METABOLISM OF LIPID-PEROXIDATION PRODUCTS BY THE GASTROINTESTINAL NEMATODES NECATOR-AMERICANUS, ANCYLOSTOMA-CEYLANICUM AND HELIGMOSOMOIDES-POLYGYRUS

Somatic extracts of the three parasitic nematodes Necator americanus, Ancylostoma ceylanicum and Heligmosomoides polygyrus were able to detoxify a model hydroperoxide and a putative natural peroxide by glutathione-dependent peroxidase activity while cytotoxic carbonyls could be metabolized by NADPH-linked reduction activities. Unlike cestodes and digeneans, the nematodes in this study could not enzymatically conjugate carbonyls with glutathione. The results indicate that the three nematodes can protect themselves against possible host-immune initiated lipid peroxidation of their membranes at the level of the hydroperoxide and at the level of cytotoxic carbonyl, although other protective enzymatic mechanisms are also likely to exist (superoxide dismutase and catalase).