Effect of Aerosolized Docosahexaenoic Acid in a Mouse Model of Atopic Asthma

Background: Docosahexaenoic acid (DHA) found in fish oil is known to depress inflammation-related mediators. We investigated a novel delivery method of tridocosahexaenoyl-glycerol (DHA-TG). Methods: BALB/c mice (6–8 weeks old) were primed intraperitoneally with ovalbumin (OVA) and Al(OH)3 on days 0 and 7, and with aerosolized OVA on day 7. Primed mice were challenged by repeated exposure to aerosolized OVA on days 15–17. Just before each exposure to aerosolized OVA, the mice were also exposed to an aerosol of emulsified DHA-TG or soybean oil, or saline (days 7 and 15–17). Bronchial hyperresponsiveness (BHR) to methacholine was measured, and bronchoalveolar lavage fluid was obtained 24 h after the last challenge (day 18). Lungs were histologically examined. Results: Bronchoalveolar lavage fluid of saline-treated mice showed an increased cellularity with predominant eosinophils. Exposure to DHA-TG significantly reduced the total cell number and the eosinophil percentage in lavage fluid, whereas soybean oil did not. Conclusion: DHA but not soybean oil exposure reduced BHR and cell infiltration to bronchovascular bundles. This type of DHA administration could be studied in clinical trials.