Antioxidant effects and potential molecular mechanism of action of Diplocyclos palmatus (L.) C. Jeffrey fruits based on systematic network pharmacology with experimental validation

Abstract

Oxidative stress arises from an imbalance between the production of reactive oxygen species (ROS), and the ability of biological systems to detoxify these reactive intermediates or repair the resulting damage. Diplocyclos palmatus (D. palmatus) is a medicinal plant, whose fruits has been reported to have antioxidant activity due to its potent bioactive compounds, and holds promise for mitigating oxidative stress and its associated diseases. Therefore, this study aims to elucidate the bioactive compounds present in D. palmatus via Gas Chromatography-Mass Spectrometry (GC–MS) analysis and evaluate their antioxidant activity via different in-vitro antioxidant assays such as, DPPH free radical scavenging assay, ABTS radical scavenging assay, ferric reducing antioxidant power assay, hydroxyl free radical scavenging assay and reactive nitrogen oxide scavenging assay. Furthermore, systematic network pharmacology, molecular docking and molecular dynamics were utilized to identify major bioactive compounds and their interactions with key proteins implicated in oxidative stress to understand the molecular mechanism of action of D. palmatus fruits. The obtained results indicated that the fruit extract had highest antioxidant activity against hydroxyl free radicals (IC50 = 476.76 µg/mL) followed by nitric oxide radicals (IC50 = 509.06 µg/mL), DPPH• (IC50 = 601.88 µg/mL), ABTS•+ (IC50 = 709.37 µg/mL) and FRAP (IC50 = 1141.76 µg/mL). In network pharmacology analysis, bioactive compounds of D. palmatus fruits were found to target numerous major cellular proteins (AKT1, GAPDH, ALB, CASP3, PTGS2, PPARG, STAT3, EGFR, ESR1 and MMP9), with a notable impact on the estrogen signaling pathway. Molecular docking and dynamics analysis further validated the antioxidant potential of D. palmatus fruits. Overall, this integrative study sheds light on the antioxidant potential of D. palmatus fruits and elucidates the molecular mechanisms underpinning their antioxidative actions. These findings not only deepen the understanding of D. palmatus phytochemistry, but also highlight its therapeutic potential as a natural antioxidant agent for combating oxidative stress-related disorders.