Anxiety disorders are the most prevalent mental health conditions worldwide, yet current treatments remain suboptimal, with benzodiazepines carrying risks of tolerance and dependence. These limitations motivate the search for novel anxiolytics. Tropical marine macroalgae represents a promising source of neuroactive metabolites. Here, we investigate the anxiolytic potential of Stypopodium zonale using a neuroproteomics-based approach in Drosophila melanogaster. Crude organic extracts were prepared via ultrasonic-assisted extraction and administered acutely to adult flies for six hours. Proteins from fly heads were quantified and analyzed using LC-MS/MS, revealing 66 significantly differentially abundant proteins (fold change ≥ |1.5|, p ≤ 0.05), 72.7% of which were less abundant in the extract-treated group. Principal Component Analysis demonstrated clear separation between control and experimental samples. Ingenuity Pathway Analysis (IPA) mapped 33 of the differentially abundant proteins to human orthologs and identified significant predicted inhibition of the Protein Kinase A (PKA) signaling pathway. An IPA Interaction Network enabled the construction of a preliminary working model, suggesting that the extract may antagonize Drosophila’s Dop1R2 (DAMB). Overall, this study integrates natural product drug discovery with neuroproteomics in an invertebrate model system, providing a foundation for future behavioral validation and isolation of bioactive compounds from S. zonale.

Anxiety disorders are the most prevalent mental health conditions worldwide, yet current treatments remain suboptimal, with benzodiazepines carrying risks of tolerance and dependence. These limitations motivate the search for novel anxiolytics. Tropical marine macroalgae represent a promising source of neuroactive metabolites. Here, we investigate the anxiolytic potential of Stypopodium zonale using a neuroproteomics-based approach in Drosophila melanogaster. Crude organic extracts were prepared via ultrasonic-assisted extraction and administered acutely to adult flies for six hours. Proteins from fly heads were quantified and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing 66 significantly differentially abundant proteins (fold change ≥ |1.5|, p ≤ 0.05), 72.7% of which were less abundant in the extract-treated group. Principal component analysis demonstrated clear separation between control and experimental samples. Ingenuity Pathway Analysis (IPA) mapped 33 of the differentially abundant proteins to human orthologs and identified significant predicted inhibition of the Protein Kinase A (PKA) signaling pathway. An IPA Interaction Network enabled the construction of a preliminary working model, suggesting that the extract may antagonize Drosophila’s Dop1R2 (DAMB). Overall, this study integrates natural product drug discovery with neuroproteomics in an invertebrate model system, providing a foundation for future behavioral validation and isolation of bioactive compounds from S. zonale.