PERITROPHIC ENVELOPE AS A FUNCTIONAL ANTIOXIDANT

The peritrophic envelope has long been considered an important microbi al barrier to midgut infection and as a selective filler for the exclu sion of dietary toxins. In this paper, we present data indicating that the peritrophic envelope (PE) of Helicoverpa iea serves as a function al antioxidant, protecting the midgut epithelium from damage by dietar y prooxidants. Results from in vitro assays indicate that PE effective ly scavenges hydroxyl radicals and reduces hydroperoxide formation in isolated midgut tissues exposed to model free radical generating syste ms. The extraordinary similarity in location and function of the PE to gastric mucins of vertebrates is discussed. (C) 1996 Wiley-Liss, Inc.