Chemical Composition, Antioxidant Activity and Mechanism of Fragaria nilgerrensis Schltdl. Fruit

To investigate the material basis and mechanisms underlying the antioxidant activity of Fragaria nilgerrensis Schlecht. fruits, water extract (FWE) and ethanol extracts (FAE) were prepared from the fruit material using reflux extraction. The total phenolic and flavonoid contents of the extracts were determined by UV-Vis spectrophotometry, and their chemical compositions were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The antioxidant activities were evaluated through in vitro assays, and a hydrogen peroxide induced oxidative stress model in Saccharomyces cerevisiae was constructed to further investigate their antioxidant capacity. Finally, network pharmacology and molecular docking techniques were employed to clarify the antioxidant mechanism of Fragaria nilgerrensis Schlecht. fruits. The results showed that the total phenolic acid contents of FAE and FWE were 216.84±0.66 and 191.90±6.67 mg GAE/g, respectively, while the total flavonoid contents were 149.30±2.99 and 120.81±26.32 mg CE/g, respectively. A total of 35 compounds, including phenolics, flavonoids, amino acids, and polysaccharides, were identified in the extracts. The IC₅₀ values of FAE and FWE for DPPH radical scavenging were 2.89±0.26 and 6.50±0.79 μg/mL, respectively, and for ABTS⁺ radical scavenging were 6.42±0.67 and 7.58±1.02 μg/mL, respectively. Additionally, both extracts prolonged the stationary growth phase of Saccharomyces cerevisiae, enhanced its resistance to oxidative stress, increased intracellular superoxide dismutase (SOD) activity, elevated reduced glutathione (GSH) levels, and decreased reactive oxygen species (ROS) and malondialdehyde (MDA) contents under oxidative stress. Network pharmacology analysis revealed that quercetin, kaempferol, naringenin, glycyrrhetinic acid and ellagic acid were the key antioxidant components, with potential antioxidant effects mediated through regulation of targets such as AKT1, IL6, ALB, ESR1 and EGFR and activation of signaling pathways including PI3K-AKT, MAPK and HIF-1. This study confirms the antioxidant potential of Fragaria nilgerrensis Schlecht. fruits extracts and provides a scientific basis for their development as functional foods.