Absorption enhancement of grape seed polyphenols by complexation with phosphatidyl choline

Abstract

Grape seed polyphenols (GPP) are reported to have various biological effects along with strong antioxidant potential. Pharmacokinetic studies of GPP reveal its poor absorption through the intestine. The objective of the present study was to enhance bioavailability of GPP by its complexation with phosphatidyl choline. A complex of GPP was prepared with phosphatidyl choline and characterized on the basis of solubility, melting point, DSC, and IR. Everted intestine sac technique was used to study ex vivo drug absorption of GPP-PC complex and plain GPP. Pharmacokinetic studies were performed in rats and the hepatoprotective activity of GPP-PC complex was also compared with GPP and GPP-PC physical mixture in isolated rat hepatocytes. Analytical reports along with spectroscopic data revealed the formation of the complex. The results of ex vivo study show that the GPP-PC complex has significantly increased absorption compared with GPP, when given in equimolar doses. The complex showed enhanced bioavailability, improved pharmacokinetics, and increased hepatoprotective activity as compared to GPP or GPP-PC physical mixtures. Enhanced bioavailability of GPP-PC complex may be due to the amphiphilic nature of the complex, which greatly enhance the lipid miscibility of GPP. The present study clearly indicates the superiority of complex over GPP, in terms of better absorption, enhanced bioavailability, and improved pharmacokinetics.