Antioxidant properties of Trifolium resupinatum and its therapeutic potential for Alzheimer?s disease

Introduction: Alzheimer's disease (AD) is the most common cause of dementia and is characterized by a progressive dete-rioration in cognitive function, which typically begins with impairment in memory. Persian clover (Trifolium resupinatum) is an annual plant found in central Asia. Due to its contents (high flavonoid and isoflavones), extensive researches have been done on its therapeutic properties, such as multiple sclerosis (MS) treatment. In this study, we investigate the neuroprotec-tive effects of this plant on Streptozotocin (STZ)-induced AD in rats.Material and methods: This research aimed to evaluate the neuroprotective effect of Trifolium resupinatum on the spatial learning and memory, superoxide dismutase (SOD), expressions of [3 amyloid 1-42 (A[31-42), and [3 amyloid 1-40 (A[31-40) in the hippocampus of STZ-induced Alzheimer rats.Results: Our data showed that Trifolium resupinatum extract administration for two weeks before and one week after AD induction significantly improves maze escape latency (p = 0.027, 0.001 and 0.02 in 100, 200, and 300 mg of the extract, respectively) and maze retention time (p = 0.003, 0.04 and 0.001 in 100, 200, and 300 mg of the extract, respectively). Also, the administration of this extract significantly increases the SOD levels from 1.72+0.20 to 2.31+0.45 (p = 0.009), 2.48+0.32 (p = 0.001) and 2.33+0.32 (p = 0.007) and decreases the expressions of A[31-42) (p = 0.001 in all concentrations of the extract) and A[31-40) (p = 0.001 in all concentrations of the extract) in the rat's hippocampus.Conclusions: This study suggests that the alcoholic extract of Trifolium resupinatum has anti-Alzheimer and neuroprotec-tive effects on rats.