Evaluation of Asarum europaeum L. Rhizome for the Biological Activities Related to Alzheimer’s Disease

Background and objectives: Asarum europaeum L. is an herbal medicine belonging to the family Aristolochiaceae. The rhizome of the plant has been used for the treatment of various diseases in complementary and alternative medicine of various countries. In Iranian traditional medicine (ITM), the aqueous extract of the rhizome has been used for the improvement and enhancement of memory. Methods: In the present study, the aqueous and hydroalcoholic extracts as well as different fractions of A. europaeum rhizome were evaluated for their cholinesterase (ChE), acetyl- and butyrylcholinesterase (AChE and BChE) inhibitory activity viamodified Ellman's method.  Results: The ethyl acetate fraction selectively showed the most suitable anti-AChE activity (IC50 = 99.69 µg/mL); none of the extracts or fractions demonstrated anti-BChE activity. In this regard, the ethyl acetate fraction was candidate for the investigation of further biological activities such as antioxidant activity, neuroprotectivity, and metal chelating ability related to Alzheimer’s disease. It depicted favorable neuroprotectivity at concentration of 100 μg/mL against the toxicity of exposure to H2O2 in PC12 cells (p£0.001, cell viability = 80/60%) and chelating ability towards zinc, iron, and copper ions. The results of antioxidant activity by DPPH assay showed that the ethyl acetate fraction was much more potent than BHA as the reference drug. Conclusion: The ethyl acetate fraction ofA. europaeum L. showed potent biological activities involved in Alzheimer’s disease and needs complementary investigations to develop an herbal product against Alzheimer’s disease.