Identification of Miscanthus floridulus as a promising anti-Alzheimer’s disease and antidiabetic agent through bioactivity evaluations and chemical composition analyses

The Poaceae family, the fifth largest family of angiosperms, has always been an important source of cereal crops, medicinal crops, and industrial crops. However, comprehensive studies on the biological activity and chemical composition of many species are lacking. In the present study, we tested the total flavonoid and total phenol contents and antioxidant, α-glycosidase, α-amylase, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE)-inhibitory activities of five Poaceae plants (Echinochloa crus-galli, Miscanthus floridulus, Sporobolus fertilis, Bromus japonicus, and Eleusine indica). As a result, the 95 % ethanol (EtOH) extract of M. floridulus (EMF) was found to possess strongest abovementioned activities among the extracts of the five different species. The IC₅₀ value of the DPPH radical scavenging activity was 23.18 ± 0.36 μg/mL, and those of the anti-AChE, anti-BChE and anti-α-glycosidase activities were 49.92 ± 1.44, 100.37 ± 2.48, and 50.01 ± 2.15 μg/mL, respectively. Forty-four compounds were identified from the EMF through liquid chromatography–hybrid ion trap-time of flight mass spectrometry (LC–IT–TOF–MS) analysis, and the majority of these compounds were flavonoids and organic acids. In general, the obtained results highlight the medicinal value of the five members of the Poaceae family. More importantly, M. floridulus has potential for the development of multitarget anti-Alzheimer’s disease (AD) and antidiabetic agents in the pharmaceutical industry.