Identification of Oleandrin and other Cardenolides with Anticancer Activity in Methanolic Extracts from Plants of the Apocynaceae Family

Abstract

Cardenolides are a family of steroid-type compounds, which due to their biological activity, have become consolidated as possible anticancer agents. The Apocynaceae family is the main source of these compounds, of which about 25% show anticancer activity. In this research, six species of the Apocynaceae family present in the Ecuadorian Amazon were considered: Himatanthus tarapotensis, Himatanthus bracteatus, cf. Aspidorperma excelsum, Rauvolfia praecox y Tabernamontana sananho; being Nerium oleander the model specie. In the methanolic extracts of these six species was evaluated the presence of oleandrin and other cardenolides, as well as the cytotoxic activity in two cancer cell lines, HeLa and D-384. It was found that the species H. tarapotensis, H. bracteatus, and cf A. excelsum possess cardenolides, among them oleandrin. Furthermore, these extracts showed strong cytotoxic activity in the evaluated cell lines without producing marked hemolytic effects. The cytotoxic activity shown by H. tarapotensis, H. bracteatus and cf. A. excelsum is greater than N. oleander and can be attributed to an additive or synergistic effect between cardenolides and another family of compounds such as triterpenoids, indole alkaloids or iridoids reported in Apocynaceaes. The results obtained confirm the potential that plant can present in the search for new agents against complex diseases.