Ethanolic Extract of Averrhoa carambola Leaf Has an Anticancer Activity on Triple-Negative Breast Cancer Cells: An In Vitro Study

<b>Background/Objectives</b>: <i>Averrhoa carambola</i>, or star fruit, is a shrub known for its medicinal properties, especially due to bioactive metabolites identified in its roots and fruit with anti-cancer activity. However, the biological effects of its leaves remain unexplored. This study aimed to assess the effects of ethanolic extract from <i>A. carambola</i> leaves on triple-negative breast cancer (TNBC), an aggressive subtype lacking specific therapy. <b>Methods</b>: Phytochemical analysis and HPLC profile and additional cell line evaluation employing MDA-MB-231 were carried out. <b>Results</b>: Phytochemical screening revealed that the ethanolic extract was rich in flavonoids, saponins, and steroids, demonstrating an antioxidant capacity of 45%. ¹H NMR analysis indicated the presence of flavonoids, terpenes, and glycoside-like compounds. Cell viability assays showed a concentration-dependent decrease in viability, with an IC₅₀ value of 20.89 μg/mL at 48 h. Clonogenic assays indicated significant inhibition of replicative immortality, with only 2.63% survival at 15 μg/mL. Migration, assessed through a wound healing assay, was reduced to 3.06% at 100 μg/mL, with only 16.23% of cells remaining attached. An additive effect was observed when combining lower concentrations of the extract with doxorubicin, indicating potential synergy. <b>Conclusions</b>: These results suggest that the ethanolic extract of <i>A. carambola</i> leaves contains metabolites with anti-cancer activity against TNBC cells, supporting further research into their bioactive compounds and therapeutic potential.