The effects of melatonin hormone and vitamin K2 on in vitro maturation of cat oocytes

The long-term conservation of 36 different wild cat species, all of which are currently threatened with extinction, requires the development of assisted reproductive technologies in domestic cats. In this context, biotechnological methods such as in vitro maturation (IVM), fertilization, and embryo production of feline oocytes play a critical role both in ensuring species sustainability and in supporting biomedical research. This study aimed to investigate the effects of various doses of melatonin hormone and vitamin K2—both of which have not been previously tested in cats—on the IVM process. Melatonin, in addition to regulating seasonal reproductive cycles, exhibits protective effects at the cellular level due to its strong antioxidant properties. Vitamin K2, on the other hand, supports cellular health and has the potential to reduce damage caused by oxidative stress. In the first phase of the study, three different doses of melatonin (10, 25, 50 µM) and vitamin K2 (0.1, 0.25, 0.5 µM) were administered. In the second phase, the most effective doses were tested in combination. Although neither compound showed a statistically significant effect on IVM rates (p>0.05), all experimental groups demonstrated higher maturation rates compared to the control group. Particularly, all doses of vitamin K2 were found to be significantly more effective than both the control and melatonin groups in preventing apoptosis (p<0.05). In conclusion, vitamin K2 was found to be effective in protecting oocytes from apoptosis, while its combination with melatonin showed a moderate increase in maturation rates, although this increase was not statistically significant.