European Journal of Biomedical and Pharmaceutical Sciences

SUSCEPTIBILITY OF BIOMPHALARIA ALEXANDRINA SNAILS TO INFECTION WITH SCHISTOSOMA MANSONI MIRACIDIA UNDER THE EFFECT OF SODIUM ALGINATES AS IMMUNOSTIMULANT

Kamelia El Sayed, Maha Ghazy Soliman, Faten A. Elfekky, Nouran A. Abo Ouf and Rasha Mohamed Gad*

ABSTRACT

Molluscs have an effective innate defense system consisting of cellular and humoral defense factors which can be modulated by immunostimulation. The effect of sodium alginates (as immunostimulant) on the immune response and susceptibility of Biomphalaria alexandrina snails and their infection with Schistosoma mansoni miracidia was studied. The snails were immersed in three different concentrations of sodium alginates (0.1 mg/ml, 0.5 mg/ml and 1.0 mg/ml) for three time intervals (1 Day, 3 Days and 7 Days). Exposure of snails to sodium alginates led to a significant increase in the total number of hemocytes in all experimental groups. The most significant increase was recorded after exposure to 0.5 mg/ml of sodium alginates for 7 days being 6650 hemocyte/ml compared to 1950 hemocyte/ml of control snails. Examination of hemocytes revealed that hemolymph contained three morphological different types of hemocytes, designated as round small, granular (spreading) hemocytes and haylinocytes, their average percentage was 20%, 62% and 18% of total cells respectively. Spreading hemocytes were the most affected cell type after treatment with sodium alginates. The most obvious effect on spreading hemocytes was after treatment with 1.0 mg/ml of sodium alginates for 7 days being 80% of total hemocytes. Infection of snails with Schistosoma mansoni miracidia was suppressed by exposure to sodium alginates and this was associated with significant reduction of cercarial production. It is concluded that exposure of Biomphalaria alexandrina snails to sodium alginates could enhance their immune ability to overcome infection with Schistosoma mansoni miracidia.

Keywords: Sodium alginates, Biomphalaria alexandrina, Schistosoma, mansoni, Hemocytes, Susceptibility and immunostimulant.