New benzimidazole-derived isothioureas as potential antileukemic agents--studies in vitro.

Isothioureas are a class of amphiphilic compounds carrying a highly basic isothiourea group of pKa ranging between 10 and 11. Hence, they exist in protonated (cation) form at physiological pH, a characteristic is of key importance for their pharmacological activity. Recently, we have found that a number of S-pentabromobenzylisothiourea derivatives show substantial cytotoxicity toward a variety of human glioblastoma, leukemia, and adenocarcinoma cell lines.

[Photodynamic reaction and oxidative stress - influence of the photodynamic effect on the activity antioxidant enzymes].

The interaction of light with a photosensitizer, accumulated in a tissue in the presence of oxygen, leads to formation of reactive oxygen species, mainly of singlet oxygen and free radicals. These factors react with biomolecules producing their oxidized states. Reactive oxygen species, such as singlet oxygen and free radicals are able to damage membranes, DNA, enzymes, structural peptides and other cellular structures leading to cell death.

Cytotoxicity of PP(Arg)(2)- and Hp(Arg)(2)-mediated photodynamic therapy and early stage of apoptosis induction in prostate carcinoma in vitro.

Porphyrin photosensitizers tend to localize in mitochondria. The depolarization of mitochondrial membrane is one of the early stages of apoptosis and Laser Scanning Fluorescence Microscopy allows to determine changes in transmembrane mitochondrial potential under influence of PDT depending on the kind of photosensitizer (PP(Arg)(2), Hp(Arg)(2)), the energy dose (5, 10, 30 and 50 J/cm(2)) and time periods (24 and 48 hours after irradiation) in the LNCaP (lymphonodal metastasis of prostate carcinoma, the androgen dependent cell line). Cyototoxicity induced by PP(Arg)(2)- and Hp(Arg)(2)-based PDT depending on energy dose and time after irradiation in prostate carcinoma is determined with MTT.

Inhibition of cell growth induced by photosensitizer PP(Arg)2-mediated photodynamic therapy in human breast and prostate cell lines. Part I.

Photodynamic therapy can become an effective alternative method to surgery. The experiments reveal that using low photosensitizer doses and relatively low energy doses allow us to obtain effective results after PDT (to limit formation of colonies by investigated cancer cells). The prostate and breast cancer cell lines were investigated: MCF-7, a human breast cancer responsive to androgen therapy; MDA-MB231, a more aggressive human breast cancer non-responsive to androgen therapy; LNCaP, a lymphonodal metastasis of prostate carcinoma responsive to androgen therapy; DU-145, a human prostate cancer non-responsive to androgen therapy.

Application of electrophoretic methods for detection of protein-porphyrin complexes.

Simple methods for detection and isolation of protein-porphyrin complexes were elaborated in our laboratory. They are based on the separation of protein-porphyrin complexes in native polyacrylamide gel and measurement of their fluorescence, with the use of two detection systems: the commercially available Gel Doc(TM) 2000 system, and a system specially designed for the purpose of these investigations, concerning protein-porphyrin interactions. The fluorescent complexes can be electro-transferred from the gel onto PVDF membrane, eluted and analyzed in order to identify the protein interacting with porphyrins.