Antioxidant, Hepatoprotective, and Anti-inflammatory Activity of an Aspen Bark Phenol Glycoside Complex in vitro

Abstract

The aim. To study the antioxidant, hepatoprotective, and anti-inflammatory properties of an aspen bark ( Populus tremula L.) phenol glycoside complex (ABPG) in vitro . Materials and methods. ABPG was obtained by solvent extraction and characterized by high-performance liquid chromatography (HPLC). Radical scavenging activity was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and iron chelating capacity was evaluated by the colorimetric ferrozine-based assay. Cellular effects were studied in HepG2 cells in models of lipotoxicity (oleic and palmitic acids), paracetamol-induced injury, and inflammatory stimulation with lipopolysaccharide (LPS) and interferon γ (IFNγ). Intracellular reactive oxygen species (ROS), reduced glutathione (GSH), neutral lipid content, or cell viability served as endpoints. Results. ABPG comprised more than 70 individual constituents; its dominant components (as a share of the total HPLC peak area) were dihydroxybenzoic acid (11.5%), methoxybenzoic acid (8.5%), luteolin (7.7%), salicin (5.4%), and hydroxybenzoic acid (1.88%). The complex showed pronounced radical scavenging activity (IC 50 = 87.6 µg/ml in the DPPH assay) and chelated Fe 2+ ions in the amount equivalent to 14.07 mg ethylenediaminetetraacetic acid per gram of the sample. In HepG2 cells, ABPG lowered ROS levels under lipotoxic conditions by 47.6% and prevented intracellular lipid accumulation by 40.4%. In paracetamol-induced injury, it restored cell viability to 77.9%; and under LPS/IFNγ stimulation, it decreased ROS production by 19.2% while raising GSH levels by 42.9%. Conclusion. The aspen bark phenol glycoside complex modulates the redox state and stress responses of hepatocytes, conferring cytoprotection through redox-dependent mechanisms. These effects underlie its antioxidant, hepatoprotective, and anti-inflammatory effects in vitro .