Abstract:  Objective To investigate the potential effect and molecular mechanism of ginkgo biloba extract (GBE) on the expression of inflammatory factors in liver tissue of mice poisoned by xylene. Methods A total of 30 clean grade healthy Kunming mice were randomly divided into normal control group, model group and ginkgo biloba extract intervention group (GBE group). Mice of three groups were granted free access to food and water. The concentration of xylene inhalation was 110-130 mg/m3 (the air samples were collected in the box, and the gas chromatogram was measured by direct injection method) in model group and GBE group. The mice in control group inhaled air. GBE group was intraperitoneally injected with 50 mg/(kg·d) of GBE. Control and model groups were intraperitoneal injected with same amount of normal saline. After 8 weeks, mice were sacrificed, and serum and liver tissues were retained. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), alkaline phosphatase (ALP) and glutamyl transpeptidase (GGT) were measured. Haematoxylin and Eosin staining was used to observe pathological changes of liver tissue. RT-PCR and Western blot assay were used to detect the expression levels of nuclear factor kappa B (NF-κB), tumor necrosis factor alpha (TNF-α) mRNA and protein in liver tissue. Results Compared with the control group, the liver tissue was damage seriously in the model group. The blood biochemical indexes (ALT, AST, TBIL, ALP and GGT) were significantly increased (P＜0.05), and the NF-κB, TNF-α mRNA and protein were significantly increased in the model group (P＜0.05). Compared with the model group, the liver tissue damage was reduced, the blood biochemical indexes (ALT, AST, TBIL, ALP and GGT) were significantly decreased (P＜0.05) and the NF-κB, TNF-α mRNA and protein were significantly down-regulated in the GBE group (P＜0.05). Conclusion Ginkgo biloba extract can reduce hepatic inflammatory response of mice poisoned by xylene through inhibiting the expression of NF-κB and TNF-α inflammatory factors.

Key words: xylenes, NF-kappa B, tumor necrosis factor-alpha, ginkgo biloba extract, liver injury