Cumarinderivate als Schutzstoffe gegen die zytotoxische und mutagene Wirkung von 5-Methoxypsoralen und UV-A in Chlamydomonas reinhardii

Abstract

The protective effects of scopoletin and related coumarin derivatives on the cytotoxicity and mutagenicity of 5-methoxypsoralen plus UV-A were investigated in arg^- cells of Chlamydomonas reinhardii.

Mutagenicity was determined by the number of Arg⁺ revenants induced by the treatment. The mutation frequency induced by 5-methoxypsoralen plus UV-A was substantially inhibited in a dose dependent fashion by the coumarin derivatives. The cytotoxicity was also inhibited in the presence of scopoletin.

The mutagenicity of 5-methoxypsoralen (1 µg/ml ≙ 4.63 µm) plus UV-A (2 kJ/m²) on arg^- cells was reduced to about 60% by 5,7-dimethoxycoumarin, 73% by scopoletin and 95% by umbelliferone at concentrations of 5 µM. All three coumarin derivatives showed a stronger but more uniformly inhibiton of mutagenicity at higher concentration levels (50-100 µM).