Protective efficacy of Eglin C from Hirudo medicinalis against Eimeria papillata-induced coccidiosis.

The current study aimed to find a new therapeutic agent from Hirudo medicinalis for murine coccidiosis. Ion-exchange chromatography was performed to separate different fractions of HEA (hirudo extract antigens). Eight different fractions were experimentally tested against murine eimeriosis induced by Eimeria papillate. The oocysts output was counted to determine the most effective fractions. For the five most effective fraction groups, jejunal histological examination and goblet cells count as well as mRNA expression of MUC2 gene using RT-PCR were performed. The data indicated that these fractions significantly decreased the oocysts output and the number of parasite developmental stages, while the goblet cell numbers and the expression of MUC2 were increased. Effective fractions were subjected to SDS-PAGE and proteomic analysis for detection of their bioactive macromolecules. The fractions reveled only a protein at 8 kDa while the results of spectroscopy and bioinformatics identified the protein as Eglin C. The pooled fractions containing Eglin C were tested in vitro to determine its stimulation for the intestinal lymphocyte proliferation and IFN-γ together with IL-6 release in the supernatant. The results showed that higher Eglin C concentrations reduced the stimulation index of lymphocyte proliferation as well as the stimulation index of IFN-γ and IL-6 production. In conclusion, Eglin C protein can be used as a target for therapeutic treatment or as an anti-inflammatory agent for coccidiosis infection.