Abstract: Objective: To investigate the mechanism of neurological protective effect of the Naoningkang granula on brain tissues of rats with intracerebral hemorrhage (ICH). Methods: Rats were randomly divided into five groups: the sham operation group， the ICH model group and the experimental groups (1.2, 2.4 and 4.8?mg·kg^-1 Naoningkang, respectively). CollagenaseⅦ was injected into the caudate nucleus to establish a rat model of ICH. After 2 hours, the Naoningkang granula was given to the experimental groups by gastrogavage, and saline was given to the other 2 groups by gastrogavage. At 3 and 7 days after treatments, brain tissues were taken. HE staining was used to observe the pathological changes. An immunohistochemical method was used to determine the PAR-1 content in brain tissues surrounding hematoma and the dry-wet weight method to assay the water content of brains. Result: The Naoningkang granula significantly improved the pathological changes, inhibited PAR-1 expression and reduced brain edema. Conclusion: PAR-1 expression is up-regulated after ICH in rats, which might play an important role in inducing nerve cell damage and brain edema. The heat-clearing and detoxication method has a significant neurological protective effect on ICH rats probably by inhibiting PAR-1 expression and reducing brain edema.

Key words: Intracerebral hemorrhage, Rats, Heat-clearing and detoxication, Thrombin receptor(PAR1), Brain edema