Characterization of tangeretin as an activator of nuclear factor erythroid 2-related factor 2/antioxidant response element pathway in HEK293T cells

Chengyu Lv; Yuqiu Li; Rong Liang; Wei Huang; Yechen Xiao; Xinqi Ma; Yongjun Wang; Haoyang Zou; Fen Qin; Chang Sun; Tiezhu Li; Jie Zhang

doi:10.1016/j.crfs.2023.100459

Characterization of tangeretin as an activator of nuclear factor erythroid 2-related factor 2/antioxidant response element pathway in HEK293T cells

Curr Res Food Sci. 2023 Feb 9:6:100459. doi: 10.1016/j.crfs.2023.100459. eCollection 2023.

Authors

Chengyu Lv^{1

2}, Yuqiu Li², Rong Liang³, Wei Huang², Yechen Xiao¹, Xinqi Ma², Yongjun Wang², Haoyang Zou¹, Fen Qin², Chang Sun², Tiezhu Li², Jie Zhang¹

Affiliations

¹ College of Food Science and Engineering, Jilin University, Changchun, 130062, China.
² Institute of Agro-food Technology, Jilin Academy of Agricultural Sciences, Changchun, 130033, China.
³ Agricultural Science and Engineering School, Liaocheng University, Liaocheng, 252059, China.

Abstract

Numerous studies have reported that tangeretin is a polymethoxylated flavone with a variety of biological activates, but little research has been done on the antioxidant mechanism of tangeretin. Hence, we investigated the effect of tangeretin on the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and its potential molecular mechanisms by in vitro and in silico research. The results of molecular docking suggested that tangeretin bound at the top of the central pore of Kelch-like ECH-associated protein 1 (Keap1) Kelch domain, and the hydrophobic and hydrogen bond interactions contributed to their stable binding. Herein, the regulation of Nrf2-ARE pathway by tangeretin was explored in the human embryonic kidney cell line HEK293T, which is relatively easy to be transfected. Upon binding to tangeretin, Nrf2 translocated to the nucleus of HEK293T cells, which in turn activated the Nrf2-ARE pathway. Luciferase reporter gene analysis showed that tangeretin significantly induced ARE-mediated transcriptional activation. Real-time PCR and Western blot assays showed that tangeretin induced the gene and protein expressions of Nrf2-mediated targets, including heme oxygenase 1 (HO-1), nicotinamide adenine dinucleotide phosphate (NADPH) quinone dehydrogenase 1 (NQO1), and glutamate-cysteine ligase (GCLM). In addition, tangeretin could effectively scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. In summary, tangeretin may be a potential antioxidant via activating the Nrf2-ARE pathway.

Keywords: Antioxidant response element; Molecular docking; Nuclear factor erythroid 2-related factor 2; Tangeretin.