Paraquat Group Research Articles

Tanshinone IIA attenuates paraquat‑induced acute lung injury by modulating angiotensin‑converting enzyme 2/angiotensin‑(1‑7) in rats.

Tanshinone IIA (TIIA) is an active compound that can be isolated from the Chinese herb, Salviamiltiorrhizae Bunge, also known as danshen. Previous studies have demonstrated that TIIA can effectively attenuate bleomycin‑induced pulmonary fibrosis in rats. However, it has not been determined whether TIIA can attenuate paraquat (PQ)‑induced acute lung injury (ALI). In the present study, the protective effects exhibited by TIIA on PQ‑induced ALI, as well as its underlying mechanisms, were investigated using Sprague‑Dawley (SD) rats. ALI animal models using rats were established via administration of PQ. Adult male SD rats were randomly divided into three groups: A control group, a PQ group and a PQ+TIIA group. Total cell count, total protein levels and lactic dehydrogenase (LDH) levels in bronchoalveolar lavage fluid (BALF), as well as myeloperoxidase (MPO) activity in lung tissues were determined. Lung histological alterations were also investigated. Angiotensin converting enzyme 2 (ACE2) and Angiotensin1‑7 [Ang‑(1‑7)] expression levels in the lung were also analyzed. The results demonstrated that administration of PQ induced marked histological alterations, and markedly increased neutrophil infiltration, lung wet/dry weight ratio, total cell count, protein content and LDH levels in BALF. In addition, PQ was revealed to significantly decrease ACE2 and Ang‑(1‑7) expression levels in lung tissues. However, it was demonstrated that TIIA attenuated these effects. Therefore, the results of the present study suggest that that TIIA may exhibit a therapeutic effect regarding PQ‑induced ALI in rats, and that ACE2 and Ang‑(1‑7) may be involved in the underlying mechanisms of this effect.

The role of TLR3/NF-kappa B signaling pathway in paraquat-induced acute lung injury

Objective To investigate the pathogenesis of paraquat (PQ) induced acute lung injury through Toll like receptor 3 (Toll-like receptor-3, TLR3), TLR induced nuclear transcription factors (Nuclear Factor- kappa B, NF-κB) and its downstream pro-inflammatory factors TNF-α, IL-1β, IL-6. Methods The acute lung injury model of mice and the acute injury model of type II alveolar epithelial cells (A549) induced by PQ were established. The PQ mediated pathological changes of lung tissue, the cell count and cytospin of bronchoalveolar lavage fluid (BALF) were evaluated, and the pro-inflammatory factors in the lung tissue of mice were determined by ELISA the viability of A549 cells mediated by PQ was detected by CCK8 assay, and the mRNA expression and protein level of TLR3, Phospho-NF-kBp65, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in the lung tissues and A549 cells were observed by Real-time PCR and Western-blotting. In control group, the mice received normal saline (NS) instead of PQ. Results Compared with the control group, the mice in PQ group showed difficulty breathing, decreased activity, reduced food intake, and weight lost. The total number of BALF cells in the PQ group was significantly increased [NS: (0.018 8±0.102 1)×105vs. PQ: (0.237 4 ± 0.121 7)×105, t=9.804, P<0.01] with macrophage [NS: (0.162 8±0.086 5)×105vs. PQ: (1.063 3 ± 0.343 3)×105, t=8.043, P<0.01], lymphocyte [NS: (0.006 6±0.005 2)×105vs. PQ: (0.171 2 ± 0.099 1)×105, t=5.243, P<0.01] and neutrophils [NS: (0.000 04±0.000 1)×105vs. PQ: (0.901 9 ± 0.652 5)×105, t=4.370, P<0.01]. In PQ group, the appearance and volume of lung tissue increased with hyperemia and edema. HE slices showed inflammatory cell infiltration and pulmonary interstitial hemorrhage. Moreover, the expressions of TNF-α, IL-1β, IL-6 in BALF of PQ group was significantly higher than those of the control group by the ELISA assay [TNF-α: NS: (2.782 1 ± 3.521 5) vs. PQ: ( 7.512 6 ± 3.459 8) pg/mL, t=3.030, P<0.05; IL-1β: NS: (22.687 5 ± 14.229 3) vs.PQ: (163.100 4 ± 81.118 3) pg/mL, t=5.391, P<0.01; IL-6: NS: (1.653 3±0.442 7) vs. PQ: (648.565 6 ± 422.606 1) pg/mL, t=4.841, P<0.01]. CCK8 results indicated that the viability of A549 cells decreased by 25.3% and 36.4% at 24h after 200~400 μmol/L PQ treatment (all P<0.05). The mRNA expressions of TNF-α, IL-1β, IL-6 in the lung tissue and A549 cells in PQ group were higher than those in the control group as well (all P< 0.05). Furthermore, Western-blotting results revealed that the protein levels of TLR3 and Phospho-NF-κBp65 in the lung and A549 cells mediated by PQ were significantly higher than those in the control group (all P < 0.05). Conclusions PQ may induce acute lung injury by up-regulation of the expressions of inflammatory factors TNF-α, IL-1β, IL-6 through the TLR3/NF-κB signaling pathway. Key words: Paraquat; Acute lung injury; Toll-like receptor-3; Nuclear Factor-κappa B; Signal pathway; Inflammatory factors; Animal model; A549 cell

Prolonged low-dose cyclophosphamide treatment after pulse therapy attenuates lung injury in rats with paraquat intoxication.

Background/AimsThis study tested the hypothesis that prolonged low-dose cyclophosphamide (CTX) treatment after pulse therapy attenuate paraquat (PQ)-induced lung injury in rats.MethodsPQ (25 mg/kg) was administered intraperitoneally to induce PQ-intoxicated rat model. The rats were randomly divided into four groups: control group (1 mL/day saline solution for 14 days), PQ group (1 mL/day saline solution for 14 days after PQ exposure), pulse group (15 mg/kg/day CTX in 1 mL of saline solution for 2 days and subsequent 1 mL/day saline solution for 12 days), and prolonged low-dose group (15 mg/kg/day CTX in 1 mL of saline solution for 2 days and subsequent 1.5 mg/kg/day CTX in 1 mL of saline solution for 12 days). A 14-day follow-up was conducted to determine the survival rat, and lung hydroxyproline (HYP), wet-to-dry weight ratios (W/Dc) and histopathological changes were evaluated.ResultsResults showed similar survival rate (55% vs. 50%, p > 0.05) between prolonged low-dose and pulse groups. Lung W/Dc (4.94 ± 0.38 vs. 5.47 ± 0.28, p < 0.01), HYP (3.34 ± 0.29 µg/mg vs. 3.65 ± 0.19 µg/mg, p < 0.001), and fibrosis score (2.69 ± 0.84 vs. 3.13 ± 0.63, p < 0.05) were lower in prolonged low-dose group than those in the pulse group.ConclusionsThese findings suggested prolonged low-dose CTX treatment after pulse therapy could attenuate PQ-induced lung injury in rats.

Punica Granatum Rind Extract Promotes Mouse Liver Mitochondrial Function and Attenuates Paraquat Toxicity in a Caenorhabditis Elegans Model

Punica granatum (pomegranate) has drawn the interest of the scientific community due to its rich array of phenolic compounds and antioxidant capacity. Evidence supports the fruit's role in preventing free radical damage in humans. Although various studies have concluded the beneficial effects of pomegranate juice, limited studies have characterized the antioxidant effects of its rind (outer covering/peel; PRE). The goal of our study was to characterize the effects of PRE on oxidative stress. We utilized mouse liver mitochondria and paraquat (PQ) toxicity in a Caenorhabditis elegans (C. elegans) model to determine the beneficial effects of PRE. Mitochondria were isolated from C57 male mice liver tissue (6 weeks of age). Phosphatidylcholine/cholesterol liposomes (Lp) were used to induce oxidative stress. Samples were then incubated at 37□ for 2 hours with or without the addition of PRE at two levels (PRE1 and PRE2 represent 60 and 120 μM Trolox equivalent/mL, respectively). Oxygen consumption rate (OCR; nmol O2 consumed/min per mg mitochondria) was used to express the activity of NADH‐CoQ oxidoreductase, succinate dehydrogenase, and cytochrome c oxidase (complex I, II, and IV of electron transport chain, respectively). Antioxidant level in PRE was determined by DPPH‐, ABTS‐ and Folin‐Ciocalteu assays. The experiment was repeated four times. Pre‐incubation of mitochondria with Lp decreased (p &lt; 0.05) OCR by 50% compared with control mitochondria without Lp. However, incubation of Lp with PRE2 increased (p &lt; 0.05) OCR for complex II and IV. No significant changes (p &gt; 0.05) in OCR were observed for complex I with incubation of Lp and PRE 1 or PRE2. Using C. elegans, an oxidative stress resistance assay was performed to explore PREs effects on paraquat toxicity. Wild‐type adult/L4 hermaphrodites were placed in 96‐well plates. PQ was dissolved to a final concentration of 50 μM and half concentration of PRE1 was added for experimental groups. Resistance to oxidative stress was measured through percentage survival at hour time intervals. After 5 hours, mean survival for PQ alone was 61.91±6.56%; PQ groups supplemented with PRE had a mean survival of 88.29±6.18%. The current study suggests that PRE may play a role in preserving mitochondrial function during oxidative stress and attenuates PQ toxicity.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The protective effect of Xuebijing on paraquat-induced HK-2 cells apoptosis and the underlying mechanisms

Objective: To investigate the protective effect and mechanism of Xuebijing (XBJ) on paraquat (PQ) -induced apoptosis in Human kidney cell line-2 (HK-2) cells. Methods: Routinely cultured HK-2 cells, (1) Cell growth inhibition experiment after PQ and XBJ intervention: PQ was divided into 0、200、400、800、1600 and 3200 μmol/L PQ groups, and the cell survival rate was detected after intervening 24、48 and 72 h. XBJ was divided into 0、5、10、20、40 mg/ml XBJ groups, and the cell survival rate was detected after intervening 24、48 and 72 h.To determine the rational drug concentration and the duration of action of XBJ and PQ. (2) PQ-induced HK-2 cell growth inhibition experiment antagonized by XBJ: The cells were divided into normal control group, PQ group (800 μmol/L) and PQ+XBJ group (The cells were pretreated with 5、10 and 20 mg/ml XBJ for 1 h, then cultured with PQ of 800 μmol/L) , After cultured 24 h、48 h and 72 h separately, the cell survival rate was detected. (3) HK-2 cells were divided into normal control group、PQ group (800 μmol/L PQ cultured for 24 h) 、PQ+XBJ group (pretreated with 10 mg/ml XBJ for 1 h, and then 800 μmol/L PQ cultured for 24 h) and XBJ group (10 mg/ml XBJ cultured 24 h). The apoptosis of cells was detected by flow cytometry. The protein expression of Bcl-2 and BAX in each group was detected by Western blotting. The expressions of caspase-3 and caspase-9 were detected by caspase-3 and caspase-9 activity kit active. Results: (1) PQ could significantly reduced the survival rate of HK-2 cells and showed time and concentration dependence. The survival rate of HK-2 cells was about 55% after 800 μmol/L PQ contacted 24 h, XBJ under 20 mg/ml was no significant effect on the survival rate of HK-2 cells after cultured 72 h. (2) Compared with the PQ group, the survival rate of HK-2 cells of PQ+XBJ group was significantly increased (P<0.05). (3) Compared with the normal control group, the cell apoptosis rate of PQ group was significantly increased (P<0.05). Compared with the PQ group, the cell apoptosis rate of PQ+XBJ group was significantly decreased (P<0.05). (4) Compared with the normal control group, Bcl-2 protein expression in PQ group was significantly decreased and BAX protein expression in PQ group was significantly increased (P<0.05) ; compared with PQ group, Bcl-2 protein expression in PQ+XBJ group was significantly increased, BAX protein expression in PQ+XBJ group was significantly decreased (P<0.05). (5) Compared with the normal control group, the activities of caspase-3 and caspase-9 in PQ group were significantly increased (P<0.05). Compared with PQ group, the activities of caspase-3 and caspase-9 in PQ+XBJ group were decreased significantly (P<0.05) . Conclusion: XBJ (10 mg/ml) has obvious protective effect on HK-2 cell injuried by PQ (800 μmol/L) , It can improve the survival rate of cells through reducing the apoptosis of HK-2 cells which induced by PQ.

Effect of paraquat on the expression of a disintegrin and metalloproteinase-17 in A549 cells

Objective: Construct a paraquat (PQ) cell fibrosis model in vitro, observe the effect of PQ on the expression of a disintegrin and metalloproteinase-17 (ADAM17) in A549 cells, and explore the role of ADAM17 in the pulmonary fibrosis induced by PQ poisoning. Methods: A549 cells are divided into normal control group, different concentration of PQ groups, CCK-8 is used to detect cell viability, screening concentration and time of PQ, cell morphology is observed under microscope; Enzyme-linked immunosorbent assay (ELISA) detectes fibrosis markers of collagen type I (Col I) and fibronectin (FN) expression. Establishment of cell model of fibrosis; distribution by immunocytochemical detection of ADAM17 in A549 cells, Reverse transcription-polymerase chain reaction and Western blot are used to detect the expression of ADAM17 mRNA and protein. Results: 1. With the increase of PQ concentration and the prolongation of the action time, the activity of A549 cells decreased (P< 0.05) , which is dose-dependent and time dependent. 2.The normal A549 cells fusion is paving stone growth and arranged more closely. After PQ induction, the cell arrangement was loose, the intercellular connection became loose, and some cells dissolved and died. 3.ELISA showed that with the increase of PQ concentration, the expression of Col I and FN increased (P<0.05) , and Col I and FN expression gradually increased with the prolongation of PQ time (P<0.05) , and the fibroblast model is successfully established. 4. Immunocytochemistry showes that ADAM17 is expressed in the cytoplasm of A549 cells. 5. RT-PCR and Western blot showed that the expression of ADAM17 mRNA and protein increased significantly with the increase of PQ concentration (P<0.05) , which is most obvious at PQ 200 μmol/L. With the prolonged action of PQ, the expression level of ADAM17 mRNA and protein also increased significantly (P<0.05) , and reached the peak in 24 h. Conclusion: PQ can induce morphological changes of alveolar epithelial cells, cause cell damage, and successfully establish a cell fibrosis model, which has a dose and time dependence on the toxicity of A549 cells. ADAM17 is overexpressed in the A549 cells induced by PQ and may be involved in the process of pulmonary fibrosis induced by paraquat.

MnTMPyP inhibits paraquat-induced pulmonary epithelial-like cell injury by inhibiting oxidative stress.

To investigate the protective effect and underlying mechanism of the superoxide dismutase mimic, manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride (MnTMPyP), on paraquat (PQ)-induced lung alveolar epithelial-like cell injury. Lung alveolar epithelial-like cells (A549) were pretreated with 10 μM MnTMPyP for 1.5 hr and then cultured with or without PQ (750 uM) for 24 hr. Cell survival was determined using the MTT assay. Apoptosis, mitochondrial transmembrane potential, reactive oxygen species (ROS) production, and Ca2+ levels were measured using flow cytometry. Glutathione reductase activity (GR activity) and caspase-3 activation were determined using spectrophotometry. Expression of the apoptosis proteins, Bcl-2 and Bax, and the endoplasmic reticulum (ER) stress proteins, glucose regulatory protein 78 (Grp78) and C/EBP homologous protein (CHOP), was measured using Western blot analysis. Cell viability, mitochondrial membrane potential, GR activity, and Bcl-2 expression were decreased, but apoptosis, ROS production, caspase-3 activity, cytoplasmic Ca2+ levels, and Bax, Grp78 and CHOP expression were all increased in the PQ group compared to the control group. There were no statistically significant changes in the MnTMPyP group. Cell viability, GR activity, mitochondrial membrane potential, and Bcl-2 protein expression were all increased, while apoptosis, ROS production, cytoplasmic Ca2+ levels, caspase-3 activity, and Bax, Grp78 and CHOP expression were all significantly reduced in the MnTMPyP group compared to PQ group. MnTMPyP effectively reduced PQ-induced lung epithelial-like cell injury, and the underlying mechanism is related to antagonism of PQ-induced oxidative stress.

Propolis supplementation attenuates the negative effects of oxidative stress induced by paraquat injection on productive performance and immune function in turkey poults

Paraquat (PQ) is used as a herbicide in agriculture and causes oxidative and inflammatory damage to animal tissues. The current study was conducted to investigate the positive effects of dietary propolis (PR), as a potent naturally produced antioxidant, on growth performance and immune function of turkey poults exposed to oxidative stress induced by PQ injection. Native male turkey poults (n = 120, 49-d-old) were randomly assigned into 4 groups: poults received a basal diet with a daily subcutaneous PQ injection of 5 mg/kg BW for 7 consecutive days (PQ group), an experimental diet containing 1 g/kg PR with a daily subcutaneous PQ injection for 7 days (PR+PQ group), or received the experimental PR diet with a daily subcutaneous injection of 0.5 mL sterile saline for 7 days (PR group); while the control poults received a basal diet with a daily subcutaneous saline injection for 7 consecutive days (C group). The productive performance in the PQ group showed a significant (P < 0.05) reduction in the weight gain (WG) and feed intake (FI), and impaired feed conversion ratio (FCR). Propolis supplementation in the PR+PQ group significantly ameliorated the PQ effects on WG and FCR. Turkey poults of the PQ and PR+PQ groups had a significant augmentation in the blood malondialdehyde (MDA), tumor necrosis factor-α (TNFα), and corticosterone levels, and in contrast, a significant reduction in the triiodothyronine (T3), when compared to the C group. While propolis significantly reduced the MDA and corticosterone, and increased the T3 levels in the PR+PQ group compared to the PQ group. Furthermore, the dietary PR supplementation significantly limited the PQ-suppressive effects on cell- and humoral-mediated immunity and lymphocyte proliferation of turkey poults. In addition, propolis supplementation in the PR and PR+PQ groups markedly reversed the PQ-induced DNA fragmentation and heat shock protein 70 (Hsp70) over-expression in blood cells. It can be concluded that PR could improve turkey immunity and performance, particularly under inflammation and oxidative stress induced by PQ exposure.

Mechanism of action for oligomeric proanthocyaniclins in pava qnat-induced acute lung injury

10 BALB/c mice were intraperitoneally injected with normal saline) . PQ group: 10 BALB/c mice were intraperitoneally injected with PQ (100 mg/kg) . PQ+OPC group: 10 BALB/c mice were administered with OPC (100 mg/kg) for 1 h before PQ (100 mg/kg) expo-sure. OPC group: 10 BALB/c mice were intraperitoneally injected with OPC (100 mg/kg) . The peripheral blood samples or lung tissue samples were collected at the designed time points for measuring the levels of oxi-dative stress indicators, the related protein levels of nuclear factor-kappa B (NF-κB) pathway and nuclear fac-tor erythroid related factor-2 (Nrf2) pathway. Results: Compared with the control group, the level of reactive oxygen species (ROS) , the content of malondialdehyde (MDA) in the PQ group were significantly induced, and the activity of superoxide dismutase (SOD) in the PQ group was decreased in the peripheral blood. As com-pared with the PQ group, the level of ROS and the content of MDA in the PQ+OPC group were significantly re-duced, the activity SOD in the PQ+OPC group was increased in the peripheral blood; the level of ROS and the content of MDA were also reduced in lung tissues in the PQ+OPC group. Moreover, compared with the con-trol group, the phosphorylation of IκBα and the expression of NF-κB p65 were increased in lung tissues in the PQ group. The phosphorylation of IκBα and the expression of NF-κB p65 were decreased in lung tissues in the PQ+OPC group as compared with the PQ group. In addition, compared with the control group, the expressions of HO-1 and Nrf2 were increased in lung tissues in OPC group, and these were decreased in lung tissues in PQ groups. Furthermore, the expressions of HO-1 and Nrf2 were also increased in lung tissues in PQ+OPC as com-pared with the PQ group. Conclusion: OPC could alleviate PQ-induced systemic toxicity in mice by regulating oxidative stress via NF-κB and Nrf2 pathway.

Protective Effects of Chymostatin on Paraquat-Induced Acute Lung Injury in Mice.

This study aims to evaluate the role of chymostatin in paraquat-induced acute lung injury. Institute of Cancer Research mice were randomly distributed into the NS, DMSO, chymostatin, paraquat or chymostatin treatment groups. Six mice from each group were intraperitoneally injected with chloral hydrate at 0, 1, 2, 4, 8, 12, 24 and 48h after treatment administration. Blood samples were collected through cardiac puncture. Lung tissues were stained with haematoxylin and eosin for the observation of lung histology. The degree of pulmonary oedema was determined on the basis of lung wet-to-dry ratio (W/D). The serum activity of cathepsin G was determined through substrate fluorescence assay. The serum levels of endothelial cell-specific molecule-1 (endocan), tumour necrosis factor-a (TNF-a), interleukin-1β (IL-1β), IL-6 and high-mobility group box protein 1 (HMGB1) were determined through enzyme-linked immunosorbent assay. The expression levels of endocan and nuclear NF-κBp65 in the lung were quantified through Western blot. Chymostatin alleviated the pathological changes associated with acute alveolitis in mice; decreased the lung W/D ratio, the activity of cathepsin G and the serum concentrations of TNF-a, IL-1β, IL-6 and HMGB1; and increased the serum concentration of endocan. Western blot results revealed that chymostatin up-regulated endocan expression and down-regulated nuclear NF-κBp65 expression in the lung. Chymostatin reversed the inflammatory effects of paraquat-induced lung injury by inhibiting cathepsin G activity to up-regulate endocan expression and indirectly inhibit NF-κBp65 activity.

Intervention of edaravone against renal injury induced by acute paraquat poisoning in rats

Objective: To investigate the dynamic change of paraquant-induced kidney injury in rats and the protective effect of edaravone. Methods: Eighty SD rats were randomly divided into 4 groups: the normal control group, paraquat poisoning group, edaravone treatment group and edaravone control group. The normal control group of 8 rats were given 1 ml of 0.9% sodium chloride through the abdominal cavity, and the same amount of fluid into the abdominal cavity after 30 minutes. The paraquat poisoning group of 24 rats were given 1 ml of paraquat solution (20 mg/kg) through the abdominal cavity to build poisoning models, and the same amount of 0.9% sodium chloride was injected into the abdominal cavity after 30 minutes. The edaravone treatment group of 24 rats were given edaravone (5 mg/kg) through the abdominal cavity after 30 minutes when the poisoning models were set up. The edaravone control group of 24 rats were given 1 ml of 0.9% sodium chloride through the abdominal cavity, and edaravone (5 mg/kg) was injected into the abdominal cavity after 30 minutes. In addition to the normal control group, the other groups processed 1 times a day to mantain 7 d. On 1, 3, 7, 21 d several rats in each group were excuted and the kidney tissue and serum samples were collected, then each pathological changes of the kidney were observed with light microscopy. Serum creatinine, KIM-1, NGAL were measured by ELISA, the expression of HSP70 protein in kidney were observed with immunohistochemical staining. Results: The pathological examination reveald that the damage of kidney tissue in the paraquat group was the most serious on 3 d, and the damage was consistently alleviated in edaravone treatment group at the same time, renal fibrosisn was unseen in each group until 21 d. Compared with normal control group, there was no statistically significant in edaravone control group (P>0.05) . The KIM-1 in blood and kidney in paraquat poisoning group were markedly increased in 1 d (P<0.05) . The NGAL in blood and creatinine were markedly increased in d7 (P<0.05) . The NGAL in kidney increased over time, but had no statistically difference with the control group (P>0.05) .Compared with paraquat poisoning group, the serum creatinine, KIM-1 in blood and kidney, the KIM-1 in kidney had decreased significantly in edaravone treatment group (P<0.05) . The NGAL in kidney has no statistically significant compared with the poisoning group (P>0.05) . HSP70 expression of kidney tissue in edaravone treatment group had significantly increased in d3 compared with the paraquat poisoning group (P<0.05) . Conclusion: Edaravone can prompt a significant rise of HSP70 in kidney tissue, reduce KIM-1 and NGAL levels, and play a protective role in kidney injury of acute paraquat poisoning.

Rapamycin protects against paraquat-induced pulmonary fibrosis: Activation of Nrf2 signaling pathway

Paraquat (PQ) is a widely used herbicide indeveloping countries worldwide, and pulmonary fibrosis is one of the most typical features of PQ poisoning. The molecular mechanism of PQ toxicity especially how to treat PQ-induced pulmonary fibrosis is still largely unknown. In animal model of pulmonary fibrosis, we used HE staining, western blotting assay and Real-time PCR assay to analyze the effects of rapamycin on the PQ-induced epithelial mesenchymal transition (EMT). We found that PQ induced the pulmonary fibrosis using HE staining and Masson's staining, and up-regulated the activity of HYP and the mRNA expressions of Collagen I and III (COL-1and COL-3) in pulmonary tissues. We also found that rapamycin down-regulated the mesenchymal cell marker Vimentin and up-regulated the epithelial cell marker E-cadherin both in mRNA and protein levels compared with PQ group. And the EMT associated transcription factor Snail was decreased by rapamycin treatment compared with PQ group. And PQ decreased the Nrf2 expression both in mRNA and protein levels, and rapamycin inhibited these effects of PQ. SFN, a activator of Nrf2, could inhibit the EMT and the expression of Snail. And knockdowon of Nrf2 could abolish the inhibitory effects of rapamycin of PQ-induced EMT. In conclusion, rapamycin protects against paraquat-induced pulmonary fibrosis by activation of Nrf2 signaling pathway.

Protective role of vitamin C on spatial memory and oxidative stress alteration during paraquat-induced toxicity in male rats

Paraquat (PQ), is one of the most widely used herbicides all over the world. PQ could induce dopaminergic cell death. Since dopamine involves in memory processing, we investigated the recovery effect of vitamin C on spatial memory along with oxidative stress parameters during PQ induced neurotoxicity in male rats. Rats were divided into five groups (n= 7): control (saline 0.9%), PQ (2.67 and 5 mg/kg), vitamin C (80 mg/kg) plus PQ (2.67), and vitamin C plus PQ (5 mg/kg). The period of intraperitoneal injection (i.p.) was once a day and for 5 consecutive days. The Morris water maze test used for studying the spatial memory. The level of lipid peroxidation (MDA), and activity of antioxidant enzymes; superoxide dismutase (SOD) and catalase (CAT), were determined in the left hemisphere of rats. Results showed that i.p. injection of PQ in both doses, 2.67 mg/kg (P<0.05) and 5mg/kg (P<0.01) significantly decreased the spatial memory. The total SOD activity in PQ-treated groups (2.67 and 5mg/kg) was significantly lower than that of control group (p<0.01). The level of CAT increased, in Vitamin C plus PQ groups in a dose-dependently manner (p<0.05). MDA was significantly increased in PQ-treated group (p<0.01). In PQ-treated groups that were supplemented with vitamin C, SOD activity and lipid peroxidation level were restored to normalcy. Our data revealed that PQ could impair the spatial memory via induction of oxidative stress in the brain tissue. Vitamin C can prevent or diminish the oxidative stress markers in the PQ-treated rats.

Changes of integrin-linked kinase expression on rats' pulmonary fibrosis induced by paraquat

Objective: To observe the expression of integrin-linked kinase on pulmonary fibrosis of paraquat (PQ) poisoning rats, and to discuss the relationship between ILK with pulmonary fibrosis induced by paraquat. Methods: Forty male Sprague-Dawley (SD) rats were randomly divided into control group and paraquat group, 20 in each group; the PQ group rats were intraperitoneally injected PQ liquid (18 mg/kg) , and the control group rats were injected the same volume of saline; 5 rats of these two groups were respectively sacrificed after 7, 14, 28, 56 days of PQ injection; according to the results of lung biopsy HE staining and Masson staining to observe the lung pathologic changes, measure the value of lung hydroxyproline and the expression of ILK. Results: HE and Masson staining of lung pathological biopsy showed, the 7th day after PQ exposure lung tissue mostly had congestion, edema, inflammatory cells infiltration; the 14th inflammation reduced, fibrosis change appeared gradually; the 28th and 56th showed the lung tissue structure disorder and occurred apparent hydroproline with blue dye in pulmonary interstitium. Compared with control group in the same experiment period, the value of lung hydroxyproline in each experiment period of PQ group increased (P<0.05) , and the value of lung hydroxyproline of PQ group rose with the increasing of the time of PQ poisoning. The expression of ILK mRNA and protein in each experiment period of PQ group was higher than the control group in the same experiment period (P<0.05) ; ILK mRNA and protein of PQ group began to increase on 7 day phase, reached the highest on 28 day phase, and decreased on 56 day phase. Conclusion: The expression of ILK mRNA and protein increased with the lung fibrosis progression of PQ poisoning rats, so ILK could be the key molecule target which induced pulmonary fibrosis of PQ poisoning.

Effect of curcumin and pirfenidone on toxicokinetics of paraquat in rat by UPLC–MS/MS

The rats were randomly divided into paraquat group, curcumin treatment group, and pirfenidone treatment group. The concentration of paraquat in rat plasma was determined by an ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method over the range of 10–2000 ng mL−1. Chromatographic separation was achieved on a BEH HILIC (2.1 mm × 100 mm, 1.7 μm) column. The mobile phase was consisted of acetonitrile and 10 mm ammonium formate buffer (containing 0.1% formic acid) with gradient elution pumped at a flow rate of 0.4 mL min−1. Protein precipitation with acetonitrile was used as sample preparation. Compared with the paraquat group, there is statistical toxicokinetic difference for curcumin treatment group and pirfenidone treatment group, AUC(0 − t) decreased (P &lt; 0.05), clearance (CL) increased (P &lt; 0.05) for curcumin or pirfenidone treatment group, and Cmax decreased (P &lt; 0.05) for curcumin treatment group. The results showed that treatment by curcumin and pirfenidone could relieve acute paraquat poisoning in rats.

The study of using cordyceps-astragalus-salvia miltiorrhiza to treat acute lung injury induced by paraquat poisoning in rats

Objective: To study the therapy of cordyceps-astragalus-salvia miltiorrhiza in treating acute lung injury and pulmonary interstitial fibrosis induced by paraquat poisoning. Methods: All 120 adult Wister male rats were randomly assigned to three groups, the paraquat poisoning group (rats were intragastric administration paraquat 50 mg/kg body weight once at the beginning) , the cordyceps-astragalus-salvia miltiorrhiza therapy group (rats were given cordyceps-astragalus-salvia miltiorrhiza 90 mg/kg body weight intragastric administration half an hour after paraquat was given, then the same dose was given once a day) ; control group (rats were intragastric administration with physiological saline) . At 7th, 14th, 21st, and 28th day rats were sacrificed postanesthetic respectively after paraquat exposure, sample of lung tissue, bronchoalveolar lavage (BAL) , and venous blood were collected. GSH, SOD, TNF-α, TGF-β1, and HYP in plasma, bronchoalveolar lavage (BAL) , and the lung homogenates were determined. Optical microscope was performed to examine pathological changes in lung. Results: Each experimental time point paraquat group and the treatment group rats serum SOD content significantly lower than the control group (P<0.05) . Each experimental time point the treatment group rats serum SOD levels increased significantly than that of paraquat group (P<0.05) . Each experimental time point paraquat group rats serum GSH content significantly lower than that of the control group (P<0.05) . Treatment group rats 7 days time GSH content significantly lower than that of the control group (P<0.05) . Treatment group 21 days, 28 days GSH content was increased significantly than that of the paraquat group (P<0.05) . Each experimental time point paraquat group rats alveolar lavage SOD content was significantly lower than that of the control group (P<0.05) . Treatment group 7 days, 14 days time SOD content was significantly lower than that of the control group (P<0.05) , Treatment group 21 days, 28 days SOD content was increased significantly than that of the paraquat group (P<0.05) . Each experimental time point paraquat group and the treatment group rats alveolar lavage GSH content significantly were lower than that of the control group (P<0.05) . Treatment group days 14 and 21 days, 28 days GSH content was increased significantly than that of the paraquat group (P<0.05) . Each experimental time point paraquat group rats alveolar lavage TNF α levels was higher than that of the control group (P<0.05) . Treatment group 7 days, 14 days the rat alveolar lavage TNF α levels was higher than that of the control group (P<0.05) . Treatment group 21 days, 28 days TNF α content significantly was decreased than that of paraquat group (P<0.05) . Paraquat group days 14 and 21 days, 28 days HYP content was significantly higher than that of control group (P<0.05) . Treatment group 21 days HYP content was significantly higher than that of control group (P<0.05) . Treatment group 28 days time HYP content in lung tissue of rats was significantly decreased than that of the paraquat group (P<0.05) . Each experimental time point paraquat group rat lung tissue (tissue homogenate) TGF-β1 content was higher than that of the control group, the difference was statistically significant (P<0.05) . Under optical microscope, the tissue damage of lung was aggravated, and reduced after cordyceps-astragalus-salvia miltiorrhiza was administrated. Conclusion: Cordyceps-astragalus-salvia miltiorrhiza can reduce inflammation factor releasing, and relieve lung injury. It has therapeutic effect on lung injury induced by paraquat poisoning.

Minocycline Protection against Paraquat Toxicity in &lt;I&gt;Drosophila melanogaster&lt;/I&gt;

We determined the effect of long-term administration (12 days) of minocycline (Mino) on the oxidative stress induced by paraquat (PQ) in D. melanogaster . After intoxication with PQ (40 mM) for 36 hours, the intoxicated group was subdivided in three groups: PQ (no further treatment after PQ intoxication), PQ-Mino (treated with Mino [0.05 mM] for 12 days after intoxication) and PQ-Control (exposed to PQ and maintained in standard medium for 12 days after intoxication). Two additional groups, not treated with PQ, were added: Control and Mino. After 36 hours intoxication the concentrations of H2O2, the activities of superoxide dismutase (SOD), Catalase (CAT), glutathione peroxidase (GSH-Px) and nitric oxide synthase (NOS) in the PQ group were increased, but the levels of nitrite and glutathione (GSH) were reduced with respect to the Control. In the group PQ also were observed an increase in the concentrations of MDA, protein carbonyl and the 8-hydroxydeoxyguanosine (8-OHdG) compared with Control. The post-treatment by 12 days with minocycline (PQ-Mino) mitigated oxidative damage induced by PQ as evidenced by the reduction in the concentration of the oxidative stress markers and by decrease damage to the lipid membrane (MDA), protein (protein carbonyl), DNA (8-OHdG) and in an increase of the extension of the life cycle of the flies with respect to PQ-Control.

Toll-like receptor 9 mediates paraquat-induced acute lung injury: an in vitro and in vivo study

AimsThis study aimed to investigate the role of Toll-like receptor 9 in paraquat-induced acute lung injury (ALI). Main methodsFor in vivo study,C57BL mice were randomly assigned into the vehicle control group, paraquat group, paraquat + TLR9 antagonist (ODN2088) group, and TLR9 antagonist (ODN2088) group (n=36 per group). After paraquat 30mg/kg ip for 2, 24 and 48h, serum samples and lung tissues were collected to evaluate ALI and TLR9 signaling by lung injury score, protein levels of TLR9, MyD88, p-IRAK4, p-p65, and serum TNF-α and IL-1β levels. As for in vitro research A549 cells were randomly divided into the control group, paraquat group, paraquat + TLR9 siRNA group, and TLR9 siRNA group. After paraquat treatment for 24h, the cells and supernatant were collected to measureTLR9, TNF-α, IL-1 mRNA expression, and detect activation of NF-κB, caspase-3. Key findingsIn vivo, the lung injury score, the TLR9, MyD88, p-IRAK4 and p-p65 protein levels, and cytokines TNF-α and IL-1β levels in paraquat group were significantly higher than that in the control group;TLR9 blocker ODN2088 pretreatment attenuated lung injury, inhibited MyD88 and NF-κB activation, and reduced TNF-α and IL-1β in serum. In vitro result shows that the gene silencing of TLR9 reduced the mRNA expression of TLR9, TNF-α and IL-1, inhibited NF-κB and caspase-3 activation, attenuated cell apoptosis. SignificanceTLR9 mediates paraquat-induced ALI, antagonizing TLR9 or silencing TLR9gene may attenuate paraquat-induced ALI.

The role of interleukin-17A in acute paraquat induced lung injury in mice

Objective To investigate the role of interleukin-17A(IL-17A)in acute paraquat(PQ)-induced lung injury in mice. Methods A total of 120 healthy SPF grade ICR male mice were randomly(random number) divided into three groups(n=40 in each): normal saline control group (NS), PQ poisoning group (PQ) and antibody neutralization group (PQ+ Ab). Mice of PQ group and PQ+ Ab group were given 5 mg/mL PQ by one gavage in a dosage of 25 mg/kg body weight, and 5 μg IL-17A neutralizing antibody intra-peritoneally administered immediately after PQ poisoning in PQ+ Ab group; Equivalent volume of normal saline instead of PQ was given to mice of NS group. Six survival mice from each group were taken for experiment at 8 h, 1 d, 3 d, 5 d, 7 d after PQ poisoning: Wet to dry ratio (W/D) of lung was determined in mice of each group. HE staining of lung tissue was used to observe the histopathological changes under the light microscope and the pathological scores were graded; Serum interleukin-17A (IL-17A), interleukin-22 (IL-22), interleukin-6 (IL-6), transforming growth factor-β(TGF-β) were detected with enzyme linked immunosorbent assay (ELISA); Expression of interleukin-23 receptor (IL-23R) in lung tissue was determined with immunohistochemical; real-time fluorescence quantification PCR (qRT-PCR) was used to detect the expression of retinoic acid related solitary nuclear receptors’ mRNA in lung tissue. Results After administration of PQ, W/D ratio increased (P<0.01), lung injury was observed in mice of PQ and PQ+ Ab groups, levels of cytokines (IL-17A, IL-22, IL-6 and TGF-β) in serum elevated (P<0.05), and the expressions of IL-23R mRNA and RORγt mRNA increased (P<0.01). But in PQ+ Ab group, W/D ratio decreased (P<0.05), lung injury was alleviated, the levels of cytokines(IL-17A, IL-22, IL-6 and TGF-β) decreased (P<0.05), and the expressions of IL-23R mRNA and RORγt mRNA reduced (P<0.05). Conclusions Since IL-17A involves in the lung injury of the mice induced by acute paraquat poisoning, blockade of IL-17A significantly alleviates the acute lung injury in mice. Key words: Paraquat; Interleukin-17A; Mice; Acute lung injury; Th17 cell

Cromolyn Sodium Attenuates Paraquat-Induced Lung Injury by Modulation of Proinflammatory Cytokines.

The current study aimed to investigate the effects of Cromolyn Sodium (CS) on proinflammatory cytokines in Paraquat (PQ)-induced lung damage in rat. Animals were randomly divided into 5 groups. Group 1 and 2 received nebulized vehicle and CS (8 mg/kg) for 3 consecutive weeks, respectively. Group 3 was treated with single oral dose of PQ (40 mg/kg). Groups 4 and 5 were PQ groups which received nebulized CS (6 and 8 mg/kg/day, respectively) from 1 week before to 2 weeks after PQ administration. Finally, the animals were scarified and the changes of hydroxyproline (HP) and histology were evaluated in lung tissue. In addition, IL-1β, TNF-α and IL-8 levels were determined in serum samples. The results showed that lung HP level as well as IL-1β, TNF-α and IL-8 were significantly lower in the CS treated rats as compared to PQ group. The best response, however, was observed with the 8 mg/kg of CS as confirmed by histology findings. This study suggests that CS may prevent progression of PQ-induced lung damage by decreasing of inflammatory cytokines.