Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 10 3 2015 10 17 420 431 EN Serpil DEGERLI Department of Parasitology, School of Medicine, Cumhuriyet University, Sivas, Turkey Bektas TEPE Department of Molecular Biology and Genetics, Faculty of Science and Literature, Kilis 7 Aralik University, Kilis,Turkey 2015 10 14 2015 10 14 Background: The aim of this study was to determine phenolic acid composi­tion and anti-parasitic effects of Peucedanum caucasicum, P. palimbioides, P. longibracteola­tum and P. chryseum on Entamoeba histolytica. Methods: Methanol extracts of the plant species were prepared by soxhlet extrac­tion. Phenolic acid compositions were determined by HPLC. Anti-prolifera­tive effect of extracts on trophozoites was determined by using trypan blue dye exclusion test. For counting the cells, approximately a hundred of E. histolytica trophozoites were examined in each time. The data were presented as mean values with standard deviations and analyzed by repeated measures of ANOVA followed by Tukey test for post-hoc pairwise comparisons. The P-value was set at 0.05 for significance level. Results: All of the extracts showed a time and dose dependent amoebicidal ac­tion on trophozoites. Among the extracts tested, P. longibracteolatum showed the strongest amoebicidal effect on the trophozoites. As expected, this plant species also exhibited time and dose dependent activity on the trophozoites. At 4.0 mg/ml extract concentration, all of the trophozoites were killed by the extract in 72nd hour. Gallic (11.144 mg/g), P-hydroxybenzoic (17.646 mg/g), and o-couma­ric acids (14.442 mg/g) were determined as the major phenolic acids of P. longibracteo­latum. Gallic and P-hydroxybenzoic acids found in P. longibracteolatum could not be determined in other extracts. Therefore, high activity potential of this plant could probably be attributed to the presence of these phytochemicals. Conclusion: P. longibracteolatum can be further evaluated as potential therapeu­tic drugs for the treatment of Entamoeba infections. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/308 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/308/284