<i>In vitro</i> and <i>In silico</i> evaluation of the antioxidant and antibacterial activities of <i>vetiveria zizanioides</i> irrigated with leachate from the fez landfill: GC–MS identification of bioactive compounds

The rapid growth of urban populations has led to excessive household waste generation, producing leachates rich in toxic organic and inorganic compounds. This study aimed to evaluate the antioxidant and antimicrobial responses of <i>Vetiveria zizanioides</i> irrigated with raw and treated leachates. Antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay (DPPH) and the ferric reducing antioxidant power assay (FRAP), while antimicrobial potential was evaluated against bacterial and fungal strains using disk diffusion. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to identify bioactive compounds, and molecular docking was performed to predict their interactions with antioxidant and antimicrobial enzyme targets. Irrigation with raw leachate decreased antioxidant capacity (DPPH IC₅₀ = 0.190 mg/mL; FRAP = 1.63 mg/mL), while treated leachate improved activity (DPPH IC₅₀ = 0.126 mg/mL; FRAP = 1.22 mg/mL). Extracts from plants exposed to raw leachate showed stronger antimicrobial effects, with an inhibition zone of 8.75 mm against Pseudomonas aeruginosa compared to 5.5 mm in the control. In addition, molecular docking revealed a strong affinity between bioactive compounds and antioxidant and antimicrobial enzyme targets. Leachate exposure modulates <i>vetiver</i> metabolism, enhancing its bioactive potential and supporting its role as a sustainable species for environmental remediation and biotechnological applications.