Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Effect of Betong Watercress and Phenethyl Isothiocyanate on N-Demethylation of Caffeine in Rats

Benjamas Janchawee^1,2 , Angkana Wongsakul¹, Sathaporn Prutipanlai¹, Pritsana Ruangrut³

¹Department of Pharmacology; ²Natural Product Research Center, Faculty of Science; ³Department of Biomedical Sciences, Faculty of Medicine, Prince of Songkla University, Songkhla 90112, Thailand.

For correspondence:- Benjamas Janchawee Email: benjamas.j@psu.ac.th Tel:+6674446678

Received: 13 April 2013 Accepted: 9 February 2014 Published: 23 April 2014

Citation: Janchawee B, Wongsakul A, Prutipanlai S, Ruangrut P. Effect of Betong Watercress and Phenethyl Isothiocyanate on N-Demethylation of Caffeine in Rats. Trop J Pharm Res 2014; 13(4):559-566 doi: 10.4314/tjpr.v13i4.11

© 2014 The authors.
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Abstract

Purpose: To investigate the effect of Betong watercress and phenethyl isothiocyanate (PEITC) on the N-demethylation of caffeine (CF) in rats.

Methods: Male Wistar rats were subjected to 2 phases of experiment. Phase I, they received a single oral dose of CF (10 mg/kg), while in phase II, they were pretreated with the following regimens: 10 mg/kg fluvoxamine, i.p.; a single oral dose of 2, 10, and 20 mg/kg PEITC; 2, 10, and 20 mg/kg PEITC, once daily for five days; single oral dose of 800 mg/kg Betong watercress; 800 mg/kg Betong watercress once daily for five days, before receiving the same dose of CF as in phase I. Serum concentrations of CF and its metabolites after 3 h of CF administration were measured. Caffeine metabolic ratios (CMRs) and ratio of serum concentration of metabolites to that of CF were calculated and compared.

Results: CMRs were decreased by a single pretreatment \with fluvoxamine (30 – 40%), PEITC (2 - 20 mg/kg) (40 – 55%), and Betong watercress (9 – 22%). The decreases caused by 10 and 20 mg/kg PEITC were significantly greater than those by fluvoxamine. CMRs were also decreased after five days of pretreatment with all doses of PEITC (43 – 69%) and Betong watercress (28 – 44%). The reduction in metabolic ratio after single- and multiple PEITC pretreatments was dose- and time-independent.

Conclusion: Betong watercress and PEITC inhibit N-demethylation of CF in rats. Such an effect indicates that they have inhibitory activity on CYP1A2 and CYP2C.

Keywords: Watercress, Phenethyl isothiocyanate, Caffeine, N-demethylation, Fluvoxamine, Cytochrome