English

Abstract

The present study elucidated the molluscicidal properties of the antihelminthic plant derivative, dihydro-artemisinin methyl ether (Artemether) against some histological and histochemical parameters of Biomphalaria alexandrina snails. Results indicated that Artemether has a toxic effect against B. alexandrina snails expressed by LC90 of 32.69 ppm, after 24 h exposure.The rate of infection with Schistosoma mansoni in snails exposed to sublethal concentrations (LC0 and LC10) of Artemether either for 1 or 7 successive days pre-miracidial exposure was significantly lower than that of control group (P < 0.001). The reduction rates of this parameter ranged from 76.9 to 87.3%. Moreover, snails treated with LC25 for 7 days were free from infection (0% infection rate). Moreover, the survival rate in snails exposed to LC25 on 1 and 7 days pre-miracidial exposure were 23.3 and 10%, respectively compared to the 93.3% in control group. Histological investigation of the exposed snails' gland showed that the mature ova lost their normal shape, disappearance of most of the oocytes, spermatogenesis and connective tissues. Moreover, complete destruction of gametogenic cells and severe damage of hermaphrodite gland tissues were clear when the exposure period increased. Haemocytes' morphology showed obvious abnormalities as decrease in their number, activation, and irregular aggregation in exposed snails were recorded. Also, snails’ exposure to LC25 of Artemether demonstrated a decreased glycogen content in hermaphrodite gland tissues while it increased in the haemolymph. In conclusion, the use of sublethal concentration ofArtemether showed remarkable molluscicidal activities against B. alexandrina snails which could be a promising and safe biological agent to control schistosomiasis disease.   Key words: Biomphalaria alexandrina snails, Schistosoma mansoni, artemether, glycogen.