Phototoxic activity and the possibilities of its testing

The photodynamically active compounds have been attracting an attention of specialists for relatively long time. The most fruitful period of their research has been probably the last decade. The structures of the photosensitizers are very different. The biological activity is based on a formation of free reactive radicals after an excitation of the molecules of the phototoxins by e.g. UV radiation. Some photosensitizers are used for treatment of various diseases in dermatology and oncology. Since the substances can occur in plants, food or cosmetics, the photodynamic activity of these compounds is necessary to be studied under various conditions. Now e.g. some photochemical reactions, cell cultures, cultures of microorganisms, suspensions of erythrocytes, and different species of animals are used to the research of the photodynamic activity of the substances.