Cytotoxic prenylflavanones from philippine stingless bee (Tetragonula biroi Friese) nests

• Main Authors: De Los Reyes, Mariquit M., Oyong, Glenn G., Ebajo, Virgilio D., Shen, Chien Chang, Ragasa, Consolacion Y.
• Format: text
• Published: Animo Repository 2018
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/737; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=1736&context=faculty_research
• Institution: De La Salle University

The dichloromethane crude extract and compounds, glyasperin A (1), propolin E (2) and propolin A (3), obtained from Philippine stingless bee (Tetragonula biroi Friese) nests, were evaluated for their cytotoxic potentials. The anti-proliferative activities of crude extract and compounds 1-3 against human cancer cell lines, breast (MCF-7) and colon (HT-29 and HCT-116), and a normal cell line, human dermal fibroblast neonatal (HDFn), were evaluated using the PrestoBlue® cell viability assay. The crude extract was most anti-proliferative against HCT-116 cells (IC50 = 1.410 μg/mL). Glyasperin A (1) exhibited the strongest effect on MCF-7 cells (2.378 μg/mL). Propolin E (2) was most cytotoxic against HCT-116 cells (2.279 μg/mL), while propolin A (3) was most inhibitory against MCF-7 cells (2.815 μg/mL). Comparing the colorectal cancer cell lines, HCT-116 was generally more susceptible under crude extract, 2, and 3 (IC50 = 1.410, 2.279, 3.013 μg/mL, respectively) than HT-29 (5.620, 5.320, 5.359). Comparing the activities of propolin E and propolin A against HCT-116 cells, 2 (IC50 = 2.279 μg/mL) was more cytotoxic than 3 (3.013). The crude extract was more cytotoxic than Zeocin against HCT-116 cells. To our best of knowledge, this is the first report on the anti-proliferative properties of crude extract and compounds from T. biroi.