Andrographolide stimulates p38 mitogen-activated protein kinase-nuclear factor erythroid-2-related factor 2-heme oxygenase 1 signaling in primary cerebral endothelial cells for definite protection against ischemic stroke in rats

Transl Res. 2016 Apr:170:57-72. doi: 10.1016/j.trsl.2015.12.002. Epub 2015 Dec 17.

Abstract

Stroke pathogenesis involves complex oxidative stress-related pathways. The nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) pathways have been considered molecular targets in pharmacologic intervention for ischemic diseases. Andrographolide, a labdane diterpene, has received increasing attention in recent years because of its various pharmacologic activities. We determined that andrographolide modulates the mitogen-activated protein kinase (MAPK)-Nrf2-HO-1 signaling cascade in primary cerebral endothelial cells (CECs) to provide positive protection against middle cerebral artery occlusion (MCAO)-induced ischemic stroke in rats. In the present study, andrographolide (10 μM) increased HO-1 protein and messenger RNA expressions, Nrf2 phosphorylation, and nuclear translocation in CECs, and these activities were disrupted by a p38 MAPK inhibitor, SB203580, but not by the extracellular signal-regulated kinase inhibitor PD98059 or c-Jun amino-terminal kinase inhibitor SP600125. Similar results were observed in confocal microscopy analysis. Moreover, andrographolide-induced Nrf2 and HO-1 protein expressions were significantly inhibited by Nrf2 small interfering RNA. Moreover, HO-1 knockdown attenuated the protective effect of andrographolide against oxygen-glucose deprivation-induced CEC death. Andrographolide (0.1 mg/kg) significantly suppressed free radical formation, blood-brain barrier disruption, and brain infarction in MCAO-insulted rats, and these effects were reversed by the HO-1 inhibitor zinc protoporphyrin IX. The mechanism is attributable to HO-1 activation, as directly evidenced by andrographolide-induced pronounced HO-1 expression in brain tissues, which was highly localized in the cerebral capillary. In conclusion, andrographolide increased Nrf2-HO-1 expression through p38 MAPK regulation, confirming that it provides protection against MCAO-induced brain injury. These findings provide strong evidence that andrographolide could be a therapeutic agent for treating ischemic stroke or neurodegenerative diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Edema / drug therapy
  • Brain Edema / metabolism
  • Brain Edema / pathology
  • Brain Ischemia / drug therapy
  • Brain Ischemia / metabolism*
  • Brain Ischemia / pathology
  • Cells, Cultured
  • Cerebral Infarction / drug therapy
  • Cerebral Infarction / metabolism
  • Cerebral Infarction / pathology
  • Diterpenes / pharmacology*
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism
  • Endothelial Cells / pathology
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism*
  • Heme Oxygenase-1 / metabolism
  • Male
  • Membrane Proteins / metabolism
  • Mice, Inbred C57BL
  • NF-E2-Related Factor 2 / metabolism
  • Neuroprotective Agents / pharmacology*
  • Rats, Wistar
  • Reproducibility of Results
  • Signal Transduction / drug effects
  • Stroke / metabolism*
  • Stroke / pathology
  • Stroke / prevention & control
  • p38 Mitogen-Activated Protein Kinases / drug effects
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Diterpenes
  • Membrane Proteins
  • NF-E2-Related Factor 2
  • Neuroprotective Agents
  • Nfe2l2 protein, mouse
  • andrographolide
  • Heme Oxygenase-1
  • Hmox1 protein, mouse
  • p38 Mitogen-Activated Protein Kinases