Phytochemical Analysis, Antioxidant, and Antineurodegenerative Properties of Gentiana lutea L. Root Extract and Derived Fractions

Abstract

Objectives Yellow gentian (Gentiana lutea L., Gentianaceae) has long been valued in traditional medicine primarily as a bitter drug. While recent studies have confirmed its pleiotropic properties, the antineurodegenerative potential of its bioactive compounds remains insufficiently studied. This study aimed to evaluate the chemical composition, in vitro antioxidant and neuroprotective activity of the primary 70% ethanol extract of G. lutea roots and its fractions obtained by liquid-liquid extraction. Methods Total phenolic content, dominant secoiridoid gentiopicroside and the main xanthone isogentisin were quantified, as well as the correlation among investigated compounds and activities of samples. The antioxidant activity was tested through DPPH (2,2-diphenyl-1-picrylhydrazyl radical), ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric-reducing ability of plasma), and β-carotene bleaching assays, while neuroprotective activity was investigated through testing against acetylcholinesterase (AChE) and tyrosinase (Tyr) activity. Results The ethyl acetate fraction exhibited significantly higher total phenolic and isogentisin contents (4.3 and 17.6 times higher than the primary extract, respectively), while the n-butanol fraction contained the highest amount of gentiopicroside (2.9 times higher than the primary extract). Antioxidant assays indicated that the ethyl acetate fraction had the strongest activity. The primary ethanolic extract demonstrated the highest acetylcholinesterase and tyrosinase inhibitory activities. Notably, the primary ethanolic extract showed promising tyrosinase inhibition (50.85% inhibition), comparable to kojic acid used as a positive control (51.81% inhibition) at the same concentration (100 μg/mL). Conclusions Therefore, G. lutea roots extract possesses significant potential for further investigation and possible utilization as a component of pharmaceutical or food products with antioxidant and anti-neurodegenerative features.