Docosahexaenoic acid reduces cellular inflammatory response following permanent focal cerebral ischemia in rats.

Abstract

Cellular inflammatory response plays an important role in ischemic brain injury and anti-inflammatory treatments in stroke are beneficial. Dietary supplementation with docosahexaenoic acid (DHA) shows anti-inflammatory and neuroprotective effects against ischemic stroke. However, its effectiveness and its precise modes of neuroprotective action remain incompletely understood. This study provides evidence of an alternative target for DHA and sheds light on the mechanism of its physiological benefits. We report a global inhibitory effect of 3 consecutive days of DHA preadministration on circulating and intracerebral cellular inflammatory responses in a rat model of permanent cerebral ischemia. DHA exhibited a neuroprotective effect against ischemic deficits by reduction of behavioral disturbance, brain infarction, edema and blood-brain barrier disruption. The results of enzymatic assay, Western blot, real-time reverse transcriptase polymerase chain reaction and flow cytometric analysis revealed that DHA reduced central macrophages/microglia activation, leukocyte infiltration and pro-inflammatory cytokine expression and peripheral leukocyte activation after cerebral ischemia. In parallel with these immunosuppressive phenomena, DHA attenuated post-stroke oxidative stress, c-Jun N-terminal kinase (JNK) phosphorylation, c-Jun phosphorylation and activating protein-1 (AP-1) activation but further elevated ischemia-induced NF-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) expression. DHA treatment also had an immunosuppressive effect in lipopolysaccharide/interferon-γ-stimulated glial cultures by attenuating JNK phosphorylation, c-Jun phosphorylation and AP-1 activation and augmenting Nrf2 and HO-1 expression. In summary, we have shown that DHA exhibited neuroprotective and anti-inflammatory effects against ischemic brain injury and these effects were accompanied by decreased oxidative stress and JNK/AP-1 signaling as well as enhanced Nrf2/HO-1 expression.

• Authors: Cheng-Yi Chang, Yu-Hsiang Kuan, Jian-Ri Li, Wen-Ying Chen, Yen-Chuan Ou, Hung-Chuan Pan, Su-Lan Liao, Shue-Ling Raung, Chen-Jung Chang, Chun-Jung Chen
• Journal: The Journal of nutritional biochemistry (J Nutr Biochem) Vol. 24 Issue 12 Pg. 2127-37 (Dec 2013) ISSN: 1873-4847 [Electronic] United States
• PMID: 24139673 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2013.

Chemical References

• Anti-Inflammatory Agents
• NF-E2-Related Factor 2
• Neuroprotective Agents
• Nfe2l2 protein, rat
• Docosahexaenoic Acids
• Interferon-gamma
• Heme Oxygenase (Decyclizing)
• Hmox1 protein, rat
• JNK Mitogen-Activated Protein Kinases

Topics

• Animals
• Anti-Inflammatory Agents (pharmacology)
• Blood-Brain Barrier (drug effects, metabolism)
• Cerebral Infarction (drug therapy)
• Disease Models, Animal
• Docosahexaenoic Acids (pharmacology)
• Gene Expression Regulation
• Heme Oxygenase (Decyclizing) (metabolism)
• Inflammation (drug therapy, metabolism)
• Interferon-gamma (metabolism)
• JNK Mitogen-Activated Protein Kinases (metabolism)
• Male
• Microglia (drug effects, metabolism)
• NF-E2-Related Factor 2 (metabolism)
• Neuroprotective Agents (pharmacology)
• Oxidative Stress (drug effects)
• Phosphorylation (drug effects)
• Rats
• Rats, Sprague-Dawley
• Signal Transduction