Planta Med 2006; 72 - S_023
DOI: 10.1055/s-2006-949756

Selected phototoxicological assays used for plant metabolites screening

V Chobot 1, 2, J Vytlačilová 1, L Kubicová 1
  • 1Faculty of Pharmacy, Charles University, Heyrovskeho 1203,500 05 Hradec Krålove, Czech Republic
  • 2Present address: Faculty of Life Sciences, University ofVienna, Althanstral!,e 14, A.1090 Vienna, Austria

In the last decade, phototoxins especially attracted the attention of pharmacists, toxicologists, cosmetologists, and food specialists [1]. Progress in phototoxicologal research relies on efforts to develop reliable screening methods.

This issue will be discussed with the aid of the thiophene polyacetylene (E)-1-[5-(hept-5-en-1,3-diynyl)-2-thienyl]ethan-1,2-diol. Together with the furocoumarin xanthotoxin as positive control phototoxicity in conjunction with UV A radiation was assessed by histidine photo-oxidation assay and Arlemia and Tubifex bioassays [2]. The determined activities were statistically explored by probit-log calculations of EC50 and LC50 values and evaluated by comparison of effective and lethal concentrations of dark controls to the irradiated sets.

The thiophene polyacetylene showed strong phototoxicity in the histidine photo-oxidation assay and in both organismic bioassays. Xanthotoxin demonstrated higher effects independent of UV radiation in the Artemia assay. The differences in the phototoxicity of both photosensitizers may be caused by their variable absorption of the test compound and different mechanisms of activity. The results demonstrate the different sensitivity of the applied assays and suggest combining various phototoxicological assessment methods.

Acknowledgements: This work was supported by Project MSM 0021620822 of the Czech Ministry of Education.

References: 1. Chobot, V. et al. (2004), Cent. Eur. J. Publ. Health 12: S31.S33. 2. Chobot, V. et al. (2006), Fitoterapia 77: 194–198.