Integrative approach to the biochemical, and toxicological fingerprinting of Polygonum glabrum. A computational and experimental synergy for a medicinal food plant

In this work, the biological and chemical fingerprints of methanol and DCM extracts from an important Polygonum species (Polygonum glabrum) was investigated. The biological fingerprint was assessed for its antioxidant, enzyme inhibitory, and cytotoxic effects. For the chemical characterization, total bioactive components, and individual secondary metabolites were determined using photometric, HPLC-PDA polyphenolic quantification, and UHPLC-MS methods. The main identified compounds were belonging to flavonoid and phenolic classes of phytochemicals. Methanol extracts contained the highest total phenolic (54.66 mg GAE/g extract) and flavonoid (27.85 mg GAE/g extract) content. The results of antioxidant assays showed that methanol extract displayed higher antioxidant (for DPPH, ABTS, FRAP, CUPRAC) activity compared to the DCM extract (which was most active for metal chelation assay). For the enzyme inhibition activity, the DCM extract was found to be active against cholinesterases, while the methanol extract exhibited the higher inhibition potential for tyrosinase, amylase, and glucosidase enzymes. Generally, the methanol extract exhibited higher biological activities which might be correlated with higher levels of the bioactive components. Moreover, three flavonoids (citrusin B, robinetin 3-rutinoside, and demethyltexasin) were selected for molecular docking studies against the tested enzymes. Furthermore, the utilization of Swiss ADME, pkCSM, and DFT computational analysis has enhanced our comprehension of the pharmacokinetic characteristics and electronic factors of the identified phytochemicals, hence advancing the possibility for drug discovery. To conclude, the results suggest that the P. glabrum extracts could be further studied as a potential candidate for developing new phyto-pharmaceuticals and functional ingredients.