Immunological and chemical analysis of proteins from Eisenia foetida earthworm

Abstract

Previous studies have demonstrated the fibrinolitic and antibacterial activities of proteins from the earthworm Eisenia foetida (Ef) but their use as a food supplement for animals and humans is still being considered. We studied proteins from this worm in order to determine chemical composition (protein, fat and heavy metal levels), electrophoretic profile in SDS-PAGE and 2D gels, induction of humoral immune response in mice and toxicity in a human cell line. Chemical analysis revealed 61.8, 11.3 and 8.7 g% of proteins, fat and ash, respectively. Levels of heavy metals were low and similar to tunny fish. Sixteen bands were obtained by SDS-PAGE with a molecular weigh range of 6.9–205 kDa while twenty-three spots were observed following 2D gel electrophoresis. After three immunizations with Eisenia foetida lysate, high titer antibodies were produced without causing immediate hypersensitivity reactions. Good cell viability was observed when Ef proteins were added to a human cell line. These results suggest that Ef proteins are safe for feeding animals intended for human consumption.