Influence of Dietary Pectin on the Hepatic Levels of Reduced Glutathione and on Lipid Peroxide Formation in Mice.

Abstract

In order to establish if dietary pectin could influence the levels of hepatic reduced glutathione (GSH) and the rate of lipid peroxide formation, we fed 8 male Balb C mice for 14 days with a standard powder diet supplemented with 5% highly methoxylated apple pectin. Another 8 mice received the standard powder diet only and served as controls. The animals were killed on the 15th day. The levels of GSH and lipid peroxides expressed in terms of malondialdehyde (MDA) were determined in liver homogenates. Besides, parameters that could be related to GSH metabolism or lipid peroxidation, such as the activity of y-glutamyl transferase (γ-GT) and the content of iron, were assessed as well. In pectin-fed animals γ-GT activity was decreased (p<0.01), whereas the level of hepatic GSH was elevated (p<0.001). A negative correlation was established between both parameters. GSH correlated also negatively with lipid peroxides, which were reduced. Iron content was only slightly decreased. The data obtained suggest that the pectin-enriched diet could influence the antioxidant processes in the liver, increasing GSH levels (at least partially by lowering γ-GT activity) and reducing the formation of lipid peroxides.