ABSTRACT
Aim: To establish ARE dual-luciferase reporter assay system and used it to identify the antioxidant substance of Scutellaria baicalensis Georgi. Methods: 293T cells were transiently co-transfected with ARE luciferase reporter plasmid PGL 4. 37 and sea kidney luciferase reporter plasmid PRL-TK. Three major active ingredients of Scutellaria baicalensis Georgi such as scutellarin, baicalein, baicalin and/or estrogen receptor (ER) specific inhibitor were added to Nrf2-ARE luciferase reporter assay system to detect whether they exerted antioxidant effect through the estrogen receptor affecting the Nrf2-ARE signaling pathway. Results: Baicalin (100 μmol · L-1) could obviously activate Nrf2-ARE pathway in 293T cells, and the induced expression was(1. 56 ±0. 01) times that of blank group (P < 0. 01). After pre-administration of ER specific inhibitor, the induced expression decreased to (1. 02 ±0. 23) times, and the antioxidant effect disappeared. After pre-administration of ER and Nrf2-ARE pathway specific inhibitor respectively, ROS in HaCaT cells injured by UVB significantly increased and and SOD was markedly down-regulated by baicalin. Conclusion Baicalin plays antioxidant activity through mediating Nrf2-ARE signaling pathway based on estrogen receptor.