FIGURE 8.
Effect of α-hederin (A and C) and hederagenin (B and D) on the generalized polarization (GPex) values for laurdan in liposomes made of DMPC (A and B) or DMPC/Chol (3:1) (C and D) as a function of temperature. The lines refer to data obtained in absence (solid line) or presence of α-hederin or hederagenin at drug/lipid molar ratios of 1.2 (dotted line) or 2.4 (dashed line). For DMPC/Chol (3:1) vesicles, these ratios correspond to a drug/cholesterol ratio of 4.8 and 9.6, respectively. The excitation wavelength was fixed at 340 nm and emission intensities at 440 nm (gel phase) and 490 nm (liquid crystalline phase). Each value is the average of three experiments. Statistical analysis was performed with Graph Pad Prism 4.0 (two-way ANOVA, comparing three data points at the beginning, physiological temperature, and the end of the curves).