Abelmoschi Corolla non-flavonoid components altered the pharmacokinetic profile of its flavonoids in rat

Abelmoschi Corolla is a well-known herbal medicine used for the treatment of chronic renal disease. Flavonoids are the major bioactive ingredients of Abelmoschi Corolla, but some non-flavonoid components also exist in this herb. In order to clarify the influences of non-flavonoid components on the pharmacokinetics profile of the flavonoid fraction from Abelmoschi Corolla (FFA), an investigation was carried out to compare the pharmacokinetic parameters of seven flavonoid components after administration of FFA and after administration of FFA combined with different non-flavonoid fractions.

A selective and sensitive UPLC-MS/MS method was established to determine the plasma concentrations of the seven compounds. Sprague-Dawley rats were allocated to four groups which orally administered FFA, FFA combined with macromolecular fraction (FFA-MF), FFA combined with small molecule fraction (FFA-SF) and FFA combined with MF-SF (FFA-MF-SF) with approximately the same dose of FFA. At different time points, the concentration of rutin (1), hyperoside (2), isoquercitrin (3), hibifolin (4), myricetin (5), quercetin-3'-O-glucose (6), quercetin (7) in rat plasma were determined and main pharmacokinetic parameters including T(1/2), T(max), AUC and C(max) were calculated using the DAS 2.0 software package. The statistical analysis was performed using the Student's t-test with P<0.05 as the level of significance.

Flavonoids almost had similar pharmacokinetics profile that were rapidly absorbed, reached the peak concentration at 30-60 min in group A, but the pharmacokinetic profiles and parameters of these flavonoids changed when co-administered with non-flavonoid components. It was found that AUC of five flavonoids but not hibifolin and quercetin in group FFA-SF and group FFA-MF-SF increased (P<0.05) in comparison with group FFA while the tendency was not observed in group FFA-MF. Moreover, seven flavonoids had varying degrees of differences in the pharmacokinetics parameters such as C(max), T(max) and T(1/2) (P<0.05) in group FFA-MF, FFA-SF and FFA-MF-SF by comparison with group FFA.

These results indicate that non-flavonoid components could improve the bioavailability and delay the elimination of some flavonoids in rat.