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Triptolide (TP) is a major active component in Tripterygium root, but its therapeutic window was very narrow due to its severe multi-organ toxicity. In this work, the effect of TP combined with glycyrrhetic acid (GA) on mRNA expression and activity of four cytochrome P450 (CYP) enzymes in rat liver was studied after intragastric administration of TP (0.05, 0.3 and 0.6 mg x kg(-1) x day(-1)) and TP (0.6 mg x kg(-1) x day(-1)) combined with GA (30 mg x kg(-1) x day(-1)) for 7 consecutive days. Compared with the control, the high dose of TP significantly up-regulated the mRNA expression levels of CYP2E1, 1A2, 3A1 and 2C11, the co-administration of TP and GA further up-regulated the mRNA expression levels of CYP3A1, 2C11 and 2E1 as compared with the high dose of TP. Meanwhile, TP at high dose and combined with GA significantly increased CYP3A-associated testosterone 6beta-hydroxylation activity (2.2-fold and 4.1-fold, respectively) as compared with the control. Because TP is mainly metabolized by CYP3A2 in male rats, the present work indicated that TP-induced increase of CYP3A activity might be an important reason for the rapidly metabolic clearance of TP in rat liver, and GA can reduce the hepatotoxicity of TP by promoting its hepatic metabolic clearance. Furthermore, the results also suggest that the drug interactions might be occurred when TP and GA were co-administered with other CYP3A substrate drug.

Abstract: The activities of four CYP450 enzymes (CYP3A, 1A2, 2El and 2C) and the mRNA expression levels of CYP1A2, 2El, 2Cll and 3A1 in rat liver were determined after Wistar rats were orally administered with brucine (BR) at three dosage levels (3, 15 and 60 mg.kg-1 per day) and the high dose of BR combined with glycyrrhetinic acid (GA, 25 mg.kg-1 per day) or liquiritin (LQ, 20 mg.kg-1 per day) for 7 consecutive days. Compared with the control, brucine caused 24.5% and 34.6% decrease of CYP3A-associated testosterone 6beta-hydroxylation (6betaTesto-OH) and CYP2C-associated tolbutamide hydroxylation (Tol-OH), respectively, and 146.1% increase of CYP2El-associated para-nitrophenol hydroxylation (PNP-OH) at the high dose level. On the other hand, (BR+GA) caused 51.4% and 33.5% decrease, respectively, of CYP2El-associated PNP-OH and CYP1A2-associated ethoxyresorufin-O-de-ethylation (EROD) as compared with the high dose of BR group. Meanwhile, (BR+LQ) caused 41.1% decrease of CYP2El-associated PNP-OH and 37.7% increase of CYP2C-associated Tol-OH. The results indicated that the co-administration of BR with GA or LQ had effect on mRNA expression and activities of the CYP450 enzymes mentioned above to some extent, and the in vivo antagonism of LQ on BR-induced CYPs adverse effects and the in vivo inhibitory action of GA on CYP2E1 and 1A2 might play an important role in the detoxification of Radix Glycyrrhizae against Strychnos nux-vomica L.

To study the influence of the compatibility of ophiopogonis tuber and Chinese magnoliavine fruit with gastrodia rhizome on the pharmacokinetics of gastrodin in rat, three dosages of compound Tianma granule extract (equivalent to gastrodin 50, 100, 200 mg x kg(-1)) and one dosage of Tianma extract (equivalent to gastrodin 100 mg x kg(-1) were administered to rats by intragastric administration separately. Plasma samples were collected at different times and treated with methanol and acetonitrile to precipitate protein. The contents of gastrodin in plasma were determined by HPLC method. The mean plasma concentration-time curves of different medication administration teams were processed with WinNonlin 5.2.1 pharmacokinetic software. The pharmacokinetic parameters of different medication administration teams were analyzed with SPSS statistics 17.0 software. The results indicated that the in vivo kinetic process of gastrodin was fitted to first-order absorption un-compartment model at low, middle dosages and zero-order absorption un-compartment model at high dosage of compound Tianma granule extract. By comparison with the pharmacokinetic parameters of gastrodin (100 mg x kg(-1)) in Tianma extract, the significant decrease for Cmax and significant increase for MRT0-infinity in compound Tianma granule extract indicated that the compatibility of ophiopogonis tuber and Chinese magnoliavine fruit with Gastrodia rhizome can delay the absorption, reduce the elimination rate and prolong the action time of gastrodin in vivo.

After oral administration of low, middle, high dose of simulative Maijunan tablets to SD rats and puerarin, hydrochlorothiazide at middle dosage to SD rats separately, plasma samples were collected at different times and treated with acetonitrile to precipitate protein. The contents of puerarin and hydrochlorothiazide in plasma were determined by HPLC method. The mean plasma concentration-time profiles of puerarin and hydrochlorothiazide at different dosages of medication administration were processed by 3P97 pharmacokinetic software and SPSS statistics 17.0 software. The results indicated that the in vivo kinetic processes of puerarin in rats were all fitted to a two-compartment open model and hydrochlorothiazide fitted to a one-compartment open model. Hydrochlorothiazide in vivo kinetic process in rats was in accordance with the linear dynamics. The combination of hydrochlorothiazide and rhynchophylla with pueraria promoted the absorption, reduced the elimination rate and prolonged the action time of puerarin in vivo. Meanwhile, the combination also promoted the absorption rate and the bioavailability, prolonged the action time and the accumulation time of hydrochlorothiazide in vivo.

A new MS-titration method for the non-covalent binding of protein-ligand based on the research of berberine and alpha1-acid glycoprotein was established. The major presumption of new method is that the total concentration of protein-ligand complex is approximately the same as the total concentration of acting protein if a certain extent of affinity is existed between protein and ligand, in addition, the mole amount of acting ligand is more than that of acting protein. The non-covalent binding behaviours between berberine and alpha1-acid glycoprotein was studied by using electrospray ionization ion trap mass spectrometry (ESI-ITMS) , and the results were verified by fluorescence quenching method. The results showed that the binding behaviours between berberine and alpha1-acid glycoprotein, for example, stability constant, number of binding site, type of the main binding force, were almost the same by using the new MS-titration method and fluorescence quenching method. Comparing with the reported MS-titration method, the presented MS-titration method in this paper is more simple and applicable, does not demand much for the devices, and can lead to reliable results in same cases.

Aim: To establish a LC-MS(n) method for the identification of anisodamine and its metabolites in rat feces., Methods: Feces samples were collected after single administration of 25 mg x kg(-1) anisodamine to rats, and dipped in water for 1 h. Samples were then extracted by ethyl acetate. The pretreated samples were separated on a reversed-phase C18 column using a mobile phase of methanol / 0.01% triethylamine (adjusted to pH 3.5 with formic acid) (60 : 40, v/v) and detected by LC-MS". Identification of the metabolites and elucidation of their structures were performed by comparing their changes in molecular masses (deltaM), retention-times and full scan MS(n) spectra with those of the parent drug and blank feces., Results: The parent drug and its seven metabolites (6beta-hydroxytropine, nor-6beta-hydroxytropine, aponoranisodamine, apoanisodamine, noranisodamine and hydroxyanisodamine, tropic acid) were found in rat feces., Conclusion: This method is sensitive, rapid, simple, effective, and suitable for the rapid identification of drug and its metabolites in biologic samples.

Aim: To identify the hydroxylate metabolites and its sulfate conjugates of daidzein in rat urine., Methods: Urine samples from 0 - 24 h were collected after single ig dose of 500 mg x kg(-1) daidzein to each of six rats. The urine samples were purified by SPE column (SPE C18) and analyzed with liquid chromatographic-tandem electrospray ionization ion trap mass spectrometry (LC-ESI/MS(n)) for potential metabolites., Results: Several new hydroxylate metabolites and its sulfate conjugates were found and identified in rat urine., Conclusion: LC-ESI/MS(n) is proved to be a simple, rapid, sensitive and specific technique for identification of the hydroxylate metabolites and its sulfate conjugates of daidzein in rat urine.

Aim: To identify the main metabolites of jatrorrhizine in rat urine., Methods: The rat urine samples were collected 0 - 72 h after ig 12 mg x kg(-1) jatrorrhizine, then the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by combining liquid chromatography and tandem electrospray ionization ion trap mass spectrometry (LC-ESI/ITMS(n)). Identification and structural elucidation of the metabolites were performed by comparing the changes in molecular masses, retention-times and full scan MS(n) spectra with those of the parent drug., Results: At least seven phase I metabolites (such as de-methyl, de-hydrogen and hydroxyl metabolites) and eleven phase II metabolites (such as glucuronide conjugates and methyl-conjugates) were identified in rat urine., Conclusion: The developed LC-ESI/ITMS(n) method is not only simple and rapid but also sensitive and specific for the identification of metabolites of jatrorrhizine in rat urine.

Aim: To identify anisodine and its metabolites in rat plasma after ingestion of anisodine by combining liquid chromatography and tandem mass spectrometry (LC-MS(n))., Methods: Plasma samples from rats after a single orally administration of 20 mg anisodine were added with methanol to precipitate protein. Then, it was analyzed by LC-MS(n). Identification and structural elucidation of the metabolites were performed by comparing their changes in molecular masses, retention-times and full scan MS(n) spectra with those of the parent drug and blank plasma., Results: The results revealed that the parent drug and its four metabolites (norscopine, scopine, hydroxyanisodine, N-oxide anisodine) existed in rat plasma., Conclusion: This method is sensitive, rapid, simple, and it is suitable for the rapid identification of drug and its metabolits.

Aim: To identify the main metabolites of stachydrine in rat., Methods: The ionization, cleavage and chromatographic characteristics of stachydrine were studied by using high-performance liquid chromatography-electrospray ionization ion trap tandem mass spectrometry (HPLC-ESI/MS) for the first time. These characteristics of stachydrine were used as the basis for the analyses of metabolites in rat urine. The 0 - 24 h urine samples of rats after ig 25 mg x kg(-1) stachydrine were collected and purified by using C10 solid-phase extraction cartridge, and then analyzed by HPLC-ESI/MS to identify stachydrine and its metabolites., Results: The parent drug (stachydrine), 6 phase I metabolites (N-demethyl, dehydrogenation, ring-oxidation) and 2 phase II metabolites (glycine conjugates of 2 ring-oxidation products) were identified existing in rat urine., Conclusion: The presented method was proved to be sensitive, rapid, high selective and specific for the identification of stachydrine and its metabolites in rat urine.

Aim: To establish a rapid and sensitive LC-MSn method for the identification of trigonelline and its main metabolites in rat urine., Methods: After optimizing the detection conditions of LC-MSn chromatography and mass spectrometry using trigonelline, its ionization and cleavage in ESI-MS and ESI-MSn modes were summarized, then serving as the basis for the metabolite analysis of trigonelline in rat urine. The 0-48 h urine samples of rats were collected after iv 8 mg x kg(-1) trigonelline, then, the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by LC-MSn., Results: The structures of trigonelline metabolites were elucidated according to the changes of the molecular weights of the metabolites (deltaM) and their cleavage pattern in ESI-ITMSn. As a result, two phase I metabolites and the parent drug were identified existing in rat urine, and two phase II metabolites were identified., Conclusion: The LC-MSn method is rapid and high sensitive and specific, it is suitable for the identification of trigonelline and its metabolites in rat urine.

Aim: To estabilish a rapid and sensitive LC-ESI-ITMSn method for the identification of ephedrine and its main metabolites in rat urine., Methods: After optimizing the detection condition of LC-ESI-ITMSn chromatography and mass spectrometry by using a standard ephedrine, the ionization and cleavage rules of ephedrine in ESI-MS and ESI-MSn modes were summarized, and then serving as the basis for the metabolite analysis of ephedrine in rat urine. Rat urine samples of 0-48 h were collected after ig 10 mg x kg(-1) ephedrine, then the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by LC-ESI-ITMSn., Results: The structures of ephedrine metabolites were elucidated according to the changes of the molecular weights of the metabolites (deltaM) and their cleavage pattern in ESI-ITMSn. As a result, three phase I metabolites and the parent drug ephedrine were identified existing in rat urine, but no phase II metabolites were found., Conclusion: The LC-ESI-ITMSn method is rapid and highly sensitive and sepecific, it is suitable for the identification of ephedrine and its metabolites in rat urine.

Aim: To identify the main metabolites of oxymatrine (OMT) in rats., Methods: To optimize the conditions of LC/ESI-ITMS' chromatograms and spectra by oxymatrine and matrine (MT), and summarize their ionization and cleavage rules in ESIMS, then serving as the basis for the metabolite analyses of oxymatrine in rats. To collect the 0-24 h urine samples of the rats after ip 40 mg x kg(-1) oxymatrine, the samples were enriched and purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by LC/ESI-ITMS. The structures of OMT metabolites were identified according to their retention times and ESI-ITMSn rules., Results: Six phase I metabolites and the parent drug OMT were found in the rat urine, and the main metabolite was MT. No phase II metabolites were found., Conclusion: The developed LC/ESI-ITMSn methods to identify the metabolites of oxymatrine in rats is not only simple and rapid but also sensitive and specific. This technology is one of the most efficient methods for the analysis of drug metabolites.

The derivatives of antipyrine and phenylbutazone are important antipyretic analgesics commonly used in clinical medicine. Although high performance liquid chromatography has been the conventional method used for the analysis of these drugs, in recent years capillary electrophoresis was validated to be a useful method in the analysis of antipyretic analgesics. However, there has been no report on the separation of antipyrine (AP), 4-aminoantipyrine (4-AAP), aminopyrine (APY), dipyrone (DIP) and phenylbutazone (PHE) in the literature. In this paper, a micellar electrokinetic capillary chromatographic (MECC) separation method was described for the five antipyretic analgesics.