ABSTRACTS – ORAL PRESENTATIONS - AMCA, spol. s r.o.

The pore-forming activity of DDHR was investigated on individual giant unilamellar
phospholipid vesicles (GUVs) made of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)
and DOPC with 30% content of cholesterol. Using multiphoton fluorescence microscopy
we observed formations of necklace-shaped structures or internal small particles inside
GUVs made of DOPC. This behaviour is consistent with the theory of pore formation
as mode of action explaining the bioactivity of some particular secondary metabolites
(Zemel at al., 2005). Content of cholesterol in GUVs inhibits formation of these structures.
Permeability of membranes after treatment with DDHR was proved in the standard dye
leakage assay performed on the same vesicle types.
We have also proved the direct interaction between cholesterol and DDHR using
FTIR spectroscopy. This interaction could play a crucial role in its bioactivity and
the ability to stain only certain membrane components in cells.
Acknowledgements
This work was supported by Long-Term Research Plans of the Ministry of Education,
Youth and Sports of the Czech Republic No. MSM0021620858. Author is thankful to
the laboratory of RNDr. Miroslav Flieger, CSc., Institute of Microbiology, Academy
of Sciences of the Czech Republic.
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P12. MODULATION OF HYPERICIN-MEDIATED PHOTODYNAMIC THERAPY USING
HISTONE DEACETYLASE INHIBITORS
Ján Kovaľ, Andrea Halaburková, Rastislav Jendželovský, Jaromír Mikeš, Peter Fedoročko
P. J. Šafárik University in Košice, Faculty of Science, Institute of Biology and Ecology,
Košice, Slovak Republic; jan.koval@upjs.sk
Photodynamic therapy (PDT) is a minimally invasive cancer treatment method which
utilizes different tumor-localizing agents that are activated by irradiation with light
of a specific wavelength. This triggers production of reactive oxygen species, which
subsequently activate processes implicated in irreversible changes to various cellular
targets leading to cell death (Dougherty et al., 1998). Hypericin (HY), a naturally occurring
aromatic polycyclic diantraquinone from St. John’s wort (Hypericum perforatum L.), has
unique photocytotoxic properties suitable for PDT.
Analytical Cytometry VII 101