Study on metabolic dynamics,metabolic enzyme phenotype and species difference of hepatic and intestinal microsome of psoralidin / 中国中药杂志

This study aims to investigate metabolic activities of psoralidin in human liver microsomes( HLM) and intestinal microsomes( HIM),and to identify cytochrome P450 enzymes( CYPs) and UDP-glucuronosyl transferases( UGTs) involved in psoralidin metabolism as well as species differences in the in vitro metabolism of psoralen. First,after incubation serial of psoralidin solutions with nicotinamide adenine dinucleotide phosphate( NADPH) or uridine 5'-diphosphate-glucuronic acid( UDPGA)-supplemented HLM or HIM,two oxidic products( M1 and M2) and two conjugated glucuronides( G1 and G2) were produced in HLM-mediated incubation system,while only M1 and G1 were detected in HIM-supplemented system. The CLintfor M1 in HLM and HIM were 104. 3,and57. 6 μL·min~(-1)·mg~(-1),respectively,while those for G1 were 543. 3,and 75. 9 μL·min~(-1)·mg~(-1),respectively. Furthermore,reaction phenotyping was performed to identify the main contributors to psoralidin metabolism after incubation of psoralidin with NADPH-supplemented twelve CYP isozymes( or UDPGA-supplemented twelve UGT enzymes),respectively. The results showed that CYP1 A1( 39. 5 μL·min~(-1)·mg~(-1)),CYP2 C8( 88. 0 μL·min~(-1)·mg~(-1)),CYP2 C19( 166. 7 μL·min~(-1)·mg~(-1)),and CYP2 D6( 9. 1 μL·min~(-1)·mg~(-1)) were identified as the main CYP isoforms for M1,whereas CYP2 C19( 42. 0 μL·min~(-1)·mg~(-1)) participated more in producing M2. In addition,UGT1 A1( 1 184. 4 μL·min~(-1)·mg~(-1)),UGT1 A7( 922. 8 μL·min~(-1)·mg~(-1)),UGT1 A8( 133. 0 μL·min~(-1)·mg~(-1)),UGT1 A9( 348. 6 μL·min~(-1)·mg~(-1)) and UGT2 B7( 118. 7 μL·min~(-1)·mg~(-1)) played important roles in the generation of G1,while UGT1 A9( 111. 3 μL·min~(-1)·mg~(-1)) was regarded as the key UGT isozyme for G2. Moreover,different concentrations of psoralidin were incubated with monkey liver microsomes( MkLM),rat liver microsomes( RLM),mice liver microsomes( MLM),dog liver microsomes( DLM) and mini-pig liver microsomes( MpLM),respectively. The obtained CLintwere used to evaluate the species differences.Phase Ⅰ metabolism and glucuronidation of psoralidinby liver microsomes showed significant species differences. In general,psoralidin underwent efficient hepatic and intestinal metabolisms. CYP1 A1,CYP2 C8,CYP2 C19,CYP2 D6 and UGT1 A1,UGT1 A7,UGT1 A8,UGT1 A9,UGT2 B7 were identified as the main contributors responsible for phase Ⅰ metabolism and glucuronidation,respectively. Rat and mini-pig were considered as the appropriate model animals to investigate phase Ⅰ metabolism and glucuronidation,respectively.

Pharmacokinetics of scutellarin and its derivant scutellarin ethyl ester in rats / 中国中药杂志

To develop a HPLC method for determination of the concentration of scutellarin and scutellarin ethyl ester and their pharmacokinetics were also compared. 104 mg kg-1of scutellarin or 114. 5 mg kg-1 scutellarin ethyl ester were given at single dose by oral gavarge. Blood samples were collected from the jugular vein. Plasma concentration was measured by HPLC. The pharmacokinetic parameters were calculated with Winnonlin program. The plasma concentration-time profile of scutellarin and scutellarin ethyl ester were both fitted with non-compartment model and both were double peaks. The main pharmacokinetic parameters of scutellarin and scutellarin ethyl ester were as follows: Tmax Cmax and AUC0-t for scutellarin were (6 +/- 1.26) h, (321.55 +/-48.31) microg L-1 and (2 974 +/-753) h micro.g L-1; for scutellarin ethyl ester, Tmax, Cmax and AUC0-t were 0.5 h, (1 550.82 +/-219.75) +/- microg L- and (6 407 +/- 399) h microg L-1. The speed ingested into the blood of scutellarin ethyl ester was faster than scutellarin, and the bioavailability of scutellarin ethyl ester was two times higher than scutellarin.

Pharmacokinetics of genistein in urine of healthy volunteers / 药学学报

In order to study the excretion of genistein (GEN) capsule, an estrogen drugs, in human, 30 healthy volunteers were selected and orally administered 50, 100, and 300 mg genistein in an parallel study. Genistein were determined in urine by LC-MS/MS and glucuronidated genistein (GENG) were indirectly determined with enzymatic hydrolysis in urine by LC-MS/MS, and the pharmacokinetic parameters were analyzed by DAS software (ver 2.0). The result showed that the concentrations of genistein in human urine were less than 1% of the GENG, and the cumulative excretion of GEN in 48 h were 0.037, 0.134, and 0.142 mg, separately, and the urinary excretion percentage were only 0.07%, 0.13%, and 0.05%, separately. But the cumulative excretion of GENG in 48 h was 5.3, 13.8, and 15.4 mg, separately, and the urinary excretion percentage were 10.6%, 13.8%, and 5.1%, separately, and the max urinary excretive rate was 0.4, 1.0, and 1.4 mg x h(-1), separately (tmax were 6 h). Studies showed that part of drug excreted through kidney in a form of GENG in human, and the cumulative urinary excretion and the maximum excretion rate of GENG showed a proportional increase conditioned with the dose in the range of 50-100 mg, but showed non-linear increase feature in 300 mg.

Chemical constituents from Exochorda racemosa / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Exochorda racemosa.</p><p><b>METHOD</b>Compounds were isolated and purified by silica gel, Sephadex LH-20, MCI gel and RP-18 column chromatography, and their structures were determined by spectroscopic analysis.</p><p><b>RESULT</b>Twenty compounds were isolated and identified as N-p-coumaroyl-N'-caffeoylputrescine (1), sutherlandin trans-p-coumarate (2), apigenin 7-O-methylglucuronide (3), astragalin (4), nicotiflorin (5), kaempferol 3-neohesperidoside (6), rutin (7), apigenin (8), luteolin (9), linalool-1-oic acid (10), betulalbuside A (11), ursolic acid (12) , corosolic acid (13), gynuramide II (14), beta-sitosterol (15), daucosterol (16), uridine (17), adenosine (18), syringin (19), and trans4-hydroxycinnamic acid (20), respectively.</p><p><b>CONCLUSION</b>All compounds were obtained from this plant for the first time, moreover, 1 was reported as a new natural product, and 2 is a naturally rare cyanogenic glycoside.</p>

Metabolites of injected chlorogenic acid in rats / 药学学报

Chlorogenic acid (5-CQA) is one of the major components in some Chinese herbal injections. However, the metabolism of 5-CQA in rats after intravenous injection has not been determined. An ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) method was applied to identify the metabolites in bile, urine, feces and plasma after a single intravenous administration of 10 mg x kg(-1) 5-CQA to rats. Using MSE and mass defect filter techniques, a total of 35 metabolites were detected in bile, urine, feces and plasma. The predominant metabolites in bile were glutathione conjugates of O-methyl-5-CQA, accounting for approximately 80% of the metabolites excreted in bile. The major components in urine were parent drug, O-methyl-5-CQA, hydrolyzed metabolites and glucuronide conjugates. The major components in feces were O-methyl-5-CQA and its cysteine conjugates. The major component in plasma was the parent drug. The urinary and fecal excretion pathways were equally important to 5-CQA in rats. These results demonstrate that 5-CQA undergoes extensively metabolism in rats and are highly reactive to nucleophiles such as GSH. This finding indicates that attention should be paid on the injections containing 5-CQA, which may covalently bind to proteins, leading to allergenic drug reactions.

Advances in study of metabolic activation of carboxyl-acid containing drugs by UGTs / 药学学报

The metabolic transformation of the drugs containing carboxylic acid groups can lead to the formation of acyl glucuronide metabolites through catalysis by glucuronosyltransferase, and produce pro-acyl glucuronide intermediate metabolites with electronic activity. Then, protein or DNA adducts appeared after a series of non-enzyme or enzyme reactions. These adducts would change the protein activity and potentially lead to idiosyncratic and genotoxicity. In this paper, we discussed the chemical activity, drug-induced mechanisms, distribution and toxicity resulting from this metabolic activation for these drugs, and stated the status and prospects of research in this field.

Identification and analysis of absorbed components in rat plasma after oral administration of active fraction of Corydalis yanhusuo by LC-MS/MS / 药学学报

To analyze and identify the constituents in rat plasma after oral administration of the active fraction of Corydalis yanhusuo, a LC-MS/MS method was established. The constituents absorbed into blood, their original crude drugs and their metabolites were identified either by comparing the retention time and mass spectrometry data with that of reference compounds or by mass spectrometry analysis and retrieving the reference literatures. Nine species are the original form in Corydalis yanhusuo, moreover, some metabolites in blood identified as glucuronide were found. The constituents absorbed into blood and the possible metabolites which demonstrate to originate from the active fraction of Corydalis yanhusuo are responsible for the observed efficacy. Its serum pharmacochemistry should be subjected to complete investigation so as to illuminate the pharmacology and active mechanism of the active fraction of Corydalis yanhusuo.

Studies on flavonoid glycosides of Sarcandra glabra / 中国中药杂志

<p><b>OBJECTIVE</b>To in vestigate the chemical constituents of Sarcandra glabra and obtain a more comprehensive understanding on its effective components.</p><p><b>METHOD</b>The constituents were isolated by various column chromatographic method and their structures were elucidated by physico-chemical properties and spectroscopic analysis.</p><p><b>RESULT</b>Five flavonoid glycosides were isolated and identified as kaempferol-3-O-beta-D-glucuronide (1), quercetin-3-O-alpha-D-glucuronide (2), quercetin-3-O-beta-D-glucuronopyranoside methyl ester (3), 5, 7, 4'-trihydroxy-8-C-beta-D-glucopyranosyl flavanone (4), neoastilbin (5), 5-O-caffeoylquinic acid methyl ester (6), 3, 4-dihydroxybenzoic acid (7), isofraxidin (8).</p><p><b>CONCLUSION</b>Compounds 1-6 were isolated from the genus Sarcandra for the first time. The glucuroide compounds compounds 1-3, were first isolated from the genus Sarcandra.</p>

Stereoselective glucuronidation of carvedilol by Chinese liver microsomes / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes.</p><p><b>METHODS</b>The metabolites of CARV were identified by a hydrolysis reaction with beta-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatography (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylisothiocyanate.</p><p><b>RESULTS</b>Two CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of K(m) and V(max) for (S)-CARV and (R)-CARV enantiomers were (118+/-44) micromol/L, (2 500+/-833) pmol/(min.mg protein) and (24+/-7) micromol/L, (953+/-399) pmol/(min.mg protein), respectively.</p><p><b>CONCLUSION</b>These results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.</p>

The effect of cotransplantation of nonparenchymal liver cells on the survival of intraperitoneally transplanted hepatocytes / 대한내과학회지

BACKGROUND: Transplantation of primary hepatocytes (PH) has been shown to provide metabolic support during acute liver failure. However, PH are known to be subject to necrosis in the peritoneal cavity. This is because cell-cell interaction plays an important role in their survival, but the peritoneal cavity can not provide such an environment. We tried to improve the survival of PH by simultaneously transplanting nonparenchymal liver cells (NPL). METHODS: PH from normal Wistar rats, either alone (10(9) cells/kg, group 1, n=10) or mixed with NPL (5x10(8) cells/kg, group 2, n=10) were transplanted into the peritoneal cavity of hyperbilirubinemic Gunn rats which are congenitally devoid of bilirubin glucuronidation. Liver cells from Gunn rats were transplanted as a control. RESULTS: Bilirubin glucuronides (BG) were detected in the bile of both group 1 and 2 rats collected at 6 hours after transplantation, and reached peak levels in 4 days. However, in the third and fourth week, BG could be detected only in group 2 animals. The serum bilirubin levels were decreased by 12.1~18.9% of basal levels in the second and third week for group 2 rats, but decreased by 15.1% only in the second week for the group 1 rats. Using in situ hybridization, albumin mRNA positive cells could be detected until the fourth week for the group 2 animals, but only until the second week for the group 1 rats. CONCLUSIONS: PH start functioning in a short time after intraperitoneal transplantation and simultaneous transplantation of NPL with PH can prolong the survival and function of transplanted hepatocytes.

Pharmacokinetic model for the enterohepatic circulation of mycophenolic acid / 药学学报

<p><b>AIM</b>To develop a pharmacokinetic model for the enterohepatic circulation of mycophenolic acid (MPA).</p><p><b>METHODS</b>Twenty healthy volunteers were orally given a single dose of 500 mg mycophenolate mofetil. Plasma samples were collected during 48 hours and MPA concentration was measured by HPLC method. Pharmacokinetic (PK) model was established based on physiological and biopharmaceutical consideration and PK parameters were obtained using nonlinear mixed effect model.</p><p><b>RESULTS</b>The proposed model included an intestinal compartment and gall bladder compartment in addition to the central compartment. The predicted time-concentration curve and AUC0-t, Cmax, Tmax estimated by the established model were in agreement with the observations.</p><p><b>CONCLUSION</b>The established model was well defined for the MPA disposition and could afford a useful approach for the further clinical investigation.</p>

Ester prodrug of scutellarin: synthesis, physicochemical property and degradation / 药学学报

<p><b>AIM</b>To establish the fundamentals for the design of scutellarin prodrug and formulation with feasible physicochemical and biopharmaceutical properties by esterifying scutellarin, an active component with poor absorption extracted from Erigeron breviscapus of Chinese medicine.</p><p><b>METHODS</b>With the method of salifying followed by esterifying, ethyl and benzyl ester of scutellarin were synthesized. Glycolamide ester of scutellarin was also synthesized with an improved method. Their structures were confirmed by MS and 1H NMR. The solubility and partition coefficient of the prodrugs were determined and their degradations were investigated in various buffers and in human plasma. The emulsion and cyclodextrin complex of glycolamide ester were prepared and the protection of the ester from degradation was compared in the intestinal tract contents. Furthermore, the degradation of glycolamide ester in the homogenates of various intestinal segments was studied. Results Three prodrugs were synthesized successfully and their structures were confirmed. Glycolamide ester of scutellarin showed better stability in the aqueous solution (t(1/2) approximately =16 d, pH 4.2) and the shortest half-life in the human serum (t(1/2) approximately =7 min). Compared with scutellarin, the solubility of glycolamide ester was increased about ten times in pH 4.0 buffer, and about thirty five times in water. Partition coefficient of the glycolamide ester increased significantly from -2.56 to 1.48. However, the ester degradation in the homogenates of intestinal mucus would be an obstacle for its absorption. The degradation rates were in the order duodenum > ileum > or = jejunum > colon. The emulsion showed a better protection of glycolamide ester from the degradation than cyclodextrin complex.</p><p><b>CONCLUSION</b>Glycolamide ester of scutellarin shows better physicochemical properties than ethyl and benzyl eater of scutellarin, but its stability in intestinal tract needs to be improved. The emulsion or / and colon-targeted delivery may be selected as one of strategies to decrease the presystemic degradation.</p>

FLAVONES FROM MARCHANTIA CONVOLUTA: ISOLATION OF APIGENIN - 7 - O-Beta-D-GLUCURONIDE AND 5-HYDROXYL-7-METHOXYL-2-METHYLCHROMONE

Dried leaves of Marchantia convoluta are largely used as hepatoprotectives; and to treat tumefaction of skins in China. Two flavones were isolated from the leaves of Marchantia convoluta by silica gel column and preparative high performance liquid chromatography (PHPLC). These compounds were identified through spectral analysis (IR; UV; 1HNMR; 13CNMR; MS) as 5-hydroxyl-7- methoxyl-2- methylchromone and a flavone glycoside; Apigenin-7-O-?-D-glucuronide

Metabolic pathways of dipfluzine in rats / 药学学报

<p><b>AIM</b>To investigate the metabolic pathways of dipfluzine in rats.</p><p><b>METHODS</b>After an oral dose of dipfluzine (80 mg x kg(-1)) to rats, urine was collected for 12 h. The metabolites of dipfluzine in urine were chromatographed and identified by LC/DAD/MS methods.</p><p><b>RESULTS</b>In the rat urine, there were 1-(4-fluorophenyl)-4-piperazinylbutanone and its glucuronide, 4-hydroxybenzophenone and its glucuronide, 4-fluoro-gamma-hydroxybenzenebutanoic acid and its glucuronide and sulfate, diphenylmethanol and its glucuronide, dipfluzine, and benzophenone.</p><p><b>CONCLUSION</b>In rats, dipfluzine was mainly metabolized in the pathways of N-desalkylation at 1- and 4-positions of piperazine ring. Some of metabolites were further conjugated with glucuronic acid and/or sulfuric acid.</p>

Dose-dependent pharmacokinetic study of genistein in Beagle dogs / 药学学报

<p><b>AIM</b>To study the pharmacokinetics of genistein at different doses in Beagle dogs.</p><p><b>METHODS</b>Suspended in 0.5% CMC-Na solution, genistein was orally administered to Beagle dogs at doses of 2.67, 5.34 and 10.68 mg.kg(-1). At various time intervals, 1.5 mL of blood was drawn from the femoral vein of dogs in their front legs. The plasma was treated with beta-glucuronidase. The genistein in plasma was extracted twice by vortexing with 2.0 mL mixture of methyl tert-tubtyl ether and pentane (v/v = 8:2). The organic phase was removed into the tubes and then evaporated in ventilation cabinet. The residue was dissolved in 50 microL of methanol. 20 microL solution was drawn and detected by high-performance liquid chromatography. The pharmacokinetic parameters were calculated by 3P97 software.</p><p><b>RESULTS</b>The plasma drug concentration-time data were fitted to the two-compartment model. When the dose was 2.67 mg.kg(-1), the MRT and AUC of parent compound were 52.9 min and 6.7 mg.min. L(-1), respectively. When the dose rose to 5.34 mg.kg(-1), the MRT and AUC of parent compound became 224.8 min and 26.1 mg.min.L(-1), respectively. However, when the dose increased to 10.68 mg .kg(-1), the MRT and AUC of parent compound increased to 267.7 min and 33.2 mg.min L(-1), respectively. The AUC of glucuronidated genistein was 33.9, 70.1 and 140.5 mg.min.L(-1) at the dose of 2.67, 5.34 and 10.68 mg.kg(-1), respectively.</p><p><b>CONCLUSION</b>Due to significant first pass metabolism, the drug was mainly existed in the form of glucuronidated genistein in the plasma. With the increase of dose, the absorption of genistein became saturated and the half life prolonged.</p>

Glucuronidation and in vitro interaction of Ginkgo flavonoids with other drugs / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To obtain the information on the glucuronidation of Ginkgo flavonoid and the interaction profile of Ginkgo flavones with other drugs in vitro.</p><p><b>METHODS</b>Ginkgo flavonoids (quercetin, isorhamnetin and keampferol) and other drugs were co-incubated with rat hepatic microsome at 25 degree; the residual concentrations of flavonoids were determined by HPLC. The enzymatic parameters of quercetin, isorhamnetin and keampferol metabolism were assessed. The interactions between flavonoids and these drugs on glucuronidation were observed.</p><p><b>RESULT</b>The K(m) values were ( 24+/-0.05), (148+/-0.09) and (110+/-0.03) micromol/L and the V(max) values were (60+/-0.21), (48+/-0.02) and (34+/-0.02) micromol x g(-1) x min(-1) for quercetin, isorhamnetin and kaempferol, respectively. The IC(50) of nifedipine propafenone ipriflavone and diphenytriazol on flavonoids metabolism were 54 - 70, 69 - 122, 85 - 98 and 210 - 362 micromol, respectively. The inhibition constants (Ki) of diphenytriazol propafenone and ipriflavone on quercetin, isorhamnetin and keampferol metabolism were (57.6, 50.5, 33.1) (33.6, 59.5, 45.2) and(13.7,24.0,15.7) microg/ml respectively. The ratio [I]/[Ki] of the plasma concentration and inhibition constant for propafenone was 0.002 - 0.003.</p><p><b>CONCLUSION</b>The metabolic level of quercetin is the strongest among three Ginkgo flavonoids. Nifedipine propafenone and ipriflavone inhibit the metabolism of quercetin, isorhamnetin and keampferol at different levels. Because of the interaction between Ginkgo flavonoids with nifedipine, caution must be taken when two drugs are used together clinically.</p>