Anthocyanins from Hibiscus syriacus L. Inhibit Oxidative Stress-Mediated Apoptosis by Activating the Nrf2/HO-1 Signaling Pathway

Abstract

Hibiscus syriacus L. is distributed widely throughout Eastern and Southern Asia and considered as the national flower of South Korea. The extraction of several plant parts of H. syriacus L. is currently used as a natural remedy for several diseases, including breast and lung cancer, microbial infection, and chronic inflammation. However, the effect of the anthocyanin extract of H. syriacus L. petals (PS) in oxidative stress conditions has not been studied. In this study, we evaluated the cytoprotective effect of PS against H2O2-induced oxidative stress in HaCaT keratinocytes. In this study, we found that PS significantly inhibited H2O2-induced apoptosis of HaCaT keratinocytes. We also revealed that PS mediated-cytoprotective effect was associated with the increased expression of heme oxygenase-1 (HO-1) arising from the activation of nuclear factor erythroid 2-related factor-2 (Nrf2). PS also decreased H2O2-induced excessive intracellular ROS generation and restored H2O2-induced mitochondrial depolarization through the downregulation of mitochondrial ROS production. Furthermore, H2O2-induced Bax and caspase-3 expression was markedly abolished in the presence of PS. The inhibition of HO-1 by zinc protoporphyrin significantly attenuated the cytoprotective effect of PS in H2O2-treated HaCaT keratinocytes along with ROS generation, indicating that HO-1 crucially affects PS-mediated cytoprotective properties. Collectively, our results suggested that, under H2O2-mediated oxidative stress conditions, PS sustained a normal level of mitochondrial membrane potential and ROS generation in HaCaT keratinocytes by activating the Nrf2/HO-1 axis, exerting cytoprotective effects against oxidative stress.

Advanced Research on the Antioxidant Activity and Mechanism of Polyphenols from Hippophae Species—A Review

“…Currently, the Nrf2/ARE signaling pathway appears to be the most important endogenous antioxidant stress pathway [65,66]. Furthermore, Nrf2 is pivotal in the host defense mechanism, and numerous key phase II enzymes, such as NQO1 and HO-1 [67], are controlled by Nrf2 transcription factor under ROS conditions [4].…”

Effect of Electroacupuncture on Spinal Cord Injury in Mice: Inhibition Of Inflammatory Response and Oxidative Stress via ApoE and Nrf2

“…Also, as mentioned above, the Nrf2/HO-1 signaling pathway plays an outstanding role in anti-oxidative activities after SCI [85,86]. Nrf2 was activated by oxidative stress after injury combined with antioxidant response elements [87] and increased its downstream anti-inflammatory and antioxidant enzymes, including HO-1 and NQO1 [86].In our study, we observed that Nrf2 was elevated after SCI, and Nrf2,HO-1 and NQO1were further increased by EA treatment combined with COG112, it could be easily predicted that Nrf2/HO-1 signaling pathway may function in oxidative stress after SCI and is involved with the effect of EA on the recovery of SCI.…”

Qualitative and Quantitative Analysis of Ukrainian Iris Species: A Fresh Look on Their Antioxidant Content and Biological Activities

“…It is also known that the level of NRF2 indicates the antioxidant capacity of the cells and its increase is linked with the enhanced ability to scavenge radicals [ 67 ]. Plants phenolic rich extracts were previously shown to exert a cytoprotective effect by increasing heme oxygenase-1 (HO-1) together with NRF2 [ 68 ]. In the current study, NRF2 activity was evaluated in HacaT normal skin cell line.…”