Role of HSP27 and reduced glutathione in modulating malathion-induced apoptosis of human peripheral blood mononuclear cells: Ameliorating effect of N-acetylcysteine and curcumin

Porphyromonas gingivalis activates Heat-Shock-Protein 27 to drive a LC3C-specific probacterial form of select autophagy that is redox sensitive for intracellular bacterial survival in human gingival mucosa

Porphyromonas gingivalis , a major oral pathobiont, evades canonical host pathogen clearance in human primary gingival epithelial cells (GECs) by initiating a non-canonical variant of autophagy consisting of Microtubule-associated protein 1A/1B-light chain 3 (LC3)-rich autophagosomes, which then act as replicative niches. Simultaneously, P. gingivalis inhibits apoptosis and oxidative-stress, including extracellular-ATP (eATP)-mediated reactive-oxygen-species (ROS) production via phosphorylating Heat Shock Protein 27 (HSp27) with the bacterial nucleoside-diphosphate-kinase (Ndk). Here, we have mechanistically identified that P. gingivalis -mediated induction of HSp27 is crucial for the recruitment of the LC3 isoform, LC3C, to drive the formation of live P. gingivalis -containing Beclin1-ATG14-rich autophagosomes that are redox sensitive and non-degrading. HSp27 depletions of both infected GECs and gingiva-mimicking organotypic-culture systems resulted in the collapse of P. gingivalis -mediated autophagosomes, and abolished P. gingivalis -induced LC3C-specific autophagic-flux in a HSp27-dependent manner. Concurrently, HSp27 depletion accompanied by eATP treatment abrogated protracted Beclin 1-ATG14 partnering and decreased live intracellular P. gingivalis levels. These events were only partially restored via treatments with the antioxidant N-acetyl cysteine (NAC), which rescued the cellular redox environment independent of HSp27. Moreover, the temporal phosphorylation of HSp27 by the bacterial Ndk results in HSp27 tightly partnering with LC3C, hindering LC3C canonical cleavage, extending Beclin 1-ATG14 association, and halting canonical maturation. These findings pinpoint how HSp27 pleiotropically serves as a major platform-molecule, redox regulator, and stepwise modulator of LC3C during P. gingivalis -mediated non-canonical autophagy. Thus, our findings can determine specific molecular strategies for interfering with the host-adapted P. gingivalis ' successful mucosal colonization and oral dysbiosis.

Immunotoxic role of organophosphates: An unseen risk escalating SARS-CoV-2 pathogenicity

Consistent gathering of immunotoxic substances on earth is a serious global issue affecting people under pathogenic stress. Organophosphates are among such hazardous compounds that are ubiquitous in nature. They fuel oxidative stress to impair antiviral immune response in living entities. Aside, organophosphates promote cytokine burst and pyroptosis in broncho-alveolar chambers leading to severe respiratory ailments. At present, we witness COVID-19 outbreak caused by SARS-CoV-2. Infection triggers cytokine storm coupled with inflammatory manifestations and pulmonary disorders in patients. Since organophosphate-exposure promotes necroinflammation and respiratory troubles hence during current pandemic situation, additional exposure to such chemicals can exacerbate inflammatory outcome and pulmonary maladies in patients, or pre-exposure to organophosphates might turn-out to be a risk factor for compromised immunity. Fortunately, antioxidants alleviate organophosphate-induced immunosuppression and hence under co-exposure circumstances, dietary intake of antioxidants would be beneficial to boost immunity against SARS-CoV-2 infection.

Carvacrol loaded beta cyclodextrin-alginate-chitosan based nanoflowers attenuates renal toxicity induced by malathion and parathion: A comparative toxicity

Most of approximately 1.8 billion people involved in agriculture protect their food products using pesticides especially insecticides which may remain in foods as pesticide residues. Among insecticides organophosphates such as malathion have been widely used around the world and others such as parathion has been restricted because of their toxicity. Carvacrol (CAR) is the main component of Satureja khuzestanica. Since chemical composition of foods can alter toxicity of pesticides, in this work, the effect of coadministration of CAR and organophosphates on renal function has been studied and compared with the effect of coadministration of carvacrol loaded beta cyclodextrin-alginate-chitosan (BAC) based nanoflowers. Serum levels of urea and creatinine and histological examination were analyzed after 10 days of administration of chemicals. Malathion and parathion significantly increased urea and creatinine and induced renal inflammation. However, coadministration of CAR or BAC-CAR modified urea and creatinine and improved renal inflammation. BAC-CAR modified serum levels of urea more efficient than CAR (P < 0.05). It is concluded that BAC could be considered as a carrier for drugs used to treat renal disorders. Carvacrol can be used in the formulation of organophosphate pesticides, which may control pests more efficiently than conventional organophosphate pesticides.

Comparative analysis of the protective effects of curcumin and N-acetyl cysteine against paracetamol-induced hepatic, renal, and testicular toxicity in Wistar rats

This study aimed to investigate the possible protective role of curcumin (CUR) vs. N-acetyl cysteine (NAC) against paracetamol (PCM)-induced oxidative damage and impairment of liver, kidney, and testicular functions, as well as hematotoxicity, in albino rats. A large single dose of PCM induced lipid peroxidation along with a significant decline in glutathione content and catalase activity in the liver, kidneys, and testicles. The apparent oxidative damage was associated with evident hepatic, renal, and testicular dysfunction, which was confirmed in histopathological lesions, and increased serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. PCM decreased serum total protein, albumin, and globulin contents; increased bilirubin, urea, and creatinine contents; and induced hematotoxicity. PCM also reduced the sperm cell count, sperm motility, and alive sperm rate and increased the sperm abnormality rate. Pretreatment of PCM-intoxicated animals with CUR or NAC substantially alleviated the increase in malondialdehyde and maintained the antioxidants at control levels. These pretreatments also minimized liver, kidney, and testicular histopathological changes and normalized their functions. CUR similarly mitigated the PCM hemato- and hepatotoxicity compared with NAC. However, it exhibited a pronounced nephroprotection, rather than reproductive protection as did NAC. Our findings demonstrate that a large single dose of PCM is not only associated with hepatotoxicity but also nephrotoxicity and reproductive toxicity. Both CUR and NAC administration provided substantial organ protection with pronounced efficacy against PCM nephrotoxicity with CUR and reproductive toxicity with NAC, which was possibly mediated through their antioxidant activities, as well as their specific characteristics.

Methamidophos induces cytotoxicity and oxidative stress in human peripheral blood mononuclear cells

Previous studies have shown that organophosphate pesticide (OP) exposure is associated with oxidative stress. Methamidophos (MET) is an OP widely used in agriculture, which is regarded as a highly toxic pesticide and it is a potent inhibitor of acetylcholinesterase. The aim of this study was to evaluate whether MET can induce oxidative stress at low concentrations in primary cultures of human peripheral blood mononuclear cells (PBMCs). PBMCs from healthy individuals were exposed to MET (0-80 mg/L) for 0-72 h. We performed the MTT and neutral-red assays to assess the cytotoxicity. As indicators of oxidative stress, the levels of reactive oxygen species (ROS) were assessed using flow cytometry, and the malondialdehyde (MDA) and reduced glutathione (GSH) levels were determined. MET decreased the viability of PBMCs in a dose-dependent manner. At concentrations of 3, 10, or 20 mg/L for 24 h, MET increased the ROS production significantly compared with the vehicle control. Similarly, MET increased the levels of MDA at the same concentrations that increased ROS (10 and 20 mg/L); however, no changes in GSH levels were observed. These results suggest that MET increased the generation of oxidative stress in PBMCs. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 147-155, 2017.

HSP27 modulates survival signaling in endosulfan-exposed human peripheral blood mononuclear cells treated with curcumin

Endosulfan, a well-known organochlorine pesticide, induces apoptosis and depletion of reduced glutathione (GSH) in human peripheral blood mononuclear cells (PBMC). Thus, for the amelioration of its effect, antioxidant and antiapoptotic potential of curcumin was evaluated. For ascertaining the attenuating effect of curcumin, various biochemical indices of cell damage such as cytotoxicity, oxidative stress, apoptosis (phosphatidylserine externalization, DNA fragmentation, and cytochrome c) in human PBMC was evaluated following endosulfan exposure (0-100 µM). To assess the role of HSP27 on endosulfan-induced apoptosis, the expression of HSP27 was examined. Curcumin (25 µM) increased cell viability significantly. As evident from the restoration of GSH, antiapoptotic potential was directly proportional to their antioxidant nature of curcumin. The present study indicates that the beneficial effect of curcumin on endosulfan-induced cytotoxicity is related to the induced synthesis of HSP27, emphasizing its antioxidant and therapeutic potential as well as underscoring the mechanism of pesticide-induced toxicity at cellular level. Taken together, these findings suggest that curcumin protects against endosulfan-induced immunotoxicity in human PBMC by attenuating apoptosis.

Crocin Effects on Human Myeloma Cells Regarding Intracellular Redox State, DNA Fragmentation, and Apoptosis or Necrosis Profile

Background:

Well-documented studies reported several pharmacological properties for crocin, the active compound of Crocus sativus, such as its antitumor, radical scavenging, antidepressant, and memory-enhancing effects.

Objectives:

We aimed to evaluate the possible cytotoxic activity of crocin on B lymphocytes in human myeloma (U266 cell line) after 24- and 48-hour treatment.

Materials and Methods:

For this purpose, cell viability was determined by the colorimetric MTT assay and cell death pattern was evaluated using Annexin V-FITC/propidium iodide (PI) apoptosis detection kit. ROS (reactive oxygen species) production and DNA fragmentation were assessed using 2′,7′-dichlorofluorescein diacetate (DCFH-DA) kit and PI staining, respectively.

Results:

The highest concentration of crocin significantly decreased ROS production after 48 hours of treatment. However, crocin had no effect on the expression level of HSP (Heat shock protein). Additionally, its administration caused a mild decline in cell viability and a mild increase in the population of DNA fragmented cells as well as apoptosis.

Conclusions:

In our study, no prominent effect was seen; therefore, in order to have a better perspective of crocin activity against cancerous cell lines, further studies are highly recommended.

Potential pharmacological strategies for the improved treatment of organophosphate-induced neurotoxicity

Organophosphates (OP) are highly toxic compounds that cause cholinergic neuronal excitotoxicity and dysfunction by irreversible inhibition of acetylcholinesterase, resulting in delayed brain damage. This delayed secondary neuronal destruction, which arises primarily in the cholinergic areas of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, could be largely responsible for persistent profound neuropsychiatric and neurological impairments such as memory, cognitive, mental, emotional, motor, and sensory deficits in the victims of OP poisoning. The therapeutic strategies for reducing neuronal brain damage must adopt a multifunctional approach to the various steps of brain deterioration: (i) standard treatment with atropine and related anticholinergic compounds; (ii) anti-excitotoxic therapies to prevent cerebral edema, blockage of calcium influx, inhibition of apoptosis, and allow for the control of seizure; (iii) neuroprotection by aid of antioxidants and N-methyl-d-aspartate (NMDA) antagonists (multifunctional drug therapy), to inhibit/limit the secondary neuronal damage; and (iv) therapies targeting chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may prevent secondary neuronal damage in both early and late stages of OP poisoning, and thus may be a beneficial approach to treating the neuropsychological and neuronal impairments resulting from OP toxicity.

Protective Effect of Silymarin against Acrolein-Induced Cardiotoxicity in Mice

Reactive α,β-unsaturated aldehydes such as acrolein (ACR) are major components of environmental pollutants and have been implicated in the neurodegenerative and cardiac diseases. In this study, the protective effect of silymarin (SN) against cardiotoxicity induced by ACR in mice was evaluated. Studies were performed on seven groups of six animals each, including vehicle-control (normal saline + 0.5% w/v methylcellulose), ACR (7.5 mg/kg/day, gavage) for 3 weeks, SN (25, 50 and 100 mg/kg/day, i.p.) plus ACR, vitamin E (Vit E, 100 IU/kg, i.p.) plus ACR, and SN (100 mg/kg, i.p.) groups. Mice received SN 7 days before ACR and daily thereafter throughout the study. Pretreatment with SN attenuated ACR-induced increased levels of malondialdehyde (MDA), serum cardiac troponin I (cTnI), and creatine kinase-MB (CK-MB), as well as histopathological changes in cardiac tissues. Moreover, SN improved glutathione (GSH) content, superoxide dismutase (SOD), and catalase (CAT) activities in heart of ACR-treated mice. Western blot analysis showed that SN pretreatment inhibited apoptosis provoked by ACR through decreasing Bax/Bcl-2 ratio, cytosolic cytochrome c content, and cleaved caspase-3 level in heart. In conclusion, SN may have protective effects against cardiotoxicity of ACR by reducing lipid peroxidation, renewing the activities of antioxidant enzymes, and preventing apoptosis.

Quantitative proteomic analysis of pregnancy-related proteins from peripheral blood mononuclear cells during pregnancy in pigs

Information obtained from peripheral blood could help us understand the underlying mechanisms in autoimmune diseases, cancer, pregnancy, and other conditions. In this paper, we present the protein map of porcine peripheral blood mononuclear cells (PBMC) to better understand the molecular expression changes that occur during pregnancy using proteomic analysis. We detected 94 differentially expressed proteins in pregnant vs. non-pregnant (NP) pigs, and a representative set of the proteins was subjected to LC-MS/MS analysis. Furthermore, the identified proteins were categorized according to their biological process and molecular function. By classifying the proteins according to their functions, a large number of differentially regulated proteins involved in anti-oxidant, detoxification and stress response pathways were found, including peroxiredoxin (PRX) 1, 2, and 6, glutathione-S-transferase (GST), annexin A2, and A6, and heat shock protein 27 (HSP 27) during pregnancy (pregnancy d of E40, embryonic day 40; E70, embryonic day 70; and E93, embryonic day 93) compared with non-pregnancy. In this study, a proteomic approach utilizing 2-DE and LC-MS/MS was applied to evaluate specific molecular expression changes during pregnancy compared with non-pregnancy. Together, these data offer new information about the proteome map and factors that are differentially regulated during maintenance of normal pregnancy.

Protective effect of NAC against malathion-induced oxidative stress in freshly isolated rat hepatocytes

PURPOSE

Induction of oxidative stress by Organophosphate compounds (OPs) has been previously reported. In the present work, the mechanism of protective effects of N-acetylcysteine as a glutathion (GSH) prodrug against malathion-induced cell toxicity was investigated. In this work, freshly isolated rat hepatocytes were used to determine the effect of NAC on malathion-induced cytotoxicity, formation of reactive oxygen species (ROS) and mitochondrial dysfunction.

METHODS

Rat hepatocytes were isolated using collagenase perfusion and then cell viability, mitchondrial membrane potential (MMP) and ROS formation were determined using trypan blue exclusion, Rhodamine 123 fluorescence and fluorogenic probe, 2', 7' -dichlorofluorescin diacetate (DCFH-DA), respectively.

RESULTS

Despite the protective effect of NAC on malathion-induced cell toxicity and MMP dysfunction, its efficacy against ROS formation was not adequate to completely protect the cells.

CONCLUSION

Cytotoxic effects of malathion regardless of its cholinergic feature, is started with gradual free radical production but, the main factor that causes cell death, is mitochondrial dysfunction, so that reduction of ROS formation alone is not sufficient for cell survival, and the maintenance of mitochondrial integrity through different mechanisms is the most ameliorative factor specially at high levels of cell damage, as NAC seemed to protect cells with various fashions apart from ROS scavenging in concentrations higher than malathion's LC50.

N-Acetylcysteine reverses mitochondrial dysfunctions and behavioral abnormalities in 3-nitropropionic acid-induced Huntington's disease

Mitochondrial dysfunction is a major event involved in the pathogenesis of Huntington's disease (HD). The present study evaluates the role of N-acetyl-L-cysteine (NAC) in preventing mitochondrial dysfunctions in a 3-nitropropionic acid (3-NP)-induced model of HD. Administration of 3-NP to rats (Wistar strain) resulted in significant inhibition of mitochondrial complexes II, IV and V in the striatum. However, no significant effect on complex I was observed. Increased generation of reactive oxygen species and lipid peroxidation was observed in mitochondria of 3-NP-treated animals. Endogenous antioxidants (thiols and manganese-superoxide dismutase) were lowered in mitochondria of 3-NP-treated animals. 3-NP-treated animals showed increased cytosolic cytochrome c levels and mitochondrial swelling. Increased expressions of caspase-3 and p53 were also observed in 3-NP-treated animals. Histopathological examination of the striata of 3-NP-treated animals revealed increased neural space, neurodegeneration and gliosis. This was accompanied by cognitive and motor deficits. NAC treatment, on the other hand, was found to be effective in reversing 3-NP-induced mitochondrial dysfunctions and neurobehavioral deficits. Our findings suggest a beneficial effect of NAC in HD.

Ameliorating effect of N-acetylcysteine and curcumin on pesticide-induced oxidative DNA damage in human peripheral blood mononuclear cells

Endosulfan, malathion, and phosphamidon are widely used pesticides. Subchronic exposure to these contaminants commonly affects the central nervous system, immune, gastrointestinal, renal, and reproductive system. There effects have been attributed to increased oxidative stress. This study was conducted to examine the role of oxidative stress in genotoxicity following pesticide exposure using peripheral blood mononuclear cells (PBMC) in vitro. Further possible attenuation of genotoxicity was studied using N-acetylcysteine (NAC) and curcumin as known modulators of oxidative stress. Cultured mononuclear cells was isolated from peripheral blood of healthy volunteers, and exposed to varying concentrations of different pesticides: endosulfan, malathion, and phosphamidon for 6, 12, and 24 h. Lipid peroxidation was assessed by cellular malondialdehyde (MDA) level and DNA damage was quantified by measuring 8-hydroxy-2'-deoxyguanosine (8-OH-dG) using ELISA. Both MDA and 8-OH-dG were significantly increased in a dose-dependent manner following treatment with these pesticides. There was a significant decrease in MDA and 8-OH-dG levels in PBMC when co-treated with NAC or/and curcumin as compared to pesticide alone. These results indicate that pesticide-induced oxidative stress is probably responsible for the DNA damage, and NAC or curcumin attenuate this effect by counteracting the oxidative stress.

Effects of a novel cystine-based glutathione precursor on oxidative stress in vascular smooth muscle cells

Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and cardiovascular disease, which is largely mediated by oxidative stress. We investigated the effect of three glutathione (GSH) precursors: N-acetyl-cysteine (NAC), cystine as the physiological carrier of cysteine in GSH with added selenomethionine (F1), and NAC fortified with selenomethionine (F2) on oxidative stress induced by spermine (a uremic toxin) in cultured human aortic vascular smooth muscle cells (VSMC). VSMC were exposed to spermine (15 microM) with or without the given antioxidants (dose 50, 100, 200, and 500 microg/ml) or vehicle (control) and assessed for intracellular GSH levels, 4-hydroxy-trans-2-nonenal (4-HNE), and incorporation of 13C from glucose into alanine and protein. Spermine exposure reduced intracellular GSH levels, increased 4-HNE, and impaired glucose metabolism through reduction in pyruvate generation and/or transamination. Treatment with NAC had no effect on intracellular glutathione level. In contrast, F1 maintained intracellular GSH at control levels at all four doses. Subsequent studies performed with 200 microg/ml of F1, F2, or NAC (optimal dose) revealed normalization of 4-HNE, whereas restoration of 13C from glucose to alanine or protein to control values was only noted in the F1 group. Spermine-induced alterations in VSMC ultrastructure were prevented in approximately 90% of cells treated with F1 but only approximately 50% of cells treated with either NAC or F2. In conclusion, F1 was more effective than NAC or F2 in ameliorating spermine-induced reduction in intracellular GSH levels and cellular alterations in VSMC. The cystine-based GSH precursor (F1) is a promising antioxidant, and further studies are needed to examine the effect of this compound in preventing CKD-associated vascular disease.