Synergistic Neuroprotection of Artesunate and Tetramethylpyrazine in Ischemic Stroke, Mechanisms of Blood–Brain Barrier Preservation

Artesunate (AS) and tetramethylpyrazine (TMP) have been proven to have therapeutic potential in ischemic stroke. Nevertheless, their synergistic treatment mechanisms and effectiveness remain unclear. A rat MCAO model was induced, and AS, combined with TMP, was administered intranasally to rats once a day for 3 days. The neurological severity scores, TTC staining, and H&E staining were implemented to analyze tissue injuries. Evans blue staining and immunohistochemistry of ZO-1, occludin, MMP-9, and TIMP-1 were implemented to evaluate the integrity of the blood-brain barrier (BBB). ELISA was used to detect the expression levels of inflammatory factors TNF-α and IL-10. TUNEL staining and the protein expression of Bax and Bcl-2 were used to evaluate the apoptosis of brain tissue cells. The core targets were predicted by network pharmacology and verified by the OGD/R cell model and siRNA in vitro. Results showed that nasal administration of AS and TMP significantly ameliorated ischemic-stroke-induced neurological dysfunction, BBB disruption, and cortical neuronal apoptosis. The protective mechanisms mainly included adjusting the expression and ratio of tight junction proteins TIMP-1 and MMP-9 in brain tissue, regulating the HIF-1α-VEGF pathway, and anti-inflammatory effects. This study provides experimental support for the further development and application of AS and TMP nasal combinations and provides the foundation for expanding the practical-application value of artemisinin and its derivatives.