Behavioral, Morphological and Histopathological Effects of Sublethal Doses of Quercetin on the Species Polycelis felina (Dalyell)*

The effect of quercetin was studied on the multi-eyed flatworm Polycelis felina (Daly.) in laboratory conditions. This is a very suitable test-organism available year-round in nature, easily maintained in the laboratory. The results showed that depending on the dose and recovery period quercetin caused locomotory (behavioral) changes in treated animals including aggregation in groups, resting and unsynchronized movements and twisting of particular body parts. Morphological changes in the form of depigmentation of certain body parts were the result of damage or deterioration of reticular and parenchymal cells. Numerous basophilic bodies representing parts of damaged and decomposed cells were determined in the gastroderm between the third and seventh day after treatment. All histological preparations revealed significant deterioration of cellular material, and therefore a damaging effect of quercetin on the multi-eyed flatworm Polycelis felina (Daly.). We found an increased number of neoblasts and reticular cells on the third day after treatment, so we concluded that quercetin in the applied doses had a stimulating effect on cell division of neoblasts and reticular cells of treated flatworms.