Curcumin attenuates intracerebral hemorrhage-induced neuronal apoptosis and neuroinflammation by suppressing JAK1/STAT1 pathway

Intracerebral hemorrhage (ICH) is a kind of fatal stroke with the highest mortality and morbidity in the world. To date, there is no effective treatment strategy for ICH. Curcumin, a major active ingredient of Curcuma longa L., possesses a potential anti-inflammatory activity in many types of disease. In the current study, the mechanism underlying curcumin attenuated ICH-induced neuronal apoptosis and neuroinflammation was explored. Herein, we studied that curcumin decreased brain edema and improved neurological function by using brain edema measurement, assessment of neurological-deficient score, immunofluorescence, and Western blotting analyses after ICH. The results showed that curcumin improved ICH-induced neuronal apoptosis and neuroinflammation. Functionally, the polarization of microglia was assessed by immunofluorescence and Western blotting analyses after ICH in the absence or presence of curcumin. The results suggested that the M1-type microglia were activated after ICH, while the effect was blocked by curcumin treatment, suggesting that curcumin alleviates the neuroinflammation and apoptosis of neurons by suppressing the M1-type polarization of microglia. Mechanically, M1 polarization of microglia was regulated by JAK1/STAT1, and the activation of JAK1/STAT1 was blocked by curcumin. Meanwhile, the protective function of curcumin can be blocked by RO8191, an activator of JAK1. Taken together, our study suggested that curcumin improved the ICH-induced brain injury through alleviating M1 polarization of microglia/macrophage and neuroinflammation via suppressing the JAK1/STAT1 pathway.