Comparison of the inhibitory activities of salvianolic acid B and Ginkgo biloba extract EGb 761 on neurotoxicity of beta-amyloid peptide / 药学学报

<p><b>AIM</b>To compare the effects of salvianolic acid B (Sal B) and Ginkgo biloba extract EGb 761 on beta-amyloid peptide (beta-AP) fibril formation and cytotoxicity to PC12 cells.</p><p><b>METHODS</b>The inhibitory effects of Sal B and EGb 761 on beta-AP1-40 fibril formation were determined by using fluorescence analysis with Thioflavin T (ThT) and electron microscopic image. beta-AP25-35 was aged by incubating at 37 degrees C for 7 d, then the protein was incubated with PC12 cells. The protective effects of Sal B and EGb 761 against cytotoxicity induced by aged beta-AP25-35 in PC12 cells were evaluated by MTT reduction assay and flow cytometric analysis. beta-AP25-35-induced accumulation of intracellular reactive oxygen species (ROS) was determined by fluorescence analysis.</p><p><b>RESULTS</b>Both Sal B and EGb 761 inhibited the formation of amyloid fibrils, protected PC12 cells from beta-AP25-35-induced cytotoxicity, and decreased ROS accumulation caused by beta-AP25-35. The effective doses of Sal B were far lower than those of EGb 761.</p><p><b>CONCLUSION</b>Sal B was much more efficient than EGb 761 in inhibiting beta-AP aggregation and in protecting PC12 cells from beta-AP-induced cytotoxicity.</p>

Clinical study on integrative Chinese and Western medicine in treating allergic purpura and preventing renal impairment / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the clinical effect in treatment of the recurrent allergic (Henoch-Schönlein) purpura and prevention of renal impairment by means of integrative Chinese and Western medicine (ICWM).</p><p><b>METHODS</b>One hundred and seventy-six children with allergic purpura were randomly divided into the treated group (Based on the Western routine therapy of the control group, Kangmin Xiaoban Yin, a kind of TCM decoction, was added for 7-10 days) and the control group. Levels of urinary beta2-microglobulin (beta2-MG) and serum IgA, IgE were measured before and after treatment. And clinical observation on the disappearance time (DT) of abdominal pain, arthralgia and purpura were implemented.</p><p><b>RESULTS</b>The DT of joint swelling, arthralgia, and purpura in the treated group was shorter than those in the control group, showing significant difference (P<0.01). Comparison between groups in urinary beta2-MG and serum IgA and IgE before treatment and 1 week after treatment were insignificantly different (P>0.05), but at 1 month and 6 months after treatment, the level of urinary beta2-MG in the treated group was lower than that in the control group, with significant difference (P<0.05), and levels of serum IgA and IgE at 1 month after treatment in the former were lower than those in the control group, also showing significant difference (P<0.05, P<0.01). Six-month recurreat rate in the treated group was 23.5%, while that in the control group. There was significant difference in comparison in 1/2-year recurrent rate (P<0.01).</p><p><b>CONCLUSION</b>ICWM in treating allergic purpura could reduce the repeated episodes and shorten the hospitalization time, and effectively prevent the renal impairment of the disease.</p>

Stereoselectivity in O-demethylation of trans tramadol in rat liver microsomes in vitro / 药学学报

<p><b>AIM</b>To study the stereoselectivity in O-demethylation of trans tramadol.</p><p><b>METHODS</b>With or without quinine and quinidine as inhibitors, rat liver microsomes were incubated in vitro with the enantiomers or the racemate of trans tramadol. The concentrations of the enantiomers of trans tramadol and O-demethyltramadol in the incubates were determined by high performance capillary electrophoresis. The O-demethylation processes were assayed by using the enzyme kinetic analysis method.</p><p><b>RESULTS</b>After incubation, the concentrations of (-)-O-demethyltramadol were higher than those of (+)-enantiomer in all rat liver microsomal incubates. Enzyme kinetic analysis showed that the Km of the formation of the enantiomers of O-demethyltramadol were similar; The Vmax and Clint of the formation of (-)-O-demethyltramadol were significantly higher than those of the formation of (+)-enantiomer. When the racemate of trans tramadol was used as the substrate, there was interaction between the two enantiomers. The Km of the formation of the enantiomers of O-demethyltramadol increased, the Vmax of the formation of (+)-O-demethyltramadol decreased, the Vmax of the formation of (-)-O-demethyltramadol increased slightly. The O-demethylation of the enantiomers of trans tramadol was shown to be inhibited competitively by quinine and quinidine. The Ki of quinine and quinidine were 1.6 and 10.8 mumol.L-1 to the formation of (-)-O-demethyltramadol, 0.8 and 3.4 mumol.L-1 to the formation of (+)-O-demethyltramadol, respectively. Furthermore, quinine and quinidine were found to have stereoselective inhibition on the formation of O-demethyltramadol, both mainly inhibited the formation of (+)-O-demethyltramadol.</p><p><b>CONCLUSION</b>The O-demethylation of trans tramadol was found to be stereoselective in rat liver microsomes in vitro, preferentially metabolized (-)-enantiomer. The stereoselectivity could be influenced by the interaction between the two enantiomers and the enzyme selective inhibitors.</p>