Evaluation of intestinal injury, inflammatory response and oxidative stress following intracerebral hemorrhage in mice

Intestinal injury is a common complication following intracerebral hemorrhage (ICH), which leads to malnutrition, impaired immunity and unsatisfactory prognosis. Previous studies have revealed the pathogenesis of intestinal injury following traumatic brain injury using ischemic stroke models. However, the effects of ICH on intestinal injury remain unknown. The present study aimed to investigate the pathological alterations and molecular mechanism, as well as the time course of intestinal injury following ICH in mice. Male C57BL/6 mice were randomly divided into the following seven groups (n=6 mice/group): Control group, which underwent a sham operation, and six ICH groups (2, 6, 12 and 24 h, and days 3 and 7). The ICH model was induced by stereotactically injecting autologous blood in two stages into the brain. Subsequently, intestinal tissue was stained with hematoxylin and eosin for histopathological examination. Small intestinal motility was measured by charcoal meal test, and gut barrier dysfunction was evaluated by detecting the plasma levels of endotoxin. Quantitative polymerase chain reaction (qPCR), immunohisto-chemistry and ELISA analysis were performed to evaluate the mRNA and protein expression levels of inflammatory cytokines [interleukin (IL)-1 beta, IL-6, tumor necrosis factor-alpha, intercellular adhesion molecule 1, monocyte chemotactic protein 1 and chemokine (C-C motif) ligand-5] in intestinal tissue and serum. Furthermore, intestinal leukocyte infiltration was detected by measuring myeloperoxidase activity. Oxidative stress was indirectly detected by measuring reactive oxygen species-associated markers (malondialdehyde content and superoxide dismutase activity assays) and the mRNA and protein expression levels of antioxidant genes [nuclear factor (erythroid-derived 2)-like 2, manganese superoxide dismutase and heme oxygenase 1] by qPCR and western blot analysis. The results demonstrated that significant destruction of the gut mucosa, delayed small intestinal motility, intestinal barrier dysfunction, and increased inflammatory responses and oxidative stress occurred rapidly in response to ICH. These symptoms occurred as early as 2 h after ICH and persisted for 7 days. These findings suggested that ICH may induce immediate and persistent damage to gut structure and barrier function, which may be associated with upregulalion of inflammation and oxidative stress markers.