The neuroprotective effects of α-iso-cubebene on dopaminergic cell death: involvement of CREB/Nrf2 signaling

Neurochem Res. 2014 Sep;39(9):1759-66. doi: 10.1007/s11064-014-1371-6. Epub 2014 Jul 1.

Abstract

As a part of ongoing studies to elucidate pharmacologically active components of Schisandra chinensis, we isolated and studied α-iso-cubebene. The neuroprotective mechanisms of α-iso-cubebene in human neuroblastoma SH-SY5Y cells were investigated. α-Iso-cubebene significantly inhibited cytotoxicity and apoptosis due to 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in dopaminergic SH-SY5Y cells. Pretreatment of cells with α-iso-cubebene reduced intracellular accumulation of ROS and calcium in response to 6-OHDA. The neuroprotective effects of α-iso-cubebene were found to result from protecting the mitochondrial membrane potential. Notably, α-iso-cubebene inhibited the release of apoptosis-inducing factor from the mitochondria into the cytosol and nucleus after 6-OHDA treatment. α-Iso-cubebene also induced the activation of PKA/PKB/CREB/Nrf2 and suppressed 6-OHDA-induced neurotoxicity. α-Iso-cubebene was found to induce phosphorylation of PKA and PKB and activate Nrf2 and CREB signaling pathways in a dose-dependent manner. Additionally, α-iso-cubebene stimulated the expression of the antioxidant response genes NQO1 and HO-1. Finally, α-iso-cubebene-mediated neuroprotective effects were found to be reversible after transfection with CREB and Nrf2 small interfering RNAs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Death / drug effects*
  • Cell Line, Tumor
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Dopaminergic Neurons / drug effects*
  • Humans
  • NF-E2-Related Factor 2 / metabolism*
  • Neuroprotective Agents / pharmacology*
  • Sesquiterpenes / pharmacology*
  • Signal Transduction / drug effects*

Substances

  • CREB1 protein, human
  • Cyclic AMP Response Element-Binding Protein
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • Neuroprotective Agents
  • Sesquiterpenes
  • alpha-iso-cubebene