Comparison of pharmacokinetics and tissue distribution of diosbulbin B in rats after intragastric administration of compound diosbuIbin B and ethanol extract from Dioscorea bulbifera L / 中国药理学与毒理学杂志

OBJECTIVE To characterize pharmacokinetics and tissue distribution of diosbulbin B (DIOB)in rats,and compare exposure and elimination of DIOB in plasma and tissues after ig adminis-tration of compound DIOB and ethanol extract of Dioscorea bulbifera L.(EEDB),respectively.METHODS Liquid chromatography coupled with tandem mass spectrometry method was developed and validated for quantitative determination of DIOB in plasma and tissue samples. The sensitivity, matrix effect, accuracy and precision of the method were determined. After a single ig administration of DIOB 1.3 mg·kg-1and EEDB 1.0 g·kg-1, respectively, plasma and tissues samples were collected separately from male SD rats at prescheduled time points.The drug-protein binding of DIOB in plasma and tissues was measured using Rapid Equilibrium Dialysis Assay. The concentration-time profiles of DIOB were analyzed using WinNonLin 6.4 to obtain pharmacokinetic parameters. RESULTS Rapid absorption and elimination of DIOB were observed in rats.The plasma maximum concentration(cmax),peak time(tmax) and eliminate half life(t1/2)of DIOB in rats receiving DIOB or EEDB were 312±67 and(131±84)μg·L-1(P<0.01), 0.12 ± 0.07 and (0.23 ± 0.17) h, and 1.17 ± 0.28 and (2.34 ± 0.83) h (P<0.05). DIOB was rapidly distributed in most tissues,with the AUC(0-24 h)of DIOB in lungs,liver and kidneys for DIOB and EEDB groups were 4527.0±557.7,183.0±51.1 and(64.4±22.4)ng·h·g-1,and 6507.9±424.3(P<0.01),467.5±202.7(P<0.05) and (238.6 ± 70.0) ng·h·g-1(P<0.05), respectively. The protein binding rate of DIOB was 38.7%-43.6%,61.3%-66.9% and 61.4%-64.7% in plasma,livers and lungs,respectively.The ratio of free concen-trations between tissue and plasma for lungs was more than 48,indicating the specific distribution of DIOB in lungs.CONCLUSION There is difference in pharmacokinetics and tissue distribution of DIOB in rats after taking compound DIOB and EEDB.Among the tissues detected,lungs are the major target of DIOB with the highest exposure level.These characterizations should be considered in pharmacological and toxicological studies of DIOB and relevant herbs.

Identification of human cytochrome P450 and UGT enzymes involved in the metabolism of ferulic acid, a major bioactive component in traditional Chinese medicines / 中国天然药物

Ferulic acid (FA) is an active component of herbal medicines. One of the best documented activities of FA is its antioxidant property. Moreover, FA exerts antiallergic, anti-inflammatory, and hepatoprotective effects. However, the metabolic pathways of FA in humans remain unclear. To identify whether human CYP or UGT enzymes are involved in the metabolism of FA, reaction phenotyping of FA was conducted using major CYP-selective chemical inhibitors together with individual CYP and UGT Supersomes. The CYP- and/or UGT-mediated metabolism kinetics were examined simultaneously or individually. Relative activity factor and total normalized rate approaches were used to assess the relative contributions of each major human CYPs towards the FA metabolism. Incubations of FA with human liver microsomes (HLM) displayed NADPH- and UDPGA-dependent metabolism with multiple CYP and UGT isoforms involved. CYPs and UGTs contributed equally to the metabolism of FA in HLM. Although CYP1A2 and CYP3A4 appeared to be the major contributors in the CYP-mediated clearance, their contributions to the overall clearance are still minor (< 25%). As a constitute of many food and herbs, FA poses low drug-drug interaction risk when co-administrated with other herbs or conventional medicines because multiple phase I and phase II enzymes are involved in its metabolism.

A new cytotoxic isocoumarin from endophytic fungus Aspergillus versicolor / 中国中药杂志

A new isocoumarin, along with five known ones,were isolated from the fermentation products of an endophytic fungus Aspergillus versicolorby using various chromatographic techniques.Their structures were elucidated on the basis of extensivespectroscopic analysis, including 1D-and 2D-NMR techniques. Compound 1 was evaluated for cytotoxicity against five human tumor cell lines. The results showed that 1 exhibited weak cytotoxicityagainst NB4, SHSY5Y and MCF7 cells with IC₅₀ values of 6.8, 4.3,8.8 μmol•L⁻¹, respectively.

The application of western blot in treponema pallidum antibody screening among blood donors / 预防医学

Objective To evaluate the application of western blot in treponema pallidum antibody screening among blood donors.Methods Through standard blood liquidation of syphilis,the sensitivity and specificity of two kinds of TP -ELISA regents and one TPPA regent were evaluated.TP -WB was used to test 279 positive specimens with TP -ELISA,and the correlation between test results of the two methods and the distribution characteristics of WB bands were analyzed. Results The sensitivity of the two kinds of TP -ELISA reagent was 1 00.00%,while the specificity were 92.86% and 85.71 % respectively.At the same,the sensitivity of TPPA reagent was 88.46%,while the specificity was 1 00.00%.In 279 positive specimens with TP -ELISA method,WB confirmed positive was 21 6,positive rate was 77.42%;Including S /Co value >5 and two kinds of ELISA reagent testing both positive specimens were 205,the WB confirmation test positive rate was 1 00.00%,accounted for 99.91 % in 21 6 WB positive samples.Orderly Logistic regression analysis,the method of ELISA S /Co value >5 and double reagent is positive,had statistical correlation with test positive for WB,respectively(P <0.01 );21 6 TP -WB positive specimens WB banding distribution analysis,TP1 7 belt with syphilis antibody IgM,TP1 5 belts and IgG +IgMand IgG exist statistical correlation respectively(P <0.01 ).Conclusion ELISA method of double reagent positive and S /Co value >5 specimens of the basic can be diagnosed with syphilis,WB test with positive results for blood donation member state judgment has guiding significance.

The evaluation of efflux transporter model based on RNA interference technology in vitro / 药学学报

In the present study, the specifically knockdown models of P-gp or MRP2 were constructed by using a series of chemically synthesized small interfering RNA (siRNA) in vitro. The expression of P-gp and MRP2 was measured by real-time PCR and Western blot, and the function was evaluated by applying P-gp and MRP2 substrate, rhodamine and methotrexate. The results showed that MRP2 siRNA-3 or P-gp siRNA-2 significantly decreased the mRNA expression of MRP2 or P-gp, the inhibition ratio was 68% or 84%; MRP2 siRNA-3 or P-gp siRNA-2 at a dose of 80 nmol x L(-1) significantly reduced the protein expression of MRP2 or P-gp at 48 h after treatment, the inhibition ratio was 62% or 70%. Meanwhile, other transporters were not influenced by siRNA. When pretreatment with MRP2 siRNA-3 or P-gp siRNA-2, the efflux of methotrexate or rhodamine decreased significantly and the intra-cellular concentration increased. The results suggested that chemically synthesized siRNA could significantly inhibit the expression and function of MRP2 and P-gp, and the model of RNAi in vitro could be used to evaluate the role of efflux transporters in transportation of drugs.

Analyzing the Chinese medicine pathogenesis of stroke / 中国中西医结合杂志

Both ischemic and hemorrhage stroke pertain to the category of wind stroke in Chinese medicine (CM). Up to date, it is deemed that the etiology and pathogenesis of wind stroke are wind, fire, sputum, qi, stasis, and deficiency. Among them, it is regarded that wind and fire are the key factors triggering wind stroke. By analyzing the time order and causality, it is found that wind stroke is prior to the onset of wind and fire, wind and fire are the secondary outcomes of wind stroke. By parallel comparing stroke with thromboembolism and hemorrhagic diseases in other Zang-organs, it can be comprehended that the reason why wind symptoms appear in stroke is due to its physiological feature of brain itself. Based on Neijing, the pathogenesis of wind stroke is proposed as follows. Tunnels of viscera (vessels) get lesions. The old pathogenic factors of sputum and stasis or the stasis formed by bleeding inside viscera consume qi, and blood of viscera and damage the spirits hidden in them. The damage of Gan-spirit causes symptoms of stroke, such as hemiplegia, deviation of eyes and mouth, and so on. Wind and fire symptoms are caused by the injury of Gan blood and yin, and/or the stagnation of fire in pericardium (the pathway organ) due to obstruction by old pathogenic factors and stasis (formed by bleeding).

A method for culturing neonatal mice cardiomyocytes in vitro and its applications in toxicity evaluation / 军事医学科学院院刊

Objective To establish a method for culturing neonatal mice cardiomyocytes, and construct an in vitro model of cardiomyocytes for assessing the cardiac toxicity of chemicals. Methods Hearts of neonatal mice of 1 day old were digested with enzyme mixture of trypsin/collagenase type Ⅱ/dispase and the cell suspensions were pre-plated to flask for a short time and then seeded on coated dishes. The cultured cells were treated with 5-fiuorine-deoxy-uridine(15 μg/ml)and uridine(35 μg/ml)to enrich cardiomyocytes that were identified according to the morphology and immunocytochemistry of α-actin antigen. Cardiac myocytes were incubated with 0-64 μg/ml of a fusarium mycotoxin butenolide(BUT) for 12 h. Cell viability was then evaluated by MTT assay. Microscopic observation showed that BUT induced significant morphological changes including cellular swelling, vacuolation and breakage of muscle fibers. Results It was found that 96% of the cultured cells were cardiomyocytes and the myocytes kept beating after 90 days of culture. Concentration-dependent decreases in cell viability following exposure of cardiac myocytes to BUT were observed. Conclusion The results indicated that relatively pure primary culture of neonatal mice cardiomyocytes is successfully established. BUT possesses the potential to induce myocardial toxicity.

Inclusion of coenzyme Q10 with beta-cyclodextrin studied by polarography / 药学学报

<p><b>AIM</b>To investigate the inclusion of coenzyme Q10 with beta-cyclodextrin (beta-CD).</p><p><b>METHODS</b>The inclusion of the electroactive guest molecule coenzyme Q10 with the host molecule beta-CD was studied by the polarography. The change of the reduction peak current of the inclusion complex with time and the change of the peak potential of the inclusion complex with beta-CD concentration were examined. In order to study the photostability, the change of the reduction peak current of both coenzyme Q10 and coenzyme Q10-beta-CD inclusion complex with time were also examined under light, separately.</p><p><b>RESULTS</b>In 0.1 mol x L(-1) HAc/NaAc (pH 4.7) buffer-ethanol/water (60:40) medium, coenzyme Q10 was included with p-CD to form an 1:1 inclusion complex. The formation constant Kf was 1.26 x 10(4) L x mol(-1) the apparent formation rate constant was 6.64 x 10(-2) min(-1). The photodegradation apparent rate constant of coenzyme Q10 as 7.77 x 10(-3) min(-1) and that of the coenzyme Q10-beta-CD inclusion complex was 3.38 x 10(-3) min(-1).</p><p><b>CONCLUSION</b>The inclusion of coenzyme Q10 with beta-CD took place. The stability of coenzyme Q10 to lights was improved in a certain degree due to the formation of the inclusion complex.</p>