In vitro cercaricidal and Schistosomicidal Activities of hydro alcoholic extract of the stem bark of Pedilanthus tithymaloides Linn (Poit). and Cytotoxicity study

ABSTRAT
Continuous attempts are being made to develop new and more effective drugs for the treatment of schistosomiasis. Thus, we demonstrated antiparasitic effects of the hydro alcoholic extract of the stem bark of Pedilanthus tithymaloïdes (Linn) Poit on cercariae and adult worms of Schistosoma mansoni. Extract from Pedilanthus tithymaloïdes (Linn) Poit (62.5 –2000 µg/mL) was tested on cercariae and adult worms of Schistosoma mansoni. Niclosamide-olamine 5% (1 µg/mL) and praziquantel (10 µg/mL) were respectively used as reference drugs. During the assays, the mortality of cercariae after 3 hours, and adult worms’ mobility and mortality after 48 hours of incubation were evaluated. Pedilanthus tithymaloïdes extract significantly increased cercariae and worm mortality in a concentration-dependent manner. The hydro alcoholic extract was active on cercariae and adult worms’ with a LC50 of 32.75 µg/mL after 1 hour and LC50 of 1047.43 μg/mL (769.71 – 1425.34 μg/mL) after 48 hours respectively. Significant reduction of motor activity (12.17 to 94.44%) was recorded for surviving worms incubated in different concentrations of the extract after 48 h. Moreover, the hydro alcoholic extract of the stem bark of Pedilanthus tithymaloïdes showed low level of toxicity on hepatocytes. This study proves that Pedilanthus tithymaloïdes extract has cercaricidal and schistosomicidal activities and then may have great potential as an antischistosomal agent for further research.
Keywords: Pedilanthus tithymaloïdes; cercaricidal activity; schistosomicidal activity; cytotoxicity; Schistosoma mansoni