Anticancer potential and toxicity of the genus Handroanthus Mattos (Bignoniaceae): A systematic review

The genus Handroanthus Mattos (Bignoniaceae) is widely used for the treatment of cancer in traditional medicine in Brazil and other South American countries. The anticancer potential of species of this genus has been reported in the literature, indicating that their chemical compounds may be effective against different tumor cell lines. In this perspective, the present study aimed to conduct a systematic review of ethnobotanical, pharmacological, phytochemical and toxicological information on Handroanthus species related to cancer treatment. Searches were conducted in the Google Scholar, PubMed®, ScienceDirect® and SciELO databases. A total of 78 articles published in the last thirty-two years (1990-2022) were eligible and included in the review. According to the scientific documents analyzed, five species of Handroanthus are widely used for the treatment of cancer in the traditional medicine of Brazil and other South American countries, including Bolivia and Argentina. The bark (88%) is the main part used in traditional preparations. Extracts and fractions from Handroanthus showed cytotoxicity against the following tumor cell lines: HL-60, MDA-MB-435, MDA-MB-231, MCF-7, HT-29, HCT-8, HCT-116, HEp-2, HepG2, CACO-2, SF-295, NCI-H292, NCI-H460, HeLa, and OVCAR-8. β-Lapachone, a naphthoquinone isolated from some species of this genus, is the most investigated compound for anticancer potential and has proved effective against some lung cancer cell lines (CL1-1, CL1-5 and A549). Results related to toxicological studies were not conclusive, considering that some extracts and compounds isolated from plants of this genus may present some degree of toxicity depending on the time of use and the concentration/dose used. Thus, despite the promising effects against various cancer cell lines, caution is needed when making use of these products.