Evaluation of indolicidin for inactivation of bovine alphaherpesvirus 1 in semen

Bovine alphaherpesvirus 1 (BoAHV1) is a reproductively important pathogen whose presence in bovine semen restricts international trade. The increasing use of controlled breeding programs highlights the need for effective viral inactivation strategies. This study evaluated the antiviral activity of the antimicrobial peptide indolicidin in bovine semen experimentally inoculated with BoAHV1. Indolicidin was synthesized by solid-phase peptide synthesis. Antiviral activity and minimum inhibitory concentration (MIC) were determined in MDBK cell cultures. The peptide was then tested in inoculated semen, and semen quality was assessed using computer-assisted sperm analysis (CASA). Indolicidin inhibited BoAHV1 in MDBK cells with an MIC of 8 µM. In semen, viral titer was significantly reduced at 10 µM with complete inactivation at 30 µM, confirmed by the absence of cytopathic effect in MDBK cells. Sperm kinematic, structural and functional integrity analysis demonstrated that semen quality parameters were preserved at concentrations up to 30 µM, while 100 µM caused a significant reduction in total and progressive motility.