MAGDALENA DRĂGUŞIN, DIANA IONESCU

Department of Biophysics, “Carol Davila” University of Medicine and Pharmaceutics,
8, Eroii Sanitari Blvd, 050474, Bucharest, Romania

Among the broad range of polyphenols, hypericin (Hyp) is known as an antidepressant, a potent virucidal agent and a therapeutic agent in treatment/detection of cancer, showing also an anti-inflammatory activity. Using an electrical method, BLM (Black Lipid Membrane), we have studied the modifications induced by the simultaneous presence of Bovine Serum Albumin (BSA)-Hyp complex and of some lyotropic anions on the electric properties of artificial lipid membranes. We ascertained that the membrane capacitance increases for all the anions and the conductance decreases for chaotropes, therefore we conclude that the interaction of BSA–Hyp complex with the membrane leads to a protective effect against the disturbances at the level of the artificial bilayer induced by the most chaotrope anions. Because BSA-Hyp complex induces a smaller increase in the electric properties of the membrane we believe that this is due to the fact that Hyp binds not only to a specific subdomain to BSA, but also nonspecifically and these nonspecifically bound Hyp molecules are released in the presence of lyotropic anions and are able to interact with the membrane. As a consequence, when Hyp is specifically bound, its interaction with the cell membrane does not take place through the lipids.

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