The green approach of nanoparticle synthesis has gained more attention by researchers because of its nontoxic, eco-friendly, biocompatible, and sustainable nature. The present research investigated the anticancer effectiveness of silver nanoparticles synthesized from marine algae Chaetomorpha linum (C. linum) against colon cancer cell HCT-116 in vitro. Biosynthesized silver nanoparticles (C-AgNPs) are characterized using UV-spectrophotometry, dynamic light scattering (DLS), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). We demonstrated the dose-dependent cytotoxic effect of C-AgNPs in human colorectal carcinoma cells (HCT-116) using MTT assay. The apoptosis induction in HCT-116 cells caused by C-AgNPs has studied fluorescence microscope by staining with fluorogenic agents 4',6-diamidino-2-phenylindole (DAPI), rhodamine 123, and 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA). By using a flow cytometric test, the apoptotic action of C-AgNPs was performed. The immunoblotting study of caspases, as well as pro-apoptotic and anti-apoptotic protein expression, was studied using the PCR technique to understand the underlying molecular mechanism of C-AgNPs on cancer cells. The apoptotic studies showed an increase in the expression of apoptotic caspase 3, caspase 9, BH3-interacting domain death agonist (Bid), and Bax, along with a decrease in the anti-apoptotic protein like Bcl-2 and Bcl-xl, thereby veritably confirmed by immunoblotting and qPCR technique. The biosynthesized C-AgNPs was an efficient anticancer agent that can induce apoptosis in the HCT-116 colon cells.
Keywords: Apoptosis; Chaetomorpha linum; Colon cancer; Cytotoxicity; HCT-116; Silver nanoparticles.