ABSTRACT:

Despite the increasing use of oregano (Origanum vulgare L.) essential oil for therapeutic purposes, pre- and postnatal development of animals offspring exposed to this oil has not yet been evaluated. In line with previous concerns of genotoxicity, in this study adult rats were exposed to different doses of oregano essential oil (3, 9 and 27% vol/vol) during pre-mating, mating, gestation and lactation. Prenatal screening included fetal development and uterine inspection, where the reproductive rate of females such as breeding, pregnancy, delivery, viability and post-implantation loss rate were measured. Postnatal evaluation of rat offspring included motor development, neuroendocrine and behavioral assessment. Body weight of rat dams and signs of dystocia were evaluated daily. Development of physic characteristics and reflex tests of puppies were also assessed. Additionally, these rats, when adults, were submitted to sexual and open field behavioral tests. The main differences among the groups were observed in the indices of mating, pregnancy and post-implantation loss (P<0.01). Results demonstrated that the treatment of parental generation with oregano essential oil has the potential to affect the developing fetuses at the highest dose used, but without causing maternal toxicity and changes in general behavior and development of the progeny.

Key words:
oregano; reproductive toxicity; progeny; reproduction; rats