Antioxidant Potential of Curculigo pilosa Rhizome Extracts in Hydrogen Peroxide Induced Oxidation In Vivo

Background: The scavenging of oxidants and the inhibition of their conversion into harmful metabolites are essential for maintaining the health of living organisms. As a result, there has been significant interest in identifying natural antioxidants. This study investigates the antioxidant potential of Curculigo pilosa rhizome extracts in mitigating oxidative stress in Drosophila melanogaster (Harwich strain) induced with hydrogen peroxide (H2O2). Methods: The radical scavenging activity of butanol (BECP), methanol (MECP), and ethyl acetate (EECP) extracts of C. pilosa was evaluated using standard assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), lipid peroxidation (LPO), nitric oxide (NO) inhibition, and ferric reducing antioxidant power (FRAP). The most potent extracts (MECP and BECP) were further assessed in vivo using H2O2-induced Drosophila. Molecular docking studies were conducted using the Schrödinger suite to evaluate the interaction between BECP-derived compounds, identified via HPLC, and Drosophila glutathione-S-transferase (GST). Results: MECP and BECP demonstrated significant antioxidant activity, comparable to butylated hydroxytoluene (BHT), in DPPH, LPO, NO inhibition, and FRAP assays. In vivo, these extracts enhanced the survival rate of Drosophila at concentrations of 2 mg and 4 mg/10 g diet. Flies treated with ascorbic acid, MECP, and BECP exhibited significantly increased (P < 0.05) negative geotaxis performance and reduced NO levels compared to H2O2-induced flies on a normal diet. Additionally, MECP and BECP significantly (P < 0.05) upregulated mRNA expression of GST and glutathione peroxidase (GPx) in H2O2-induced flies. Molecular docking revealed that phlorizin and curculigoside had high binding affinities to Drosophila GST (-6.65 kcal/mol and -6.54 kcal/mol, respectively), comparable to glutathione (-5.97 kcal/mol). Conclusion: The butanol and methanol extracts of Curculigo pilosa rhizome enhanced the free radical scavenging capacity of Drosophila melanogaster and mitigated H2O2-induced oxidative stress, likely due to their bioactive antioxidant compounds. These findings suggest the potential of C. pilosa as a natural source of antioxidants for managing oxidative stress-related conditions.