The discovery of mesenchymal stem cell-derived exosomes (MSCs-derived exosomes) has shed a new light in the development of disease-modifying treatments for Alzheimer (AD). The present study is an attempt to investigate the influence of these extracellular vesicles (exosomes) in Alz therapy. A total of 38 adult female albino Wistar rats were randomly assigned to the following groups: Control group (C) of 8 rats given saline; Alzheimer's group (Alz) of 15 ovariectomized animals inoculated orally with AlCl₃ (17mg/Kg b.wt/day) for 2 months after 6 weeks of surgical operation and 15 Alzheimer's disease-induced rats treated (i.v) with (10⁷ MSCs-derived exosomes/rat/week). After 2 and 4 weeks animals were sacrificed by ether inhalation anesthesia where brains were removed and processed for histological investigation by Hx&E and biochemical analysis for measuring β-Amyloid 1-42 and Brain derived neurotrophic factor (BDNF) levels.