Background Previous studies in a rat model showed expressions of caspase-3 (p20) and NF-κB (p65) in different time after TBI. We test the activation changes of caspase-3 and NF-κB of human specimen after traumatic brain injury (TBI) in this study to see whether they could be markers to estimate post-intervals of TBI for forensic practice. Material and methods Caspase-3 (p20) and NF-κB (p65) immunohistochemical staining were performed on 39 TBI specimens (dead from TBI) and eight controls (dead from none TBI reasons) grouped 0, 12, 24, 48, 72, 168, 264 and 480 h. Positive cells were counted and image analysis techniques were used to determine the morphological changes in each group. Results Immunohistochemical analysis showed a marked induction of caspase-3 (p20) in every injured group compared with normal controls; each positive group has it's morphological character with variant positive cell count. NF-κB (p65) did not showed markedly change compared with normal controls until 168 h after TBI and almost all nerve cells were stained by NF-κB (p65) in 264 and 480 h groups. Conclusion NF-κB (p65) could contribute to estimate delayed death cases after TBI for forensic applications. Caspase-3 (p20) estimating post-TBI intervals are dubious but could suggest TBI exists.
