AIM: To study the pharmacokinetics of phenolic acids from Mailuoning injection in rats. METHODS: SD rats were given a single i.v. administration dose of Mailuoning injection 10 mL/kg, plasma and urine were collected before and after injection. Phenolic acid components in plasma and urine were measured by LC/MS. Pharmacokinetic parameters were determined from the plasma concentration-time data and urinary excretion-time data with the DAS software package. RESULTS: After i.v. of Mailuoning injection, chlorogenic acid (CGA), 1, 5-dicaffeylquinic acid (1,5-DCQA), 3, 4-dicaffeylquinic acid (3,4-DCQA), 3, 5-dicaffeylquinic acid (3,5-DCQA) and caffeic acid (CA) were quickly excrectioned. The t1/2 of CGA, 1,5-DCQA, 3,4-DCQA, 3,5-DCQA and CA were 0.649, 0.334, 0.479, 0.486 and 0.330 h, respectively. AUC0-∞ were (22.522±2.716), (0.353±0.062), (3.620±1.246), (5.287±1.627) and (2.257±0.360) mg·L-1·h, respectively. After i.v. of Mailuoning injection, CGA, 1,5-DCQA, 3,4-DCQA, 3,5-DCQA and CA can all be detected in the urine. The amounts of CGA, 1,5-DCQA, 3,4-DCQA, 3,5-DCQA and CA excreted from urine during 0-24 h were (122.22±26.49)%, (3.30±1.26)%, (0.24±0.11)%, (1.93±0.77)% and (18.61±4.99)% of dose given in rats, respectively. CONCLUSION: After i.v. of Mailuoning injection, phenolic acids can be excreted quickly. Only a small quantity of 1,5-DCQA, 3,4-DCQA, 3,5-DCQA and CA were excreted from urine. 3,4-DCQA and 3,5-DCQA may be metabolized into CGA in the rat plasma.

AIM: To evaluate the protective effect of luteolin on endothelial dysfunction induced by tert-butyl hydro-peroxide (t-BOOH). METHODS: We observed the effect of luteolin on t-BOOH-induced contractions in the aorta rings with or without endot helium, which were incubated with luteolin (10-6 to 10-4 mol/L) for 30 min before determining the concentration-response to t- BOOH. Cultured endothelial cell line (ECV304) was pretreated with different concentrations of luteolin (10-6 to 10-4 mol/L) for 30 min and then exposed to 10 -5 mol/L t-BOOH for 24 hours. Cell morphology was observed , and cell viability was determined by MTT assay. Meanwhile, RT-PCR was used to measure the expression of eNOS and COX-1. RESULTS: Increasing concentrations of t-BOOH produced concentration-dependent cont ractions in aorta rings isolated from rats, luteolin effectively attenuated the contraction in a concentration-dependent manner, and the relaxation response was greater in intact endothelium segments. In MTT and RT-PCR assays, luteolin effectively reduced the cytotoxicity of t-BOOH to endothelium cell and increased the expression of nitric oxide synthase (eNOS) mRNA, which was greatly down-regulated by t-BOOH. CONCLUSION: Luteolin effectively protects the endothelium from the impairment of oxidative stress, and the protection could be related to its negative modulation towards t-BOOH-induced contractions in the aorta.

AIM: To evaluate the cytotoxicity of a novel anticholinergic drug penehyclidine hydrochloride (PHC) and its four optical isomers R-1, R-2, S-1, and S-2. METHODS: Two in vitro assays, MTT assay and neutral red uptake assay, were used to evaluate the cytotoxicity following PHC and its isomers exposure to HepG2 cells at different concentrations. RESULTS: PHC and its isomers induced decreases of viability of HepG2 cells in a concentration-dependent manner. Comparison of the cytotoxicity of the five anticholinergic agents with 50% inhibitory concentration (IC50) values indicated that the order of potency was PHC>R-2>R-1>S-2>S-1 for MTT assay, and R-2>PHC≈R-1>S-2>S-1 for neutral red uptake assay. CONCLUSION: With respect to the cytotoxicity of the four isomers on HepG2 cells, the R configuration was more potent than the S configuration, and R-2 was the most potent isomer whereas S-1 was the least potent isomer among the four optical isomers.

AIM: To evaluate the cardiac contractility and relaxation by Doppler tissue imaging (DTI) combined with myocardial contrast echocardiography (MCE) via injection of contrast media, Albunex. METHODS： Nineteen healthy mongrel dogs were conducted 60 min ligation of left anterior descending coronary artery (LAD), followed by reperfusion of 60, 120 and 180 min to establish an acute myocardial ischemic-reperfused canine model. (1) MCE was performed by bolus injection of Albunex at pre-reperfusion and at post-reperfusion. The perfused defect area defined by MCE at pre-reperfusion was regarded as risk area (RAMCE), while perfused defect area at post-reperfusion was regarded as no-reflow area (NRAMCE). When the ratio of NRAMCE to RAMCE exceeded 25%, myocardial reperfusion was considered incomplete, I.e., no-reflow group; If the ratio was <25%, myocardial reperfusion was considered adequate, I.e., reflow group. (2) Left ventricular ejection fraction (LVEF) and wall thickness ratio (△T%) of LV anterior wall were determined. (3)S-wave, e-wave and a-wave velocities at the LV anterior wall were determined by DTI. The e/a ratio was measured. RESULTS: The results of MCE showed 7 dogs in reflow group and 10 dogs in no-reflow group. (1) LVEF in reflow group gradually increased with time course after myocardial reperfusion, and in no-reflow group, however, LVEF increasingly declined with ongoing myocardial reperfusion. At the same reperfusion time point, LVEF of no-reflow group was significantly lower than that of reflow group. (2) △T% in reflow group improved gradually, and however, it can not come back to that of baseline at 180-min reperfusion. △T% in no-reflow group had no signal of recovery with progressive reperfusion. (3) S-wave, e-wave velocities measured by DTI significantly declined after ligation of LAD, and a-wave velocity increased, leading to decline of e/a. After myocardial reperfusion, s-wave, e-wave velocities and e/a in reflow group gradually increased at post-reperfusion, and a-wave velocity somewhat declined. In no-reflow group, on the other hand, s-wave, e-wave velocities and e/a progressively declined and a significant difference was present between reflow group and no-reflow group (P<0.05). CONCLUSION: Cardiac contractility and relaxation can not be recovered during myocardial microvascular impairment. This change may be further deteriorated with size enlargement of no-reflow area. DTI may provide a sensitive, reliable method for quantifying cardiac contractility and relaxation.

To establish an HPLC mehod for the analysis of pharmacokinetics of salvianolic acid B in rats. METHODS: The biological samples were extracted with acetic ether. The chromatographic conditions were as follows: Hypersil ODS column (200 mm×4.6 mm, 5μm) was used. The mobile phase was acetonitrile-water(with Ammoniom Acetate 0.25 mol/L) was set at 328 nm. RESULTS: Salvianolic acid B was injected intravenously at doses of 1.6, 3.2, 6.4 mg/kg. The terminal elimination half-life(t1/2) of α phase and β phase was (3.1±0.1) min and (31.5±3.2) min. The extents of excrement,urine and biliary excretion of salvianolic acid B were 1.43%±0.90%, 0.77%±1.01% and 8.82%±4.11%. The tissue concentration of salvianolic acid B was as followed in order: Cheart>Cliver>Clung>Cintestine>Ckidney>Cspleen>Cstomach. The plasma protein binding rate of salvianolic acid B in human plasma and in rat was similar(89.2%±1.8%,92.5%±1.5%). CONCLUSION: The method is accurate, stable and reliable, and can be used for the investigation of salvianolic acid B in pharmacokinetics research. Salvianolic acid B eliminates fast and it shows a high plasma protein binding rate, the mainly excretion way of salvianolic acid B is from biliary.

AIM: To illustrate the effects of drug transporters on the bile efflux of ibuprofen glucuronide(IBG), the difference of bile excretion and plasma concentration of ibuprofen(IB) and its glucuronides was studied in EHBR and normal SD rat(SDR). METHODS: After 20 mg/kg of IB enantiomers administrated intravenously, the bile and blood were collected from the rats and the concentration of IB and their glucuronide were measured by HPLC methods. RESULTS: The bile excretion of IBG was obviously (but no totally) suppressed in EHBR (1.7%±1.0%, 0.6%±0.9% of the dose respectively for S-IBG and R-IBG) compared with that in SDR (18.4%±4.0% and 3.0%±2.4% of the dose respectively for S-IBG and R-IBG), for both kinds of rats, there are more S-IBG excreted than that of R-IBG. As the result of reduction of IBG excreted in bile, the concentration of IBG was higher in blood in EHBRs. CONCLUSION: The results suggest that Mrp2 is the most important transporter for IBG, and other transporter(s) may participate in the process.

BACKGROUND: There is a growing recognition that the adipose tissue is an endocrine organ that secretes signaling molecules such as adiponectin and resistin. The peroxisome proliferator activated receptor γ (PPARγ) is expressed in high levels in the adipose tissue. Thiazolidinediones are selective PPARγ agonists with insulin-sensitizing properties. It has been postulated that thiazolidinediones such as rosiglitazone exert their pharmacodynamic effects in part through modulation of resistin (implicated in insulin resistance) and adiponectin (an insulin-sensitizing molecule) expression subsequent to activation of PPARγ. There are conflicting data, however, on the biological direction in which resistin expression is modulated by PPARγ agonists and whether an increase in adiponectin expression can occur in the face of an upregulation of resistin. METHODS: Using the murine 3T3-L1 adipocytes as a model, we evaluated the changes in resistin and adiponectin gene expression after vehicle, rosiglitazone (10 μmol/L, a PPARγ agonist), GW9662 (5 μmol/L, a selective PPARγ antagonist) or GW662 and rosiglitazone co-treatment.RESULTS: In comparison to vehicle treatment, rosiglitazone increased the average adiponectin and resistin mRNA expression by 1.66- and 1.55-fold, respectively (P＜0.05). Importantly, GW9662 also upregulated adiponectin expression (by 1.57-fold, P＜0.05) but did not influence resistin expression (P＞0.05). Co-treatment with rosiglitazone and GW9662 maintained the adiponectin upregulation (1.87-fold increase from vehicle, P＜0.05) while attenuating resistin upregulation (1.31-fold increase from vehicle, P＜0.05) induced by rosiglitazone alone (1.55-fold increase from vehicle, P＜0.05). CONCLUSION: This study presents new evidence that adiponectin transcript is upregulated with both a PPARγ agonist (rosiglitazone) and antagonist (GW9662), while GW9662 co-treatment does not block rosiglitazone-induced adiponectin upregulation. These data collectively suggest that biological mechanisms independent from PPARγ may underlie thiazolidinedione pharmacodynamics on adiponectin expression. Moreover, increased adiponectin expression by GW9662, in the absence of an upregulation of resistin expression, lends further support on the emerging clinical potential of PPARγ antagonists in treatment of insulin resistance. Decreased resistin expression may not be crucial for the insulin-sensitizing effect of rosiglitazone. These findings may serve as a foundation for future dose-ranging and time-course studies of thiazolidinedione pharmacodynamics on adipocytokine expression in human adipocytes.

AIM: To determine the interactions with response-surface modeling methodologies when sevoflurane (Sevo) and remifentanil (Remi) were administered simultaneously. METHODS: (1) Patients, Study design and drug delivery: Based on parallel slices design, sixty-five patients were randomly assigned to inhale a specific end-tidal concentration of sevoflurane (0.3% to 3.4%), with different level of remifentanil (0-10 ng/mL). The responses to laryngoscopy were observed for each given concentration pair. (2) Pharmacokinetic/pharmacodynamic analysis with response surface mode: The probability of no response (P) was assessed in the modeling process as below. P=(Us+Ur)r/[U50/I(Q)]r+(Us+Ur)r RESULTS AND DISCUSSION: NONMEM estimated average values (RSE%) of the model parameters for laryngoscopy of C50,Sevo, C50,remi, U50, r, Imax and Qmax are 1.71% (12.9), 12.4 ng/mL (19.0), 6.62 (10.6), 1.53 (8.76), 2.31 (8.23), 0.706 (2.46), respectively. The inter-individual variability (CV%) in parameter Imax and inter-occasion variability (S.D.) in this model are 12.7 and 0.0316, respectively. It is concluded that the response-surface modeling approach provided a novel method to study drug-drug interactions.

To evaluate the effect of components in Guanxin Ⅱ prescription on the pharmacokinetic profiles of paeoniflorin and ferulic acid. METHODS: Drug concentrations of rat plasmas after intravenous injection of paronia pall (PPE) or ferulic acid (FA) extract solution, as well as oral administration of PPE and FA solution, and different kinds of decoctions based on Guanxin Ⅱ prescription were determined by an HPLC system. NONMEM (nonlinear mixed-effect modeling) method was used to analyze the population pharmacokinetics of PF and FA. RESULTS: A two-compartment model with first order degradation in absorption phase, and an ordinary two-compartment model were adequately describe PF and FA pharmacokinetic profiles, respectively. The mean of PF population parameters, CL1, V1, CL2, V2, Ka0, and Ka1, were 0.509 L/h, 0.104 L, 0.113 L/h, 0.123 L, 0.135 /h, and 0.0135 /h, respectively, while the typical values of CL1, V1, CL2, V2, Ka1, and F in FA model were 0.295 L/h, 0.025 L, 0.0331 L/h, 0.0518 L, 0.110 /h, and 0.40, respectively. Inter-individual variabilities were estimated and dose formulation (DF) was identified as a significant covariate in the model. CONCLUSION: The results indicate that the pharmacokinetic behaviors of index components in Guanxin Ⅱ prescription can be influenced by different dose formulations administrated in rats.

BACKGROUND: Metoprolol is a selective β1-Blocker commonly used in essential hypertension. It is metabolized by CYP2D6. CYP2D6*10, which was identified to decrease activity of CYP2D6, is the main variance in Chinese population. β1-adrenergic receptor, with Ser49Gly and Gly389Arg polymorphisms, is the target of metoprolol. It was still unknown that whether the CYP2D6 and β1-adrenergic receptor had a synergic effect on metoprolol antihypertension therapy. AIM: To clarify the genetic polymorphism associated with metoprolol pharmacokinetics and pharmacodynamics in antihypertension therapy. METHODS: 125 mild-to-med essential hypertension patients were enrolled in this study. Patients were mono-therapied with metoprolol for 12 weeks. Blood pressure was monitored every 4 weeks. PCR-RFLP method was use to identify CYP2D6*10 and β1-adrenergic receptor Ser49Gly and Gly389Arg polymorphisms. Plasma metoprolol concentration was measured by HPLC- fluorescence detection. RESULTS: Trough blood level (C0) of metoprolol was associated with CYP2D6*10 variance in a gene-dose-effect manner, whereas the extent of blood pressure decrease was not significant different in CYP2D6*1*1, *1*10 and CYP2D6*10*10 patients. After 12 weeks metoprolol therapy, Gly49 carriers had stronger decrease in systolic and diastolic blood pressure than that of Ser49 homozygotes. Similarly, subjects homozygous for Arg389 had stronger decrease in blood pressure than that of Gly389 carriers. CONCLUSION: CYP2D6*10 variance significantly change the pharmacokinetics of metoprolol, and the genetic polymorphisms of β1-adrenergic receptor were associated with the pharmacodynamics of metopolol in antihypertension therapy.