Objective:To establish an HPLC method for the content determination of viterxin in Stenoloma chusana( L. ) Citing. Methods:A Waters Symmetry C18 (250 mm × 4. 6 mm, 5 μm) column was used, and the mobile phase was acetonitrile-0. 1% glacial acetic acid solution (27∶73) at the flow rate of 1. 0 ml·min-1 . The detection wavelength was at 339nm, and the column temperature was 30℃. Results:The linear relationship of viterxin was good within the range from 10. 03 to 90. 27μg·ml-1 . The average recovery was 100. 48%(RSD=0. 98%). Conclusion:The established method is accurate and sensitive with good reproducibility, which can be applied in the determination of viterxin of Stenoloma chusana( L. ) Citing.

BACKGROUND:Stem cell therapy has broad prospects in improving cardiac remodeling after myocardial infarction;however,alteration in the myocardial microenvironment affects the therapeutic efficacy of stem cells.Exercise preconditioning is similar to ischemic preconditioning and can have a protective effect on the myocardium.However,little attention has been paid to the effects and mechanisms of the combined effects of exercise preconditioning and stem cell transplantation. OBJECTIVE:To observe the effect of exercise preconditioning on bone marrow mesenchymal stem cell transplantation in rats with myocardial infarction and to explore the mechanism of local inflammatory microenvironment. METHODS:Eighty female SD rats were randomly divided into sham operation group,model group,transplantation group,and combination group,with 20 rats in each group.The rat model of myocardial infarction was made by ligating the left anterior descending branch of coronary artery.The sham operation group was only threaded without ligature.The transplantation and combination groups were injected with bone marrow mesenchymal stem cells of male rats into the myocardium after modeling.In addition,the combination group also required 8 weeks of treadmill exercise(i.e.,exercise preconditioning)before modeling.Four weeks after stem cell transplantation,exercise performance was measured by incremental exercise exhaustion test;cardiac structure and function were measured by echocardiography;left ventricular hemodynamics was measured by pressure-volume catheterization,and myocardial histopathology was observed by in situ staining and myocardial collagen volume fraction was obtained.Quantitative reverse transcription polymerase chain reaction was used to detect left ventricular pro-inflammatory factor(interleukin-1β,interleukin-6,tumor necrosis factor-α),anti-inflammatory factor(interleukin-10),sex-determining region of Y chromosome,and fetal genes(atrial natriuretic peptide,brain natriuretic peptide,β-myosin heavy chain)mRNA expression level at 1,7 days and 4 weeks after stem cell transplantation. RESULTS AND CONCLUSION:(1)Four weeks after stem cell transplantation:compared with sham operation group,exercise performance,and left ventricular ejection fraction were reduced(P<0.05);myocardial infarction area,cardiomyocyte cross-sectional area,and collagen volume fraction were increased(P<0.05);the mRNA expression of fetal genes and pro-inflammatory factors were up-regulated(P<0.05),and the mRNA expression of interleukin-10 was down-regulated(P<0.05)in the model group.Compared with the model group,exercise performance and left ventricular ejection fraction were increased(P<0.05);myocardial infarction area,cardiomyocyte cross-sectional area,and collagen volume fraction were decreased(P<0.05);mRNA expression of fetal genes and pro-inflammatory factors was down-regulated(P<0.05),and that of interleukin-10 had no significant change(P>0.05)in the transplantation group.Compared with the transplantation group,all the above indicators in the combination group were further improved(P<0.05).(2)One day and 7 days after stem cell transplantation,compared with the transplantation group,the mRNA expression of sex-determining region of Y chromosome in the combination group increased(P<0.05).(3)Correlation analysis showed that interleukin-1β,interleukin-6(except on the 1st day after transplantation),and tumor necrosis factor-α were negatively correlated with the mRNA expression of sex-determining region of Y chromosome(P<0.05),while interleukin-10 was positively correlated with that of sex-determining region of Y chromosome(P<0.05).These findings suggest that exercise preconditioning can enhance the effect of bone marrow mesenchymal stem cell transplantation in rats with myocardial infarction,which is characterized by suppression of cardiac remodeling and further amelioration of cardiac function.The mechanism is related to the improvement of the myocardial inflammatory microenvironment to promote bone marrow mesenchymal stem cell retention and survival.

ObjectiveTo compare the effects of Taxillus chinensis from different hosts with different meridian affinity on bone microstructure and bone metabolism in ovariectomized osteoporotic rats， and investigate its mechanism of action. MethodEighty-eight specific-pathogen-free （SPF）-grade female Sprague-Dawley （SD） rats were selected and randomly divided into 11 groups： sham-operated group， model group， low-， medium- and high-dose groups of T. chinensis from Morus alba （2.5， 5， and 10 g·kg^-1）， low-， medium- and high-dose groups of T. chinensis from Cinnamomum cassia （2.5， 5， and 10 g·kg^-1）， and low-， medium- and high-dose groups of T. chinensis from C. burmannii （2.5， 5， and 10 g·kg^-1）. After 12 weeks of drug intervention， the rats were examined for proximal femur bone density and bone microstructure using dual-energy X-ray absorptiometry （DXA） and micro-computed tomography （Micro-CT）. Histopathological changes in rat femur were observed by the hematoxylin-eosin staining （HE）. Contents of serum estradiol （E₂）， bone Gla protein （BGP）， bone alkaline phosphatase （BALP）， tartrate-resistant acid phosphatase 5b （TRACP-5b） and pre-collagen type Ⅰ amino-terminal protopeptide （PINP） were measured by the enzyme-linked immunosorbent assay （ELISA）. Real-time quantitative polymerase chain reaction （Real-time PCR） was employed to detect the messenger ribonucleic acid （mRNA） expressions of bone morphogenetic protein-2 （BMP-2）， Smad1， Smad9 and recombinant runt-related transcription factor 2 （Runx2） in rat humerus. Western blot was used to detect the protein expressions of BMP-2， p-Smad1/5/9 and Runx2 in rat humerus. ResultCompared with that in the sham-operated group， the femur microstructure of rats in the model group was significantly disrupted， with significant decreases in bone mineral density （BMD） value， bone volume fraction （BV/TV）， trabecular number （Tb.N）， and trabecular thickness （Tb.Th） （P<0.01）， and significant increases in trabecular separation （Tb.Sp） and structure model index （SMI） （P<0.01）. The serum levels of BGP， BALP， TRACP-5b and PINP were significantly increased （P<0.05， P<0.01）， and E₂ levels were significantly decreased （P<0.01）. The mRNA expressions of BMP-2， Smad1， Smad9， and Runx2 were significantly decreased in rat humerus （P<0.01）， and the protein expressions of BMP-2， p-Smad1/5/9， and Runx2 were significantly reduced （P<0.01）. Compared with the model group， the administration groups of T. chinensis from different hosts all elevated the BMD， BV/TV， Tb.N， Tb.Th， Tb.Sp， and SMI levels in the femur， improved bone microstructure， increased serum E₂ levels （P<0.05， P<0.01）， lowered the levels of serum BGP， BALP， TRACP-5b， and PINP， upregulated the mRNA expression of BMP-2， Smad1， and Runx2 and upregulated the mRNA expression levels of Smad9 （P<0.05， P<0.01）， and upregulated the protein expressions levels of BMP-2， p-Smad1/5/9， and Runx2 （P<0.01）. The best effect was observed in the group of T. chinensis from C. cassia. ConclusionT. chinensis from different hosts improved osteoporosis in ovariectomized rats， with the group of T. chinensis from C. cassia being the most potent among the administered groups， and its treatment of osteoporosis may regulate the balance of bone conversion by regulating BMP/Smad signaling pathway.