Characterization of Anticancer Principles of Celosia argentea (Amaranthaceae)

Background

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.

Objective

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

Materials and Methods

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.

Results

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.

Conclusion

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.