Extraction-dependent phenolic shifts drive antioxidant and multi-enzyme inhibitory activities of Onosma rechingeri methanolic extracts

The bioprospecting of Onosma species for multifunctional phenolics is gaining momentum, yet the impact of extraction methods on bioactivity is underexplored. This study compared methanolic extracts of O. rechingeri obtained via ultrasound-assisted extraction (UAE-ME), maceration (MAC-ME), and Soxhlet (SOE-ME). Total phenolic and flavonoid content was highest in SOE-ME. Luteolin-7-glucoside and hesperidin were abundant in MAC-ME, while SOE-ME was richest in rosmarinic acid. SOE-ME showed superior electron-transfer antioxidant activity, while metal chelation favored UAE-ME and MAC-ME. Enzyme inhibition varied by extraction: MAC-ME was most effective against AChE and α-amylase, SOE-ME against tyrosinase. Correlation analysis revealed distinct compound-activity associations: tyrosinase aligned with electron transfer, AChE and α-amylase with chelation. Docking suggested luteolin-7-glucoside as a strong α-amylase binder (–9.09 kcal/mol) and rosmarinic acid as a promising in silico binder of AChE and TYRP1. Overall, extraction strategy significantly alters chemical profiles and bioactivity, but these findings should be interpreted as preliminary because they are based on crude extracts, in vitro assays, correlation analysis with a limited sample set, and docking predictions; therefore, they highlight the need for targeted fractionation and further biological validation.