Oral administration of 2-docosahexaenoyl lysophosphatidylcholine displayed anti-inflammatory effects on zymosan A-induced peritonitis.
Nøgleord
Abstrakt
Lysophosphatidylcholines (lysoPCs) have been known to be bioactive lipid mediators, which take part in various biological and pathological processes. In the present study, we examined the anti-inflammatory actions of 2-docosahexaenoyl lysophosphatidylcholine (2-docosahexaenoyl-lysoPC) in vitro as well as in vivo systems. When RAW 264.7 cells were treated with 2-docoshexaenoyl-lysoPC, a concentration-dependent decrease of LPS-induced formation of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), or IL-6 was observed. Additionally, oral administration of 2-docosahexaenoyl-lysoPC was found to inhibit zymosan A-induced plasma leakage dose-dependently in mice with ED(50) value of 50 μg/kg and E (max) value of about 65%. Moreover, mechanistic study revealed that the anti-inflammatory action of 2-docosahexaenoyl-lysoPC seemed to be related largely to LTC(4) inhibition, but not PGE(2) inhibition. Moreover, 2-(17-hydroperoxydocosahexaneoyl)-lysoPC, intravenously administrated, was more effective than 2-docosahexaenoyl-lysoPC in the inhibition of zymosan A-induced plasma leakage, suggesting that 2-(17-hydroperoxydocosahexaneoyl)-lysoPC, a product from oxygenation of 2-docosahexaenoyl-lysoPC by 15-lipoxygenase (LOX), may be an active metabolite, intimately responsible for anti-inflammatory actions, generated from 2-docosahexaenoyl-lysoPC. In a related study, 2-docosahexaenoyl-lysoPC was found to be more efficient than 1-docosahexaenoyl-lysoPC or docosahexaenoic acid (DHA) as substrate for 15-lipoxygenases such as soybean LOX-1, leukocyte 12/15-LOX, and human 15-LOX-2. Taken altogether, it is suggested that 2-docosahexaenoyl-lysoPC and its oxygenation products may exert anti-inflammatory action after oral administration.