OBJECTIVETo investigate the protective effect and mechanism of Naoningkang Granule (NG), a Chinese medicinal preparation formulated for clearing heat and detoxication, on brain tissue in intracerebral hemorrhagic (ICH) rats.

METHODSRats were randomly divided into 5 groups: the sham operated group, the model group and the high-, medium- and low-dose NG groups. Collagenase VII was injected into caudate nucleus to induce rat model of ICH, corresponding dosage of NG was started to give to the 3 NG groups by gastrogavage 2 h after modeling, and saline of equal volume was given to the other 2 groups instead. The brain tissue of rats was taken in batches at the 3rd and 7th day for pathomorphological observation using HE stain, and detection of thrombin receptor-1 (PAR-1) expression and nerve cell apoptosis in the peripheral tissue of hemorrhagic brain with immunohistochemistry and TUNEL assay, as well as for measurement of water content in brain tissue by wet-to-dry weight method.

RESULTSPAR-1 expression elevated in the model rats. As compared with the model group, the pathomorphological changes significantly improved, PAR-1 expression decreased, apoptotic cells re-duced and brain edema alleviated in the 3 NG groups.

CONCLUSIONOverexpression of PAR-1 in the brain tissue might mediate the nerve cell apoptosis and brain edema in ICH rats. The mechanism of NG in protecting hemor-rhagic brain tissue might be related with its actions in inhibiting the post-cerebral high PAR-1 expression to re-duce cell apoptosis and relieve brain edema.