European Journal of Biomedical and Pharmaceutical Sciences

INFLUENCE OF IMMUNOSTIMULATORY ?-GLUCAN ON BIOMPHALARIA ALEXANDRINA SNAILS UNDER LABORATORY AND SIMULATED FIELD CONDITIONS

Maha Ghazy Soliman, Kamelia El Sayed, Nouran A. Abou Ouf, Faten Abd-El Hamid El Fekky and Rasha Mohamed Gad*

ABSTRACT

β- glucans are natural biomolecules with immunomodulator activity. Biomphalaria alexandrina snails were immersed in β- glucan under laboratory conditions to evaluate the susceptibility of snails to infection with Schistosoma mansoni miracidia. The effect of β- glucan on infection rate of snails under simulated natural conditions was also evaluated. Exposure of snails to 1.0 mg/ml of β-glucan for 7 days recorded the most significant increase in hemocytes count compared to control snails. Spreading hemocytes were the most affected cell type after treatment with β- glucan recording 73% of total hemocytes after treatment with 1.0 mg/ml of β- glucan for 7 days. Infection rate of snails with Schistosoma mansoni miracidia was suppressed by exposure to β- glucan and this was associated with significant decrease in the total number of cercariae. Tested antioxidant enzymes after 1, 7, 14 and 21 days post immunostimulatory exposure and infection with Schistosoma mansoni miracidia recorded a significant increase. A pattern of retarded infection combined with deformation and degeneration in sporocysts was noticed in snails exposed to β- glucan compared to normally infected snails. Exposure of snails to β-glucan under simulated natural conditions reduced the infection rate of snails by 38.0%, 46.5% and 33.9% respectively. It is concluded that exposure of Biomphalaria alexandrina snails to β- glucan could enhance their immune ability to overcome infection with Schistosoma mansoni miracidia, so it is a promising candidate as biocontrol agent for schistosomiasis in Egypt.

Keywords: ?- glucan, Biomphalaria alexandrina, Susceptibility, Antioxidant enzymes, Infection dynamics and simulated natural conditions.