Metabolomics-based profiling with chemometric approach to delineate the bio-pharmaceutical properties of fruit extracts from Ligustrum vulgare L

Ligustrum vulgare L. (Family: Oleaceae) is an evergreen shrub native to North-west Africa, Europe and Western Asia. In the present work, infusion (water), ethyl acetate, methanol and n-hexane extracts of the fruits of L. vulgare L. were studied for their in vitro antioxidant and enzyme inhibitory properties along with their untargeted polyphenolic profile (using an ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry approach). Untargeted metabolomics coupled to multivariate statistics showed that Ligustrum fruit extracts were very abundant in polyphenols, such as flavonoids, tyrosols and lignans, with ethyl acetate allowing the highest recovery among the extraction solvents tested. The methanolic extract inhibited the highest acetylcholinesterase (AChE), tyrosinase and glucosidase activity (4.23 mg galatamine equivalent (GALAE)/g, 132.85 mg kojic acid equivalent (KAE)/g and 1.94 mmol acarbose equivalent (ACAE)/g respectively) while the ethyl acetate extract inhibited the highest butyrylcholinesterase (BChE) and amylase activity (4.92 mg GALAE/g and 0.73 mmol ACAE/g, respectively). However, the infusion showed the weakest activity against all the enzymes studied. However, the extract showed highest antioxidant property in the antioxidant assays (except for phosphomolybdenum). The present paper is the first comprehensive report on L. vulgare fruits and thus our findings are of considerable interest to design new bioproducts for the pharmaceutical and cosmeceutical industry in the future.