Nervonic acid confers neuroprotection in a zebrafish model of diabetic neuropathy by promoting myelin repair and metabolic modulation

Introduction Diabetic neuropathy (DN) is one of the most common and debilitating complications of type 2 diabetes mellitus (T2DM), yet effective therapeutic strategies remain limited. Nervonic acid (NA) is recognized for its neuroprotective and anti-inflammatory properties. However, its role in DN has not been fully elucidated. In this study, we investigated the protective effects of NA against T2DM-induced DN using a zebrafish model and explored the underlying molecular mechanisms. Methods T2DM was induced in zebrafish larvae through a high-fat, high-glucose diet combined with a low dose of streptozotocin. Larvae were subsequently treated with NA at concentrations of 125, 250, or 500 μg/mL. Motor function, myelin integrity, neutrophil infiltration, and reactive oxygen species (ROS) levels were evaluated using fluorescence imaging and histological staining. Gene expression analysis was performed by quantitative real-time PCR. Metabolomics coupled with KEGG enrichment analysis was applied to identify NA-regulated metabolic pathways. Results NA significantly preserved myelin integrity, reduced neutrophil infiltration, and lowered ROS levels in DN zebrafish. Expression of myelin-related genes ( mbpa and mpz ) was upregulated, while pro-inflammatory cytokines were downregulated following NA treatment. Metabolomic profiling revealed that NA reversed diabetes-associated dysregulation in purine metabolism, energy metabolism, vitamin B6 pathways, and redox homeostasis. Key metabolites including guanosine monophosphate, adenosine triphosphate, pyridoxal 5′-phosphate, and L-glutathione were markedly restored toward normal levels. Discussion These findings demonstrate that NA confers robust neuroprotection in DN by alleviating inflammation and oxidative stress, preserving neuronal structure and function, and reprogramming key metabolic pathways.