Solubilization of resveratrol in micellar solutions of different bile acids

Abstract

Bile acids are a special group of biological surfactants which can express different physiological and pharmacological effects. Micellar solutions of bile acids can solubilizate poorly soluble organic substances and improve their resorbtion. Above their critical micellar concentration (CMC) values, bile acids can cause interruption of membrane's integrity. Resveratrol (trans-3,5,4′-trihydroxystilbene) is a stilbene phytoalexine and studies reported that it can prevent or reduce diseases such as cancer and coronary heart disease. In this study, we examined affinity of different bile acids (CA, 12-MDCA, 12-MCA, 7-MCA, 7,12-DCA, 3,7,12-TCA) micellar solutions for resveratrol solubilization. CMC values for bile acids were determined by conductivity measurements. Concentration of micellar solutions were 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 CMC value, for each acid respectively. At the same time, we investigated membranolytical potential of each acid. Solubilizated resveratrol was quantified using HPLC system with UV detection. Membranolytical potential was determined from citrate rabbit blood. Structures of mixed micelles of each bile acid and resveratrol were explained, and multiple linear regression equations for solubilization of resveratrol on different concentrations of bile acids were obtained. Micellar solution of 3,7,12-TCA had the biggest affinity for resveratrol solubilization and then, in decreasing order 7-MCA > 7, 12-DCA > 12-MCA > 12-MDCA > CA. Also, 3,7,12-TCA had the lowest membranolytical potential. © 2009 Elsevier B.V. All rights reserved.