To investigate the effect of isoliquiritigenin (ISL) on the expression of inflammatory factor interleukin-6 (IL-6) and anti-inflammatory factor IL-10 after traumatic brain injury (TBI) in rats, and the protective effect of ISL on brain after TBI.

Seventy five male Wistar rats were randomly divided into blank control group (n=5), TBI group (n=35) and ISL intervention group (n=35) according to the random table, after making TBI model by Feeney method. The enzyme-linked immunosorbent assay method was used to measure the changes of IL-6 and IL-10 at each time point of 3, 12, 24, 48, 72 h, 5 and 7 d after TBI and after TBI intervention by ISL, and colleagues used dry and wet weight method to measure the changes in brain tissue water content, find out its correlation and internal connections.

The expression levels of IL-6 and IL-10 in TBI group and ISL intervention group were significantly higher than those in control group (P<0.05). After intervention with ISL, the expression level of IL-6 in TBI group was lower than that in TBI group at each time point, while the expression level of IL-10 in TBI group was higher than that in TBI group at each time point, and the differences were statistically significant (P<0.05). The water content of brain tissue increased after TBI, and decreased significantly at 72 h and 5 d after ISL intervention (P<0.05). Pearson correlation analysis showed that with the increase of IL-6, the level of IL-10 in TBI group was also increased, there is a positive correlation between them (r=0.925, P=0.000); IL-6 was increased and IL-10 was increased in ISL intervention group, there is a positive correlation between them(r=0.888, P=0.000).

ISL can protect the brain by inhibiting the over expression of inflammatory factors and promoting the expression of anti-inflammatory factors after TBI, reducing the inflammatory reaction and brain edema after TBI.