Anticoccidial Effects of Tirmania nivea Extract and In Silico Evaluation of Its Phytochemicals Against Eimeria spp.

Coccidiosis, caused by Eimeria spp., is a major parasitic disease affecting livestock and laboratory animals, with increasing drug resistance driving the search for natural alternatives. Tirmania nivea, an edible desert truffle rich in bioactive compounds, remains underexplored for this purpose. This study assessed in vitro anticoccidial activity of T. nivea methanolic extract (TNE) against oocyst sporulation and investigated molecular interactions of its major constituents with two key Eimeria enzymes, L-lactate dehydrogenase (LDH) and calcium-dependent protein kinase 1 (CDPK1), using molecular docking. TNE was prepared by methanol-water extraction of fruiting bodies and characterized by GC-MS, identifying 15 major compounds. In vitro assays showed a significant, dose-dependent inhibition of oocyst sporulation, analyzed by one-way ANOVA with post hoc multiple comparisons (p < 0.05). The highest concentration (300 mg/mL) achieved 94.12% and 92.86% inhibition at 72 and 96 h, respectively, exceeding the reference drug amprolium. Docking analyses revealed strong binding affinities of lupeol and estradiol to LDH and CDPK1 (-7.31 to -7.46 and -8.23 to -8.96 kcal/mol, respectively), supported by hydrogen bonding and hydrophobic interactions. ADMET predictions indicated favorable pharmacokinetic properties and low toxicity. These findings support T. nivea as a promising natural anticoccidial candidate targeting essential metabolic and signaling pathways.