Pretreatment with Xuebijing injection alleviates systemic inflammatory response induced by severe heat-stroke via ameliorating intestinal injury in rats / 中华危重病急救医学

ABSTRACT

ObjectiveTo observe the effect of Xuebijing injection pretreatment on systemic inflammatory response induced by severe heat-stroke, and to investigate the mechanism of alleviation of intestinal injury in rats. Methods Thirty-six healthy adult male Wistar rats with grade SPF were randomly assigned into three groups with randomized number method, namely sham group, severe heat-stroke model group, and Xuebijing pretreatment group (XBJ group), with 12 rats in each group. The animals were placed in a pre-warm chamber [temperature (40±2)℃, humidity (65±5)%] in order to induce typical heat-stroke. The duration of heat-stress was 60 minutes, while the animals in sham group were exposed to ambient temperature of 25℃. Arterial blood samples were collected at the beginning and the end of heat-stress, the concentrations of tumor necrosis factor-α(TNF-α), interleukins (IL-1β, IL-6), and lipopolysaccharide (LPS) in peripheral blood were determined by enzyme linked immunosorbent assay (ELISA). The intestinal tissues were harvested after heat-stress, and the pathological changes in intestine tissues were observed after hematoxylin-eosin (HE) staining and under optical microscope. The pathological injury scores were calculated. Immunohistochemistry was performed to determine inducible nitric oxide synthase (iNOS) expression in intestinal tissue. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Western Blot was used to measure the tight junction protein occludin expression.Results The concentrations of TNF-α, IL-1β, IL-6 and LPS in blood of the rats after heat-stress in model group were significantly higher than those of sham group [TNF-α (μg/L) 443.00±110.10 vs. 98.36±44.61, IL-1β (μg/L) 436.37±163.64 vs. 64.24±16.15, IL-6 (μg/L) 342.70±92.42 vs. 54.40±13.22, LPS (μg/L) 0.68±0.22 vs. 0.09±0.02, allP< 0.01], but the levels of these parameters in XBJ group were significantly lower than those of model group [TNF-α (μg/L)340.45±68.57 vs. 443.00±110.10, IL-1β (μg/L) 191.33±82.78 vs. 436.37±163.64, IL-6 (μg/L) 192.21±37.89 vs. 342.70±92.42, LPS (μg/L) 0.43±0.17 vs. 0.68±0.22, allP< 0.01]. Infiltration of inflammatory cells, necrosis and hemorrhage in intestinal mucosa were found in the intestine of heat-stroke animals in model group. The pathological lesions in XBJ group were milder than those of model group, with a decreased pathological injury score compared with model group (2.10±1.15 vs. 3.20±0.67,P< 0.01). The expression of iNOS and apoptosis of cells in intestinal tissue in model group were increased compared with that of sham group, but they were significantly less marked in XBJ group compared with model group [iNOS (adjustedA value) 0.32±0.15 vs. 0.74±0.17, apoptotic index 0.23±0.08 vs. 0.56±0.07, bothP< 0.01]. The order of expression for occludin protein from high to low was sham group, XBJ group and model group (A value was 0.96±0.25, 0.62±0.20, 0.33±0.11, respectively). Furthermore, there was significant difference in the expression of occludin protein between model group and both XBJ group and sham group (bothP<0.01).Conclusions Xuebijing injection alleviates inflammation and endotoxemia produced by severe heat-stroke in rats. The mechanism may be related to amelioration of oxidative injury, apoptosis, and dysfunction of tight junction protein occludin expression.