The Open Cell Development & Biology Journal
2010, 2 : 1-7Published online 2010 May 25. DOI: 10.2174/1874085501002010001
Publisher ID: TOCBJ-2-1
RESEARCH ARTICLE
Omega-3 and Omega-6 Fatty Acids Kill Thymocytes and Increase Membrane Fluidity
2 Institute for Health and the Environment, University at Albany, Rensselaer, NY 12144, USA
* Address correspondence to this author at the Institute for Health and the Environment, University at Albany, 5 University Place, A 217, Rensselaer, NY 12144, USA; Tel: 518-525-2660; Fax: 518-525-2665; E-mail: carpent@uamail.albany.edu
ABSTRACT
Background:
Omega-3 but not omega-6 fatty acids are thought to promote cardiovascular health by increasing membrane fluidity.
Methods:
The actions of acute application of omega-3 [docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic (EPA, 20:5n-3) and α-linolenic acid (ALA, 18:3n-3)] and omega-6 [docosatetraenoic acid (DTA, 22:4n-6), arachidonic acid (ARA, 20:5n-6) and linoleic acid (LNA, 18:2n-6)] fatty acids on plasma membrane fluidity and cytotoxicity were investigated using mouse thymocytes. Membrane fluidity was assessed by determining fluorescence polarization of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) and cell death was assessed by using propidium iodide (PI).
Results:
Membrane fluidity in omega-3 treated cells was significantly increased in the order of DHA>EPA>ALA, but DTA and ARA also increased fluidity and were even more potent. Both omega-3 and omega-6 fatty acids were acutely cytotoxic to thymocytes at concentrations that altered membrane fluidity, and omega-6 fatty acids caused more cell death than omega-3s.
Conclusions:
The omega-6 fatty acids, DTA and ARA, are more potent than long chain omega-3 fatty acids in causing an increase in membrane fluidity in thymocytes.
General Significance
Our results suggest that the beneficial effects of fish consumption are unlikely to be secondary to a selective action of omega-3 fatty acids on membrane fluidity.