Determination of plasma protein binding rate of protoapigenone form Macrothelypteris torresiana

OBJECTIVE To develop a HPLC method for the determination of protoapigenone in human/rat plasma and study the plasma protein binding rate of protoapigenone.METHODS The equilibrium dialysis combined with HPLC was carried out for the determination of the plasma concentration and plasma protein binding rate of protoapigenone.RESULTS Human plasma protein binding rates of protoapigenone at low,middle and high concentrations (200,500,1 000 μg·L-1) were (90.5±1.2)%,(89.6±1.7)% and (91.4±1.4)%,respectively.Accordingly,rat plasma protein binding rates of protoapigenone at low,middle and high concentrations were (80.7±2.2)%,(81.1±1.8)% and (81.9±1.3)%,respectively.CONCLUSION The high binding power of protoapigenone to human/rat plasma protein was confirmed by the proposed method of equilibrium dialysis combined with HPLC.Human or rat plasma protein binding rates of protoapigenone at low,medium and high concentrations showed no significant difference (P0.05).However,the plasma protein binding rates of protoapigenone towards the human plasma and rat plasma were significantly different (P0.01).