Veratric Acid and the Cytotoxic Activity of Handroanthus impetiginosus Inner Bark Extract: No Association

Handroanthus impetiginosus is a medicinal tree and a source of bioactive compounds whose cytotoxicity has often been associated with lapachol, α-lapachone, and β-lapachone. Because these compounds may occur at low concentrations, this study evaluated veratric acid as an alternative phytochemical marker of the cytotoxic activity of an inner bark extract. The hydroethanolic extract was obtained by dynamic maceration, lyophilized, and characterized for total polyphenol content, antioxidant activity, and phytochemical profile. Cytotoxic effects of the extract and veratric acid were assessed in HUVEC, MDA-MB-231, A549, and HepG2 cells. The extract reduced tumor-cell viability more strongly than HUVEC viability under the tested conditions. In contrast, veratric acid at extract-equivalent concentrations did not reduce cell viability. These findings indicate that veratric acid does not account for the cytotoxicity of the extract and is therefore unsuitable as a marker of this biological effect under the conditions evaluated.