Related Experiment Video
Updated: May 26, 2026
Determination of Chemical Inhibitor Efficiency against Intracellular Toxoplasma Gondii Growth Using a Luciferase-Based Growth Assay
Published on: April 29, 2020
A new type of pterocarpanquinone that affects Toxoplasma gondii tachyzoites in vitro
Juliana de Araujo Portes1, Chaquip Daher Netto, Alcides José Monteiro da Silva
1Laboratório de Tecnologia em Cultura de Células, Centro Universitário Estadual da Zona Oeste (UEZO) - Av. Manuel Caldeira de Alvarenga, 1203, Campo Grande, Rio de Janeiro, RJ, CEP: 23070-200, Brazil. julianaportes@yahoo.com.br
Abstract:
Toxoplasma gondii, the agent of Toxoplasmosis, is an obligate intracellular protozoan able to infect a wide range of vertebrate cells, including nonprofessional and professional phagocytes. Therefore, drugs must have intracellular activities in order to control this parasite. The most common therapy for Toxoplasmosis is the combination of sulfadiazine and pyrimethamine. This treatment is associated with adverse reactions, thus, the development of new drugs is necessary. In previous studies, naphthoquinone derivatives showed anti-cancer activity functioning as agents capable of acting on groups of DNA, preventing cancer cells duplication. These derivatives also display anti-parasitic activity against Plasmodium falciparum and Leishmania amazonensis. The derivative pterocarpanquinone tested in this work resulted from the molecular hybridization between pterocarpans and naphtoquinone that presents anti-tumoral and anti-parasitic activities of lapachol. The aim of this work was to determine if this derivative is able to change T. gondii growth within LLC-MK2 cells. The drug did not arrest host cell growth, but was able to decrease the infection index of T. gondii with an IC(50) of 2.5 μM. Scanning and transmission electron microscopy analysis showed morphological changes of parasites including membrane damage. The parasite that survived tended to encyst as seen by Dolichos biflorus lectin staining and Bag-1 expression. These results suggest that pterocarpanquinones are drugs potentially important for the killing and encystment of T. gondii.
Insights
A novel pterocarpanquinone derivative effectively reduced Toxoplasma gondii infection in host cells. This compound demonstrated anti-parasitic activity, causing parasite membrane damage and promoting encystment, suggesting potential for new toxoplasmosis treatments.
Area of Science:
- * Molecular parasitology
- * Drug discovery and development
- * Cell biology
Background:
- * Toxoplasma gondii causes toxoplasmosis, requiring intracellularly active drugs.
- * Current treatments (sulfadiazine and pyrimethamine) have adverse effects, necessitating new therapies.
- * Naphthoquinone derivatives show promise with anti-cancer and anti-parasitic activities.
Purpose of the Study:
- * To evaluate the efficacy of a pterocarpanquinone derivative against T. gondii.
- * To assess the compound's impact on host cell viability and parasite growth.
- * To investigate the morphological and developmental effects of the drug on T. gondii.
Main Methods:
- * In vitro culture of T. gondii within LLC-MK2 cells.
- * Drug efficacy assessment via infection index and IC(50) determination.
- * Morphological analysis using scanning and transmission electron microscopy.
- * Encystment assessment via Dolichos biflorus lectin staining and Bag-1 expression.
Main Results:
- * The pterocarpanquinone derivative decreased T. gondii infection index (IC(50) = 2.5 μM) without affecting host cell growth.
- * Electron microscopy revealed parasite membrane damage.
- * Surviving parasites exhibited increased encystment, indicated by lectin staining and Bag-1 expression.
Conclusions:
- * Pterocarpanquinone derivatives show significant anti-parasitic activity against T. gondii.
- * The compound induces parasite membrane damage and promotes encystment.
- * These findings highlight pterocarpanquinones as potential therapeutic agents for toxoplasmosis.
