Neuroprotective potential of a novel marine metabolite from S. rhizophila BGNAK1 targeting acetylcholinesterase in Alzheimer's disease.

UNLABELLED: Secondary metabolites from the marine bacterium Stenotrophomonas rhizophila strain BGNAK1 were evaluated for neuroprotective activity using biochemical and cellular assays relevant to Alzheimer's disease. The crude extract exhibited significant acetylcholinesterase (AChE) inhibitory activity with an IC₅₀ value of 106.0163 µg/mL, indicating effective modulation of cholinergic function. Antioxidant evaluation revealed strong free radical scavenging capacity, with DPPH radical inhibition of and 97% at 1.0 mg/ml. The extract also significantly reduced intracellular reactive oxygen species levels, showing a reduction compared to untreated control cells at the highest tested concentration. Cytotoxicity analysis using PC12 and SH-SY5Y neuroblastoma cell lines demonstrated > 85% cell viability across all tested concentrations, confirming good biocompatibility. No significant morphological alterations or growth inhibition were observed under treatment conditions. Overall, these results demonstrate that metabolites derived from S. rhizophila BGNAK1 exert multi-target neuroprotective effects through combined cholinesterase inhibition and antioxidant mechanisms. Although direct neuronal injury models were not employed, the integrated biochemical and cellular findings provide quantitative evidence supporting the neurotherapeutic potential of marine bacterial metabolites and justify further investigation into their role in Alzheimer's disease-oriented drug discovery. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-026-04751-w.