Biological Activities of Flavonoids from the Wood Extract of Artocarpus heterophyllus L. (Jackfruit)

Abstract

Background: Artocarpus heterophyllus L. (Jackfruit) has been used traditionally as treatment for inflammation and cancer. The aim of this study was to isolate compounds from A. heterophyllus wood extract and evaluate their biological activities such as anti-tumor promoting effect on Epstein-Barr virus early antigen induction, melanogenesis inhibitory activity on the B16 mouse melanoma 4A5 cell line and cytotoxic activity against three human cancer cell lines (HL60, A549, SK-BR-3). Methods: A. heterophyllus wood was extracted with n-hexane and methanol. The ethyl acetate soluble- fraction separated from the methanol extract was separated and purified with column chromatography to isolate compounds. The structures of isolated compounds were elucidated with spectroscopic methods. These compounds were evaluated for their biological activities. Results: Thirteen known compounds including four prenylflavonoids were isolated from the wood extracts. Nine flavonoids (2, 3, 5-11) exhibited potent anti-tumor promoting activity with IC50 values of 259-296 molar ratio / 32 pmol TPA. Two flavonoids, Norartocarpetin (6) at concentration of 30 μM and cyanomaclurin (11) at the concentration of 100 μM showed melanin content value of 47.6 % and 80.1 %, respectively. Two prenylflavonoids, cudraflavone B (2) and artocarpin (5), showed cytotoxicity against the human cancer cell lines tested. Cudraflavone B (2) showed cytotoxicity against all three human cancer cell lines whereas artocarpin (5) only exhibited cytotoxicity against two out three cell lines testes. The IC50 values were comparable to or better than cisplatin. Conclusion: From the view point of structure activity relationships of the flavonoids isolated, side chains such as prenyl and 3-methyl-1-butenyl moiety were key for their potent biological activities.