Medicinal plants are alternative medicine’s key weapons. Thanks to the medicinal effects some plants turned out to have, they have been chosen by people to heal or at least ameliorate various affections. Nature is continuously changing: some species become extinct, others are born and some cross time. Despite the trend to enhance plant-based medicines, research data in this field is still incomplete. The experimental research in this paper aimed at evaluating the hepatoprotective capacity of the Plantago major (plantain) species in albino mice –NMRI stain, after experimental poisoning by Diclofenac. Using physiological and biochemical methods and techniques, we researched potential structural and functional changes ocurred further to the experimental poisoning by Diclofenac.