Dl-3-n-butylphthalide (NBP) has been widely used to treat ischemic stroke in China. To investigate the mechanisms underlying NBP activity, we established a permanent middle cerebral artery occlusion (pMCAO) rat model and injected the rats with 4 mg/kg/d NBP for nine days. We then assessed neuroinflammation, neovascularization and nerve regeneration within the brain. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry imaging (MALDI-TOF MSI) was used to determine the phospholipid distribution, while laser ablation-inductively coupled plasma mass spectrometry imaging (LA-ICP MSI) was used to measure Foxp3, Ki-67 and pCREB levels in the brain. Immunohistochemistry was used to investigate the expression of NLR family pyrin domain containing 3 (NLRP3) and its inflammatory products, caspase-1 and interleukin-1β, in brain tissues. NBP attenuated ischemic damage and ameliorated neurological deficits in rats with pMCAO. In the ischemic brain region, NBP reduced phosphatidylethanolamine (18:0), NLRP3, caspase-1 and interleukin-1β levels, but increased levels of Foxp3, Ki-67, pCREB and several phospholipids. In molecular docking analyses, NBP bound to NLRP3, interleukin-1β, caspase-1, Foxp3, and Ki-67. These results demonstrate that NBP reduces neuroinflammation in brain tissues and promotes nerve and blood vessel regeneration, thus protecting neuromorphology and function.
Keywords: Dl-3-n-butylphthalide; LA-ICP MSI; MALDI-TOF MSI; ischemia; neuroinflammation.