Treatment of Bronchial Asthma With Borage and Echium Seed Oils

Leukotrienes are important in the pathogenesis of inflammation, and leukotriene modifying drugs are now an established treatment for bronchial asthma and rhinitis. Drugs that inhibit the biosynthesis of leukotrienes are likely to be more effective than the currently available drugs that antagonize a single leukotriene receptor. Dietary supplementation with gamma linolenic acid (GLA) in borage seed oil provides effective inhibition of leukotriene generation but also increases circulating free arachidonic acid (AA), which has pro-inflammatory potential. The n-3 fatty acid, eicosapentaenoic acid (EPA), prevented the conversion of GLA to AA. However, EPA is extracted from fish oil, is not well-tolerated due to its taste, and at higher doses appeared to blunt the inhibition of leukotriene biosynthesis by GLA. Stearidonic acid (SDA) is a precursor of EPA that is extracted from Echium plantagineum; it is converted to EPA in humans and it does not have the organoleptic properties of EPA.

We recently completed a dose-ranging study in which we determined the dose of SDA that is sufficient to inhibit the rise in circulating levels of arachidonic acid while maintaining effective inhibition of leukotriene generation.

The goal of the present study is to test the efficacy of dietary supplementation with GLA and SDA (provided in borage seed oil and echium seed oil) in treating bronchial asthma.

Inclusion criteria

• Diagnosis of bronchial asthma
• Male or female 18 years to 65 years of age
• FEV1 50 to 90% of predicted, or personal best.
• Improvement of >=12% FEV1 with bronchodilator

Exclusion criteria

• Pregnant or nursing
• Smoking history of > 10 pack years or active smoking within the past year.
• Due to possible effects on leukotriene biosynthesis, use of the following asthma treatments within the preceding month will be exclusion criteria:

• leukotriene modifying drugs,
• theophylline
• oral steroids.
• dietary supplements with fatty acids or other products that may interfere with leukotriene generation.
• Treatment within the previous three months with omalizumab (monoclonal antibody directed against IgE)
• Subjects will not be permitted to take non-steroidal anti-inflammatory drugs in the week prior to any measurements of ex vivo leukotriene generation because of their effects on leukotriene biosynthesis via inhibition of prostaglandin generation.
• A history of aspirin-sensitive asthma
• Significant abnormalities in CBC, differential white cell count, renal function, and liver function, or urinalysis.
• Any serious co-morbid medical condition.