Bouea macrophylla is a tree widely grown throughout South East Asia. It is used in folk medicine for the treatment of various illnesses. The present study aimed to identify the chemical constituents and to test the antimicrobial and anticancer activities of an ethanol extract from B. macrophylla leaves. The extract exhibited excellent antibacterial properties against 9 out of 10 target microorganisms. including four Gram-negative bacteria (Escherichia coli, Shigella flexneri, Vibrio cholera, and Pseudomonas aeruginosa) and four Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, and Bacillus cereus), as well as a fungus (Candida albicans). In addition, the extract was also tested on HeLa and human colorectal carcinoma (HCT116) cells to evaluate its cytostatic effects. The ethanol extract was able to inhibit the proliferation of HeLa and HCT116 cells, showing IC50 = 24 ± 0.8 and 28 ± 0.9 µg/mL, respectively, whereas the IC50 values of doxorubicin (standard) were 13.6 ± 1.3 and 15.8 ± 1.1 µg/mL respectively. Also, we identified various bioactive compounds in the extract such as polyphenols, flavonoids, caryophyllene, phytol, and trans-geranylgeraniol by GC-MS, which could contribute to the extract's biological activities. Therefore, our findings strongly indicate that the constituents of the B. macrophylla ethanol extract could be active against the tested bacteria and fungi as well as cancer cells. Further investigation is needed to understand the mechanisms mediating the antimicrobial and anticancer effects and identify signaling pathways that could be targeted for therapeutic application.
Keywords: Bouea macrophylla; HCT116; HeLa; antimicrobial activity; extract.