RESUMO
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. SUMMARY: 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.
