title: Naringenin exerts cytoprotective effect against paraquat-induced toxicity in human bronchial epithelial BEAS-2B cells through NRF2 activation.
abstract: We have previously shown that paraquat (PQ)-induced oxidative stress causes dramatic damage in various human cell lines. Naringenin (NG) is an active flavanone, which has been reported to have beneficial bioactivities, including antioxidative, anti-inflammatory, and antitumorigenic activities, with a relatively low toxicity to normal cells. In this study, we intended to assess the cytoprotective effect of NG against PQ-induced toxicity in the human bronchial epithelial BEAS-2B cell line. Co-treatment with NG in PQ-treated BEAS-2B cells can reduce PQ-induced cellular toxicity. NG can also decrease the generation of intracellular ROS caused by PQ treatment. We also observed that treatment with NG in PQ-exposed BEAS-2B cells can significantly induce the expression of antioxidant-related genes, including GPX2, GPX3, GPX5, and GPX7. NG co-treatment can also activate the NRF2 transcription factor and promote its nuclear translocation. In addition, NG co-treatment can induce the expression of NRF2-downstream target genes such as that of heme oxygenase-1 (HO-1) and
  quinone oxidoreductase 1 (NQO1). A small interfering RNA study revealed that the knockdown of NRF2 can abrogate NG-mediated protection of the cells from PQ-induced cellular toxicity. We propose that NG effectively alleviates PQ-induced cytotoxicity in human bronchial epithelial BEAS-2B cells through the NRF2-regulated antioxidant defense pathway, and NG might be a good therapeutic candidate molecule in oxidative stress-related diseases.
authors.affiliation: Department of Microbiology, School of Medicine, Soonchunhyang University, Cheonan 330-090, Republic of Korea.
authors.forename: Biswajit
authors.initials: B
authors.lastname: Podder
authors.forename: Ho-Yeon
authors.initials: HY
authors.lastname: Song
authors.forename: Yong-Sik
authors.initials: YS
authors.lastname: Kim
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001980:Bronchi; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D019610:Cytoprotection / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D044950:Flavanones / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006540:Herbicides / Q000633:toxicity*; D006801:Humans; D010084:Oxidation-Reduction; D010269:Paraquat / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D044950:Flavanones; D006540:Herbicides; D017382:Reactive Oxygen Species; C005273:naringenin; D010269:Paraquat