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The review deals with photosensitizing properties of drugs and plant extracts. Some compounds are able to cause side effects such as phototoxicity and photoallergy. Revealing and study of harmful photosensitizers is actual problem in connection with changing photoecological situation.

Photosensitizing and photoprotecting efficiency of about a hundred of compounds, mainly drugs, was studied. The method based on chemiluminescence occurred along with photooxidation of glycyltryptophan under irradiation in UVB range in solution was used for testing. As a measure of photosensitizing efficiency the concentration of photosensitizer which induced two-fold increase of chemiluminescence intensity was chosen. The most effective photosensitizers are riboflavin, FAD, furagin, psoralene, vicasol, benzobarbital, mydocalm, angelicyn, furadonin, ethacridin, diazolin, folic acid. With regard to pharmacological doses of drugs in organism more dangerous sensitizers (in descending order) are p-aminosalicylic acid, furagin, riboflavin, benzobarbital, thiopental, chloramphenicol, nicodin, mydocalm, furadonin, oxolonic acid, furazolidone, psoralene, nicotinamide and diazolin. Photoprotecting effect was described by the concentration at which chemiluminescence intensity decreased twice. The most effective photoprotectors are etamsilat, quercetin, ftivazid, chlorpromazine, diprazine, thioridazine, aminophenazone, oxaphenamide. Concentration dependence for some of these drugs (etamsilat, chlorpromazine, diprazine, thioridazine) is non-monotonous: they inhibit photooxidation in low concentration (about 10(-7)-10(-6) M), but at higher concentrations (10(-5)-10(-4) M) photosensitization dominates over photoprotection.

Photoecological consequence of ozone holes are considered. Analysis of the total UV-radiation intensity and the short-wave edge of atmospheric transmittance depending on ozone content is presented. Characteristic times of some photodamages to skin and eyes have been estimated under ozone content reducing. A role of photosensitizers including drugs in phototoxical effects is discussed. Possible ways of photoprotection are considered.

2,5-dihydroxybenzolsulphonate was shown to actively interact with the superoxide radical O2-. formed under UV-radiation of glycyltryptophan aqueous solutions or under visible light illumination of glycyltryptophan and riboflavine. The constant of the rate of reaction of 2,5-dihydroxybenzolsulphonate with O2-. was determined to be equal to 1.3 X 10(9) M-1s-1. A photosensitized effect of 2,5-dihydroxybenzolsulphonate under illumination with the light with 280 nm was found. The sensitization efficiency of glycyl-tryptophan oxidation increases when the experiments are carried out in the oxygen atmosphere.