Computational Investigation of Cinnamon Phytochemicals Targeting Key Cancer Signaling Pathways: Molecular Docking, ADMET and Molecular Dynamics Simulations Analysis

Abstract

Cancer remains one of the leading causes of morbidity and mortality worldwide, highlighting the need for safe and effective therapeutic strategies targeting multiple oncogenic pathways. Cinnamon (Cinnamomum spp.) contains several bioactive phytochemicals with reported antioxidant and anticancer properties; however, their potential interactions with key cancer-associated signaling proteins have not been comprehensively investigated. In this study, an integrated computational and preliminary experimental approach was employed to evaluate four major cinnamon phytochemicals, namely e-cinnamaldehyde, eugenol, p-cymene, and cinnamic acid. Consensus molecular docking was performed using AutoDock Vina (v1.2.7), Smina (v2020.12.10), and GNINA (v1.3.3) against phosphoinositide 3-kinase (PI3K), nuclear factor kappa B (NF-κB), and mammalian target of rapamycin (mTOR). Docking analyses were complemented by protein-ligand interaction profiling, pharmacokinetic and toxicity prediction (ADMET), and a 100 ns molecular dynamics simulation with MM/GBSA binding free-energy analysis of the selected mTOR-p-cymene complex. In addition, the antioxidant activity and cytotoxic effects of a crude methanolic cinnamon bark extract were evaluated using in vitro antioxidant assays and MTT assays against HCT-116 and HT-29 colorectal cancer cell lines. Consensus docking predicted that all four phytochemicals were capable of interacting with the selected protein targets, although the predicted binding profiles varied among the compounds. Eugenol showed comparatively more favorable predicted interactions with PI3K, p-cymene produced the lowest predicted docking score for NF-κB, and cinnamic acid displayed a comparatively consistent predicted multitarget binding profile across PI3K, NF-κB, and mTOR. ADMET analysis suggested that all compounds satisfied major drug-likeness criteria and exhibited predicted oral bioavailability, although potential cytochrome P450 interactions and hepatotoxicity were predicted for some compounds. Molecular dynamics simulation indicated that the selected mTOR-p-cymene complex maintained a stable binding pose throughout the simulation, while MM/GBSA analysis yielded a modest binding free-energy estimate (ΔG_bind = −4.70 ± 8.20 kcal/mol), which should be interpreted cautiously because of the observed energetic variability. The crude methanolic cinnamon bark extract exhibited antioxidant activity and reduced the viability of HCT-116 and HT-29 colorectal cancer cells in a concentration-dependent manner. Collectively, these findings provide computational predictions of potential interactions between selected cinnamon-derived phytochemicals and cancer-associated signaling proteins and are consistent with the preliminary observation that the crude cinnamon extract exhibits antioxidant activity and cytotoxic effects in colorectal cancer cell lines. However, the computational analyses do not establish direct inhibition of the PI3K/NF-κB/mTOR signaling pathway, and the biological assays were performed using a crude extract rather than isolated phytochemicals. Therefore, further studies using purified compounds, biochemical target validation, pathway-specific cellular analyses, and in vivo models are required to determine whether the predicted protein-ligand interactions contribute to the observed biological activity.