Original article

Gynura bicolor aqueous extract attenuated H₂O₂ induced injury in PC12 cells

¹ Department of Food Nutrition and Health Biotechnology, Asia University, Taichung 413, Taiwan
² Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan

^* Corresponding author. Department of Food Nutrition and Health Biotechnology, Asia University, No. 500, Liufeng Rd., Wufeng Dist., Taichung 413, Taiwan. E-mail address: wangzh@asia.edu.tw (Z.-H. Wang)

Received: 31 January 2019
Accepted: 1 March 2019

Abstract

Background: Protective effects of Gynura bicolor aqueous extract (GAE) at three concentrations upon nerve growth factor (NGF) differentiated-PC12 cells against H₂O₂ induced injury were examined.

Methods: NGF differentiated-PC12 cells were treated with GAE at 0.25%, 0.5% or 1%. 100 μM H₂O₂ was used to treat cells with GAE pre-treatments. After incubating at 37 °C for 12 hr, experimental analyses were processed.

Results: H₂O₂ exposure decreased cell viability, increased plasma membrane damage, suppressed Bcl-2 mRNA expression and enhanced Bax mRNA expression. GAE pre-treatments reversed these changes. H₂O₂ exposure reduced mitochondrial membrane potential, lowered Na⁺-K⁺-ATPase activity, and increased DNA fragmentation and Ca²⁺ release. GAE pre-treatments attenuated these alterations. H₂O₂ stimulated the production of reactive oxygen species (ROS), interleukin (IL)-1beta, IL-6 and tumor necrosis factor-alpha, lowered glutathione content, and reduced glutathione peroxidase (GPX) and catalase activities. GAE pretreatments maintained GPX and catalase activities; and concentration-dependently diminished the generation of ROS and inflammatory cytokines. H₂O₂ enhanced mRNA expression of nuclear factor kappa (NF-κ) B and p38. GAE pre-treatments decreased mRNA expression of NF-κB and p38. Conclusion: These findings suggested that GAE might be a potent neuronal protective agent.