Study the antitumor activity of thymoquinone on Plk1 receptor using molecular docking

Recently, there is growing interest in the natural bioactive components having anticancer activity.Thymoquinone (TQ) is an anticancer phytochemical commonly found in black cumin (nigella sativa). Thymoquinone exhibits anticancer activity via numerous mechanisms of action, specifically by showing selective antioxidant and oxidant activity, interfering with DNA structure, affecting carcinogenic signaling molecules/pathways and immunomodulation [1]. It targets cellular copper, which is presentin the chromatin and is closely associated with DNAbase guanine, and causes oxidative breakage to DNAand consequent cancer cell death [2].A number of carcinogenic signaling pathways or signaling molecules have been reported as thymoquinone’starget.Serine/threonine kinase (Plk1) has been established as one of the most promising targets for molecular anticancer intervention. In this study, we discuss the potential of thymoquinone as anticancer molecule and its mechanism of action by using molecular docking studies.The crystal structure of serine/threonine kinase Plk1(PDB entry 3FC2) was obtained from the Protein Data Bank (http://www.rcsb.org./pdb). Molecular docking technique was performed to investigate the probable interactions. B3lyp/6-31g method was used to determine docking data such as binding energy (Kb) and inhibition constant (Ki) values. The results show moderate antitumor activity of the thymoquinone