Protocatechuic acid inhibits hepatitis B virus replication by activating ERK1/2 pathway and down-regulating HNF4α and HNF1α in vitro.

AIMS: Protocatechuic acid (PCA) is a phenolic compound found in many antiviral Chinese herbal medicines. HNF4α and HNF1α, the members of hepatocyte nuclear factor (HNF) family, play an important regulatory role in the gene transcription of hepatitis B virus (HBV). Previous studies found that PCA inhibited HBV antigen secretion and HBV DNA replication in HepG2.2.15 cells, but its anti-HBV mechanism has not been fully understood. We aim to illustrate the anti-HBV mechanism of PCA. MATERIALS AND METHODS: MTT was used to estimate cytotoxicity. The content of HBsAg or HBeAg was detected using an enzyme-linked immunosorbent assay kit. HBV DNA in cell-free culture media was detected by PCR kit. HNF1α and HNF4α mRNA expression was detected by real-time PCR. HNF1α, HNF4α and ERK1/2 protein expression was detected by western blotting and HBV promoter activity was tested by luciferase reporter assay. KEY FINDINGS: Our results demonstrated that PCA inhibited the gene transcription and protein translation of HNF1α and HNF4α in Huh7 and HepG2.2.15 cells, as well as the promoter activities of HBV X and preS1 in Huh7 cells transfected with the luciferase reporter plasmid of HBV promoter. Further study suggested that PCA induced the phosphorylation of extracellular-signal-related kinase (ERK) 1/2, and thereby inhibited HNF4α and HNF1α expression in HepG2.2.15 cells to exert its antiviral activity. SIGNIFICANCE: To our knowledge, this study is the first to reveal the anti-HBV mechanism of PCA. Our results demonstrate that PCA inhibits HBV replication by activating ERK1/2 pathway and subsequently down-regulating HNF4α and HNF1α in HepG2.2.15 cells.

In vivo effect of triptolide combined with glycyrrhetinic acid on rat cytochrome P450 enzymes.

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.

Effects of brucine combined with glycyrrhetinic acid or liquiritin on rat hepatic cytochrome P450 activities in vivo.

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.

[Pharmacokinetics of gastrodin from compound Tianma granule in rats].

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.

New modified iris suture technique for pupillary dilation in aphakic eyes during vitreoretinal surgery.

To describe a modified simple iris suture for pupillary dilation technique during vitrectomy in cases with a miotic pupil. Four translimbal incisions were created with a sharp straight blade at 1:30, 10:30, 4:30, and 7:30 o'clock, respectively. The straight needle of 10-0 polypropylene suture and a Sinskey IOL hook was used to displace the pupillary margin toward the limbus. In 3 cases, four sutures caused a 6-mm to 9-mm square-shaped pupil, and the pupil was allowed to return to a smaller size at the end of the operation. It is simple and may reduce postoperative complications.

Gene expression profiling of mice liver tissue after intragastric administration of Chinese nutgall extract.

Kunming mice (male, weight 20 +/- 2g) were daily intragastric administration of Chinese nutgall extract (0.2 mL/10 g body weight, equal to 8 g Chinese nutgall material/1 kg body weight) for 30 days. Liver tissue mRNA were extracted from normal control group and Chinese nutgall treated group respectively, then were reversely transcribed to cDNA with dUTP labeled by different fluorescence (Cy3, Cy5) as hybridization probes. Both of the cDNA probes were mixed equally in 20 microL of hybridization solution and hybridized with mice complete genome oligonucleotide microarray. The fluorescent signals were acquired by laser scanner and analyzed by GenePix Pro 4.0 software. The biological function analysis and the pathway analysis of differentially expressed genes were performed according to Gene Ontology database. As a result, there were 461 genes differentially expressed in Chinese nutgall treated group, in which 373 genes were function-known and the others were function-unknown. Among the 461 genes, 267 genes were up-regulated and the others were down-regulated. The differentially expressed genes were involved in metabolism, DNA binding and transcription, protein synthesis and modification, cell cytoskeleton and cell adhesion, cell cycle and differentiation, ion channels and transporters, signal transduction, immune response and apoptosis of liver cell. The presented work might be quite important for understanding the pathogenic mechanisms of liver injury induced by Chinese nutgall.

[Pharmacokinetics of puerarin and hydrochlorothiazide from maijunan tablets in rats].

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.

[Study on the interaction between cinnamic acid and human serum albumin by fluorescence quenching method].

The albumin is the richest protein in blood circulatory system, which can combine with many drugs and play an important role in transporing protein. In the present work, the non-covalent interaction between human serum albumin and cinnamic acid was studied by using fluorescence quenching method. The results showed that cinnamic acid had a powerful ability to quench the fluorescence of human serum albumin at excitation and emission wavelengths of lambda(ex) = 286 nm and lambda(ex) = 340 nm, respectively, in the reaction solution of pH 7.4. The binding constants(K) at 37 and 47 degrees C were found to be 1.276 7 x 10(3) and 3.404 1 x 10(3) L x mol(-1), with the number of binding site(n) of 0.758 6 and 0.835 6, respectively, suggesting that the reaction temperature is advantageous for the binding reaction in a way. The changes in the thermodynamic parameters of binding interaction at 37 and 47 degrees C indicated that the main binding force between cinnamic acid and human serum albumin was hydrophobic force. These provide important information for studying the pharmacological effects of cinnamic acid and the influence of cinnamic acid on the configuration change of HSA.

[Simultaneous determination of geniposide, baicalin and berberine hydrochloride in Angong Niuhuang pill by RP-HPLC].

OBJECTIVE: A new method for the simultaneous quantitative determination of geniposide, baicalin and berberine hydrochloride in Angong Niuhuang pill using reversed phase high performance liquid chromatographic method had been developed. METHOD: The optimum chromatographic conditions were as follows: Agilent Zorbax SB - C18 column (4.6 mm 250 mm, 5 m), acetonitrile-H2O (containing 6 mmol L(-1) KH2PO4, pH 4.6) gradient elution; as a detection wavelength of 343 nm. RESULT: The calibration curves of geniposide, baicalin and berberine were linear at the ranges of 4.50-110.00, 5.00-153.00, 6.40-191.00 mg L(-1), respectively. The limits of detection of the method were 0.77 ng for geniposide, 1.53 ng for baicalin and 1.43 ng for berberine hydrochloride. The recoveries of the method were 104.44% (RSD 1.79% ) for geniposide, 96.98% (RSD 1.76%) for baicalin, 101.08% (RSD 3.1%) for berberine hydrochloride. CONCLUSION: This method had been successfully applied to determine the content of geniposide, baicalin and berberine hydrochloride in Angong Niuhuang pill.

[Methodology of electrospray ion trap mass spectrometry for analyzing the non-covalent binding of protein and low-molecular-weight ligand].

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.

Gene expression profile analyses of mice livers injured by Leigongteng.

AIM: To analyze the gene expression profiles of mice livers injured by Leigongteng and explore the relationship between the differentially expressed genes and liver damage. METHODS: The experimental mice were randomly divided into a control group and a liver-injured group in which the mice were administrated 33 mu gamma of triptolide/kg per day for 30 d. Liver mRNAs were extracted from animals in both groups and were reverse-transcribed to cDNA with dUTP labeled by different fluorescence (Cy3, Cy5) as hybridization probes. The mixed probes were hybridized with oligonucleotide microarray chips. The fluorescent signal results were acquired by scanner and analyzed with software. RESULTS: Among the 35852 target genes, 29 genes were found to be significantly differentially expressed, with 20 genes up-regulated and 9 genes down-regulated. The reliability of the differentially expressed genes was validated by RT-PCR experiments of 5 randomly selected differentially expressed genes. CONCLUSION: Based on the biological functions of the differentially expressed genes, it is obvious that the occurrence and development of liver damage induced by Leigongteng in mice are highly associated with immune response, metabolism, apoptosis and the cell skeleton of liver cells. This might be important for elucidating the regulatory network of gene expression associated with liver damage and it may also be important for discovering the pathogenic mechanisms of liver damage induced by Leigongteng.

[Identification of hydroxylate metabolites of daidzein and its sulfate conjugates in rat urine by LC-ESI/MS(n)].

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.

[Liquid chromatography-tandem electrospray ionization ion trap mass spectrometric assay for the metabolites of jatrorrhizine 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.

[Analysis of anisodine and its metabolites in rat plasma by liquid chromatography-tandem mass spectrometry].

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.

[HPLC-ESI/MS analysis of stachydrine and its metabolites in rat urine].

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.

[HPLC-MSn analysis of trigonelline 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.

[Detection of anisodamine and its metabolites in rat feces by tandem mass spectrometry].

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.

[Comparing studies on the differences of CCl4 liver injury and immunity liver injury mice models].

Comparison between CCl4 liver injury model and immunity liver injury model was studied through physiological, biochemical and gene expression profile methods, and the pathological mechanism of them were discussed. There are significant changes about the physiological, biochemical parameters including ALT,AST between two model groups and normal control group. Among the 14112 target genes, 379 and 293 differentially expressed genes were screened out from the both two model groups respectively in gene expression profile experiments, including 105 common, differentially expressed genes. The results indicate that the two models of CCl4 and immunity have some similarities. However, the differences between them are also obvious. It is useful for the further investigation on the liver-injury mechanism and pathological process of the two different liver-injury models.

[Analysis of ephedrine and its metabolites in rat urine by HPLC-ESI-ITMSn].

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.