Norflurazon--an inhibitor of essential fatty acid desaturation in isolated liver cells.

Norflurazon is a herbicide known to inhibit carotene biosynthesis and linolenic acid biosynthesis in plants. In the present work, the effect of norflurazon on the metabolism of studied in isolated rat liver cells and in rat liver microsomes, incubated with [1-14C] labeled linolenic acid (18:3, n-3), dihomogammalinolenic acid (20:3, n-6) and eicosapentaenoic acid (20:5, n-3). Norflurazon (0.1 mM, 1.0 mM) was found to inhibit essential fatty acid desaturation. The delta 6 desaturation is inhibited more efficiently than the delta 5 and delta 4 desaturation. The chain elongation of essential C18 fatty acids to their C20 and C22 homologs was not inhibited by norflurazon.