Cancer is one of the most important causes of death all around the world. Screening plants and their secondary metabolites as
cytotoxic agents is one of the common methods for identifying new compounds used in
chemotherapy and inhibition
cancer process. Caesalpinia bonduc (L.) Roxb. from the Fabaceae family was used for improving
wound,
fever,
tumor, hydrocele,
hernia,
smallpox,
toothache,
inflammation, and as
astringent,
anthelmintic,
antidiabetic, and
antimalarial agent in
traditional medicine. A bioassay-guided study of this species led to the isolation of three
flavonoids. At first, the cytotoxicity of
methanol extract of aerial parts (leaves and stems), seeds, and legumes of this plant was tested against MCF-7 and PC-3 by MTT assay. The
methanol extract of legumes showed better inhibitory activities (IC50 < 500 µg/mL). As a result, this extract was selected for fractionation. In the next step, the
ethyl acetate (EtOAc) fraction was selected for
phytochemical analysis based on the inhibitory activity (IC50 = 170 ± 0.9 µg/mL). In this way, total
phenol content (625 ± 7.2 GAE/g extract) and
antioxidant activity (IC50 = 6.1 ± 0.3 µg/mL) was compared by
BHT (IC50 = 13.5 ± 0.7 µg/mL). Finally, three compounds including,
quercetin-3-methyl ether (1),
kaempferol (2), and
kaempferol-3-O-α-L-rhamnopyranosyl-1→2)-β-D-xylopyranoside (3) were isolated from EtOAc fraction, and all isolated compounds were tested for their cytotoxicity and compound 1 showed better inhibitory activity than other two compounds. This study suggests that Caesalpinia bonduc could be considered for further investigations as a natural source of biological compounds.