Anti-inflammatory effects of alpha linolenic acid on human corneal epithelial cells.

Abstract

PURPOSE:

Systemic polyunsaturated fatty acids (PUFAs) were shown to improve the symptoms of dry eye syndrome due to their anti-inflammatory effects. This study evaluated the in vitro anti-inflammatory effects of PUFAs on human corneal epithelial (HCE) cells.

METHODS:

HCE cells were incubated for 2 hours with different concentrations of PUFAs: alpha-linolenic acid (ALA), gamma-linolenic acid (GLA), and linoleic acid (LA). Oleic acid (OA) and dexamethasone (DM) served as negative and positive controls, respectively. Cells were stimulated with either polyinosinic:polycytidylic acid (poly I:C) or lipopolysaccharide (LPS) complex. The protein contents and mRNA expression levels of IL-6, IL-8, IL-1β, and TNF-α were evaluated with multiplex fluorescent bead immunoassay and real-time PCR, respectively. The expression of inhibitory factor-κBα (I-κBα) was evaluated with real-time PCR.

RESULTS:

The protein and mRNA levels of IL-6, IL-8, IL-1β, and TNF-α were significantly increased after stimulation with LPS or poly I:C. Following treatment with ALA, a significant decrease was demonstrated in the protein content of TNF-α to 23.81% (P < 0.001), IL-6 to 46.71% (P < 0.001), IL-1β to 20.86% (P < 0.05), and IL-8 to 52.21% (P < 0.001). Similar results were demonstrated at the mRNA level. The anti-inflammatory effects of ALA were similar to those of DM for all of the pro-inflammatory cytokines. The ALA inhibition of the pro-inflammatory cytokines was associated with a significant reduction of I-κBα.

CONCLUSIONS:

ALA may serve as a potent anti-inflammatory agent in ocular surface inflammation. The anti-inflammatory effects of ALA are comparable to those of corticosteroids, and are mediated through NF-κB signal transduction.

• Authors: Nir Erdinest, Or Shmueli, Yoni Grossman, Haim Ovadia, Abraham Solomon
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 53 Issue 8 Pg. 4396-406 (Jul 03 2012) ISSN: 1552-5783 [Electronic] United States
• PMID: 22669722 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Inflammatory Agents, Non-Steroidal
• I-kappa B Proteins
• IL6 protein, human
• Interleukin-1beta
• Interleukin-6
• Interleukin-8
• Lipopolysaccharides
• NFKBIA protein, human
• RNA, Messenger
• Tumor Necrosis Factor-alpha
• alpha-Linolenic Acid
• NF-KappaB Inhibitor alpha
• Oleic Acid
• Dexamethasone
• Poly I-C

Topics

• Anti-Inflammatory Agents, Non-Steroidal (pharmacology)
• Blotting, Western
• Cell Survival
• Cells, Cultured
• Dexamethasone (pharmacology)
• Epithelium, Corneal (drug effects, metabolism)
• Fluorescent Antibody Technique
• Humans
• I-kappa B Proteins (genetics)
• Interleukin-1beta (genetics)
• Interleukin-6 (genetics)
• Interleukin-8 (genetics)
• Lipopolysaccharides (pharmacology)
• NF-KappaB Inhibitor alpha
• Oleic Acid (pharmacology)
• Poly I-C (pharmacology)
• RNA, Messenger (metabolism)
• Real-Time Polymerase Chain Reaction
• Tissue Donors
• Tumor Necrosis Factor-alpha (genetics)
• alpha-Linolenic Acid (pharmacology)