Effect Of Pyrrolidine Dithiocarbamate Research Articles

The possible protective effect of the nuclear factor kappa B inhibitor pyrrolidine dithiocarbamate on tramadol-induced testicular damage in rats

BackgroundTramadol provokes oxidative stress that gives rise to apoptosis with alterations in the cellular structure and adversely influences male fertility. A specific inhibitor of nuclear factor kappa B (NF-κB), pyrrolidine dithiocarbamate (PDTC), has observable antioxidant and anti-inflammatory characteristics and enhances the improvement of organs damage caused by various agents. The impact of PDTC on testicular damage caused by tramadol has not been previously examined.ObjectiveThis study was designed to investigate the potential impact of pyrrolidine dithiocarbamate on testicular damage provoked by chronic tramadol usage.Materials and methodsForty healthy adult male albino rats were included in this study. Rats were randomly and equally divided into 4 groups: group (I), control group; group (II), pyrrolidine dithiocarbamate (PDTC) group; group (III), tramadol (Tr) group; and group (IV), Tr + PDTC group. This study measured serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and free testosterone levels. Testicular malondialdehyde (MDA), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPX), and caspase-8 and caspase-3 activities were also detected. Immuno-histochemical evaluation of inducible NOS (iNOS) expression in testicular tissue along with histopathological examination of testicular tissue has been studied.ResultsTramadol caused a significant reduction in serum FSH, LH and testosterone levels, epididymal sperm count, and motility, as well as testicular GPX and SOD activities. On the other hand, a significant elevation of testicular MDA, IL-1β, IL-6, and TNF-α levels and caspase-8 and caspase-3 activities were found. However, PDTC administration with tramadol showed significantly increased sperm production and motility and alleviated tramadol-induced disturbance in other measured parameters in the Tr + PDTC group compared to the Tr group. Moreover, co-administration of PDTC with tramadol significantly alleviated the histopathological structure of testicular tissue and the increased iNOS expressions noticed in the tramadol-treated group.ConclusionConsidering the protective effects of PDTC against the reproductive toxicity induced by tramadol, this compound can be used as a possible protective and treating target for tramadol-induced reproductive toxicity.

Pyrrolidine Dithiocarbamate Suppresses Cutibacterium acnes-Induced Skin Inflammation.

Cutibacterium acnes (C. acnes), a Gram-positive anaerobic bacterium, proliferates in hair follicles and pores and causes inflammation in the skin of young people. The rapid growth of C. acnes triggers macrophages to secrete proinflammatory cytokines. Pyrrolidine dithiocarbamate (PDTC) is a thiol compound that exerts antioxidant and anti-inflammatory effects. Although the anti-inflammatory function of PDTC in several inflammatory disorders has been reported, the effect of PDTC on C. acnes-induced skin inflammation remains unexplored. In the present study, we examined the effect of PDTC on C. acnes-induced inflammatory responses and determined the mechanism by using in vitro and in vivo experimental models. We found that PDTC significantly inhibited the expression of C. acnes-induced proinflammatory mediators, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and NOD-like receptor (NLR) pyrin domain-containing 3 (NLRP3), in mouse-bone-marrow-derived macrophage (BMDM) cells. PDTC suppressed C. acnes-induced activation of nuclear factor-kappa B (NF-κB), which is the major transcription factor for proinflammatory cytokine expression. In addition, we found that PDTC inhibited caspase-1 activation and IL-1β secretion through suppressing NLRP3 and activated the melanoma 2 (AIM2) inflammasome but not the NLR CARD-containing 4 (NLRC4) inflammasome. Moreover, we found that PDTC improved C. acnes-induced inflammation by attenuating C. acnes-induced IL-1β secretion in a mouse acne model. Therefore, our results suggest that PDTC has potential therapeutic value for the amelioration of C. acnes-induced skin inflammation.

Protective and therapeutic effects of pyrrolidine dithiocarbamate in a rat tongue cancer model created experimentally using 4-nitroquinoline 1-oxide.

Tongue tumors, which are oropharyngeal tumors, are increasing in frequency. Pyrrolidine dithiocarbamate (PDTC) is a powerful antioxidant and antitumoral agent. To evaluate the protective and therapeutic effects of PDTC in a tongue cancer model induced with 4-nitroquinoline 1-oxide (4-NQO). We included 40 rats in the trial and assigned them randomly to 5 groups. Group 1 (cancer, n = 7): 4-NQO (0-12 weeks); group 2 (protection, n = 8): 4-NQO (0-12 weeks) + PDTC (300 mg/kg/day, 0-12 weeks); group 3 (therapy-high dose, n = 10): 4-NQO (0-12 weeks) + PDTC (600 mg/kg/day, weeks 12-30); group 4 (therapy-low dose, n = 10): 4-NQO (0-12 weeks) + PDTC (300 mg/kg/day, weeks 12-30); and group 5 (control). Cardiac blood samples were taken to analyze oxidative stress parameters (total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI)). Histopathological assessment was performed under a light microscope. The results of the histopathological assessment showed that the model we used in group 1 was successful, which was consistent with the literature. The PDTC dose administered in group 2 could not prevent tumor formation. Group 3 demonstrated that PDTC in high doses is effective as a therapeutic agent. Group 4 indicated that PDTC in low doses has no therapeutic effect. The results of the biochemical assessment showed that in group 3, TOS and OSI values were significantly lower than in groups 1, 2 and 4. No significant difference was found in the TOS and OSI values between groups 5 and 3. Our study demonstrated histopathologically that in an experimentally generated tongue cancer model, application of 600 mg/kg/day of PDTC led to a significant reduction in the size of the tumor. This was supported by the biochemical parameters.

Pyrrolidine dithiocarbamate and dexamethasone are novel treatments of Acute Exogenous Lipoid Pneumonia

BackgroundAcute exogenous lipoid pneumonia (AELP) is characterized by pulmonary inflammation. This mainly occur in children who have ingested sewing machine oil or other mineral oils accidentally. Despite emerging evidences revealing that inhibiting inflammation improves acute exogenous lipoid pneumonia, the actual process of inhibiting inflammation remains unknown. This study aimed to evaluate the effects of PDTC and dexamethasone on AELP to gain insight into the mechanism of AELP. MethodsThe experimental rats were randomly divided into 10 groups: NS control group (NS3 group, NS5 group), Oil inhalation group (AE3 group, AE5 group), PDTC intervention group (PDTC3 group, PDTC5 group), DXM intervention group (DXM3 group, DXM5 group), PDTC + DXM combined intervention group (PDTC + DXM3 group, PDTC + DXM 5 group). Enzyme-linked immunosorbent assay (ELISA) was used to determine concentrations of macrophage migration inhibitory factor (MIF), interleukin-6 (IL-6) and tumor necrosis factor-α (TNFα) in bronchoalveolar lavage fluid (BALF) and serum samples. On the other hand, western blotting was used to measure the expression levels of nuclear factor-κB p65 (NF-κB p65) and b-cell leukemia 2 (Bcl-2) in the lungs. Hematoxylin and Eosin (H&E) staining was performed to evaluate changes in the lung tissue. The wet-to-dry lung weight ratio was subsequently used to determine the pulmonary edema of the lungs. ResultsThere were increased MIF levels in both serum and BALF samples of the AE group. Pyrrolidine dithiocarbamate (PDTC) and dexamethasone (DXM) independently and in combination reduced pulmonary inflammation induced by the sewing machine oil by regulating MIF expression. TNF-α and IL-6 levels in serum and BALF samples of the AE group were higher than those of the NS control animals. However, their levels decreased after treatment with either PDTC, DXM or PDTC + DXM. Similarly, NF-κBp65 expression increased after oil inhalation but decreased after treatment with either PDTC, DXM or PDTC + DXM. PDTC, DXM and PDTC + DXM treatment significantly reduced pulmonary inflammation and pulmonary edema of the lung tissue following induction of acute exogenous lipoid pneumonia. ConclusionsIndividual or combined use of PDTC and DXM can ameliorate pulmonary inflammation induced by inhalation of sewing machine oil by inhibiting the NF-κB pathway in young rats. These findings provide novel insights that will greatly contribute in treatment of AELP.

519-P: Acute Kidney Injury Sensitivity in Diabetic Murine Model

Background: We recently reported that diabetes can upregulate two discrete isoforms of the MMP-2 (full length and N-terminal truncated, FL-MMP-2, NTT-MMP-2) in renal tubules and especially, inducible NTT-MMP-2 could be related to renal tubular damage. Also, pyrrolidinedithiocarbamate (PDTC), NF-Kb inhibitor, can suppress NTT-MMP-2 selectively. This study was conducted to analyze the effects of acute kidney injury on diabetic animal model and test the effect of PDTC in acute kidney injury with diabetes. Methods: We performed unilateral ischemia-reperfusion injury (uIRI) in streptozotocin-induced diabetic animals as a model of acute kidney injury and followed for 48 hours and six weeks. Mice were randomized into four groups as follows; control (A), non-DM+uIRI (B), DM+uIRI (C), DM+uIRI+PDTC (D). Results: In a 48-hour experiment, tubular necrosis was more severe in diabetic IR kidney compared with nondiabetic IR kidney. Outer medulla in group C was becoming devastated and led to the extensive coagulative necrosis. Those findings were diminished by PDTC. Peritubular capillary density was increased by PDTC and cortical macrophage density was decreased by PDTC compared to group B and C. The nitrotyrosin was lesser expressed by PDTC compared to group B and C. In a six-week experiment, IRI caused the kidney to be stiffen and shrink both in group B and C and PDTC can ameliorate these gross changes compared to group C. Peritubular capillary density was increased by PDTC compared to group C. Cortical macrophage density was higher than group B and D and PDTC ameliorate the recruitment of macrophage in renal cortex. The expression of cleaved caspase-3/caspase 3 in group C was higher than group B and D. Conclusion: Ischemia-reperfusion injury caused more intense renal damage in diabetic murine model and could lead to chronic renal change related to inflammation and apoptotic pathway. These changes may be mitigated by PDTC treatment associated with anti-oxidative mechanism and inhibition of NTT-MMP-2. Disclosure S. Song: None. S. Kim: None. I. Kim: None. Funding National Research Foundation of Korea (2016R1A2B4008243)

Effects of NF-κB inhibitor on nuclear factor-κB and intercellular adhesion moceule-1 in lung injury associated with radiation of rats

Objective: To investigate the mechanism of lung injury caused by radiation-induced lung injury by observing the change of nuclear factor (NF-κB) and intercellular adhesion moceule-1 (ICAM-1) in rats and the effects of pyrrolidine dithiocarbamate (PDTC) . Methods: 80 SD female rats were randomly classified into 4 groups: control group, radiation group, PDTC treatment group and PDTC group.The radiation induced pulmonary injury model was preformed by using 6 MV X-rays to deliver 8 Gy per day for 5 consecutive days with 40 Gy in total to the thorax of each animal.PDTC was given from 3 d before radiation to 30 d after the first radiation. Rats in control group and PDTC group received the same dose of saline. Animals were sacrificed at 8 week and 24 week after radiation, respectively. The lungs were removed and processed for HE and Masson staining, hydroxyproline content measurement, and real-time quantitative reverse transcription-polymerase chain (RT-PCR) ICAM-1mRNA and NF-κB p65mRNA were detected, Statistical analysis were carried out. Results: Compared with radiation group, there was an obvious amelioration in pathological injury of lung tissue in PDTC treatment group. The lung coefficient and the content of Hyp in PDTC treatment group were significantly lower than those in radiation group (t=3.651, 5.293, 2.348 and 4.126, respectively, allP<0.05) , while slightly higher than those in control group. The levels of ICAM-1mRNA and NF-κB p65mRNA were significantly higher in radiation group than that in PDTC treatment group (allP<0.05) , There were no significant differences in these indicators between control group and PDTC group (P>0.05) . Conclusion: The expression of ICAM-1mRNA and NF-κB p65mRNA is increased in rats with radiation-induced lung injury. Suggest that ICAM-1 and NF-κB are a key factor lead to radiation-induced lung injury. PDTC may inhibits NF-κB activity and further significantly deceases expression of ICAM-1, leading to significantly attenuated pulmonary inflammation and fibrosis, which provides a new therapeutic target for the prevention and treatment of radiation-induced lung injury.

Microglia activation contributes to quinolinic acid-induced neuronal excitotoxicity through TNF-α.

It has been reported that activation of NF-κB is involved in excitotoxicity; however, it is not fully understood how NF-κB contributes to excitotoxicity. The aim of this study is to investigate if NF-κB contributes to quinolinic acid (QA)-mediated excitotoxicity through activation of microglia. In the cultured primary cortical neurons and microglia BV-2 cells, the effects of QA on cell survival, NF-κB expression and cytokines production were investigated. The effects of BV-2-conditioned medium (BCM) on primary cortical neurons were examined. The effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, and minocycline (MC), an inhibitor of microglia activation, on QA-induced excitotoxicity were assessed. QA-induced NF-κB activation and TNF-α secretion, and the roles of TNF-α in excitotoxicity were studied. QA at the concentration below 1mM had no apparent toxic effects on cultured primary neurons or BV-2 cells. However, addition of QA-primed BCM to primary neurons did aggravate QA-induced excitotoxicity. The exacerbation of QA-induced excitotoxicity by BCM was partially ameliorated by inhibiting NF-κB and microglia activation. QA induced activation of NF-κB and upregulation of TNF-α in BV-2 cells. Addition of recombinant TNF-α mimicked QA-induced excitotoxic effects on neurons, and neutralizing TNF-α with specific antibodies partially abolished exacerbation of QA-induced excitotoxicity by BCM. These studies suggested that QA activated microglia and upregulated TNF-α through NF-κB pathway in microglia. The microglia-mediated inflammatory pathway contributed, at least in part, to QA-induced excitotoxicity.

Pyrrolidinedithiocarbamate attenuates bleomycin-induced pulmonary fibrosis in rats: Modulation of oxidative stress, fibrosis, and inflammatory parameters

ABSTRACTObjective: The current study aimed to investigate the modulatory effects of pyrrolidinedithiocarbamate (PDTC; 100 mg/kg) on bleomycin-induced pulmonary fibrosis (5 mg/kg; intratracheal) in rats. Materials and Methods: Rats were randomly assigned to three groups: normal control, bleomycin control, and PDTC-treated groups. Lung injury was evaluated through histological examination, immunohistochemical detection of inducible nitric oxide synthase (iNOS) in lung tissue and evaluating the total and differential leucocytes count in bronchoalveolar lavage fluid. Lung tissue was used for biochemical assessment of lung content of hydroxyproline, transforming growth factor beta-1 (TGF-β1), tumor necrosis factor-alpha (TNF-α) as well as analysis of lipid peroxides, reduced glutathione (GSH), and total nitrite contents. Results: PDTC attenuated bleomycin-induced pulmonary fibrosis as evidenced by histological observations, decreased iNOS expression and prevention of bleomycin-induced altered total and differential leukocytes count. Additionally, PDTC caused a significant decrease in lung contents of hydroxyproline, TGF-β1, TNF-α, lipid peroxides, and total nitrite coupled with increase in lung GSH content as compared to bleomycin control group. Conclusion: PDTC attenuated bleomycin-induced pulmonary fibrosis in rats via its anti-inflammatory, antioxidant, and antifibrotic activities.

Effects of pyrrolidine dithiocarbamate on proliferation and nuclear factor-κB activity in autosomal dominant polycystic kidney disease cells.

BackgroundPyrrolidine dithiocarbamate (PDTC) reduces renal cyst growth in a rodent model of polycystic kidney disease (PKD) but the mechanism of action is not clear. Here, we investigated the hypothesis that PDTC reduces the proliferation of cystic epithelial cells in vitro in a nuclear factor (NF)-κB-dependent manner.MethodsImmortalized autosomal dominant PKD (ADPKD) cells that are heterozygous (WT9-7) and homozygous (WT-9-12) for a truncating Pkd1 mutation, and immortalized normal human tubular cells (HK-2), were exposed to NF-κB-inducing agents with or without PDTC. Cell proliferation and apoptosis were assessed by bromodeoxyuridine assay and Annexin V flow cytometry, respectively. NF-κB activity was assessed by luciferase reporter assay and western blotting for nuclear p65, p50, and RelB subunits and cytoplasmic phosphorylated-IκBα.ResultsSerum-induced proliferation was similar in all cell lines over 72 h. PDTC demonstrated anti-proliferative effects that were delayed in ADPKD cells compared to HK-2. Basal NF-κB-dependent luciferase reporter activity was lower in ADPKD cells compared to normal cells. Classical NF-κB stimulants, lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α, increased NF-κB luciferase activity in HK-2, whereas in PKD cell lines, NF-κB activity was only induced by TNF-α. However, neither stimulant altered proliferation in any cell line. PDTC reduced TNF-α-stimulated NF-κB activity in HK-2 only.ConclusionsPDTC reduced proliferation in ADPKD cells but did not consistently alter NF-κB activation, suggesting that other signalling pathways are likely to be involved in its ability to attenuate renal cyst growth in vivo.Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-015-0193-3) contains supplementary material, which is available to authorized users.

A Central Role for JNK/AP-1 Pathway in the Pro-Oxidant Effect of Pyrrolidine Dithiocarbamate through Superoxide Dismutase 1 Gene Repression and Reactive Oxygen Species Generation in Hematopoietic Human Cancer Cell Line U937.

Pyrrolidine dithiocarbamate (PDTC) known as antioxidant and specific inhibitor of NF-κB was also described as pro-oxidant by inducing cell death and reactive oxygen species (ROS) accumulation in cancer. However, the mechanism by which PDTC indices its pro-oxidant effect is unknown. Therefore, we aimed to evaluate the effect of PDTC on the human Cu/Zn superoxide dismutase 1 (SOD1) gene transcription in hematopoietic human cancer cell line U937. We herein show for the first time that PDTC decreases SOD1 transcripts, protein and promoter activity. Furthermore, SOD1 repression by PDTC was associated with an increase in oxidative stress as evidenced by ROS production. Electrophoretic mobility-shift assays (EMSA) show that PDTC increased binding of activating protein-1 (AP-1) in dose dependent-manner suggesting that the MAPkinase up-stream of AP-1 is involved. Ectopic NF-κB p65 subunit overexpression had no effect on SOD1 transcription. In contrast, in the presence of JNK inhibitor (SP600125), p65 induced a marked increase of SOD1 promoter, suggesting that JNK pathway is up-stream of NF-κB signaling and controls negatively its activity. Indeed, using JNK deficient cells, PDTC effect was not observed nether on SOD1 transcription or enzymatic activity, nor on ROS production. Finally, PDTC represses SOD1 in U937 cells through JNK/c-Jun phosphorylation. Taken together, these results suggest that PDTC acts as pro-oxidant compound in JNK/AP-1 dependent-manner by repressing the superoxide dismutase 1 gene leading to intracellular ROS accumulation.

Pyrrolidine dithiocarbamate restores gastric damages and suppressive autophagy induced by hydrogen peroxide

It is well known that gastric barrier is very important for protecting host from various insults. Simultaneously, autophagy serving as a prominent cytoprotective and survival pathway under oxidative stress conditions is being increasingly recognized. Thus, this study was conducted for investigating the effect of pyrrolidine dithiocarbamate (PDTC) on gastric barrier function and autophagy under oxidative stress induced by intragastric administration of hydrogen peroxide (H2O2). The gastric tight junction proteins [zonula occludens-1 (ZO1), occludin, and claudin1], autophagic proteins [microtubule-associated protein light chain 3I(LC3I), LC3II, and beclin1], and nuclear factor kappa B (NF-κB) signaling pathway (p65 and IκB kinase α/β) were determined by Western blot. The results showed that H2O2 exposure disturbed gastric barrier function with decreased expression of ZO1, occludin, and claudin1, and reduced gastric autophagy with decreased conversion of LC3I into LC3II in mice. However, treatment with PDTC restored these adverse effects evidenced by increased expression of ZO1 and claudin1 and increased conversion of LC3I into LC3II. Meanwhile, H2O2 exposure decreased normal human gastric epithelial mucosa cell line (GES-1) viability in a concentration-dependent way. However, after being exposed to H2O2, GES-1 exhibited autophagic response which was inconsistent with our in vivo results in mice, while PDTC failed to decrease autophagy in GES-1 induced by H2O2. Simultaneously, the beneficial effect of PDTC on gastric damage and autophagy in mice might be independent of inhibition of NF-κB. In conclusion, PDTC treatment restores gastric damages and reduced autophagy induced by H2O2. Therefore, PDTC may serve as a potential adjuvant therapy for gastric damages.

Pyrrolidine dithiocarbamate inhibits enterovirus 71 replication by down-regulating ubiquitin–proteasome system

Enterovirus 71 (EV71) is the main causative pathogen of hand, foot, and mouth disease (HFMD). The severe neurological complications caused by EV71 infection and the lack of effective therapeutic medicine underline the importance of searching for antiviral substances. Pyrrolidine dithiocarbamate (PDTC), an antioxidant, has been reported to inhibit the replication of coxsackievirus B (CVB) through dysregulating ubiquitin–proteasome system (UPS). In this study, we demonstrated that PDTC exerted potent antiviral effect on EV71. Viral RNA synthesis, viral protein expression, and the production of viral progeny were significantly reduced by the treatment of PDTC in Vero cells infected with EV71. Similar to the previous report about the inhibitory effect of PDTC on UPS, we found that PDTC treatment led to decreased levels of polyubiquitinated proteins in EV71-infected cells. The inhibitory effect of PDTC on UPS was further confirmed by the increased accumulation of cell cycle regulatory proteins p21 and p53, which are normally degraded through UPS, while the expression levels of both proteins remained unchanged. We also showed that PDTC had no impact on the activity of proteasome. Thus, we demonstrated that the down-regulation of PDTC on UPS was the result of its inhibition on ubiquitination. More importantly, this study provides evidence that the inhibition on UPS was required for the antiviral activity of PDTC, since MG132, a potent proteasome inhibitor, significantly inhibited the cytopathic effect and viral protein synthesis in EV71-infected cells. We also found that the antioxidant property of PDTC did not contribute to its antiviral effect, since N-acetyl-l-cysteine, a potent antioxidant, could not inhibit viral replication. In addition, CPE and viral protein synthesis were not inhibited in the cells pretreated with PDTC 2h before viral infection and then cultured in the media with no PDTC supplement, while the antioxidant effect of PDTC was retained. PDTC also showed significant inhibition on apoptosis induced by EV71 infection when it was applied at the early stage of viral infection. Our results collectively suggest that PDTC could be a potential anti-EV71 compound which possesses both antiviral and anti-apoptotic capacity.

Protective effects of the nuclear factor kappa B inhibitor pyrrolidine dithiocarbamate on experimental testicular torsion and detorsion injury.

Testicular torsion results with the damage of the testis and it is a surgical emergency. Pyrrolidine dithiocarbamate (PDTC) is a low-molecular-weight antioxidant and potent inhibitor of nuclear factor kappa B (NF-κB) activation. In this study, we aimed to investigate the effects of PDTC to testicular torsion-detorsion (T/D) injury. Forty adult male Sprague-Dawley rats were separated into four groups. A sham operation was performed in group I. In group II, torsion is performed 2 hours by 720 degree extravaginally testis. In group III, 4 h reperfusion of the testis was performed after 2 h of testicular torsion. In group IV, after performing the same surgical procedures as in group III, PDTC (100 mg/kg, intravenous's) was administered before 30 min of detorsion. The testes tissue malondialdehyde (MDA), superoxide dismutase (SOD) catalase (CAT) level was evaluated. Histological evaluations were performed after hematoxylin and eosin staining. Testicular tissue MDA levels were the highest in the T/D groups compared with treatment group. Administration of PDTC prevented a further increase in MDA levels. Significant decrease occurred in CAT and SOD levels in treatment group compared with the control group. The rats in the treatment group had normal testicular architecture. The results suggest that PDTC can be a potential protective agent for preventing the biochemical and histological changes related to oxidative stress in testicular injury caused by testis torsion.

Pyrrolidine dithiocarbamate protects against scopolamine-induced cognitive impairment in rats

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that leads to disturbances of cognitive functions. Although the primary cause of AD remains unclear, brain acetylcholine deficiency, oxidative stress and neuroinflammation may be considered the principal pathogenic factors. The present study was constructed to investigate the anti-amnestic effect of pyrrolidine dithiocarbamate (PDTC) on scopolamine-induced behavioral, neurochemical and biochemical changes in rats. PDTC (50 and 100mg/kg) and donepezil (2.5mg/kg) were orally administered for 14 successive days. Dementia was induced at the end of the treatment period by a single injection of scopolamine (20mg/kg; i.p.), and Y-maze test was conducted 30min thereafter. Rats were then sacrificed and homogenates of cortical and hippocampal tissues were used for the estimation of noradrenaline, dopamine, serotonin and heat shock protein 70 contents along with acetylcholinesterase activity. In addition, certain oxidative stress markers, pro-inflammatory and anti-inflammatory cytokines were assessed. Histological examination of cortical and hippocampal tissues was also performed. Scopolamine resulted in memory impairment that was coupled by alterations in the estimated neurotransmitters, heat shock protein 70, acetylcholinesterase activity, oxidative stress as well as inflammatory biomarkers. Histological analysis revealed serious damaging effects of scopolamine on the structure of cerebral cortex and hippocampus. Pretreatment of rats with PDTC in both doses mitigated scopolamine-induced behavioral, biochemical, neurochemical and histological changes in a manner comparable to donepezil. The observed anti-amnestic effect of PDTC makes it a promising candidate for clinical trials in patients with cognitive impairment.

The effects of pyrrolidine dithiocarbamate on the activation of Nrf2 pathway after paraquat induced lung injury in rats

Objective To explore the effects of pyrrolidine dithiocarbamate （PDTC） on the acute lung injury and the activation of Nrf2 pathway after Paraquat （PQ） induced lung injury. Methods Forty- eight adult male SD rats with lung injury induced by PQ were randomly （random number） divided into control group and PDTC group. Three animals were sacrificed at every 1-week interval, 7d, 14d and 21 days after PQ intoxication, and the lungs of rats were removed for acute lung injury score after HE staining, and for lung fibrosis assessment after Masson staining, and the levels of reduced glutathione （ GSH ） and malondialdehyde （MDA） in the lung tissue homogenate were assayed and the phosphorylation of Nrf2 （nuclear-E2-related factor 2） was detected by Weston blot. The mean values of detected variables between two groups were compared by t test, and survival curve was tested by Wilcoxon （Gehan） test. Results The intoxication symptoms of rats were obvious, and 4 rats in control group and 9 rats in PDTC group survived until 21days. The survival time of animals in PDTC group was longer than that in control group （Wilcoxon（Gehan） = 10. 17023, P =0. 001 ）. The levels of MDA in control group were higher than those in PDTC group, while the levels of GSH in control group were lower than those in PDTC group. The levels of phosphorylation of Nrf2 in PDTC group were higher than those in control group at 1-week intervals, 1-week： （0.32±0.04） vs. （0.23±0.05）, P=0.003; 2-week： （0.62±0.06） vs. （0.33±0.03）, P〈 0.001; 3-week： （0.61 ±0.04） vs. （0.33 ±0.05）, P〈0.001. The acute lung injury （ALl） scores in PDTC group were lower than those in control group, 1-week ： （ 5 ± 0. 95 ） vs. （ 8 ± 1.23 ）, P = 0. 002 ; 2- week： （9 ±1.18） vs. （11±1.02）, P=0.019; 3-week： （11 ±1.33） vs. （12 ±1.42）, P=0.002. The percentages of lung fibrosis at 1-week intervals after PQ intoxication were （40. 87 ± 7.25 ） %, （43.38±5.71）% and （45.91 ± 3.97）% in control group, and they were higher than those in PDTC group （32. 92 ±2. 34）%, （33.45 ±3.04）% and （35.27 ± 3.81 ）% in PDTC group, P =0. 017, 0. 001 and 0. 001 respectively. Conclusions Attenuation of acute lung injury and lung fibrosis, and prolongation of survival time of SD rats by PDTC were associated with activation of Nrf2 pathway. Key words: Paraquat; Oxidative stress ; Acute lung injury; Pyrrolidine dithiocarbamate ; Nrf2 pathway

Pyrrolidine Dithiocarbamate (PDTC) Attenuates Luteolin-Induced Apoptosis in Human Leukemia HL-60 Cells

Studies have indicated that flavonoid luteolin is a potential inhibitor of tumor cell proliferation and may function as an anticarcinogenic agent. Pyrrolidine dithiocarbamate (PDTC), a synthetic compound, may exhibit biphasic effects on apoptosis depending on the experimental context. Previously, we found that luteolin induced the activation of the proapoptotic proteins, such as Bad, Bid, and Bax, in HL-60 human leukemia cells. We also explored the modulatory effects and molecular mechanisms of PDTC on the cytotoxicity of luteolin in HL-60 cells; PDTC could interfere with luteolin’s ability to cleave poly(ADP-ribose)-polymerase (PARP) and DNA fragmentation of factor-45 (DFF-45). In the current study, we further investigated the effect of PDTC on the luteolin-induced death-receptor pathway and the cleavage of the Bcl-2 family members. We found that the combination of luteolin and PDTC increased the survival of the HL-60 cells such that PDTC inhibited both extrinsic and intrinsic pathways in luteolin-induced apoptosis.

Down-Regulation of Matrix Metalloproteinase-9 by Pyrrolidine Dithiocarbamate Prevented Retinal Ganglion Cell Death After Transection of Optic Nerve in Rats

Purpose: To investigate the effects of pyrrolidine dithiocarbamate (PDTC), a nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) inhibitor, on the expression of matrix metalloproteinases (MMP) and MMP-mediated apoptosis in retinal ganglion cells (RGCs) following the transection of the optic nerve (ON) in rats.Materials and Methods: The ON of adult male Sprague-Dawley rats was transected. The expression of MMP-2, MMP-9, and NF-κB was measured by Western blot analysis and immunohistochemical analysis following transection. In situ zymography was also performed to localize gelatinolytic activity in the retinas. PDTC was injected intravitreally immediately following transection of the ON to evaluate the effect on the expression of NF-κB and MMP as well as its anti-apoptotic effect and neuroprotective effect on RGCs.Results: Significant up-regulation of MMP-9, and NF-κB was observed 7 days post-transection; however, this was not observed for MMP-2. PDTC at concentrations of 0.5 mM suppressed the up-regulation of MMP-9 and NF-κB, inhibiting gelatinolytic activity in the RGC layer. Meanwhile, far fewer apoptotic RGCs were detected and more surviving RGCs were preserved in PDTC-treated retinas 7 days post-transection compared to retinas in the control group. However, this kind of neuroprotective effect was not significant at 14 days post-transection.Conclusions: This study demonstrated that PDTC, mediated in part through the down-regulation of MMP-9, could contribute to delaying the death of RGCs following transection of the ON.

Impact of Pyrrolidine Dithiocarbamate and Interleukin-6 on Mammalian Target of Rapamycin Complex 1 Regulation and Global Protein Translation

Interleukin-6 (IL-6) is a proinflammatory cytokine that exerts a wide range of cellular, physiological, and pathophysiological responses. Pyrrolidine dithiocarbamate (PDTC) antagonizes the cellular responsiveness to IL-6 through impairment in signal transducer and activator of transcription-3 activation and downstream signaling. To further elucidate the biological properties of PDTC, global gene expression profiling of human HepG2 hepatocellular carcinoma cells was carried out after treatment with PDTC or IL-6 for up to 8 h. Through an unbiased pathway analysis method, gene array analysis showed dramatic and temporal differences in expression changes in response to PDTC versus IL-6. A significant number of genes associated with metabolic pathways, inflammation, translation, and mitochondrial function were changed, with ribosomal protein genes and DNA damage-inducible transcript 4 protein (DDIT4) primarily up-regulated with PDTC but down-regulated with IL-6. Quantitative polymerase chain reaction and Western blot analyses validated the microarray data and showed the reciprocal expression pattern of the mammalian target of rapamycin (mTOR)-negative regulator DDIT4 in response to PDTC versus IL-6. Cell treatment with PDTC resulted in a rapid and sustained activation of Akt and subsequently blocked the IL-6-mediated increase in mTOR complex 1 function through up-regulation in DDIT4 expression. Conversely, down-regulation of DDIT4 with small interfering RNA dampened the capacity of PDTC to block IL-6-dependent mTOR activation. The overall protein biosynthetic capacity of the cells was severely blunted by IL-6 but increased in a rapamycin-independent pathway by PDTC. These results demonstrate a critical effect of PDTC on mTOR complex 1 function and provide evidence that PDTC can reverse IL-6-related signaling via induction of DDIT4.

P4‐259: Mechanism for the protective effect of pyrrolidine dithiocarbamate against oxidative stress in AD: induction of the Nrf2‐ARE pathway

P4‐259: Mechanism for the protective effect of pyrrolidine dithiocarbamate against oxidative stress in AD: induction of the Nrf2‐ARE pathway

Therapeutic effects of pyrrolidine dithiocarbamate on acute lung injury in rabbits

BackgroundAcute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is an early characteristic of multiple organ dysfunction, responsible for high mortality and poor prognosis in patients. The present study aims to evaluate therapeutic effects and mechanisms of pyrrolidine dithiocarbamate (PDTC) on ALI.MethodsAlveolar-arterial oxygen difference, lung tissue edema and compromise, NF-κB activation in polymorphonuclear neutrophil (PMN), and systemic levels of tumor necrosis factor-alpha (TNFa) and intercellular adhesion molecule-1 (ICAM-1) in rabbits induced by the intravenous administration of lipopolysaccharide (LPS) and treated with PDTC. Production of TNFa and IL-8, activation of Cathepsin G, and PMNs adhesion were also measured.ResultsThe intravenous administration of PDTC had partial therapeutic effects on endotoxemia-induced lung tissue edema and damage, neutrophil influx to the lung, alveolar-capillary barrier dysfunction, and high systemic levels of TNFa and ICAM-1 as well as over-activation of NF-κB. PDTC could directly and partially inhibit LPS-induced TNFa hyper-production and over-activities of Cathepsin G. Such inhibitory effects of PDTC were related to the various stimuli and enhanced through combination with PI3K inhibitor.ConclusionNF-κB signal pathway could be one of targeting molecules and the combination with other signal pathway inhibitors may be an alternative of therapeutic strategies for ALI/ARDS.