Metabolomic analysis and pharmacological validation of the cerebral protective effect of 3,4-dihydroxybenzaldehyde on cerebral ischemia-reperfusion injury

3,4-Dihydroxybenzaldehyde (DBD), one of the active components of Gastrodia elata, has a cerebral protective effect and can effectively combat cerebral ischemia/reperfusion (I/R) injury in rats. However, the metabolite profiles and underlying mechanisms associated with DBD remain unclear. To explore the level of energy metabolism and pharmacological targets in brain tissue following DBD treatment of stroke. The right middle cerebral artery of the rats was occluded for 2 h and reperfused for 24 h to simulate brain I/R injury. Pharmacological results showed that DBD reduced cerebral infarct volume, improved neurological function and increased adenosine triphosphate (ATP) content. Mitochondria are the primary sites for ATP generation and cellular energy supply and decreasing mitochondrial dysfunction can alleviate the energy expenditure of ischemic stroke. Through further experiments, it was found that mitochondrial damage was recovered following DBD treatment, which was manifested by the improvement of mitochondrial morphology under an electron microscope and the reduction of oxidative stress damage. The metabolomics of middle cerebral artery occlusion/reperfusion (MCAO/R) rat brain tissue was studied by the liquid chromatography-tandem mass spectrometry metabolomics method. Significantly different metabolites were screened and the pathways involved included amino sugar and nucleotide sugar metabolism and pentose phosphate pathway. Finally, the present study performed targeted metabolic profiling and validated potential therapeutic targets. Uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) levels were decreased in the MCAO/R group but significantly increased in the DBD group. TdT-mediated dUTP nick end labeling (TUNEL) staining, hematoxylin and eosin staining and western blotting showed that brain cell apoptosis was inhibited and neuronal morphology improved. Among them, the regulatory enzyme O-GlcNAc transferase (OGT) of UDP-GlcNAc appeared to be significantly increased and neuronal apoptosis was inhibited following DBD treatment, which was verified by western blotting. Therefore, by analyzing mitochondrial dysfunction following I/R and the characterization of potential markers in mitochondrial energy metabolism, it was shown that OGT could inhibit neuronal apoptosis as a potential therapeutic target for brain I/R injury.