Anticancer effect of sequential extracts from Curcuma caesia rhizomes on human cancer cell lines and characterization of selected polyphenols in active extracts by LC-MS/MS

The objective of the present study is to quantify and compare in vitro cytotoxic properties of crude extracts sequentially extracted in solvents from the least polar hexane to the most polar water (hexane, petroleum ether, benzene, chloroform, ethyl acetate, methanol and water) from fresh and dry rhizomes of black turmeric on human cancer cell lines and further identification of phenolic acids and flavonoids by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the active extracts. Of the extracts analyzed, chloroform and ethyl acetate extracts exhibited significant cytotoxicity on the tested cells. LC-MS/MS analysis of the active extracts (chloroform and ethyl acetate) revealed the presence of 14 phenolic acids and 9 flavonoids for the first time in the rhizomes of C. caesia, phenolic acids present in high concentration being gallic and vanillic acids in chloroform extracts, vanillic and protocatechuic acids in ethyl acetate extracts and catechin being the most abundant flavonoid. The active ingredients gallic acid, vanillic acid, protocatechuic acid and catechin present in these extracts may act as lead compounds for the development of new drugs against cancer.