Background: Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is a widespread zoonotic infection posing serious health risks, particularly among immunocompromised individuals and pregnant women. Standard treatments—such as pyrimethamine and sulfadiazine—are often limited by adverse effects, toxicity, and drug resistance. Recently, interest has grown in herbal medicine as a complementary or alternative therapy due to its accessibility and reduced side effect profile.

Methods: This review evaluated 50 peer-reviewed preclinical and in vitro case studies examining the antiparasitic, immunomodulatory, antioxidant, and anti-inflammatory effects of plant-derived compounds against T. gondii. Data sources included PubMed, Scopus, and Google Scholar, selecting studies published between 2004 and 2022. The analysis focused on the model used, compound type, treatment outcomes, targeted parasite stage, and safety profiles.

Results: Approximately 94% of studies reported significant reductions in parasite load, particularly at the tachyzoite stage. Bioactive compounds such as thymoquinone (Nigella sativa), berberine (Berberis vulgaris), allicin (Allium sativum), and artemisinin (Artemisia annua) demonstrated notable efficacy. Many treatments enhanced host immunity (e.g., increased IFN-γ, IL-12) and reduced oxidative stress markers (e.g., MDA) with minimal toxicity. About 20% of studies noted synergistic benefits when herbal compounds were combined with standard drugs, allowing for dose reduction and decreased toxicity.

Conclusions: Herbal medicines offer promising therapeutic benefits in toxoplasmosis management. Their multi-targeted mechanisms and favorable safety profiles support their potential as adjunct or alternative therapies. Nonetheless, the findings are predominantly preclinical. To advance these compounds toward clinical application, further standardized trials and pharmacological studies are essential.

Keywords: Toxoplasmosis, Toxoplasma gondii, Herbal medicine, Phytotherapy, Medicinal plants, Antiparasitic activity, Immunomodulation, Antioxidants, Case study review, Alternative therapy.

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Yahya Jirjees Salman

Professor of Microbiology-Kirkuk Medical Faculty-Iraq