Effect of Extracts of the Endemic Plants Centaurea lydia and Phlomis nissolii on Toxoplasma gondii.

Objective: This study aimed to investigate the potential antitoxoplasma activities of extracts of the endemic plants Centaurea lydia and Phlomis nissolii in a fibroblast cell culture infected with T. gondii trophozoites.

Methods: WI-38 cell lines treated with plant extracts (55 μg/mL each) and an untreated control were infected with 5×105 T. gondii trophozoites, and the number of parasites in the medium was determined on days 7, 14, and 24.

Results: No cytotoxic effects of C. lydia and P. nissolii extracts were detected at concentrations of 0.86-55 μg/mL in the WI-38 cell line, and the absence of the cytotoxicity of these extracts on the fibroblast cell line was considered as a positive effect. C. lydia extract at 55 μg/mL had marked activity against T. gondii trophozoites. A 47.5-fold increase was observed in the number of trophozoites in the control group, while a 84-fold decrease was found in the C. lydia extract group. However, a 36-fold increase was detected in the P. nissolii extract group, indicating no antitoxoplasma activity.

Conclusion: The extract of C. lydia, an endemic plant, was found to be a good drug candidate for treating toxoplasmosis. The in vitro activity of the extract of this endemic plant should be further investigated in animal models in vivo.