Abstract
Various phytochemicals have been reported to protect against oxidative stress. However, the mechanism underlying has not been systematically evaluated, which limited their application in disease treatment. Nuclear factor erythroid 2-related factor 2 (Nrf2), a central transcription factor in oxidative stress response related to numerous diseases, is activated after dissociating from the cytoskeleton-anchored Kelch-like ECH-associated protein 1 (Keap1). The Keap1-Nrf2 protein-protein interaction has become an important drug target. This study was designed to clarify whether antioxidantive phytochemicals inhibit the Keap1-Nrf2 protein-protein interaction and activate the Nrf2-ARE signaling pathway efficiently. Molecular docking and 3D-QSAR were applied to evaluate the interaction effects between 178 antioxidant phytochemicals and the Nrf2 binding site in Keap1. The Nrf2 activation effect was tested on a H(2)O(2)-induced oxidative-injured cell model. Results showed that the 178 phytochemicals could be divided into high-, medium-, and low-total-score groups depending on their binding affinity with Keap1, and the high-total-score group consisted of 24 compounds with abundant oxygen or glycosides. Meanwhile, these compounds could bind with key amino acids in the structure of the Keap1-Nrf2 interface. Compounds from high-total-score group show effective activation effects on Nrf2. In conclusion, phytochemicals showed high binding affinity with Keap1 are promising new Nrf2 activators.