Usefulness of the SOS Chromotest in the study of medicinal plants as radioprotectors

Purpose: The aim of this work is to investigate the usefulness of a modified protocol of the SOS Chromotest to detect antigenotoxicity activities against γ-rays of plant extracts with proven antioxidant activity, and to elucidate the antigenotoxic mechanisms involved in radioprotection using this system. Materials and methods: The methodology developed was assayed with amifostine, the most studied radioprotector, and with Phyllanthus orbicularis HBK, Cymbopogon citratus (DC) Stapf and Pinus caribaea Morelet extracts, using pre- and post-treatment procedures. Results: The P. caribaea and C. citratus extracts were antigenotoxic against γ-rays when the cells were pre-treated with both extracts, suggesting a possible antigenotoxic action through a free radical scavenging mechanisms. Amifostine and the P. orbicularis extract were also antigenotoxic under pre- and post-treatment conditions, indicating that several antimutagenic components of this plant extract may also operate by some intracellular mechanism, unlike its antioxidant activity. Conclusions: The results have demonstrated the usefulness of the modified SOS Chromotest assay in the screening of phytochemical radioprotectors as well as in the study of their antimutagenic mechanisms. © 2006 Taylor & Francis.