Dias, Sandra D.F.Andrade, L.P.Rolo, JoanaGaspar, CarlosRuivo, Patrícia GomesOliveira, Ana SofiaFerreira, Sandra SaraivaOliveira, Rita PalmeiraOliveira, José Martinez deGonçalves, José CarlosDelgado, F.M.G.Oliveira, Ana Palmeira de2025-10-242025-10-242025DIAS, Sandra D.F. [et al.] (2025) - Reproductive toxicity assessment of four portuguese plant hydrolates: Effects on oocyte maturation and sperm viability. Animals. DOI: 10.3390/ani15192838http://hdl.handle.net/10400.11/10340Ethical review and approval were waived for this study due to the use of materials that were collected at the slaughterhouse and were going to be discarded. The study design is in compliance with an established protocol between Universidade da Beira Interior (Covilhã, Portugal) and the slaughterhouse “OVIGER” (Alcains, Portugal).Extracts of aromatic medicinal plants have been extensively studied regarding their numerous bioactivities. However, despite being highly used by humans, studies on the safety of these extracts for animal use are scarce. In this study, we aim to contribute to the determination of the safety profile of plant extracts by focusing on the reproductive toxicity of hydrolates (a by-product of essential oils production) of four endogenous Portuguese plants—Cistus ladanifer, Cupressus lusitanica, Helychrisium italicum, and Thymbra capitata—by studying their effects on bovine oocytes and spermatozoa. To achieve our aims,we determined the oocyte maturation and viability rate in the bovine in vitro maturation test (bIVM) and the bovine sperm viability using the eosin–nigrosin test, in the presence of five concentrations of each hydrolate at half-log intervals (% v/v of culture media). We found that hydrolates did not affect oocyte maturation or viability (maximum concentration tested: 0.2%, v/v). Regarding the sperm viability test, we found that T. capitata and C. ladanifer hydrolates impaired sperm viability (p < 0.05) (maximum concentration tested: 0.2%, v/v), in comparison with the negative control. In summary, we found that H. italicum and C. lusitanica hydrolates were safe regarding oocyte maturation, oocyte viability, and sperm viability, being candidates to be included in bovine husbandry as feeding additives.engCistus ladaniferCupressus lusitanicaHelychrisium italicumOocyteReproductive toxicitySpermatozoaThymbra capitataViabilityresearch article2025-10-21cv-prod-458473210.3390/ani15192838