlighted the active yeast defence network to counter altered redox state arise due to high salinity. The stress-induced responses also constituted substantial variations in membrane fluidity and production of biodiesel-quality lipids. Further findings like low thermal degradation temperature (at ∼ 265°C) and high chitin (can be converted into chitosan) entity in yeast de-oiled biomass primarily derived from yeast cells grown under contaminated environment; sea and sewage wastewater, signified its potential utilization for chitosan recovery, a commercially important product. Conclusively, this study elucidated a competent model of yeast-based biorefinery approach integrating seawater-wastewater utilization and simultaneous production of biodiesel and value-added products vital for a sustainable and circular bioeconomy.

Hydromethanolic extract of Ipomoea cairica leaf extract ameliorate the oxidative activity of cadmium chloride in the hearts and testes of male Wistar rats

Background: Ipomoea cairica (L.) sweet Convolvulaceae also known as morning glory or ‘Railway creeper’ is a traditional herb that has been used in treating various diseases throughout the world. Some of the reported pharmacological activities include antioxidant, anti-inflammatory, and antiviral. Cadmium is a toxic metal that can cause both hearts and testicular damage and its major mechanism is oxidative stress. Objective: Therefore, this study was done to investigate the effect of I. cairica leaf extract (ICE) against cadmium chloride-induced hearts and testicular damage in Wistar rats. Materials and Methods: Twenty male Wistar rats were divided into 4 groups of 5 animals each. Group I: Control (administered distilled water), Group II (administered 35 mg/kg CdCl2 intraperitoneally), group III (orally administered 100 mg/kg ICE and CdCl2), group IV (orally administered 100 mg/kg, I. cairica and CdCl2). Animals were sacrificed via cervical dislocation 24 hours after the last administration. The hearts and testes were collected and processed for biochemical assays. Biochemical assays evaluated were Malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and Glutathione-S-transferase (GST). Results: Results showed that Cd exposure significantly increases the level of MDA, decreased the concentration of GSH (non-enzymatic antioxidant), and decreased the activity of CAT, SOD, and GST (enzymatic antioxidants). Treatment with ICE prevented the alteration of redox status by CdCl2, as observed in the significant decrease in MDA concentration, and increase in GSH concentration when compared with the animals in the untreated groups. In addition, treatment with I. cairica also caused a significant increase in the activity of CAT, SOD, and GST as compared to the untreated group (P

Plant NADPH-dependent thioredoxin reductases are crucial for the metabolism of sink leaves and plant acclimation to elevated CO2.

Plants contain three NADPH-thioredoxin reductases (NTR) located in the cytosol/mitochondria (NTRA/B) and the plastid (NTRC) with important metabolic functions. However, mutants deficient in all NTRs remained to be investigated. Here, we generated and characterised the triple Arabidopsis ntrabc mutant alongside with ntrc single and ntrab double mutants under different environmental conditions. Both ntrc and ntrabc mutants showed reduced growth and substantial metabolic alterations, especially in sink leaves and under high CO2 (HC), as compared to the wild type. However, ntrabc showed higher effective quantum yield of PSII under both constant and fluctuating light conditions, altered redox states of NADH/NAD+ and glutathione (GSH/GSSG) and lower potential quantum yield of PSII in sink leaves in ambient but not high CO2 concentrations, as compared to ntrc, suggesting a functional interaction between chloroplastic and extra-chloroplastic NTRs in photosynthesis regulation depending on leaf development and environmental conditions. Our results unveil a previously unknown role of the NTR system in regulating sink leaf metabolism and plant acclimation to HC, while it is not affecting full plant development, indicating that the lack of the NTR system can be compensated, at least to some extent, by other redox mechanisms.

Mitochondrial Oxidative Metabolism: An Emerging Therapeutic Target to Improve CKD Outcomes.

Chronic kidney disease (CKD) predisposes one toward end-stage renal disease (ESRD) and its associated morbidity and mortality. Significant metabolic perturbations in conjunction with alterations in redox status during CKD may induce increased production of reactive oxygen species (ROS), including superoxide (O2●-) and hydrogen peroxide (H2O2). Increased O2●- and H2O2 may contribute to the overall progression of renal injury as well as catalyze the onset of comorbidities. In this review, we discuss the role of mitochondrial oxidative metabolism in the pathology of CKD and the recent developments in treating CKD progression specifically targeted to the mitochondria. Recently published results from a Phase 2b clinical trial by our group as well as recently released data from a ROMAN: Phase 3 trial (NCT03689712) suggest avasopasem manganese (AVA) may protect kidneys from cisplatin-induced CKD. Several antioxidants are under investigation to protect normal tissues from cancer-therapy-associated injury. Although many of these antioxidants demonstrate efficacy in pre-clinical models, clinically relevant novel compounds that reduce the severity of AKI and delay the progression to CKD are needed to reduce the burden of kidney disease. In this review, we focus on the various metabolic pathways in the kidney, discuss the role of mitochondrial metabolism in kidney disease, and the general involvement of mitochondrial oxidative metabolism in CKD progression. Furthermore, we present up-to-date literature on utilizing targets of mitochondrial metabolism to delay the pathology of CKD in pre-clinical and clinical models. Finally, we discuss the current clinical trials that target the mitochondria that could potentially be instrumental in advancing the clinical exploration and prevention of CKD.

Oxidative Stress, Cytotoxic and Inflammatory Effects of Azoles Combinatorial Mixtures in Sertoli TM4 Cells.

Triazole and imidazole fungicides are an emerging class of contaminants with an increasing and ubiquitous presence in the environment. In mammals, their reproductive toxicity has been reported. Concerning male reproduction, a combinatorial activity of tebuconazole (TEB; triazole fungicide) and econazole (ECO; imidazole compound) in inducing mitochondrial impairment, energy depletion, cell cycle arrest, and the sequential activation of autophagy and apoptosis in Sertoli TM4 cells (SCs) has recently been demonstrated. Given the strict relationship between mitochondrial activity and reactive oxygen species (ROS), and the causative role of oxidative stress (OS) in male reproductive dysfunction, the individual and combined potential of TEB and ECO in inducing redox status alterations and OS was investigated. Furthermore, considering the impact of cyclooxygenase (COX)-2 and tumor necrosis factor-alpha (TNF-α) in modulating male fertility, protein expression levels were assessed. In the present study, we demonstrate that azoles-induced cytotoxicity is associated with a significant increase in ROS production, a drastic reduction in superoxide dismutase (SOD) and GSH-S-transferase activity levels, and a marked increase in the levels of oxidized (GSSG) glutathione. Exposure to azoles also induced COX-2 expression and increased TNF-α production. Furthermore, pre-treatment with N-acetylcysteine (NAC) mitigates ROS accumulation, attenuates COX-2 expression and TNF-α production, and rescues SCs from azole-induced apoptosis, suggesting a ROS-dependent molecular mechanism underlying the azole-induced cytotoxicity.

Cytostatic and cytotoxic effects of a hot water and methanol extract of Acokanthera oppositifolia in HepG2 hepatocarcinoma cells

Ethnopharmacological relevanceHerb-induced liver injury is poorly described for African herbal remedies, such as Acokanthera oppositifolia. Although a commonly used treatment for pain, snake bites and anthrax, it is also a well-known arrow poison, thus toxicity is to be expected. Aim of the studyThe cytotoxicity and preliminary mechanisms of toxicity in HepG2 hepatocarcinoma cells were assessed. Materials and methodsThe effect of hot water and methanol extracts were on cell density, oxidative status, mitochondrial membrane potential, fatty acids, caspase-3/7 activity, adenosine triphosphate levels, cell cycling and viability was assessed. Phytochemicals were tentatively identified using ultra-performance liquid chromatography. ResultsThe hot water extract displayed an IC50 of 24.26 μg/mL, and reduced proliferation (S- and G2/M-phase arrest) and viability (by 30.71%) as early as 24 h after incubation. The methanol extract had a comparable IC50 of 26.16 μg/mL, and arrested cells in the G2/M-phase (by 18.87%) and induced necrosis (by 13.21%). The hot water and methanol extracts depolarised the mitochondrial membrane (up to 0.84- and 0.74-fold), though did not generate reactive oxygen species. The hot water and methanol extracts decreased glutathione (0.42- and 0.62-fold) and adenosine triphosphate (0.08- and 0.26-fold) levels, while fatty acids (2.00- and 4.61-fold) and caspase-3/7 activity (1.98- and 5.82-fold) were increased. ConclusionExtracts were both cytostatic and cytotoxic in HepG2 cells. Mitochondrial toxicity was evident and contributed to reducing adenosine triphosphate production and fatty acid accumulation. Altered redox status perturbed proliferation and promoted necrosis. Extracts of A. oppositifolia may thus promote necrotic cell death, which poses a risk for inflammatory hepatotoxicity with associated steatosis.

Isometamidium chloride alters redox status, down-regulates p53 and PARP1 genes while modulating at proteomic level in Drosophila melanogaster

As trypanocide, several side effects have been reported in the use of Isometamidium chloride. This study was therefore, designed to evaluate its ability to induce oxidative stress and DNA damage using D. melanogaster as a model organism. The LC50 of the drug was determined by exposing the flies (1–3 days old of both genders) to six different concentrations (1 mg, 10 mg, 20 mg, 40 mg, 50 mg and 100 mg per 10 g of diet) of the drug for a period of seven days. The effect of the drug on survival (28 days), climbing behavior, redox status, oxidative DNA lesion, expression of p53 and PARP1 (Poly-ADP-Ribose Polymerase-1) genes after five days exposure of flies to 4.49 mg, 8.97 mg, 17.94 mg and 35.88 mg per 10 g diet was evaluated. The interaction of the drug in silico with p53 and PARP1 proteins was also evaluated. The result showed the LC50 of isometamidium chloride to be 35.88 mg per 10 g diet for seven days. Twenty-eight (28) days of exposure to isometamidium chloride showed a decreased percentage survival in a time and concentration-dependent manner. Isometamidium chloride significantly (p < 0.05) reduced climbing ability, total thiol level, Glutathione-S-transferase, and Catalase activity. The level of H2O2 was significantly (p < 0.05) increased. The result also showed significant (p < 0.05) reduction in the relative mRNA levels of p53 and PARP1 genes. The in silico molecular docking of isometamidium with p53 and PARP1 proteins showed high binding energy of −9.4 Kcal/mol and −9.2 Kcal/mol respectively. The results suggest that isometamidium chloride could be cytotoxic and a potential inhibitor of p53 and PARP1 proteins.

Comparative Effects of Whole Stevia Leaf and Rebaudioside A on Oxidative Stress in Male Obese Sprague Dawley Rats

Background: Obesity is a dilemma nowadays for increasing percentage of people worldwide. Obesity induced oxidative stress due to increased tissue lipid levels, threatened redox state of cell and increased free radical formation leads to tissue oxidative stress. Fatty liver disease is a very common disorder related with obesity resulting in storage of fat goblets in the liver tissues leading to altered redox state called oxidative stress. Aim: To relate the outcome of Stevia and Rebaudioside A on Oxidative stress (MDA, SOD) in Obese Sprague Dawley Rats. Place and duration of study: Physiology Department of Islamabad Medical and Dental College, Islamabad, in collaboration with National Institute of Health (NIH) from 1st January 2020 to 30th June 2022. Methodology: One hundred and twenty healthy male Sprague Dawley rats were included. The animals were divided randomly into four groups of 30 rats each by simple randomization technique. Group 1 was given normal diet while the other three groups were given high fat diet. Stevia leaves and Rebaudioside A (rebiana) were further added for six weeks in the diet of Group 3 and 4 respectively. All animals were sacrificed at the end of study. Results: High fat diet induced oxidative stress in obese group was restored to approximate normal values of SOD (0.001) and MDA (0.001) by treatment with stevia and rebiana both (0.899). Conclusion: Stevia and Rebiana both cause improvement of oxidative stress unrewarding of expensive extraction procedures. Keywords: Stevia rebaudiana, Rebaudioside A, Sprague Dawley rats, Oxidative stress, NAFLD

Ellagic acid mitigates rotenone-induced damage via modulating mitochondria function in Drosophilamelanogaster.

Constant, systematic exposure to rotenone has been utilized in animal models to induce Parkinsonism. Ellagic acid is a polyphenol with anti-inflammatory and antioxidative properties which is found in numerous natural fruits. Here, we investigated the therapeutic effects of ellagic acid in rotenone-induced toxicity in Drosophila melanogaster evaluating their antioxidant and mitoprotective properties. Adult flies were treated with rotenone and ellagic acid through their diet for 7 days, thereafter markers of neurotoxicity (acetylcholinesterase, monoamine oxidase, tyrosine hydroxylase), antioxidant and oxidative stress markers (hydrogen peroxide, nitric oxide, lipid peroxidation, protein carbonyl contents, catalase, total thiol, and nonprotein thiol) was measured. Mitochondrial respiration was also evaluated in the flies. Survival assay was carried out with both genders of the flies, and we observed a significant increase in the survival rate of flies exposed to both rotenone and ellagic acid when compared with the increased mortality rate in the groups exposed to rotenone alone. The impaired locomotion, altered redox status, and enzymes of neurotoxicity induced by rotenone were significantly ameliorated by ellagic acid to levels comparable to the control. In addition, rotenone-induced complex 1 inhibition and altered bioenergetic state were restored upon ellagic acid supplementation. These findings show the beneficial properties of ellagic acid against pesticides induced toxicity.