Supercritical CO2-Derived Tomato Extract Activates Signaling Pathways to Reduce Oxidative Stress and Inflammation in Astrocyte Cells.

BACKGROUND/

OBJECTIVES

In this study, we investigated the effect on antioxidant defenses of a tomato extract obtained by supercritical CO2 extraction (sCO2TE), evaluating whether this green extraction method preserves biological activity compared to a conventional tomato extract (CTE) and focusing on superoxide dismutase (SOD) and glutathione peroxidase (GPx) regulation, Nuclear factor erythroid 2-related factor 2 (NRF2) activation, reactive oxygen species (ROS) and lipid peroxidation modulation.

METHODS

Human glioblastoma astrocytoma U-373 cells were pre-treated with sCO2TE or conventional tomato extract (CTE) and subsequently exposed to sodium arsenite (AsNaO2) to induce oxidative stress, or lipopolysaccharide (LPS) to trigger inflammatory signaling. Cell viability was assessed by Trypan Blue and MTT [3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide]; cell toxicity by propidium iodide staining. Intracellular ROS and lipid peroxidation were measured by flow cytometry. Gene expression of NRF2, SOD1 and GPX1 was analyzed by qRT-PCR, NRF2 activation and modulation of ERK1/2 (Extracellular Signal-Regulated Kinase 1/2) and NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells) were evaluated by Western blot.

RESULTS

Pre-treatment with sCO2TE significantly reduced AsNaO2-induced ROS production and lipid peroxidation, showing a stronger effect compared to CTE. sCO2TE enhanced the expression of NRF2 phosphorylation and its downstream targets SOD1 and GPX1, particularly under oxidative stress conditions. In addition, sCO2TE attenuated LPS-induced phosphorylation of ERK1/2 and NF-κB p65, suggesting anti-inflammatory activity.

CONCLUSIONS

These findings demonstrate that sCO2TE preserves the antioxidant and anti-inflammatory properties of tomato-derived bioactives. The comparable efficacy of sCO2TE and CTE supports the use of sCO2 as a sustainable and solvent-free extraction method for the development of nutraceutical formulations targeting oxidative stress and neuroinflammation.