Pomegranate and licorice juices modulate metformin pharmacokinetics in rats.

OBJECTIVES Food or drinks may significantly alter the pharmacokinetics and pharmacodynamics of drugs which may lead to adverse events. A drug such as metformin is widely used to regulate plasma glucose level and pomegranate and licorice have been identified to help in type-2 diabetes management. However, the interactions of the latter on metformin pharmacokinetics were not studied. Therefore, we aimed here to study the impact of pomegranate and licorice on metformin pharmacokinetics in rats. METHODS Juices were given to rats for two days and half an hour before metformin (20 mg/kg) oral administration. Blood samples, then, were collected at different time intervals, processed and analyzed using validated reliable HPLC method. Plasma profile and pharmacokinetic parameters were calculated for each group. RESULTS AND CONCLUSION Pre-administration of pomegranate significantly reduced metformin maximum plasma concentration from 1410 to 1031 ng/ml. On the other hand, pre-administration of licorice significantly delayed metformin reaching its maximum plasma concentration. In conclusion, pre-administration of pomegranate may potentially reduce efficacy of metformin while licorice might delay metformin action. Thus, both juices should be cautiously administrated with metformin, the mainstay drug for type-2 diabetes mellitus management.