Sakdiphong Punpai, Panupong Mahalapbutr, Panyakorn Taweechat, Ronnakorn Leechaisit, Kiattawee Choowongkomon, Ratchanok Pingaew, Wanlaya Tanechpongtamb
Colorectal cancer is strongly associated with chronic inflammation, in which cyclooxygenase-2 (COX-2) plays a pivotal role in tumor progression, making it an important therapeutic target. In this study, the antiproliferative activity of 1,4-naphthoquinones (3-18) in SW480 cells was investigated, and selected derivatives were characterized using computational and in vitro approaches. Initial antiproliferative screening identified compounds 3, 8, and 12 as the most potent candidates, prompting further investigation into their molecular mechanisms. These compounds were further assessed for their predicted interactions with COX-2 using AutoDock Vina and molecular dynamics (MD) simulations, followed by in vitro COX-2 inhibition and cell-based cytokine assays. Hoechst 33342, JC-1 staining, cell cycle analysis, and apoptosis assays were used to evaluate cellular responses. Through integrated computational and experimental approaches, we demonstrated that three compounds bind favorably within the COX-2 active site with key residues in a manner comparable to that of rofecoxib. Consistent with their ability to target COX-2, compounds 3, 8, and 12 showed potent in vitro COX-2 inhibitory at nanomolar (IC50 values of 10-18 nM) and modulated LPS-induced inflammatory responses, significantly reducing TNF-α, IL-8, and IL-10 release. The compounds were also associated with mitochondrial dysfunction, cell cycle changes, and apoptosis, with compound 12 emerging as the most active derivative and showing the strongest antiproliferative and pro-apoptotic effects. Our findings establish compound 12 as a promising lead candidate for the development of new anti-colorectal cancer agents and provide mechanistic insights into the interplay between COX-2 inhibition, inflammatory modulation, and apoptosis induction in inflammation-associated colorectal carcinogenesis.