Identification of Oxidative-Stress-Reducing Plant Extracts from a Novel Extract Library-Comparative Analysis of Cell-Free and Cell-Based In Vitro Assays to Quantitate Antioxidant Activity

• Published in: Antioxidants Vol. 13; no. 3; p. 297
• Main Authors: Heckmann, Mara, Stadlbauer, Verena, Drotarova, Ivana, Gramatte, Theresa, Feichtinger, Michaela, Arnaut, Verena, Atzmüller, Stefanie, Schwarzinger, Bettina, Röhrl, Clemens, Blank-Landeshammer, Bernhard, Weghuber, Julian
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28.02.2024; MDPI
• Subjects: Analysis; antioxidant; Antioxidants; Biodiversity; Biological products; Carotenoids; Chronic illnesses; Cocoa; Comparative analysis; Ethylenediaminetetraacetic acid; extract library; Flowers & plants; Fragaria ananassa; Medicine, Botanic; Medicine, Herbal; Nitric oxide; Oxidation; Oxidative stress; Phenolic compounds; Plant extracts; Polyphenols; Raw materials; Reactive oxygen species; ROS; screening; Austria; Germany; NO; antioxidant; screening; plant extracts; ROS; extract library; oxidative stress
• ISSN: 2076-3921; 2076-3921
• DOI: 10.3390/antiox13030297

Numerous underexplored plant species are believed to possess considerable potential in combating oxidative stress and its associated health impacts, emphasizing the need for a comprehensive methodological screening approach to assess their antioxidant capacity. This study investigated 375 plant extracts, utilizing both cell-free and cellular methods to evaluate their antioxidant properties. Target-based antioxidant capacity was evaluated by the total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) assays. Cell-based assays employed the H DCF-DA probe to measure reactive oxygen species (ROS) levels and the Griess assay to quantify nitric oxide (NO) levels in stressed Caco-2 and RAW264.7 cells, respectively. The highest TPC and FRAP values were found in extracts of and leaves. Several plant extracts significantly reduced stress-induced ROS or NO levels by at least 30%. Distinctive selectivity was noted in certain extracts, favoring the significant reduction of NO (e.g., extract), of ROS (e.g., subsp. extract), or of both (e.g., extract). A strong correlation between TPC and FRAP values and moderate correlations between the results of the cell-free and cell-based assays were evident. These findings highlight the great antioxidant potential of underexplored plant extracts and the diversity of the underlying mechanisms, emphasizing the importance of a multifaceted approach for a comprehensive assessment.