Effect of dietary argan oil on fatty acid composition, proliferation, and phospholipase D activity of rat thymocytes

Objective: Argan oil is receiving increasing attention due to its potential health benefits in the prevention of cardiovascular risk, but no information to date is available about its possible effect on immune cells and functions. Methods: To address this issue male rats were fed one of five diets that contained fish. oil, argan oil, olive oil, coconut oil, or sunflower, oil for 4 wk. The fatty acid composition of, plasma and thymocyte lipids was then analyzed in relation to the mitogen-induced proliferation and phospholipase D (PLD) activity of thymocytes. Results: The 18:2 omega-6 proportion in thymocyte phospholipids from rats fed argan oil was significantly lower than that observed in phospholipids from rats fed sunflower oil and fish oil but higher than that found in the olive oil and coconut oil groups. Further, a significant positive linear relation was found between thymocyte proliferation and the 18:2 omega-6 proportion in thymocyte phospholipids, whatever the diet. The proliferation response of thymocytes to mitogenic activation was also inversely correlated to PLD activity measured in intact thymocytes. Subsequent western blotting experiments indicated that the diet-induced variations in PLD activity mainly reflected variations in the expression of PLD2 protein. Conclusions: On the whole, the present study shows that the effects of argan oil on immune cells are very similar to those of olive oil, and that, as a consequence, argan oil can be used as a balanced dietary supply without marked adverse effects on immune cell function. (C) 2006 Elsevier Inc. All rights reserved.