Imidazopyridine derivatives as promising anti-Toxoplasma gondii agents: in vitro studies, in vivo testing, and molecular modeling analysis

Bibliographic Information
Authors: Sabt A.; Okasha H.; Farag H.; Fahmy Z.H.; Selim E.A.H.; Ibrahim H.A.A.; Thabit M.G.; Radwan A.F.; Eldehna W.M.; R. Mostafa R.
Journal: RSC Advances
Publisher: Royal Society of Chemistry
Publication Date: 2026
Volume / Issue: Volume 16 / Issue 35
Pages: 36803–36819
ISSN: 20462069
DOI: 10.1039/d6ra04816a
Scopus: View on Scopus
Document Type: Article
Access: All Open Access; Gold Open Access; Green Open Access
Authors and Affiliations
Sabt A., Chemistry of Natural Compounds Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre, Dokki, Cairo, 12622, Egypt; Okasha H., Biochemistry and Molecular Biology Department, Theodor Bilharz Research Institute, Giza, Egypt; Farag H., Pesticide Chemistry Department, Chemical Industries Research Institute, National Research Centre, Cairo, Egypt; Fahmy Z.H., Department of Parasitology, Theodor Bilharz Research Institute, Giza, Egypt; Selim E.A.H., Department of Parasitology, Theodor Bilharz Research Institute, Giza, Egypt; Ibrahim H.A.A., Pediatric Department, Faculty of Medicine, Cairo University, Cairo, Egypt; Thabit M.G., Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Pharos University (PUA), Alexandria, Egypt; Radwan A.F., Department of Biochemistry, Faculty of Pharmacy, Egyptian Russian University, Badr City, Cairo, 11829, Egypt, Department of Laboratory Sciences, College of Pharmacy, University of Kut, Wasit, 52001, Iraq; Eldehna W.M., Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt; R. Mostafa R., Department of Medical Parasitology, Faculty of Medicine, Cairo University, Cairo, Egypt
Abstract
Toxoplasmosis continues to pose significant challenges to public health and animal husbandry, thereby generating an ongoing need for the development of novel therapies through innovative approaches. In response to the persistent pursuit of an optimal chemotherapeutic agent, the present study designed and synthesized new small molecules (6 and 9a–d) featuring an imidazopyridine scaffold linked to isatin derivatives via a hydrazide moiety. The efficacy of these compounds was evaluated against Toxoplasma gondii (ME49 strain) in both in vitro and in vivo murine models of chronic infection. Notably, most of the tested compounds exhibited significant antiparasitic activity. Compound 9a showed the lowest calculated LD50 value, indicating strong potency, while compound 9c demonstrated excellent cysticidal activity in vitro, achieving 100% cyst mortality at concentrations ≥100 µg mL−1. In vivo, compound 9c was the most effective treatment, reducing brain cyst burden by 82.7%. Molecular analyses indicated that compound 9c significantly reduced T. gondii DNA levels and strongly downregulated pro-inflammatory cytokines. Molecular docking analyses further validated the effective interactions between the synthesized compounds and the target enzyme T. gondii calcium-dependent protein kinase-1 (TgCDPK1). Collectively, these results highlight the promising anti-Toxoplasma potential of imidazopyridine–isatin hybrids, which provides a foundation for the further development of these hybrid molecules as therapeutic agents against toxoplasmosis. This journal is © The Royal Society of Chemistry, 2026.
Keywords
Biosynthesis; Brain; Molecular docking; Molecular modeling; Scaffolds (biology); Animal husbandry; Imidazopyridines; In-vitro; In-vivo; Innovative approaches; Molecular modeling analysis; Synthesised; Toxoplasma gondii; Vitro studies; Vivo testing; Molecules
Citation Information
Scopus Citations: 0
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