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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., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: Osmanthus fragrans flowers are used as folk medicine and additives for teas, beverages and foods. The metabolites of O. fragrans flowers from different geographical origins were inconsistent in some extent. Chromatography and mass spectrometry combined with multivariable analysis methods provides an approach for discriminating the origin of O. fragrans flowers., Objective: To discriminate the Osmanthus fragrans var. thunbergii flowers from different origins with the identified metabolites., Methods: GC-MS and UPLC-PDA were conducted to analyse the metabolites in O. fragrans var. thunbergii flowers (in total 150 samples). Principal component analysis (PCA), soft independent modelling of class analogy analysis (SIMCA) and random forest (RF) analysis were applied to group the GC-MS and UPLC-PDA data., Results: GC-MS identified 32 compounds common to all samples while UPLC-PDA/QTOF-MS identified 16 common compounds. PCA of the UPLC-PDA data generated a better clustering than PCA of the GC-MS data. Ten metabolites (six from GC-MS and four from UPLC-PDA) were selected as effective compounds for discrimination by PCA loadings. SIMCA and RF analysis were used to build classification models, and the RF model, based on the four effective compounds (caffeic acid derivative, acteoside, ligustroside and compound 15), yielded better results with the classification rate of 100% in the calibration set and 97.8% in the prediction set., Conclusions: GC-MS and UPLC-PDA combined with multivariable analysis methods can discriminate the origin of Osmanthus fragrans var. thunbergii flowers. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

Edible flowers contain numerous phytochemicals which contribute to their health benefits, and consumption of edible flowers has increased significantly in recent years. While many researchers have been conducted, no literature review of the health benefits of common edible flowers and their phytochemicals has been compiled. This review aimed to present the findings of research conducted from 2000 to 2015 on the species, traditional application, phytochemicals, health benefits, and the toxicology of common edible flowers. It was found in 15 species of common edible flowers that four flavonols, three flavones, four flavanols, three anthocyanins, three phenolic acids and their derivatives were common phytochemicals and they contributed to the health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, anti-obesity, and neuroprotective effect. Toxicology studies have been conducted to evaluate the safety of common edible flowers and provide information on their dosages and usages.