Multidirectional investigations on different parts of Allium scorodoprasum L. subsp. rotundum (L.) Stearn: Phenolic components, in vitro biological and in silico propensities

Allium species have been widely used for culinary and medicinal purposes. This study attempts for the first time to investigate into the enzyme inhibitory potential of different plant parts of Allium scorodoprasum L. subsp. rotundum (L.) Stearn, also known as wild garlic or leek in Turkey. The antioxidant and enzyme inhibitory potential of the flower, stem, and bulb extracts of A. scorodoprasum were assessed using in vitro bio-assays. The phenolic composition of the different plant parts was also established. The flower extract, having high phenolic content (27.69 mg GAEg extract), showed potent antioxidant activity as a metal chelating agent (22.27 mg EDTAE/g extract), radical scavenger (34.83 and 66.02 mg trolox equivalent (TE) /g extract, for 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assays, respectively) and reducing agent (90.53 mg TE/g extract, for the cupric reducing antioxidant capacity assay). Besides, the flower extract was a potent inhibitor of butyrylcholinesterase (3.16 mg galantamine equivalent (GALAE)/g extract) and tyrosinase (55.21 mg kojic acid equivalent/g extract). The flower extract was rich in rosmarinic acid. In silico studies revealed that rosmarinic acid established several hydrogen bonds and  interactions in the enzymatic cavity of butyrylcholinesterase. On the other hand, the stem extract of A. scorodoprasum showed inhibitory action against acetylcholinesterase (2.17 mg GALAE /g extract) and α-amylase (0.55 mmol acarbose equivalent/g extract). Interestingly, we noted that the bulb extract of A. scorodoprasum, inferior in phenolic compounds, showed the least activity. These results suggest that the different plant parts of A. scorodoprasum possessed different biological activities and might be used as a medicinal food plants for specific therapeutic applications.