Efficacy of praziquantel against Giardia lamblia in rats: parasitological, pathological and therapeutic study.

Rats were divided into two experimental groups received single or split doses of PZQ, and two control groups one infected untreated and the other normal healthy rats. The effect of infection on rat growth, on jejunal and duodenal architecture were studied histopathologically after H&E staining. The jejunal ultrastructure was examined by SEM and TEM. The effect of PZQ was evaluated using the same techniques. It was observed that infected as well as infected treated animals gained less weight than healthy control. Intensity of infection decreased gradually after treatment. Cure rate was 100% after split dose and 80% after a single dose. Altered villus height and cryptic depth were the characteristic changes in the architecture of the duodenum and jejunum, more pronounced in the latter. Split dose of PZQ revealed more improvement of the histopathological findings than a single dose. By SEM, circular imprints representing defects in the villi were observed in the jejunum. By TEM deformation of microvillar architecture was observed together with organellar changes in the RER and the mitochondria, after PZQ treatment.