Fig. 5
Chalcones-pretreated parasites. A pretreatment was carried out by incubating T. gondii tachyzoites with C2 (8 µg/mL), C4 (8 µg/mL), C9 (32 µg/mL), S + P (200 + 8 µg/mL) or only culture medium for 1 h. (A): β-galactosidase assay was performed 3 h later to obtain T. gondii invasion rate (% of T. gondii invasion). Significant differences (P < 0.05) were analyzed using one-way ANOVA and Dunnett´s multiple comparisons post-test. (B): β-galactosidase assay was performed 24 h later and T. gondii proliferation was expressed in percentages (% of T. gondii proliferation). Significant differences (P < 0.05) were analyzed using Kruskal–Wallis test and Dunn’s multiple comparison post-test. Untreated parasites (M) represent the negative control and were considered as 100% of invasion and proliferation, respectively. Data are expressed as means ± SEM from three experiments performed in eight replicates. *Comparison between untreated/infected and infected/treated cells. #Comparison to S + P-treated cells. Representative scanning electron microscopy (SEM) images showing: (C) untreated T. gondii tachyzoite, (D) tachyzoite pretreated with S + P (200 + 8 µg/ml), (E) C2 (8 µg/mL), (F) C4 (8 µg/mL) and (G) C9 (32 µg/mL). Scale bars (bottom right) 2 μm. Loss of tachyzoite surface integrity or hole-like structures was indicated by white arrows.
