Effects of Xiao-Cheng-Qi decoction on brain edema and inflammatory factors in rats with severe traumatic brain injury

Abstract

To observe the effects of the Chinese medicine prescription Xiao-Cheng-Qi decoction (XCQD) on acute brain edema and inflammatory factors in rats with severe traumatic brain injury (sTBI). A total of 108 male Sprague-Dawley (SD) rats were divided into control group, sham operation group, sTBI model group, and XCQD low, medium, high dose groups by random number table method, with 18 rats in each group. sTBI rat model was prepared according to the modified Freeney method. At 6 hours after injury, the XCQD low, medium, and high dose groups were given XCQD 1.80, 2.78, and 4.59 g/kg by gavage, respectively, and the other three groups were given the same amount of normal saline, once a day for 3 days. After 3 days of injury, rats in each group were sacrificed after the modified neurologic severity score (mNSS) assessed. Pathological changes of brain tissue were observed under light microscope after hematoxylin eosin (HE) staining, water content of brain tissue was measured by dry-wet specific gravity method, and the expressions of aquaporin 4 (AQP4), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in brain tissue were detected by Western blotting. Serum TNF-α and IL-1β levels were detected by enzyme linked immunosorbent assay (ELISA). Compared with the normal group, the mNSS score of rats increased significantly, the structure of brain tissue was disordered, and pathological changes appeared such as inflammation, edema, pyknosis of nerve nuclei, water content, the protein expressions of AQP4, TNF-α and IL-1β in brain tissue, and the contents of TNF-α, IL-1β in serum were significantly increased. After XCQD intervention, the above indexes were significantly improved. Compared with sTBI model group, the mNSS score of XCQD medium and high dose groups significantly decreased (6.94±1.16, 6.88±1.02 vs. 8.61±1.09, both P < 0.05), and the pathological changes such as brain edema and inflammation were alleviated. Brain tissue water content, AQP4 protein expression and contents of serum TNF-α, IL-1β in XCQD low, medium, and high dose groups significantly decreased compared with sTBI model group [brain tissue water content: (78.25±0.71)%, (77.62±0.44)%, (76.70±0.74)% vs. (80.08±0.66)%; the expression of brain AQP4 protein (AQP4/β-actin): 0.86±0.13, 0.84±0.22, 0.65±0.13 vs. 1.08±0.14; serum TNF-α (ng/L): 106.34±15.07, 95.75±17.26, 89.00±17.36 vs. 141.96±29.47; serum IL-1β (ng/L): 90.41±12.88, 72.82±13.51, 71.32±16.79 vs. 128.57±22.56, respectively, all P < 0.05]. The protein expressions of TNF-α,IL-1β in brain tissue of XCQD medium and high dose groups also significantly decreased compared with sTBI model group [TNF-α (TNF-α/β-actin): 0.90±0.24, 0.79±0.35 vs. 1.17±0.15; IL-1β (IL-1β/β-actin): 0.91±0.21, 0.68±0.28 vs. 1.23±0.08, respectively, all P < 0.05]. Brain tissue water content, the expression of brain AQP4 protein, the levels of brain tissue and serum IL-1β in XCQD high dose group improved more significant than those of XCQD low dose group. XCQD can alleviate the acute brain edema in sTBI rats, and it is dose-dependent. The mechanism may be relevant to reduce the secondary inflammatory response of sTBI by inhibiting the expression of inflammatory factors TNF-α and IL-1β.