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Objective To establish a method for qualitative and quantitative analysis of Zhendian Kaiqiao Granules. Methods Gentiane Radix et Rhizoma, Scuteliariae Radix, Rhei Radix et Rhizoma, Radices Paeoniae Alba in the preparation were identified by TLC. Gentiopicrin and paeoniflorin were determined by HPLC. The analysis was performed on a Phenomenex C18 column (250 mm × 4.6 mm, 5 μm), with the mobile phase of methyl alcohol-water (12:88). The flow rate was 1.0 mL/min and the column temperature was maintained at room temperature; the detection wavelengths were set at 273 nm (gentiopicrin) and 230 nm (paeoniflorin). Results Gentiane Radix et Rhizoma, Scuteliariae Radix, Rhei Radix et Rhizoma, Radices Paeoniae Alba could be detected by TLC. Gentiopicrin showed a good linear relationship at a range of 2.396–11.980 μg, r=0.999 6. The average recovery was 99.72%, and RSD was 2.70%. Paeoniflorin showed a good linear relationship at a range of 2.728–13.640 μg, r=0.999 0. The average recovery was 98.74%, and RSD was 2.42%. Conclusion The established method is simple, reliable and reproductive.The method can be used for control quality of Zhendian Kaiqiao Granules.
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Objective To evaluate differences in genes expression of rat bone marrow stromal cells (rBMSCs) under continuous mechanical strain by gene microarray technology．Methods rBMSCs were isolated and cultured in vitro. Continuous stresses with amplitude of 10% and frequency of 1 Hz were applied on rBMSCs for 6 hours by Flexercell mechanical loading system to investigate rBMSC gene expression profiles, and quantitative PCR was used to verify gene expression changes related to osteoblastic differentiation. Results Compared with the control group, 1 244 differentially expressed genes were found in mechanical loading group, among which 793 genes were up-regulated, while 451 genes were down-regulated．GO (gene ontology) analysis suggested that differentially expressed genes were mainly involved in multicellular organismal development, cell differentiation, chemotaxis, cell adhesion and so on. Four signaling pathways as Notch, Wnt, FGF and IGF might participate in the regulation of stress-induced osteoblastic differentiation. PCR validation results were consistent with the gene chip results. Conclusions Mechanical stress could induce osteoblastic differentiation of the BMSCs, while several differentially expressed genes screened by gene microarray may attribute to this process.
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Objective To study the effect of continuous strain on the proliferation and osteogenic differentiation of rat bone marrow stromal cells(BMSCs) in vitro. Methods Rat BMSCs were obtained from adult female Sprague-Dawley rats (3-month old), and purified by full-blood attachment culture. BMSCs between passage 3—5 were seeded on Flexercell mechanical loading system(10%, 1 Hz), and divided into 1 h group, 6 h group, 12 h group, 24 h group, 48 h group, respectively, according to the time subjected to strain. Effects of continuous strain on the morphology, proliferation and osteogenic differentiation of BMSCs were observed and analyzed. Results (1) Compared with the control group, cells subjected to 10% strain showed the particular orientation. Their alignment elongated mostly in the direction perpendicular to the strain axis in a time-dependent manner. (2)10% continuous strain could significantly decrease the proliferation of BMSCs. (3) Continuous strain could increase mRNA expression of ALP, COLⅠand Runx2 in a time-dependent manner. Compared with the control group, mRNA expression of ALP was increased significantly at 24 h, COLⅠat 24 h and 48 h, and Runx2 at 6 h. mRNA expression of osteocalcin (OC) ascended greatly in the beginning, but went down gradually and was significantly lower than that of control at 48 h（P＜0.05）. (4) Continuous strain could induce an increase in Runx2 protein level. A sharp increase in Runx2 protein was observed at 6 h(P＜0.05) , then Runx2 protein level decreased slowly with its mRNA expression being significantly lower than that of control at 24 h（P＜0.05） Conclusions Continuous strain could induce rat BMSCs to orient in an orderly manner, suppress its proliferation activity, but stimulate the osteoblastic differentiation at the early stage.
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Objective To investigate the effect of intermittent tensile strain on the proliferation and osteogenic differentiation of rBMSCs (rat bone mesenchymal stem cells). Methods Intermittent tensile strain was applied on rBMSCs in vitro by Flexcell 4 000 Tension System (10% elongation amplitude, 0.5 Hz, twice every day, 4 h every time), then effects of the strain after 1, 3, 5, 7 d on cell morphology, cell proliferation, and the relative expression of Cbfα1（core binding factor α1），ALP and collagen I mRNA as well as Cbfα1 protein were measured. Results Intermittent tensile strain slowed the proliferation of rBMSCs from the first day to the seventh day. The relative expression of ALP and collagen I mRNA increased by 3~6 times from the third day（P＜0.05）, meanwhile the expression of Cbfα1 mRNA and protein was up-regulated under the mechanical stimulation. Conclusions Mechanical stretch plays an important role in the proliferation and differentiation of rBMSC, and approprite intermittent tensile strain can slow the proliferation of rBMSC and promot its osteogenic differentiation.
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<p><b>OBJECTIVE</b>To study the inhibitory effect of erythritol by contrast to xylitol on growth and acid production of Streptococcus mutans (S. mutans).</p><p><b>METHODS</b>S. mutans were incubated respectively in 0.5%, 1%, 2%, 4%, 8%, 12%, 16% erythritol or xylitol culture medium under anaerobic conditions. The A and pH value of the mediums were measured at 0, 2, 4, 6, 8, 10, 12, 18, 24 hours, following the profile plots by SPSS.</p><p><b>RESULTS</b>The data of A were higher in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. The data of pH were lower in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while higer in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. It indicated that the growth and acid production of S. mutans were higer in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration.</p><p><b>CONCLUSION</b>Compared with xylitol, erythritol in low concentration has weaker effort on the growth and acid production of S. mutans, while having stronger effort in high concentration.</p>