Docking Prediction for Luteolin Inhibiting TNF-α and NF-κB Pathway

Chinese traditional medicine uses luteolin for treatment of hypertension, inflammatory diseases, and cancer. Luteolin inhibits NF-κB activity at low micromolar (μM) concentrations, and does not exhibit any cytotoxic effects up to 100 μM. In this paper, we predict and analyze the ability of luteolin to inhibit TNF-α and NF-κB pathways including TNFR1, TRADD, TRAF2, RIP1, and IKKβ. Homology models of TNF-α and NF-κB pathways, including TNFR1, TRADD, TRAF2, RIP1, and IKKβ, were constructed using the Swiss-Model protein-modeling server, and verified by PROCHECK, VERIFY3D and ERRAT software. Protein-ligand interactions were determined by executing docking the six TNF-α and NF-κB pathway models, including TNFR1, TRADD, TRAF2, RIP1, and IKKβ, with luteolin using AUTODOCK 4.0 software. We used AUTODOCK 4.0 and LIGPLOT software packages to provide analysis of binding sites. Results indicate that luteolin binds to TNFR1, TRADD, TRAF2, and RIP1 through covalent bonding. Thus, luteolin may inhibit the TNFR1, TRAF2, TRADD, and RIP1 from complexation. Luteolin may also block the ATP binding sites of IKKβ, which inhibits tyrosine and serine kinases by competing with ATP binding sites and reducing the ability of IKKγto recruit the IKK complex to RIP following stimulation of TNF-α, by blocking the IKKβ substrate binding site. Therefore, luteolin is an effective inhibitor of the NF-κB pathway including TNFR1, TRADD, TRAF2, RIP1, and IKKβ.