OBJECTIVE: To observe whether metformin (MET) inhibits transforming growth factor-β₁ (TGF-β₁)/Smad3 signaling pathway by activating adenosine activated protein kinase (AMPK), so as to alleviate the pulmonary fibrosis caused by paraquat (PQ) poisoning in mice. METHODS: Male C57BL/6J mice were randomly divided into the Control group, PQ poisoning model group (PQ group), MET intervention group (PQ+MET group), AMPK agonist group (PQ+AICAR group), and AMPK inhibitor group (PQ+MET+CC group), according to a random number table method. A mouse model of PQ poisoning was established by one-time peritoneal injection of 1 mL PQ solution (20 mg/kg). The Control group was injected with the same volume of normal saline. After 2 hours of modeling, the PQ+MET group was given 2 mL of 200 mg/kg MET solution by gavage, the PQ+AICAR group was given 2 mL of 200 mg/kg AICAR solution by intraperitoneal injection, the PQ+MET+CC group was given 2 mL of 200 mg/kg MET solution by gavage and then 1 mL complex C (CC) solution (20 mg/kg) was intraperitoneally injected, the Control group and PQ group were given 2 mL of normal saline by gavage. The intervention was given once a day for 21 consecutive days. The 21-day survival rate of ten mice in each group was calculated, and the lung tissues of remaining mice were collected at 21 days after modeling. The pathological changes of lung tissues were observed under light microscope after hematoxylin-eosin (HE) staining and Masson staining, and the degree of pulmonary fibrosis was evaluated by Ashcroft score. The content of hydroxyproline in lung tissue and oxidative stress indicators such as malondialdehyde (MDA) and superoxide dismutase (SOD) were detected. The protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), phosphorylated AMPK (p-AMPK), TGF-β₁ and phosphorylated Smad3 (p-Smad3) in lung tissue were detected by Western blotting. RESULTS: Compared with the Control group, the 21 days survival rate was significantly reduced, lung fibrosis and Ashcroft score were significantly increased in PQ group. In addition, the content of hydroxyproline, MDA and the protein expressions of α-SMA, TGF-β₁ and p-Smad3 in lung tissue were significantly increased, while the activity of SOD and the protein expressions of E-cadherin and p-AMPK were significantly decreased in PQ group. Compared with the PQ group, the 21 days survival rates of mice were significantly improved in the PQ+MET group and PQ+AICAR group (70%, 60% vs. 20%, both P < 0.05). The degree of pulmonary fibrosis and the Ashcroft score were significantly reduced (1.50±0.55, 2.00±0.63 vs. 6.67±0.52, both P < 0.05). The content of hydroxyproline and MDA in lung tissue, as well as α-SMA, TGF-β₁ and p-Smad3 protein expressions were significantly reduced [hydroxyproline (mg/L): 2.03±0.11, 3.00±0.85 vs. 4.92±0.65, MDA (kU/g): 2.06±1.48, 2.10±1.80 vs. 4.06±1.33, α-SMA/GAPDH: 0.23±0.06, 0.16±0.06 vs. 1.00±0.09, TGF-β₁/GAPDH: 0.28±0.03, 0.53±0.05 vs. 0.92±0.06 p-Smad3/GAPDH: 0.52±0.04, 0.69±0.06 vs. 1.11±0.10, all P < 0.05], SOD activity and the protein expressions of E-cadherin and p-AMPK were significantly increased [SOD (μmol/g): 39.76±1.35, 33.03±1.28 vs. 20.08±1.79, E-cadherin/GAPDH: 0.91±0.08, 0.72±0.08 vs. 0.26±0.04, p-AMPK/GAPDH: 0.62±0.04, 0.60±0.01 vs. 0.20±0.04, all P < 0.05]. However, these protective effects of MET were inhibited by the addition of AMPK inhibitor CC solution. CONCLUSIONS MET can effectively alleviate the degree of pulmonary fibrosis in mice poisoned with PQ, and its mechanism may be related to the activation of AMPK and inhibition of TGF-β₁/Smad3 signaling pathway, which can be inhibited by AMPK inhibitor CC.
Mice ; Male ; Animals ; Pulmonary Fibrosis/drug therapy* ; Paraquat ; AMP-Activated Protein Kinases/pharmacology* ; Metformin/pharmacology* ; Hydroxyproline/pharmacology* ; Saline Solution ; Mice, Inbred C57BL ; Lung/metabolism* ; Transforming Growth Factor beta1/pharmacology* ; Cadherins ; Superoxide Dismutase

Objective: To investigate the effects of duration, temperature and shake on paraquat (PQ) concentration in the blood of PQ-exposed rats during the specinen preservation and transportation. Methods: In March 2021, 60 SD male rats of Specific Pathogen Free class were randomly divided into low-dose group (10 mg/kg PQ) and high-dose group (80 mg/kg PQ). Each group was divided into 5 subgroups (normal temperature group, cold storage group, 37 ℃ storage group, shaking on normal temperature group and shaking on 37 ℃ group), six rats in each subgroup. The rats were given intraperitoneal injection of PQ, 1 h after exposure, the blood samples were obtained by cardiac extraction. After different interventions, the concentrations of PQ were detected and compared before and after the intervention in each subgroup. Results: In the shaking on 37 ℃ group, the results of PQ concentrations in PQ-exposed rats were significantly lower than those before the intervention (P<0.05). In the other subgroups, the results were not significantly different compared with before intervention (P>0.05) . Conclusion: The concentration of PQ in the blood of rats exposed to PQ was decreased by shaking for 4 hours at 37 ℃.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Paraquat/pharmacology* ; Lung

Objective: To investigate the protective effect and mechanism of Nicotinamide Riboside (NR) on lung injury caused by Paraquat intoxicated mice. Methods: Eighty clean male BALB/C mice were selected and averagely divided forty mice into 4 groups with 10 mice in each group, PQ group was given 25% PQ solution (60 mg/kg) by one-time gavage. PQ+NR group were intraperitoneally injected with NR solution (300 mg/kg) 1 hour before given the same amount of PQ solution (60 mg/kg) by one-time gavage, The Control group were given the same amount of saline by one-time gavage, The same amount of NR was intraperitoneally injected before NR group were given saline by one-time gavage. Observed and recorded general condition of PQ intoxicated mice. Observed and recorded the death of mice every half an hour and counted the mortality and drew survival curve of each group after 72 hours exposure. another forty mice were averagely divided and treated by the same way. After 24 hours of modelling, mice were anaesthetized and killed. Then blood was extracted after eyeball was removed. The changes of TNF-a、IL-6 and MPO in serum of mice were detected by ELISA.Two lung tissues were removed from the chest and used to measure the D/W ratio of the lung. The pathological changes of lung were observed and scored under light microscope.The levels of SOD, MDA and Caspase-3 in lung tissues were determined by chemical colorimetry. The expression of Sirt1 and Nrf2 in lung tissues was detected by Western-blot. Results: Compared with the Control group and the NR group, the mice in the PQ group had a poor general condition, such as depression, crouching, skin disorder and reduced activity, food, urine and feces. The symptoms in the PQ+NR group were reduced compared with the PQ group. The survival rate at 72 hours after exposure: 80% in the PQ+NR group and 40% higher than that in the PQ group (P=0.029) . Compared with Control group and NR group, the D/W ratio (0.09±0.07) , lung pathology score under light microscope (11.80±0.37) , TNF-a (39.89±1.48) pg/ml、IL-6 (77.29±2.38) pg/ml、MPO (0.31±0.01) μg/ml、SOD (6.62±0.30) U/mgprot、MDA level (1.21±0.14) mmol/mgprot, Caspase-3 activity (356.00± 27.16) %, Sirt1 and Nrf2 protein expression (1.02±0.14、0.82±0.06) were significantly decreased in PQ group (P=0.004、0.023) ; Compared with PQ group, PQ+NR group significantly increased the D/W ratio (0.10±0.10) , decreased the pulmonary pathology score under light microscope (7.400.51) , decreased TNF-a (33.00± 0.65) pg/ml、IL-6 (52.23±4.23) pg/ml、MPO leve (0.23±0.01) μg/mll, increased SOD leve (9.28±0.45) U/mgprotl, decreased MDA level (0.78±0.02) mmol/mgprot, decreased Caspase-3 activity (222.80±7.59) %, and increased the protein expressions of Sirt1 and Nrf2 (1.62±0.16、1.06±0.04) (P=0.048、0.035) . Conclusion: NR can prolong the survival time of PQ poisoned mice; NR intervention can effectively inhibit the inflammatory response, peroxidation injury and apoptosis of PQ poisoned mice; NR intervention can upregulate the expression of Sirt1 and Nrf2 protein and effectively reduce the lung injury of PQ poisoning.
Animals ; Caspase 3/metabolism* ; Interleukin-6/metabolism* ; Lung ; Lung Injury/metabolism* ; Male ; Mice ; Mice, Inbred BALB C ; NF-E2-Related Factor 2/metabolism* ; Niacinamide/pharmacology* ; Paraquat/toxicity* ; Pyridinium Compounds/pharmacology* ; Sirtuin 1/metabolism* ; Superoxide Dismutase/metabolism*

Allyl Compounds ; Animals ; Lung ; Male ; Paraquat/pharmacology* ; Poisons ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Sulfides

To explore the dose-effect relationship between vitamin C and paraquat (PQ) poisoning rats.
 Methods: A total of 40 Sprague-Dawley (SD) rats were randomly divided into 4 groups: a control group, a PQ poisoning group, a vitamin C group 1 and a vitamin C group 2 (n=10 in each group). 150 mg/kg PQ was perfused into rat stomach to establish PQ poisoning rat model. In PQ poisoning group, 30 mg/kg methylprednisolone and 2.5 mg/kg cyclophosphamide were injected peritoneally on the basis of PQ poisoning rat model. In vitamin C1 and C2 group, vitamin C was injected at a dosage of 5 or 500 mg/kg, respectively. The control group only received normal saline (NS). The malondialdehyde (MDA), liver and kidney function as well as arterial blood gas in the blood were examined 36 h later. At the end, the rats were killed and took the liver tissues for pathological examination and weight ratio calculation. The glutathione peroxidase (GSH-PX), ctychrome C (Cyt C) in the liver tissues were detected by chromatometry, and the Bcl-2 was detected by Western blot.
 Results: Compared with the PQ poisoning group, the MDA and Cyt C were decreased, the GSH-PX was increased, and liver and kidney functions were improved in the vitamin C group 1 (all P<0.01); but in the vitamin C group 2, the MDA increased and liver/kidney functions were impaired (all P<0.01). The expression of Bcl-2 in the PQ poisoning group was lower than that in the control group; compared with the PQ poisoning group, it was increased in the vitamin C1 group, while it was decreased in the vitamin C group 2 (both P<0.01). There was no obvious difference in the lung function, wet/dry weight ratio and pathological changes between the poisoning group and experimental groups (all P>0.05).
 Conclusion: Vitamin C at the low dose shows a certain degree of protection for the liver and kidney in the PQ poisoning rats model through it antioxidative activity and anit-apoptosis activity, while vitamin C at the high does may promote oxidation. Meanwhile, vitamin C doesn't show protective effect on lung in the PQ poisoning rats.
Animals ; Apoptosis ; drug effects ; Ascorbic Acid ; administration & dosage ; pharmacology ; Cytochromes c ; drug effects ; metabolism ; Dose-Response Relationship, Drug ; Glutathione Peroxidase ; drug effects ; Kidney ; drug effects ; pathology ; physiopathology ; Lung ; drug effects ; pathology ; physiopathology ; Malondialdehyde ; metabolism ; Paraquat ; toxicity ; Protective Agents ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Vitamins

OBJECTIVETo explore the pathogenesis of paraquat poisoning and observe the change in lipid peroxidation of rats treated with different doses of curcumin.

METHODSA total of 50 8-week-old male Wistar rats (clean grade) were randomly divided into high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin treatment group, poisoned group, and blank control group. Glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels in rat serum were measured at 1, 3, 7, 14, and 21 d post paraquat injection.

RESULTSCompared with the blank control group, other groups had significantly higher MDA levels but lower SOD, GSH-PX, and CAT activities. The high-dose, low-dose curcumin plus conventional treatment, and high-dose curcumin treatment groups had significantly lower serum lipid peroxidation levels compared with the poisoned group and among them the high-dose curcumin plus conventional treatment group had the most significant improvement.

CONCLUSIONCurcumin can significantly decrease serum lipid peroxidation level in rats and inhibit and delay the occurrence and progression of the damage to the body.

Animals ; Catalase ; blood ; Curcumin ; pharmacology ; Glutathione Peroxidase ; blood ; Lipid Peroxidation ; drug effects ; Male ; Malondialdehyde ; blood ; Paraquat ; toxicity ; Random Allocation ; Rats ; Rats, Wistar ; Superoxide Dismutase ; blood

OBJECTIVETo investigate the protective effect of ulinastatin (UTI) on HK-2 cells during paraquat (PQ)-induced injury and its underlying mechanisms.

METHODSRoutinely cultured HK-2 cells were divided into blank control group, PQ group, UTI+PQ group and UTI group. Cell viability was determined by CCK-8 assay. The concentration of PQ in HK-2 cells were measured by high performance liquid chromatography (HPLC). The production of total reactive oxygen species (ROS) were detected by fluorescence microscopy. The activities of superoxide dismutase activity (SOD) and the content of malondialdehyde (MDA) in HK-2 cells were observed by chemical colorimetry. The levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTSPQ, even at a dose of 200 µM, could significant suppress the viability of HK-2 cells in a dose-dependent and time-dependent. UTI showed no significant inhibitory effect on the viability of HK-2 cells when given at a dose below 8 000 U/ml (P > 0.05). Compared with the PQ group, the UTI+PQ group had significantly increased the viability of HK-2 cells in a dose-dependent of UTI (P < 0.05). Compared with the PQ group on the same hour, the UTI+PQ group showed decreased in PQ concentration in HK-2 cells (P < 0.05 for all except 6 h). Compared with the blank control group, the PQ group had significantly decreased SOD activity and significantly increased ROS level and MDA content (P < 0.05). Compared with the PQ group, the UTI+PQ group had significantly increased SOD activity and significantly decreased ROS level and MDA content (P < 0.05). Compared with the blank control group, the PQ group had significantly increased IL-6 and TNF-α level (P < 0.05); Compared with the PQ group, the UTI+PQ group had significantly decreased IL-6 and TNF-α level (P < 0.05).

CONCLUSIONUTI significantly reduces the PQ-induced oxidative damage and inflammatory injury and its mechanism may be by reducing the accumulation of PQ in HK-2 cells.

Cell Line ; Cell Survival ; drug effects ; Glycoproteins ; pharmacology ; Humans ; Interleukin-6 ; metabolism ; Malondialdehyde ; metabolism ; Oxidative Stress ; Paraquat ; toxicity ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the effect of paraquat (PQ) on reactive oxygen species (ROS) and neutrophil apoptosis and its possible signal transduction pathways.

METHODSCultured neutrophils were treated with different concentrations of PQ for 6-24 h. The apoptosis rate of neutrophils and ROS content were determined by flow cytometry. The exoressions of nuclear factor kappa B (NF-κB) and Caspase 3 were detected by Western blot. These parameters were checked again after NF-κB and Caspase 3 antagonist were applied.

RESULTSPQ could boost ROS generation and depress neutrophil apoptosis significantly. At the same time PQ could enhance the expression of NF-κB and inhibit the expression of Caspase 3. These effects could be reversed by ROS inhibitor diphenyleneiodonium (DPI) and NF-κB inhibitor pyrrolidinedithiocarbamate (PDTC).

CONCLUSIONPQ is a potent inducer of ROS and can inhibit neutrophil apoptosis by activating NF-κB and surpressing Caspase 3 activity.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cells, Cultured ; NF-kappa B ; antagonists & inhibitors ; metabolism ; Neutrophils ; cytology ; drug effects ; Paraquat ; toxicity ; Pyrrolidines ; pharmacology ; Reactive Oxygen Species ; metabolism ; Signal Transduction ; Thiocarbamates ; pharmacology

OBJECTIVETo investigate the effects of total flavonoids from astragalus complanatus (FAC) on paraquat poisoning-induced pulmonary fibrosis in rats.

METHODSThe rats were divided into six groups randomly: control group, paraquat group, prednisolone group and FAC low-dose, middle-dose, high-dose group. Pulmonary fibrosis model was replicated by intratracheal injection of paraquat. In the mext day,the rats were treated by intragastric administration once a day. After 28 days, the rats were sacrificed. The lung index and the levels of HYP and T-AOC were measured, and the pathologic changes of the lung tissue were obtained by HE staining. The levels of TGF-β, Smad2, α-SMA protein were analyzed by Western blot.

RESULTSFAC improved the activity of T-AOC in serum and reduced pulmonary index and the content of HYP as well (P<0.05 or P<0.01), the alveolitis and fibrosis extent were attenuated. The expression of Smad2 significantly decreased in groups of FAC low-dose, middle-dose and high-dose (0.31±0.11, 0.45±0.12 and 0.30±0.05) as compared with that of the PQ group (0.85±0.34) (P<0.05). The expression of α-SMA significantly decreased in groups of FAC low-dose, middle-dose and high-dose (0.31±0.11, 0.35±0.07 and 0.32±0.10) as compared with that of the PQ group (0.45±0.08) (P<0.05). The expression of TGF-β significantly decreased in groups of FAC low-dose, middle-dose and high-dose (0.35±0.04, 0.27±0.05 and 0.18±0.04)as compared with that of the PQ group (0.63±0.11) (P<0.05).

CONCLUSIONFAC can alleviate PQ-induced pulmonary fibrosis in rats through inhibiting TGF-β/Smad signaling pathway.

Actins ; metabolism ; Animals ; Astragalus Plant ; chemistry ; Flavonoids ; pharmacology ; Lung ; pathology ; Paraquat ; poisoning ; Phytochemicals ; pharmacology ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; Rats ; Smad2 Protein ; metabolism ; Transforming Growth Factor beta ; metabolism

OBJECTIVETo explore the mechanism of paraquat (PQ) poisoning and to observe the changes in inflammatory cytokines in PQ-exposed rats treated in different ways.

METHODSFifty 8-week-old clean male Wistar rats were randomly divided into high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin group, PQ poisoning group, and blank control group. On days 1, 3, 5, 7, 14, and 21 after PQ exposure, serum levels of transforming growth factor-β₁(TGF-β₁) , tumor necrosis factor-α (TNF-α) , and interleukin-6 (IL-6) were measured. The pathological changes in lung tissue were evaluated by HE staining.

RESULTSCompared with the blank control group, the high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin group, and PQ poisoning group had significantly increased serum levels of TGF-β₁, TNF-α, and IL-6 (P<0.05) , and the three cytokines in each group reached peak levels on day 14 after exposure. Compared with the PQ poisoning group, the high-dose curcumin group had significantly reduced serum levels of TGF-β₁, TNF-α, and IL-6 (P<0.05). On day 21 after exposure, there were no significant differences in serum levels of TGF-β₁, TNF-α, and IL-6 between the high-dose curcumin plus conventional treatment group and the low-dose curcumin plus conventional treatment group (P>0.05). The HE staining revealed alveolar inflammatory changes on days 1~7 and massive pulmonary fibrosis on days 14~21 in the high-dose curcumin plus conventional treatment group, low-dose curcumin plus conventional treatment group, high-dose curcumin group, and PQ poisoning group, but the above changes were milder in the high-dose curcumin group than in the PQ poisoning group.

CONCLUSIONFor rats with PQ poisoning, curcumin can significantly reduce inflammatory response and pathological changes in lung tissue and inhibit and delay the development and progression of body injury.

Animals ; Curcumin ; pharmacology ; Cytokines ; blood ; Interleukin-6 ; blood ; Lung ; pathology ; Male ; Paraquat ; poisoning ; Pulmonary Fibrosis ; pathology ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Transforming Growth Factor beta1 ; blood ; Tumor Necrosis Factor-alpha ; blood