Dual Anticancer and COX-2 Inhibitory Activity of Tailored Paracetamol-Alkanesulfonate Conjugates: A Promising Therapeutic Approach

Abstract

Innovative paracetamol-alkanesulfonate conjugates (5a–l) were designed and synthesized through a multi-step process starting with acetaminophen. Their dual functionality as anticancer agents and inhibitors of cyclooxygenase-2 (COX-2), created through a multi-step reaction sequence beginning with acetaminophen, was investigated. The anticancer activity was assessed across seven different cancer cell lines: HOS (osteosarcoma), A-549 (lung), MCF-7 (breast), HT-29 (colon), PC3 (prostate), Caco-2 (colorectal), and HCT-116 (colorectal). Among these conjugates, 5d showed exceptional activity against the Caco-2 cell line. The tested compounds demonstrated potent COX-2 activity with IC₅₀ values extending from 0.052 to 0.096 µM. Moreover, compounds 5d, 5h, and 5i displayed remarkable COX-2 selectivity, as reflected by their high selectivity indices and substantially weaker COX-1 inhibition compared to celecoxib, the reference drug. These results are further supported by COX-2 overexpression assays in Caco-2 cells, where compound 5d significantly downregulated COX-2 protein levels, reinforcing its potential as a safer and selective COX-2 inhibitor. Further investigation into the mechanism of action revealed that compound 5d promotes apoptosis by enhancing the expression of the proapoptotic Bax protein while simultaneously reducing levels of antiapoptotic Bcl-2, ultimately leading to increased caspase-3 expression, cell cycle arrest, and apoptosis. To understand the structural basis for this activity, molecular docking and dynamics simulations were conducted, which confirmed that compound 5d forms stable interactions within the catalytic pockets of both Bcl-2 and BAX receptors. These findings suggest that compound 5d has significant potential as a dual-acting therapeutic agent.