[Protective effect and mechanism of Angong Niuhuang pill in sepsis-associated brain dysfunction of rats]

To observe the protective effect of Angong Niuhuang pill on brain function of rats with sepsis, explore its protective mechanism, and provide the experimental basis for clinical application of Angong Niuhuang pill in the treatment of sepsis-associated encephalopathy (SAE).

Thirty male Sprague-Dawley (SD) rats were divided into sham operation group, sepsis model group and Angong Niuhuang pill group according to random number table method, with 10 rats in each group. The sepsis model was established by cecal ligation and puncture (CLP); rats in sham operation group received open and closed abdomen. The rats in the Angong Niuhuang pill group were given Angong Niuhuang pill (0.3 g/kg) by gastric irrigation daily for 3 days before CLP, and the drugs were administrated 12 hours after modeling again. After 24 hours of CLP, the neuroreflex scores were evaluated, white blood cell count (WBC), the levels of serum neuron-specific enolase (NSE) and S100β were detected. Then the brain tissue was harvested. After hematoxylin-eosin (HE) staining, the pathological changes of brain tissue were observed under the light microscope. The mRNA expressions of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in brain tissue were detected by polymerase chain reaction.

Compared with the sham operation group, the total score of neuroreflex scores in the sepsis model group and the Angong Niuhuang pill group were significantly reduced (4.43±1.40, 6.57±1.90 vs. 9.40±0.84, both P < 0.05), WBC, serum NSE, S100β were significantly increased [WBC (×10⁹/L): 8.07±1.32, 5.84±0.94 vs. 3.60±0.32; NSE (μg/L): 1.04±0.14, 0.61±0.07 vs. 0.16±0.04; S100β (ng/L): 255.624±30.25, 97.72±15.41 vs. 46.88±12.03, all P < 0.05], and the mRNA expressions of IL-6 and TNF-α in brain tissue were significantly increased [IL-6 mRNA (2^-ΔΔCt): 5.668±2.195, 3.605±1.014 vs. 0.997±0.329; TNF-α mRNA (2^-ΔΔCt): 18.996±0.913, 1.746±0.710 vs. 0.674±0.132, all P < 0.05]. Compared with the sepsis model group, the total score of neuroreflex scores in the Angong Niuhuang pill group was significantly increased (6.57±1.90 vs. 4.43±1.40, P < 0.05), WBC, serum NSE, S100β concentration, and the mRNA expressions of IL-6 and TNF-α in the brain were significantly reduced [WBC (×10⁹/L): 5.84±0.94 vs. 8.07±1.32, NSE (μg/L): 0.61±0.07 vs. 1.04±0.14, S100β (ng/L): 97.72±15.41 vs. 255.62±30.25, IL-6 mRNA (2^-ΔΔCt): 3.605±1.014 vs. 5.668±2.195, TNF-α mRNA (2^-ΔΔCt): 1.746±0.710 vs. 18.996±0.913, all P < 0.05]. Brain histopathological observation showed that the hippocampal neurons in the sepsis model group were disordered arrangement, a large number of neuronal nuclei were contracted, and the tissue was loose with obvious edema. Compared with the sepsis model group, the Angong Niuhuang pill group had less nuclear shrinkage and tissue edema.

The pretreatment of the Angong Niuhuang pill can improve the brain dysfunction of septic rats and reduce the expression of pro-inflammatory cytokines in the brain. It is speculated that the Angong Niuhuang pill can protect the brain function in sepsis by inhibiting the inflammatory reaction in the brain.