Role of Autophagy (BECLIN -1) and Apoptotic (BAX) Associated Proteins in Discrimination between Antemortem and Postmortem Burn injuries in Rats Skin Biopsies

Background: Determining whether burn injuries occurred during life is a crucial topic in forensic medicine. Objectives: This research was studying the expression of the autophagy (Beclin-1) and apoptotic (Bax) associated proteins in rats skin tissues after burn infliction and evaluating the possible application value of these changes in identifying antemortem and postmortem injury. Materials and methods: The 25 rats were divided into 5 groups: the control group, the 0-hour antemortem injury group, the 24-hour antemortem injury group, the 0-hour postmortem injury group, and the 24-hour postmortem injury group. Burn models were induced with a digital thermostat water bath kettle (100°C) for 10 sec. The changes in levels of the Beclin-1 and Bax proteins were detected by Western blotting and the ELISA assay method, respectively, along with histopathological evaluation. Results: There was a reduction in expression levels of Beclin-1 in antemortem injured groups at time intervals 0 and 24-hour, which was statistically significant in the 24-hour antemortem burned group as compared to other studied groups. Estimation of Beclin-1 in both 0- and 24-hour postmortem injured groups revealed an elevation that was found to be significant in the 24-hour postmortem injured group. Estimation of the changes in Bax levels after burn infliction among the studied groups illustrated an elevation in both 0-hour and 24-hour antemortem burned groups, which was significant in 24-hour antemortem injured rats as compared to other groups. Our results illustrated a significant difference in Bax level found between both antemortem burn-inflicted groups and that postmortem burned groups at 24-hour. Conclusion: determination of Beclin-1 and Bax-associated protein levels might be used as novel biomarkers for differentiation between antemortem and postmortem burn injuries in a forensic context.