Interaction Study: Effect of Eurycoma longifolia (ELO) extract on Rosiglitazone Pharmacokinetic profile in Diabetic rats

This study examined the effect of Eurycoma longifolia (ELO) extract on the pharmacokinetic profile of rosiglitazone in diabetic male rats. Old diabetics male rats were divided into intravenous and oral administration groups. Each group was further divided into two sub-groups for a single rosiglitazone and a combination of ELO extract and rosiglitazone (n = 6). Oral administration of the ELO extract at a dose of 50 mg/kg BW, 30 min before rosiglitazone administration, was performed for intravenous and oral studies. Blood samples (0.5 mL) were collected from the test animals at 0 (predose), 0.25, 0.5, 1, 2, 3, 5, 8, and 12 h after intravenous injection and at 24h for oral studies. The HPLC method reported by Mamidi et al. (2003) was used to analyse the rosiglitazone levels. A T-test was employed to compare pharmacokinetic parameters. The AUC0--∞, Kel, and T1/2 decreased by 31.49%, 3.03%, and 3.85%, respectively, after intravenous injection. By contrast, the Vd and CL increased by 37.63% and 15.50%, respectively. Whereas for oral study shows a decrease in some pharmacokinetic parameters, namely AUC0--∞ (8.01%), Cmax (12.95%), T1/2 (7.23%), and F (5.71%), and an increase in the parameters Kel (13.04%), Tmax (15.52%), Vd (46.38%), and CL (43.30%). Intravenous study results revealed that ELO had no effect on the rosiglitazone pharmacokinetic profile (P>0.05). Meanwhile for the oral study, ELO did not significantly decrease rosiglitazone bioavailability but significantly increased the CL and Vd parameters (P < 0.05).