A method of treating or preventing gonadal or uterine toxicity induced by an agent in a subject is provided. Accordingly there is provided a method comprising administering to a subject a therapeutically effective amount of pigment epithelium-derived factor (PEDF), thereby treating or preventing the gonadal toxicity induced by the agent. Also provided is, a method comprising determining gonadal function in a subject; and administering to the subject a therapeutically effective amount of PEDF, thereby treating or preventing the gonadal toxicity induced by the agent. Also provided is a PEDF for use in the treatment or prevention of gonadal toxicity induced by an agent in a subject. Also provided are cell culture, a medium, a kit and method for improving oocyte quality ex-vivo.