Acacia macrostachya is used in Burkina Faso folk medicine for the treatment of inflammation
and cancer. The purpose of this study was to evaluate the antioxidant and cytotoxic effects of this
plant. The cytotoxic effects of root (dichloromethane B1 and methanol B2) and stem (dichloromethane
B3 and methanol B4) bark extracts of A. macrostachya were assessed on chronic K562 and acute
U937 myeloid leukemia cancer cells using trypan blue, Hoechst, and MitoTracker Red staining
methods. The antioxidant content of extracts was evaluated using DPPH (2,2-diphenyl-1-picryl-
hydrazyl) and FRAP (ferric reducing antioxidant power) methods. The root bark extracts B1 and
B2 of A. macrostachya demonstrated higher cytotoxicity with IC50 values in a low μg/mL range on
both U937 and K562 cells, while the stem bark B4 extract selectively affected U937 cells. Overall,
healthy proliferating peripheral blood mononuclear cells (pPBMCs) were not or barely impacted
in the range of concentrations cytotoxic to cancer cells. In addition, A. macrostachya exhibited
significant antioxidant content with 646.06 and 428.08 μg ET/mg of extract for the B4 and B2
extracts, respectively. Phytochemical screening showed the presence of flavonoids, tannins, alkaloids,
and terpenoids/steroids. The results of this study highlight the interest of A. macrostachya extracts for
the isolation of anticancer molecules.

Acacia macrostachya; antioxidant; cytotoxicity; cancer; leukemia; lymphoma