Résumé:
A competent immune system is capable of detecting and eliminating not only viruses and
bacteria, but also cancer cells. However, these cells can develop an escape strategy allowing
the formation of malignant tumor following immunosuppression. It is therefore necessary to
look for new anti-tumor drugs with an immunostimulatory potential. Research in this field
focuses on the extraction and purification of these molecules from medicinal plants. However,
the aim of our work is to seek and demonstrate the immunomodulatory effect of animal
extracts: the Helix aspersa snail, a species widely used and widely consumed in the
Mediterranean countries. Our work begins with a characterization of the extracts (slime,
homogenate and aqueous extract) and an evaluation of the toxic dose in order to choose the
appropriate doses to use during our experiments. The extracts showed no toxicity to
experimental animals; Therefore, the doses of 20 ml / Kg of slime, 5 mg / Kg of homogenate
and 300 μl / mouse of aqueous extract were chosen. The immunomodulatory effect was
shown to be immunostimulatory when performing a carbon clearance test, which led us to
investigate other therapeutic effects. Our extracts also exert an anti-inflammatory effect
against chemo-induced experimental colitis. Untreated chronic colitis is likely to develop as a
colorectal tumor. The anti-inflammatory effect of the extracts prompted us to check the antiproliferative effect. The investigation of the antitumor effect was carried out in vitro, on a
culture of MCF7 mammary tumor cells and in vivo, on an experimental chemo-induced
colorectal cancer. In vitro experiments showed an inhibition of tumor cell proliferation at
56.39%. In vivo, observation of the histological sections of the colonists confirmed that the
extracts repaired the architecture of the colonic mucosa after the installation of the chemoinduced tumor. The Helix aspersa snail has several therapeutic effects. It would therefore be
interesting to introduce it into the daily diet as a preventive or supplementary food for a
curative purpose.
