Showing papers by "Catarina Satie Takahashi published in 1998"

In vitro and in vivo study of the clastogenicity of the flavone cirsitakaoside extracted from Scoparia dulcis L. (Scrophulariaceae).

Abstract: The mutagenic effect of the flavone cirsitakaoside extracted from the medicinal herb Scoparia dulcis was evaluated in vitro by using human peripheral blood cultures treated with doses of 5, 10, and 15 μg of the flavone/ml culture medium for 48 h. The compound proved to be mutagenic at the highest concentration tested (15 μg/ ml). Furthermore, the proliferative index was significantly reduced in all cultures treated with the flavone, although the mitotic index was not reduced. However, the clastogenic activity of the flavone cirsitakaoside was not observed when Swiss mice were treated orally with doses of 10, 20, and 30 mg/animal for 24 h. Teratogenesis Carcinog.

Chromosome damage induced by DNA topoisomerase II inhibitors combined with g-radiation in vitro

Abstract: Combined radiation and antineoplastic drug treatment have important applications in cancer therapy. In the present work, an evaluation was made of two known topoisomerase II inhibitors, doxorubicin (DXR) and mitoxantrone (MXN), with g-radiation. The effects of DXR or MXN on g-radiation-induced chromosome aberrations in Chinese hamster ovary (CHO) cells were analyzed. Two concentrations of each drug, 0.5 and 1.0 µg/ml DXR, and 0.02 and 0.04 µg/ml MXN, were applied in combination with two doses of g-radiation (20 and 40 cGy). A significant potentiating effect on chromosomal aberrations was observed in CHO cells exposed to 1.0 µg/ml DXR plus 40 cGy. In the other tests, the combination of g-radiation with DXR or MXN gave approximately additive effects. Reduced mitotic indices reflected higher toxicity of the drugs when combined with radiation.