Hypericum erectum alcoholic extract inhibits Toxoplasma growth and Entamoeba encystation: an exploratory study on the anti-protozoan potential

AbstractHypericum erectum is an important ethnobotanical medicine in East Asian tradition. To explore the anti-parasitic potential ofH. erectum, inhibitory effects on the growth of intracellular parasiteToxoplasma and on the encystation of intestinal parasiteEntamoeba were examined. The constituents inH. erectum alcoholic extracts and fractions separated by solvent-partitioning were analysed by high resolution LC –MS.Toxoplasma gondii growth inhibition assay was performed using GFP-labelledT. gondii strain PTG-GFP by measuring the fluorescence intensity. Anti-Toxoplasma drug pyrimethamine was used as a positive control.T. gondii-induced immune reaction was assessed by quantitative PCR and fluorescence microscopy, using co-culture of PTG-GFP and monocyte-macrophage cell line Raw264. The inhibitory effect on the encystation ofEntamoeba invadens was measured by flow-cytometry, where paromomycin was used as a positive control.H. erectum methanol (MeOH) extract (50  µg/mL) and ethyl acetate (EtOAc) fraction (50 µg/mL) inhibited the growth ofT. gondii, while 50%MeOH extract and hydrophilic fractions were ineffective. Co-culture withT. gondii reduced the viability of macrophages, however macrophages were protected in the presence ofH. erectum MeOH extract or EtOAc fraction (above 10  µg/mL). The MeOH extract and EtOAc fraction also effectively suppressed the encystation ofE. invadens at 1  mg/mL. Hypericine, a major constituent in MeOH extract and EtOAc fraction, inhibitedT...
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research