Systemic Transplantation Effect of Human Adipose Tissue Derived Mesenchymal Stem Cells on Cognitive Deficits and Hippocampal Antioxidant Capacity in Trimethyltin Model of Alzheimer's Disease

Introduction: Stem cell-based therapies create new hope for the treatment of Alzheimer's disease (AD). Since the mesenchymal stem cells have neuroprotective and regeneration effects, this study aimed to investigate the memory, learning, and antioxidant capacity of the hippocampus following human adipose-derived mesenchymal stem cell (Ad-MSC) transplantation in Trimethyltin (TMT) rat's model of AD. Material & Methods: In total, 24 male Wistar rats were randomly divided into three groups (8 animals per group) of control (without any treatment), TMT+PBS (Trimethyltin+Phosphate buffer saline), and TMT+Ad-MSC (Trimethyltin+Stem cells). For the induction of the AD, TMT was peritoneally injected (8 mg/Kg). After 48 h, the TMT+Ad-MSC group received 1 million stem cells intravenously. One month after transplantation, avoidance and working memories were evaluated. Afterward, hippocampal levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and malondialdehyde (MDA) were measured using ELISA. Findings: The results showed a significant increase in the percentage of correct motor frequency in the Y maze, a decrease in the spent time in the dark room (P<0.05), and an increase in the latency time to the dark room in the TMT+Ad-MSC group, compared to the TMT+PBS group (P<0.01). Moreover, a significant increase in the CAT, SOD, and GPX enzymes activity, as well as a decrease in the MDA level in the hippocampus were observed in the TMT+Ad-MSC group, compared to the TMT+PBS group (P<0.05). Discussion & Conclusion: Xenotransplantation of human adipose tissue stem cell improved learning and memory, reduced tissue oxidative stress, and increased hippocampal antioxidant capacity in an animal model of AD.