Modulatory effect of alpha -linolenic acid-rich garden cress (Lepidium sativum L.) seed oil on inflammatory mediators in adult albino rats.

摘要

Vegetable oils containing alpha -linolenic acid (ALA; 18:3n-3) have been shown to modulate the functions of immunocompetent cells. The aim of the present study was to understand the modulatory effect of ALA-rich garden cress (Lepidium sativum L.) seed oil (GCO) on lipid composition, spleen lymphocyte (SL) proliferation and inflammatory mediator production by peritoneal macrophages (PM Phi ) in rats. Female Wistar rats were fed diets containing either GCO (2.5, 5.0 and 10%, w/w) or sunflower oil (SFO, 10% w/w) for 8 weeks. Ex vivo proliferation of SL was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. IL-2 and TNF- alpha in SL and PM Phi were analysed by ELISA. Inflammatory mediators such as NO, leukotriene B₄ (LTB₄) and H₂O₂ were measured in mitogen-activated PM Phi . GCO significantly increased the levels of ALA, EPA and DHA, but reduced linoleic acid and arachidonic acid in SL and PM Phi lipids. GCO (10%) significantly decreased the concanavalin A (Con-A)- and phytohaemagglutinin-mediated proliferation of SL by 54 and 38%, respectively, in comparison with SFO. A marginal decrease in IL-2 and TNF- alpha was observed in Con-A-stimulated SL and lipopolysaccharide-stimulated PM Phi . LTB₄ levels in Ca ionophore-stimulated PM Phi were reduced by 40% in GCO-fed rats. NO release in response to various stimuli was significantly decreased in PM Phi of GCO-fed rats. The present study is the first report on the modulatory efficacy of GCO on immunomediators in rats. GCO modulated inflammatory mediators such as NO and LTB₄, and thus may play a role in alleviating inflammatory conditions favourably.