Abstract
Dietary supplements and foods can interact with various drugs, leading to possible clinical concerns. This study aimed to investigate the effect of orally administered sinapic acid (SA) on the pharmacokinetics of aripiprazole (APZ) in rats and its possible modulatory effects on hepatic cytochrome P450 (CYP3A2 and CYP2D6) expression in the liver tissues. Single dose and multiple dose parallel groups of wistar rats were categorized into six groups (n = 6 each) which abstained from food for 12 h prior to the experiment, while water was allowed ad libitum. The investigation was carried out for single dose: Group I was treated with normal saline orally for 15 days (normal control). Group II was administered normal saline orally for 15 days and received APZ (3 mg/kg p.o.) on day 15. Group III received SA (20 mg/kg p.o.) for 15 days and received APZ (3 mg/kg p.o.) on day 15. Group IV was treated with SA (20 mg/kg p.o.) for 15 days. For the multiple dose study, Group I was treated with normal saline orally for 15 days (normal control); Group II received APZ (3 mg/kg p.o.) daily for 15 days; Group III was administered with SA (20 mg/kg p.o.) and APZ (3 mg/kg p.o.) for 15 days and Group IV received SA (20 mg/kg p.o.) for 15 days. The group I and IV were kept common in single and multiple dose groups. After last APZ dose, plasma samples were collected and APZ concentrations were determined using an UPLC-MS/MS technique. The pharmacokinetic parameters were calculated using a non-compartmental analysis. The concomitant administration of APZ with SA (as single or multiple dose) resulted in an increase in APZ absorption and a decrease on its systemic clearance. This was associated with a reduction in CYP3A2 and CYP2D6 protein expressions by 33-43% and -71-68% after the single and multiple co-administration, which are two enzymes responsible of the metabolism of APZ. Therefore, a reduction in the metabolic clearance appears to be the mechanism underlying the drug interaction of dietary supplement containing SA with APZ. Therefore, the concomitant administration of SA and APZ should be carefully viewed. Further investigations are required to assess the clinical significance of such observations in humans.