Natural stilbenes effects in animal models of Alzheimer's disease

Alzheimer's disease is one of the most frequent neurodegenerative diseases. This pathology is characterized by protein aggregates, mainly constituted by amyloid peptide and tau, leading to neuronal death and cognitive impairments. Drugs currently proposed to treat this pathology do not prevent neurodegenerative processes and are mainly symptomatic therapies. However, stilbenes presenting multiple pharmacological effects could be good potential therapeutic candidates. The aim of this review is to gather the more significant papers among the broad literature on this topic, concerning the beneficial effects of stilbenes (resveratrol derivatives) in animal models of Alzheimer's disease. Indeed, numerous studies focus on cellular models, but an in vivo approach remains of primary importance since in animals (mice or rats, generally), bioavailability and metabolism are taken into account, which is not the case in in vitro studies. Furthermore, examination of memory ability is feasible in animal models, which strengthens the relevance of a compound with a view to future therapy in humans. This paper is addressed to any researcher who needs to study untested natural stilbenes or who wants to experiment the most effective natural stilbenes in largest animals or in humans. This review shows that resveratrol, the reference polyphenol, is largely studied and seems to have interesting properties on amyloid plaques, and cognitive impairment. However, some resveratrol derivatives such as gnetin C, trans-piceid, or astringin have never been tested on animals. Furthermore, pterostilbene is of particular interest, by its improvement of cognitive disorders and its neuroprotective role. It could be relevant to evaluate this molecule in clinical trials.