Effect of α-Linolenic Acid on the Metabolism of ω-3 and ω-6 Polyunsaturated Fatty Acids and Histamine Release in RBL-2H3 Cells

Abstract

We examined the effect of a-linolenic acid (18:3 (n-3)) pretreatment on the metabolism of ω-3 and co-6 polyunsaturated fatty acids and histamine content and release of RBL-2H3 cells. RBL-2H3 cells grew without reduction in number when incubated with subculture media for 3 d and then placed again in serum-free medium with bovine serum albumin (BSA) and epidermal growth factor (EGF). Cholesterol pullulan (10 μg /ml) emulsified a-linolenic acid (20μg/ml) was recommended as an additional form serum free medium. We determined the fatty acid composition in all neutral lipids, free fatty acids and all phospholipids in a-linolenic acid-treated cells. In all cases the concentration of a-linolenic acid and docosahexenoic acid (DHA, 22:6 (n-3)) was increased, while linolenic acid (18:2 (n-6)) was slightly and arachidonic acid (20:4 (n-6)) was markedly decreased. Content of histamine in a-linolenic acid-treated cells was remarkably lower than that of untreated cells. Accordingly, net histamine release stimulated by antigen or A23187 was also markedly decreased in the a-linolenic acid-treated cells, as was the percent histamine release stimulated by antigen. Results from our in vitro experiment suggest that the anti-allergic effect of a-linolenic acid may be caused either by the decrease in histamine content or by inhibition of the release of chemical mediator resulting from changes in the fatty acid composition. © 1994, The Pharmaceutical Society of Japan. All rights reserved.