Characterization of Anticancer Principles of Celosia argentea (Amaranthaceae)

An Indian origin, Celosia argentea is a weed growing during rainy season traditionally claimed for treating several ailments. Early researches on C. argentea were focused on the anti-cancer screening of seeds, with few reports on aerial parts.

To isolate and characterize bioactive compounds of aerial parts of C. argentea and evaluate their anticancer potential.

The methanolic aerial part extract was fractionated on column chromatography using chloroform: methanol mixture. The fractions; 80:20 and 95:5 were purified on MCI-HP20 HPLC column. Chromatographically pure compounds were pooled, concentrated and characterized spectroscopically. The compounds were further screened for anti-oxidant and cytotoxic potential.

Isolated compounds were confirmed as: (1) Luteolin-7-O-glucoside and (2) phenolic, 1-(4-hydroxy-2-methoxybenzofuran-5-yl)-3-phenylpropane-1,3-dione. Both exhibited significant antioxidant potential with IC50 values of 20.80 and 21.30 μg/ml for 2,2-diphenyl-1-picrylhydrazyl assay (***P < 0.001) and significant Trolox equivalent antioxidant capacity (TEAC) values for 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (*P < 0.05) and ferric reducing antioxidant potential assay (****P < 0.0001). In 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay, Compound 1 and 2 showed potent cytotoxicity against SiHa, HCT, MCF-7 cancer cell lines at 20 μg/ml (****P < 0.0001) and 18 μg/ml (**P < 0.01), respectively, without affecting the normal Vero cells. Both compounds enabled maximum reduction in cell viability at 50 μg/ml against HT-29 (***P < 0.001) and MCF-7 cell lines (**P < 0.01) in try pan blue viability assay. Apoptosis occurred at concentrations of 47.33 ± 0.8 μg/ml and 56.28 ± 1.2 μg/ml for Compound 1 and 35.15 ± 0.4 μg/ml and 28.05 ± 0.3 μg/ml for Compound 2 for HT-29 and MCF-7 respectively.

A novel anticancer phenolic compound; (1-(4-hydroxy-2-methoxybenzofuran-5-yl)-3-phenylpropane-1,3-dione), isolated from aerial parts of C. argentea was a valuable finding of the research.

The present study validated the potential of the plant C. argentea as an antioxidant, and anticancer remedy with two valuable isolations. Although one of them is a known compound: Luteolin 7-0 glycoside, the other isolated phenolic compound;-{1-(4-hydroxy-2-methoxybenzofuran-5-yl)-3-phenylpropane-1,3-dione}, is the first to be reported and thus can be considered as a valuable outcome of this research work.