الفهرس 
I. IntroductionOnly 14 pages are availabe for public view
 |  | from | 233 |  |  |
| | | from | 233 | | |
Abstract
The present study was carried out to evaluate the cercaricidal effects of different concentrations prepared from methanol extracts of plants Solanum nigrum and Callistemon citrinus (plant molluscicides) against S. mansoni cercariae by an in vitro study. Also, to study the effect of sublethal concentration of both plant extracts on the infectivity of S. mansoni cercariae by an in vivo study.
The results could be summarized as follows:
In vitro study
1. Cercaricidal activity:
It was found that the methanol extract of S. nigrum was more toxic to S. mansoni cercariae than that of C. citrinus as LC90 values were 50 and 60 mg/L, respectively after one hour of exposure. Also, cercariae exposed to sublethal concentrations of these plant extracts, e.g. 20 and 25 mg/L for S. nigrum and 30 and 40mg/L for C. citrinus, were attenuated and seen creeping at the bottom of the aquaria.
2. Molecular study (RAPD-PCR):
The cercariae used in this work were divided into the following groups:
Group A: Control non exposed cercariae.
Group B: Cercariae exposed to S. nigrum at concentration 25.