spectroscopic studies on the interaction of anti cancer rosemary with ctdna

Background: some herbal anticancer agents have direct interactions with dna. objectives: the present study aimed to investigate the interaction of ctdna with rosemary flowers. materials and methods: we used uv-vis, fluorescence and circular dichroism (cd) spectroscopic techniques. results: the absorption of dna at 260 nm increased on addition of rosemary. herb extract quench the fluorescence of etbr bound to ctdna. the stern-volmer constant (k) value for rosemary extract is 0.39 (mg/ml)-1. finally, the cd spectra indicate that rosemary induces some conformational changes in ctdna structure such as b to c-form transition. conclusions: our results illustrate that rosemary extracts interact with ctdna through minor groove binding. this is one of the molecular mechanisms underlying anticancer effects of rosemary.