Aim: To study the effects of diphenytriazol on cytochrome P-450 (CYP) enzymes.
Methods: SD rats were pretreated with diphenytriazol. The catalytic activities of rat liver microsomes were determined by assaying ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-dealkylase. Phenacetin and aminopyrine were selected as the substrate of CYP1A and CYP2B, respectively. The concentration of remaining substrate in microsomal incubates was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). The inhibition of fluvoxamine or alpha-naphthoflavone on phenacetin metabolism was measured.
Results: Phenacetin was significantly metabolized in the diphenytriazol-treated microsomes and the metabolic degree increased according to the diphenytriazol-treatment days. There existed a significant correlation between the metabolic degree of phenacetin and EROD in the microsomes pretreated with diphenytriazol. Both fluvoxamine and alpha-naphthoflavone inhibited the metabolism of phenacetin significantly, and the inhibition constants (K(i)) were (5.4+/-1.0) micromol/L and (10.4+/-0.5) micromol/L, respectively. The activity of microsomes pretreated with diphenytriazol for 4 d was similar to that in b-naphthoflavone group, but was significantly different from those in control group and phenobarbital group.
Conclusion: These results reveal that diphenytriazol is a novel inducer of CYP1A.
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Zhejiang Da Xue Xue Bao Yi Xue Ban
March 2008
Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
Objective: To observe the metabolism-based interaction of diphenytriazol and flavone compounds.
Methods: Flavone compounds kaempferol, isoharmnten and Elsholtzia blanda benth extract were chosen as the substrate of glucuronidation in the phase II metabolism. The metabolism was investigated in different rat liver microsome incubates pretreated with beta-naphthoflavone (BNF), diphenytriazol and tea oil (control).
Acta Pharmacol Sin
April 2004
Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310031, China.
Aim: To study the effects of diphenytriazol on cytochrome P-450 (CYP) enzymes.
Methods: SD rats were pretreated with diphenytriazol. The catalytic activities of rat liver microsomes were determined by assaying ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-dealkylase.
Chem Biol Interact
December 2003
Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, 353 Yanan Road, Hangzhou, Zhejiang 310031, PR China.
Zolmitriptan is a novel and highly selective 5-HT(1B/1D) receptor agonist used as an acute oral treatment for migraine. There are few reports regarding the in vitro metabolism of zolmitriptan. Previous studies indicated zolmitriptan was metabolized via CYP1A2 in human hepatic microsomes.
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