The caspase-1 activity was detected as we previously described [10]. In brief, perihematomal brain samples were quick-freezed and fractured in a reaction buffer which contains 50 mM NaCl, 10% glycerol, 1 mM DTT, 1 mM EDTA, 1 mM bestatin, 1 mM pepstatin, 1 mM 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride, and 50 mM HEPES (pH 7.4) by using the TissueLyser II kit (Qiagen, Valencia, CA, USA). After centrifugation and quantification, the protein concentration was adjusted to a final concentration of 2.5 mg/ml. The substrate of caspase-1, Ac-YVAD-p-nitroaniline (p-NA) (Enzo Life Sciences, Farmingdale, NY, USA) was further employed to detect the activity of caspase-1 colorimetrically in the clarified lysates. The data were calculated as (Δ[p − NA]/Δtime)/(total protein) and expressed as the relative changes relative to the controls finally.