Relative quantification of neuronal polar lipids by UPLC-MS reveals the brain protection mechanism of Danhong injection

Abstract

Promising results from clinical trials have fueled a growing acceptance of Danhong injection (DHI) as a Chinese Materia Medica standardized product for the treatment of ischemic stroke. However, little information is available on the underlying mechanisms of DHI especially in lipidomics. In this study, experiments on permanent middle cerebral artery occlusion (MCAO) in mice were carried out to confirm the protective effect of DHI. Furthermore, primary mouse cortical neurons subjected to oxygen-glucose-deprivation (OGD) were used to investigate the protective mechanisms of DHI. A UPLC-MS profiling analysis for neuronal polar lipids including phosphatidylcholines (PCs), sphingomyelins (SMs) and ceramides (Cers) was carried out in order to study the potential biomarkers in this OGD-induced neuron injury model. The results showed that pretreatment with DHI resulted in a significantly smaller infarct volume and better neurological scores than pretreatment with saline in MCAO mice. In an OGD-induced neuron injury model, DHI exhibited remarkable neuroprotection by reducing the neuronal damage and excessive accumulation of intracellular reactive oxygen species, suppressing intracellular free calcium influx and apoptosis. Meanwhile, 28 biomarkers of PCs, SMs and Cers sub-species of neuronal injury induced by OGD have been identified for the first time. The perturbations could be partly reversed by DHI intervention such as PC (17:0,0:0), PC (18:0,0:0), PC (16:0,0:0), PC (P-16:0,0:0) and SM (18:0,16:0). The results specifically provide information on the relationships between PCs, SMs, Cers sub-species and neuronal damage mechanisms during an ischemic stroke. Overall, we found that the therapeutic effects of DHI on cerebral ischemia are partially due to interferences with the PC and SM metabolisms.