GREEN SYNTHESIS OF GOLD NANOPARTICLES OF ISOLATED CITRUS BIOFLAVONOID FROM ORANGE: CHARACTERIZATION AND IN VITRO CYTOTOXICITY AGAINST COLON CANCER CELL LINES COLO 320DM AND HT29

The aim of the present research was to perform green synthesis of gold nanoparticles of isolated citrus bioflavonoid from Citrus sinensis (orange) peel extract and to evaluate its anticancer potential. Methanolic extract of orange peel was obtained by Soxhlet extraction and citrus bioflavonoid was isolated by using column chromatography. Gold nanoparticles were developed by green synthesis method, wherein 1 % aqueous solution of isolated citrus bioflavonoid were mixed with 1% solution of HAuCl4 and incubated at ambient temperature for 4 to 5 hours and observed for the color change which indicated formation of nanoparticles. Obtained gold nanoparticles were evaluated by UV visible spectra, FTIR, SEM, XRD analysis and for antimicrobial potential against E coli, S.aureus and P. aeruginosa. Cytotoxicity study was carried out by using in vitro assays, namely MTT, SRB and Tryphan blue assay, against colon cancer cell line Colo 320 DM, and HT 29. results of SEM showed that nanosized particles in the range of 80-100nm were formed. Results of cytotoxicity studies revealed that CBFGNP exhibited 72.28% inhibition, against Colo320 DM whereas pure CBF showed 70.46% inhibition. Against HT 29, CBFGNP exhibited 69.79% inhibition, whereas for MTT assay and SRB assay, CBFGNP showed 80.15% and 58.29% inhibition, respectively. Moreover, CBFGNP exhibited 90.29% and 85% non viability against Colo320 DM and HT29. Based on the results, it can be concluded that gold nanoparticles of citrus bioflavonoid (CBFGNP) exhibits more cytotoxicity against Colo320 DM and HT29 as compared to pure citrus bioflavonoid when assessed by three different in vitro cytotoxicity assays.