Investigation of Antiparasitic Effects of Eisenia fetida Extract (Annelida, Lumbricidae) against Toxoplasma gondii: In vitro Study

Background: Toxoplasmosis, which is caused by Toxoplasma gondii, is a widespread parasitic disease that affects approximately one-third of the world's population. Due to the significant side effects of anti-Toxoplasma drugs, it is necessary to acquire new drugs with low toxicity, high activity, cheaper and more effective. Objective: Earthworm has long been used as a therapeutic source of medicine in China and other parts of the Far East. Therefore, the purpose of the present study was to investigate of antiparasitic effects of Eisenia fetida extract against T. gondii in the Vero cell line. Materials and Methods: The effects of the extract on the parasite, Vero cell, and the parasitized cells were estimated by MTT assay in vitro. Apoptosis was also measured by flow cytometer in three groups of extract-treated parasites, extract-treated Vero cells, and extract-treated parasitic Vero cells, respectively. Results: The inhibitory effect of E. fetida extract and sulfadiazine was more than 85% and 65% on the parasite, respectively. Intracellular multiplication of the parasite in Vero cells during the 3 hours test showed a significant decrease compared to the 1-hour test (p<0.05). Flow cytometric analysis showed that with increasing concentration of E. fetida, apoptosis increased significantly (p<0.05). Conclusion: The results showed that E. fetida extract in vitro could have a significant antiparasitic effect against T. gondii.