Estrogenic and chemopreventive activities of xanthones and flavones of Syngonanthus (Eriocaulaceae)

Estrogenicity assay: Methanol extract of S. nitens (Sn) and xanthones 2, 5, 3 and 4 were significantly different (∗) from negative control (DMSO) (α = 0.05) and were considered estrogenic in the recombinant yeast assay (RYA). Antimutagenicity assay (Ames test): All the isolated compounds displayed more strong antimutagenic activity for TA100, reaching the inhibiting 62% (1); 55% (2); 51% (3); 89% (5); 69% (6); 75% (7); 85% (8) and 75% (9) of the mutagenic effect of aflatoxin B1. 4 showed more significantly results for TA98 and inhibited 54% of the mutagenicity caused by benzo[a]pyrene. ∗Concentrations that were significantly different from positive controls (TA100: Aflatoxin B1; TA98: benzo[a]pyrene) (α = 0.05).