Metabolomics profiling, bio-pharmaceutical properties of Hypericum lanuginosum extracts by in vitro and in silico approaches

Hypericum species are important as a source of natural-bioactive compounds in the Turkish folk medicine. Among them, Hypericum lanuginosum has not been explored so far for its biological properties. The current study aimed to determine the antioxidant activity, enzyme inhibitory potential, and phenolic content (spectrophotometric and liquid chromatography/high resolution mass spectrometry (LC-HRMS) analysis) of different solvent extracts (ethyl acetate, methanol, and aqueous) of H. lanuginosum aerial parts. Twenty one phenolic compounds including phenolic acids, acylquinic acids, flavonoids and bioflavonoids were identified by LC-HRMS profiles. Quinic acid was the dominant compound in all H. lanuginosum extracts. The highest total phenolic (168.56 mg gallic acid equivalent (GAE)) and flavonoid (53.22 mg rutin equivalent (RE)) contents were observed in the aqueous extract. Also, the aqueous extract was the best antioxidant, showing the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) scavenging, ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), and activity in the phosphomolybdenum assay. The methanol extract exhibited the strongest metal chelating and inhibitory effect on alpha-amylase and tyrosinase. In contrast, the most efficient inhibitor of cholinesterases and alpha-glucosidase was the ethyl acetate extract. Docking showed that the selected compounds are all possible inhibitor candidates of tyrosinase. To conclude, each solvent extract of H. lanuginosum varied in its chemical and biological profile but overall, possess a good source of many natural agents which can be used to manage ailments inked with oxidative stress.