Faculty of Veterinary Medicine, Urmia University Veterinary Research Forum 2008-8140 17 7 2026 07 01 In vitro efficacy of Ziziphus vulgaris L. and Camellia sinensis L. extracts against Giardia duodenalis cysts 497 503 730949 10.30466/vrf.2025.2064604.4809 EN Kamal Taheri Lak Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Farnaz Malekifard Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Mohammad Yakhchali Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 0000-0002-5882-1827 Journal Article 2025 07 01 There is an increasing interest in exploring plant extracts as potential new treatment options for these ailments. <em>Ziziphus vulgaris</em> L. and <em>Camellia sinensis</em> (L.) Kuntze are medicinal plants widely used in different traditional medical practices, especially in Iranian traditional medicine, for addressing a range of health issues. Although their biological properties are well-established, their effectiveness against <em>Giardia duodenalis</em> cysts is still uncertain. This research aimed to assess the impact of <em>Z. vulgaris</em> and <em>C. sinensis</em> extracts on <em>G. duodenalis</em> cysts in vitro and to compare their effectiveness with metronidazole. Cysts were extracted from stool samples and concentrated using a 0.85 M sucrose solution. Extracts of <em>Z. vulgaris</em> and <em>C. sinensis</em> were prepared at concentrations of 25.00, 50.00, and 100 mg mL^-1. The impacts of these extracts at different concentrations were evaluated at 10, 15, 30, 60, and 180 min, and the results were compared to control groups. The collected data were documented and statistically analyzed. The findings revealed that <em>Z. vulgaris</em> extract at a concentration of 100 mg mL^-1 and <em>C. sinensis</em> extract at a concentration of 50.00 mg mL^-1 showed similar effectiveness to metronidazole in eliminating <em>Giardia </em>cysts. In addition, the cytotoxic effects of Z. vulgaris and C. sinensis extracts, in comparison with metronidazole, indicated a rise in fatality rates with prolonged exposure times and higher extract concentrations. Therefore, it could be concluded that extracts of <em>Z. vulgaris</em> and <em>C. sinensis</em> were as effective as metronidazole for killing <em>Giardia </em>cysts in vitro. https://vrf.iranjournals.ir/article_730949_afe394a2ba848309f02c18219cc7d38e.pdf