Effects of Ginkgo biloba extract on heart and liver mitochondrial functions: mechanism(s) of action

Abstract

Background: One of the possible applications of liposomes in medicine is an enhancement of reverse cholesterol transport mediated by high density lipoproteins (HDL). Interaction between HDL and liposomes generates new lipoprotein fraction migrating with pre-beta mobility in agarose gel. Aims: Here, we investigated the distribution of apo A-I and apo A-II in the pre-beta mobility fractions generated at liposomal-phosholipids/HDL-phospholipids (L-PL/HDL-PL) ratios 1:1, 3:1 and 5:1. Methods: Human serum containing HDL as a sole lipoprotein fraction and lecithin liposomes were incubated at 37C for 1 hour. Aliquots of incubation mixtures were analyzed by two-dimensional non-denaturing 2-27% polyacrylamide gradient gel electrophoresis (2D PAGGE). Pre-beta mobility fraction and intact liposomes were precipitated from incubation mixture with heparin and CaCl2 and then examined using non-denaturing 2-27% polyacrylamide gradient gel electrophoresis (PAGGE). Results: Immunoblots of 2D PAGGE of incubation mixtures revealed the presence of apo A-I and/or apo A-II containing lipoproteins migrating with pre-beta mobility. The range of Stokes diameters of apo A-I containing lipoproteins varied from 7.4 to 11.3 nm, with dominating fraction of diameters 8.3–11.3 nm. The diameters of apo A-II containing particles were mildly bigger and ranged from 8.7 to 13.4 nm. However, one could distinguish two main classes of particles with diameters 9.7–10.5 nm and 8.7–9.1 nm. Immunoblots of PAGE demonstrated that irrespectively of L-PL/HDL-PL ratio in incubation mixture, pre-beta mobility fractions were composed of similar classes of particles. Apo A-I containing population formed three species of particles with diameters from 12.4-10.0, 8.9 and 7.7 nm. On the other hand, apo A-II containing population included two bands of particles with diameters of 9.1 and 7.5 nm. Conclusions: Our results indicate, [...].