ABSTRACT
ObjectiveTo explore the mechanism of Buyang Huanwutang combined with bone marrow mesenchymal stem cell （BMSC） transplantation in the treatment of spinal cord injury （SCI）. MethodDifferent concentrations （12.5， 25， 50 g·kg-1） of Buyang Huanwutang were administrated to rats by gavage. The spinal cord function of rats was measured by modified Tarlov score， and the most suitable concentration of Buyang Huanwutang was screened out. SD rats were then divided into 6 groups， namely， the sham operation group （gavage of equal amount of normal saline）， the model group （gavage of equal amount of normal saline）， the Buyang Huanwutang group （gavage of 25 g·kg-1 Buyang Huanwutang）， the BMSC transplantation group （tail vein injection of BMSCs 1 mL）， the Buyang Huanwutang+BMSC group （gavage of 25 g·kg-1 Buyang Huanwutang and tail vein injection of BMSCs 1 mL）， the Buyang Huanwutang+BMSC+LY294002 group （gavage of 25 g·kg-1 Buyang Huanwutang and tail vein injection of BMSCs 1 mL and 40 mg·kg-1 LY294002）， with 10 rats in each group. The spinal cord function was measured by the modified Tarlov score， inclined plate test， and latency of cortical somatosensory evoked potential. Immunohistochemistry was used to detect the number of 5-bromo-2-deoxyuracil nucleoside （Brdu）-labeled positive cells in the spinal cord tissue. The protein expression levels of phosphorylated protein kinase B （p-Akt）， glycoprotein 130 （gp130）， and interleukin-6 （IL-6） in spinal cord were detected by Western blot. ResultAs compared with the sham operation group， the Tarlov score and the critical angle of tilt plane in the model group were significantly decreased （P<0.05）， and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 were significantly increased （P<0.05）. As compared with the model group， the Tarlov score and the critical angle of tilt plane in the sham operation group and each treatment group were significantly increased （P<0.05）， and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 were significantly decreased （P<0.05）. As compared with the BMSC group， the Tarlov score and the critical angle of inclined plane in the Buyang Huanwutang+BMSC group increased （P<0.05）， the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 decreased （P<0.05）， and the number of Brdu-labeled positive cells increased 5 weeks after transplantation （P<0.05）. As compared with the Buyang Huanwutang+BMSC group， the Tarlov score and the critical angle of the inclined plane in the Buyang Huanwutang+BMSC+LY294002 group increased （P<0.05）， and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 decreased significantly （P<0.05）. Five weeks after transplantation， the number of Brdu-labeled positive cells increased significantly in the Buyang Huanwutang+BMSC+LY294002 group （P<0.05）. ConclusionBuyang Huanwutang can promote BMSCs migration and restore spinal cord function by inhibiting phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signal.
ABSTRACT
ObjectiveTo investigate the effect of calycosin-mediated glucoprotein130/Janus kinase/signal transducer and activator of transcription factor （GP130/JAK/STAT） signaling pathway on oxidative injury of astrocytes in spinal cord. MethodAstrocytes in rat spinal cord were isolated and identified by immunofluorescence detection of glial fibrillary acidic protein （GFAP）. The cells were respectively pre-treated with 5， 10， 20 μmol·L-1 calycosin for 12 h， and then 100 μmol·L-1 H2O2 （24 h） was added to induce oxidative injury. Cell counting kit-8 （CCK-8） assay was employed to detect cell proliferation and select the optimal concentration of calycosin. The following experimental groups were designed： control group， model group （100 μmol·L-1 H2O2）， calycosin group （20 μmol·L-1 calycosin）， calycosin + LY294002 group （20 μmol·L-1 calycosin + 10 μmol·L-1 LY294002）， and calycosin + Stattic group （20 μmol·L-1 calycosin + 3 μmol·L-1 Stattic）. CCK-8 assay and immunofluorescence method were used to detect the proliferation of cells and flow cytometry was applied to detect cell apoptosis and cycle. The protein expression of phosphorylated （p）-JAK2， p-STAT3， p-protein kinase B （Akt）， GP130， and interleukin-6 （IL-6） was detected by Western blotting. ResultCompared with the control group， the model group showed low proliferation activity and high apoptosis rate of cells （P<0.05）. Compared with the model group， calycosin （20 μmol·L-1） group displayed high proliferation activity and low apoptosis rate of cells （P<0.05）. Compared with calycosin （20 μmol·L-1） group， both phosphatidylinosirtol-3-kinases （PI3K） inhibitor LY294002 and STAT3 inhibitor Stattic significantly reduced the proliferation activity and increased the apoptosis rate of cells （P<0.05）. The protein expression of p-JAK2， p-STAT3， p-Akt， GP130， and IL-6 in the model group was higher than that in the control group （P<0.05）， and the expression of the above indicators was lower in each treatment group than in the model group （P<0.05）. ConclusionCalycosin can promote the proliferation and inhibit the apoptosis of astrocytes with oxidative injury by inhibiting the phosphorylation of PI3K/Akt pathway and JAK2/STAT3 pathway.
ABSTRACT
ObjectiveTo investigate the effect of calycosin-mediated glucoprotein130/Janus kinase/signal transducer and activator of transcription factor （GP130/JAK/STAT） signaling pathway on oxidative injury of astrocytes in spinal cord. MethodAstrocytes in rat spinal cord were isolated and identified by immunofluorescence detection of glial fibrillary acidic protein （GFAP）. The cells were respectively pre-treated with 5， 10， 20 μmol·L-1 calycosin for 12 h， and then 100 μmol·L-1 H2O2 （24 h） was added to induce oxidative injury. Cell counting kit-8 （CCK-8） assay was employed to detect cell proliferation and select the optimal concentration of calycosin. The following experimental groups were designed： control group， model group （100 μmol·L-1 H2O2）， calycosin group （20 μmol·L-1 calycosin）， calycosin + LY294002 group （20 μmol·L-1 calycosin + 10 μmol·L-1 LY294002）， and calycosin + Stattic group （20 μmol·L-1 calycosin + 3 μmol·L-1 Stattic）. CCK-8 assay and immunofluorescence method were used to detect the proliferation of cells and flow cytometry was applied to detect cell apoptosis and cycle. The protein expression of phosphorylated （p）-JAK2， p-STAT3， p-protein kinase B （Akt）， GP130， and interleukin-6 （IL-6） was detected by Western blotting. ResultCompared with the control group， the model group showed low proliferation activity and high apoptosis rate of cells （P<0.05）. Compared with the model group， calycosin （20 μmol·L-1） group displayed high proliferation activity and low apoptosis rate of cells （P<0.05）. Compared with calycosin （20 μmol·L-1） group， both phosphatidylinosirtol-3-kinases （PI3K） inhibitor LY294002 and STAT3 inhibitor Stattic significantly reduced the proliferation activity and increased the apoptosis rate of cells （P<0.05）. The protein expression of p-JAK2， p-STAT3， p-Akt， GP130， and IL-6 in the model group was higher than that in the control group （P<0.05）， and the expression of the above indicators was lower in each treatment group than in the model group （P<0.05）. ConclusionCalycosin can promote the proliferation and inhibit the apoptosis of astrocytes with oxidative injury by inhibiting the phosphorylation of PI3K/Akt pathway and JAK2/STAT3 pathway.
ABSTRACT
Abstract A method based on dispersive solid phase extraction-high performance liquid chromatography-tandem mass spectrometry for determination of 19 kinds of nonprotein nitrogen compounds including melamine, cyromazine, amidinourea, aminotriazine, 3-aminotriazole, 4-aminotriazole, allantoin, cyanuric acid, dicyandiamide, thiourea, semicarbazide, L-leucine, L-isoleucine, L-arginine, L-hydroxyproline, L-theanine, ammeline, ammelide and guanidine in powdered formulas was presented. The nonprotein nitrogen compounds were degreased by chloroform and extracted by acetonitrile, with MgSO4 to remove water and C18 to clean up. The samples were separated on Merck ZIC HILIC column (150 mm í2. 1 mm, 5 μm, 20 nm) with gradient elution. The electrospray ionization was operated in the positive mode and negative mode, and monitored by the multiple reaction monitoring ( MRM) mode. Allation was quantified by external standard method and the other 18 kinds of nonprotein nitrogen compounds were quantified by internal standard method. All of the correlation coefficients (r) were higher than 0. 99. The limits of quantitation (LOQ) were 0. 05-5. 0 mg/kg, the average recoveries were between 82 . 2% and 115 . 0%, and the relative standard deviations were less than 20%.
ABSTRACT
A method based on solid phase extraction-liquid chromatography-tandem mass spectrometry for the simultaneous determination of 76 veterinary drugs in foodstuffs of animal origin was presented. The residues derived from pork, shrimp, milk, liver and egg were extracted by acetonitrile combined with citrate buffer containing magnesium cation. The extracts were distilled and redissolved with citrate buffer followed by a further cleanup procedure using polymer connected with cation exchange SPE column. The residues retained in column were rinsed with methanol and mixture of methanol and ammonium hydroxide(95∶ 5, V/V). Sample matrix-matched calibration was used to determine the residue contents by external standard. The method provided a LOQ of 0.5 μg/kg(β-agonist and triphenylmethane), 1.0 μg/kg(benzodiazepine and nitroimdazole), 5.0 μg/kg(benzimidazole) and 20.0 μg/kg(sulfanilamide), linear relationship more than 0.907 and a recovery ranged from 59.4% to 115.3% with a RSD between 2.6% and 27.3% in sample matrix. The practical inspection using the method offered two positive samples for ractopamine and diazepam with a residual concentration of 0.92 and 6.5 μg/kg.