RESUMEN
Dioscin has a wide range of biological effects and broad application prospects. However the studies concerning the toxicology and mechanism of dioscin is small. This article is to study the hepatotoxicity of dioscin and the effect of dioscin treatment on expression of aryl hydrocarbon receptor (AhR) mRNA and CYP1A mRNA and protein in HepG2 cells in vitro. Dioscin 0.5-32 µmol · L(-1) exposed to HepG2 cells for 12 h, cell viability was examined by CCK-8 assay and the release rate of lactate dehydrogenase (LDH) was to evaluate cell membrane damage. HepG2 cells morphologic changes were quantified by inverted Microscope, and the effect on production of reactive oxygen species (ROS) was detected by flow cytometry. The mRNA expression of CYP1A and AhR was evaluated by RT-RCR. The protein expression of CYP1A1 was detected by western blot. The cell viability was significantly inhibited after HepG2 cells were exposed to dioscin 0.5-32 µmol · L(-1). Compared with the control, the LDH release rate and ROS were significantly increased. The expression of CYPlA and AhR mRNA was increased. The expression of CYP1Al protein was increased after dioscin treatment, and resveratrol, an AhR antagonist, could downregulate the expression of CYP1A1. It follows that large doses dioscin has potential hepatotoxicity. The possible mechanism may be dioscin can active aryl hydrocarbon receptor (AhR) and induce the expression of CYP1A.
Asunto(s)
Humanos , Supervivencia Celular , Enfermedad Hepática Inducida por Sustancias y Drogas , Citocromo P-450 CYP1A1 , Genética , Diosgenina , Toxicidad , Células Hep G2 , L-Lactato Deshidrogenasa , Secreciones Corporales , ARN Mensajero , Especies Reactivas de Oxígeno , Metabolismo , Receptores de Hidrocarburo de Aril , GenéticaRESUMEN
To study the effect of Panax notoginseng saponins (PNS) on liver drug metabolic enzyme activity, mRNA and protein expressions in rats. Male Wistar rats were randomly divided into nine groups. After administration of the test drugs, their liver microsomes, liver total RNA and total protein were extracted to detect the regulating effect of PNS on liver drug metabolic enzyme activity-related subtype enzymatic activity, mRNA and protein expression by substrate probe, quantitative PCR and Western Blot technology. The result of this experiment was that PNS could significantly induce CYP1A2 and CYP2E1 enzyme activity, mRNA expression, CYP2E1 protein expression level. PNS significantly induced CYP3A mRNA expression, but with no significant effect in CYP3A enzyme activity level. PNS had no significant effect CYP1A1 and CYP2B mRNA expressions and enzyme activity levels. PNS had selective regulations on different P450 subtypes, and the major subtypes were CYP1A2 and CYP2E1. In clinical practice, particularly in the combination with CYP1A2 and CYP2E1 metabolism-related drugs, full consideration shall be given to the possible drug interactions in order to avoid potential toxic and side effects. Meanwhile, whether the induction effect of CYP2E1 gets involved in ginsenoside's effect incavenging free radicals deserves further studies.
Asunto(s)
Animales , Masculino , Sistema Enzimático del Citocromo P-450 , Genética , Metabolismo , Medicamentos Herbarios Chinos , Farmacología , Hígado , Microsomas Hepáticos , Panax notoginseng , Química , Ratas Wistar , Saponinas , FarmacologíaRESUMEN
<p><b>OBJECTIVE</b>To study the modulatory effect of Panax gingseng and coadministration with Veratrum nigrum on the activity and mRNA expression of cytochrome P450 isoenzymes in rat liver.</p><p><b>METHOD</b>Rat liver microsomal cytochrome P450, b5, aminopyrine N-demethylase(APND), p-nitrophenol-hydroxylase(pNPH)activities were quantitated by UV chromatography. The mRNA expression level of five CYP isoenzymes CYP1A1, CYP2B1/2, CYP2C11, CYP2E1 and CYP3A1 were detected by semi-quantitative reverse transcriptase-polymerase chain reaction(RT-PCR).</p><p><b>RESULT</b>P. gingseng coadministrated with V. nigrum obviously decreased the P450 contents of liver microsomes, and the b5 contents. Both single and combined used inhibited the activities of aminopyrine N-demethylase. At the mRNA level, the expression of CYP2C11 markedly induced exposure to V. nigrum, but combinative groups decreased the expression of CYP2C11. The combination of P. gingseng and V. nigrum induced the expression of CYP1A1. P. gingseng has inhibitory effect on CYP2B1/2 and inductive effect used with V. nigrum. The combination of P. gingseng with V. nigrum also induced the expression of CYP3A1.</p><p><b>CONCLUSION</b>P. gingseng used singly has some different modulation effects compared with combinative used, which may occur because of drug-drug interaction based on cytochrome P450. To elucidate the drug-drug interaction, it needs further analysis and metabolism research.</p>
Asunto(s)
Animales , Femenino , Masculino , Ratas , Aminopirina N-Demetilasa , Metabolismo , Sistema Enzimático del Citocromo P-450 , Genética , Citocromos b5 , Metabolismo , Incompatibilidad de Medicamentos , Medicamentos Herbarios Chinos , Farmacología , Técnicas In Vitro , Isoenzimas , Genética , Microsomas Hepáticos , Metabolismo , Panax , Química , ARN Mensajero , Genética , Ratas Wistar , Veratrum , QuímicaRESUMEN
A group of symptoms are caused by vascular compression upon facial and acoustic nerves at the cerebellopontine angle. Surgical exploration by retro-sigmoidal or retro-labyrinthine route suggested that the sites of compression were in the segment of nerves near the internal acoustic meatus.Following decompression the results were very satisfactory