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OBJECTIVE To study the protective effects of ligustrazine-scutellarein twin drug ST-11 on rat adrenal medullary pheochromocytoma PC12 cell injury induced by oxygen-glucose deprivation/reperfusion (OGD/R) and its mechanism. METHODS PC12 cells were divided into blank group, model group, nimodipine group (positive control, 5 μmol/L) and different concentration groups of ST-11 (5, 10, 20 μmol/L). After 24 hours of pre-administration intervention, all the other groups except the blank group were cultured in glucose-free DMEM culture medium containing 10 mmol/L Na2S2O4 for 4 hours with glucose deficiency and hypoxia. After 4 hours of glucose and oxygen re-introduction, the survival rate of cells in each group, the contents of lactate dehydrogenase (LDH), catalase (CAT), glutathione (GSH), malondialdehyde (MDA) and superoxide dismutase (SOD) in cell supernatant, apoptosis rate, the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP), the protein expressions of B-cell lymphoma 2 related X protein (Bax), B-cell lymphoma 2 (Bcl-2) and caspase-3 were all detected in each group. RESULTS Compared with blank group, the cell survival rate, the contents of CAT, GSH and SOD in cell supernatant, MMP level, relative expression of Bcl-2 and Bcl-2/Bax ratio in model group decreased significantly (P<0.05), while the contents of LDH and MDA, ROS level, apoptosis rate, relative expressions of Bax and caspase-3 were significantly increased (P<0.05). Compared with model group, above indexes of ST-11 groups (except for the protein expression of caspase-3 in 5 μmol/L ST-11 group) were reversed signifi-cantly (P<0.05). CONCLUSIONS ST-11 has a certain protec-tive effect on OGD/R-injured PC12 cells, and its effects may be related to reduction of oxidative stress and inhibition of cell apoptosis.
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OBJECTIVE To study the protective effects of twin drugs of tetramethylpyrazine-scutellarein (TMSC4) on cerebral ischemia-reperfusion injury (CIRI) model rats and its mechanism. METHODS One hundred and five SD rats were randomly divided into sham operation group, model group, scutellarein group (0.7 mmol/kg), tetramethylpyrazine group (0.7 mmol/kg), and TMSC4 low-dose, medium-dose and high-dose groups (0.35, 0.7, 1.4 mmol/kg), with 15 rats in each group. Sham operation group and model group were given constant volume of normal saline intragastrically, and other groups were given relevant drug intragastrically, once a day, for consecutive 14 d. Except for sham operation group, all other groups were treated to establish the CIRI model using the thread occlusion method. After 2 hours of ischemia and 22 hours of reperfusion, the brain index and brain water content of the rats were measured. Serum levels of interleukin 1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α), the levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and catalase (CAT) in brain tissues, the situation of neuronal cell apoptosis, and the protein expressions of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and cleaved-caspase-3 were evaluated. RESULTS Compared with sham operation group, the brain index, brain water content, the serum levels of IL-1β, IL-6 and TNF-α, the levels of MDA in brain tissues, the brain cell apoptosis and the protein expressions of Bax and cleaved-caspase-3 in model group were significantly increased (P<0.05); the levels of SOD, GSH- Px and CAT and the protein expression of Bcl-2 in brain tissues were significantly decreased (P<0.05). Compared with model group, the above indexes of rats were reversed significantly in administration groups (P<0.05), while the reverse effects of TMSC4 medium-dose and high-dose groups were significantly better than those of scutellarein group and tetramethylpyrazine group (P<0.05). CONCLUSIONS TMSC4 has a certain protective effect in CIRI model rats, the mechanism of which may be related to relieving inflammatory reaction and oxidative stress, inhibiting cell apoptosis.
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In order to search for new adefovir analogues as anti-HBV agents with enhanced antiviral activity and hepatotrophic property,adefovir bis L-amino acid ester was used as lead compound to produce ten adefovir mono L-(thio)amino acid ester, mono bile acid ester derivatives(6a-6j). The design based on bile acid prodrug strategy,which can improve drug oral bioavaliability and liver-targeted enrichment by using enterohepatic circula-tion of bile acid.Sub-structure combination method was adopted to introduce L-(thio)amino acid ester and bile acid ester fragments on the phosphonate functionality of adefovir. The structures of target compounds were confirmed by 1H NMR, 13C NMR,ESI-MS and ESI-HRMS.HepG 2.2.15 cell were used for in vitro anti-HBV activity assessment.Compound 6c with high antiviral activity(EC500.92μmol/L,SI 512.63)was further investi-gated for its tissue distribution in mice.The results showed that content of compound 6c in liver was higher than that of adefovir dipivoxil,and in contrast its content in kidney was lower than that in positive control at all time points(0.25-12 h).Compound 6c exhibits higher antiviral activity,selective index and higher liver distribution,making it a potential anti HBV agent for further investigation.
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Aim To establish in vitro blood-brain barrier (BBB) model with characteristics of simulation of in vivo BBB by primi-tive co-culture of brain-microvessel endothelial cells (BMECs) with brain-microvessel pericytes (BMPC)and astrocytes (AS). Methods BMECs,BMPC and AS from SD rats were primitively isolated,purified and cultured,and then primitive culture cells were identified by cellular morphological and immunocytochemi-cal staining methods.Five types of in vitro BBB models were es-tablished by using Millicell culture insert (pore diameter 0.4μm)and their barrier functions were evaluated by detection of transendothelial electrical resistance (TEER),permeability of sodium fluorescent (Na-FLU ),expression of alkaline phospha-tase (AKP)and γ-glutamyl transpeptidase (γ-GT1 ),and simi-larity of permeation amount for positive drugs in vitro and in vivo BBB conditions.Results Primitive culture of BMECs presented typical pebbles-like structure,BMPC presented larger soma with branching property,AS presented slender synapse and shallower cytoplasm.Moreover,immunocytochemical staining results iden-tified primitive cells were targeted cells.TEER value for co-cul-ture of BMECs,BMPC and AS reached (478 ±25 )Ω· cm2 , permeability coefficients (Papp )value of Na-FLU was [(8.23 ± 0.78) ×10 -6 ]cm·s-1 ,expression of AKP and γ-GT1 were (6.90 ±0.27 )King unit · g-1 Pro and (4.39 ±0.32 )μg · g-1 Pro respectively.Moreover,good correlation could be found in Papp for positive controls in vitro and in vivo BBB models (R2=0.92).Conclusion The established in vitro BBB model by using primitive co-culture of BMECs with BMPC and AS posses-ses in vivo BBB properties in cell morphology,structures and barrier functions,and can be used as a powerful tool for studying physiology,pathology of BBB and screening candidate com-pounds.
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Aims To establish a UPLC-MS/MS meth-od for the determination of plasma concentration of scutellarein and its metabolite and to study their phar-macokinetics in rat plasma. Methods The analysis was achieved by BEH C18 column with a mobile phase composed of 0 . 1 % formic acid in acetonitrile and 0 . 1% aqueous formic acid using step gradient elution. A TQD tandem mass spectrometry equipped with electros-pray ionization source was used as detector and opera-ted by multiple reaction monitoring( MRM) positive ion mode. After intravenous injection of scutellarein, the concentrations of scutellarein and its major metabolite glucuronide scutellarin in rat plasma were determined at different time points. The pharmacokinetic parame-ters were calculated by DAS 2. 0 software. Results Good linearity was achieved for scutellarein, the ex-traction recovery was between 80 . 5 % to 90 . 5 %, the precisions and accuracy were good. The result showed the pharmacokinetic profiles of scutellarein and glucu-ronide scutellarin both fit to the two-compartment mod-el. Conclusion The above mentioned method is spe-cific, rapid, sensitive and suitable for the pharmacoki-netic studies of scutellarein and its metabolite.
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Aim To study the pharmacokinetic char-acteristics of serial compounds that took the scutellarin and scutellarein as lead compounds by using the model of in vitro liver microsomes, and to screen compounds whose medicinal properties were superior to scutellarin and scutellarein. Methods The content of candidate compounds at different times by incubation system of rat liver microsome was determined using UPLC-MS/MS method. Candidate compounds that contained opti-mum T1/2 and CLint were screened. Enzyme kinetics and conversions of candidate compounds were com-pared with those of scutellarin and scutellarein. Re-sults The T1/2 and CLint were optimum of W11 com-pared with those of scutellarin and scutellarein; the Vmax, Km and CLint of compound W11 were (10.25 ±2.59 ) μmol · min-1 · g-1 , ( 4.64 ±0.24 ) μmol · L-1 and ( 2.29 ±0.23 ) L · min-1 · g-1; the Vmax , Km and CLint of scutellarin were (45.95±9.50) μmol · min-1 · g-1 , ( 10.19 ± 1.66 ) μmol · L-1 and (4.48±0.20) L·min-1 ·g-1; W11 might be me-tabolized into scutellarin and M1 ( a compound with mo-lecular weight of 577 after demethylating ) . Conclu-sion The pharmacokinetic properties of candidate compound W11 are better than those of scutellarin, and it could release scutellarin.
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Aim To establish a highly purified,active and prac-tical extract and primitive culture method for rat brain microvas-cular endothelial cells ( BMECs) for providing materials for con-struction in vitro blood-brain barrier ( BBB) model. Methods Cerebral cortex of 1-2 week SD rats was collected,and successive digestion with typeⅡcollagenase and collagenase/dispase, sieve filtration and then twice gradient centrifugation in 20% BSA and 44% Percoll condition were used to obtain brain microvascular section. After that brain microvascular section was seeded in cul-ture bottle and then primarily cultured. Inverted microscope and factor-VIII relative antigen immunostaining methods were used for cellular morphological observation and identification. Results BMECs climbed out the vessel segment and proliferated with ad-herence after 2 h in vitro culture,and they became typical peb-bles structure after further 3-4 d culture. Morever, factor-VIII relative antigen immunostaining identified that expression for the endothelial cells was positive,cytoplasm was brown and positive cells account for more than 99%. Conclusion Rat BMECs with high purity could be extracted and cultured by using the above methods,and it has great potential for construction in vitro BBB model and in depth studies on biological characteristics and func-tions of BMECs.
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Aim To establish an ideal hyperlipidemia animal model by a new way.Methods 30 mice were randomly divided into control group, positive control group and model group.The mice of control group were only fed with a standard diet.Those of positive control group were fed with high fat diet.Those of model group were fed with a standard diet and enough milk.After 30 days the TG, TC, HDL-C and LDL-C of serum and hepatic and LI were detected and pathological changes in the liver of mice were observed microscopically.Results Compared with the control group, the mice of model group developed hyperlipidemia with LI and the serum and the hepatic TG, TC, LDL-C elevated significantly, while HDL-C were significantly lower.The histopathological research showed hepatocellular macrovesicular steatosis and hepatitis in the model group.Conclusion An ideal model of hyperlipidemia is successfully established with standard diet and milk fed to mice for 30 days.