The efficiency of N-heterocylic analogs against Biomphalaria alexandrina snails infected with Schistosoma mansoni; immune responses, histological structure and protein pattern

Schistosomiasis is one of the most important tropical diseases. Analogs of nitrogen-based heterocycles hold a unique position in medicinal chemistry as a valuable source of therapeutic agents. This study aims to investigate the effects of different concentrations (0.25 and 1 ppm) of quinoline derivative as 7-chloro 4-amino ethyl amino quinoline hydrochloride salt (CAAQ) on survival, growth rates, mortality, immune response, histological structure and protein patterns of Biomphalaria alexandrina snails with/without S. mansoni infection under the effect. Exposure of snails to 0.25 and 1 ppm significantly (P ≤ 0.001) increased mortality and marginally decreased growth rates. In addition, exposure increased hayalinocytes (17.3 and 17.4 %, respectively) when compared to the control (5 %), decreased the granulocytes “spreading and non-spreading” (48.5 % , 51.6 % and 34.2 %, 31 %, respectively) when compared to the control (56.1 and 38.9 %, respectively). Exposure to both concentrations decreased the phagocytic haemocytes and increased the unphagocytic haemocytes percentages compared to the control snails. The present results indicated that the histological effect of CAAQ exposure on non and/or infected snails caused marked changes in the histological architecture of the ovotestis and digestive gland. The sub-lethal concentrations of CAAQ caused disturbance in the tissue total protein content of the ovotestis and digestive gland. SDS-PAGE of total protein pattern in ovotestis and digestive gland of exposed-infected snails showed occasional appearance and/or absence of certain protein bands. In conclusion, CAAQ modulated the immune responses of B. alexandrina with/without S. mansoni infection, histological structure and protein expression (SDS-PAGE). Consequently, CAAQ was recommended as a molluscicide of plant origin for the control program of schistosomiasis.