Protective mechanism of Xuebijing injection against heat stroke in rats.

This study aimed to investigate the protective mechanism of Xuebijing injection (XBJ) against heat stroke (HS) in rats. Adult male Sprague Dawley rats were randomly divided into normal control (NC), normal saline-treated HS (NS-HS) and XBJ-treated HS (XBJ-HS) groups. At 47 and 57 min from the initiation of heat stress (42.5-43.5°C), the plasma levels of certain cytokines [interleukin (IL)-1β, IL-6 and tumor necrosis factor-α], biochemical indicators (creatinine, blood urea nitrogen, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase) and coagulation indicators (activated partial thromboplastin time, prothrombin time, fibrinogen degradation products and D-dimer) were detected, and microscopy of the liver tissue of the rats was conducted. At 47 and 57 min after the initiation of the heat stress, the levels of the cytokines, coagulation indicators and biochemical indicators in the NS-HS group were significantly higher than those in the NC group (P<0.05). In the NS-HS group, the levels of the aforementioned indices were significantly reduced compared with those in the NC and NS-HS groups (P<0.05). In the NS-HS group, serious liver cell congestion, nuclear swelling and central vein dilation were visible, along with the appearance of bubbles in the liver tissue. In the XBJ-HS group, only a small number of congestive liver cells were identified, with occasional nuclear swelling but no bubbles, which was similar to the observations in the NC group. Early intervention treatment of HS with XBJ is able to reduce the systemic inflammatory response and coagulation activity and decrease the tissue ischemia and injury degree, thus extending the survival time of rats with HS.