Electroacupuncture at "Ganshu" (BL18) and "Yanglingquan" (GB34) alleviates hepatic ischemia-reperfusion injury by inhibiting translocation and release of high mobility group protein 1 in rats / 针刺研究

ABSTRACT

OBJECTIVE: To explore the protective effect of electroacupuncture (EA) on hepatic ischemia-reperfusion injury (HIRI) and the expression of high mobility group protein 1 (HMGB1) in liver tissues in rats. METHODS: A total of 40 male SD rats were randomly divided into 4 groups, namely sham control, HIRI model, "Ganshu"(BL18) -"Yanglingquan"(GB34) and non-acupoint group, with 10 rats in each group. The HIRI model was induced by blocking the arteries, veins and bile ducts supplying the middle and left lobes of the liver for 1 h, and reperfusion for 4 h to induce an area of about 70% HIRI. EA was applied to bila-teral BL18 and GB34, or non-acupoints about 6-8 mm to the bilateral BL18 for 30 min before modeling. Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels were measured by using an automatic biochemical analyzer. Serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and HMGB1 levels were assayed by ELISA. Hematoxylin - eosin (H.E.) staining was used to observe histopathological changes of the liver tissue by using tissue injury scaling (0-3 scores). The expression of HMGB1 protein in liver tissues was detected by immunohistochemical staining, Western blot and PCR, separately. RESULTS: Following modeling and compared with the sham group, the levels of serum ALT, AST, TNF-α, IL-6, and HMGB1 contents, the number of HMGB1 immunoreaction (IR)-positive cells, and HMGB1 protein and mRNA were significantly increased (P＜0.01). After the treatment, the contents of serum ALT, AST, TNF-α, IL-6, and HMGB1, liver HMGB1 IR-positive cells, protein and mRNA were considerably down-regulated in the BL18-GB34 group (P0.05) in contrast to the model group. H.E. stain showed a higher liver injury score in the model group than in the sham group (P<0.01), and a lower liver injury score in the BL18-GB34 group (not the non-acupoint group) relevant to the model group (P<0.05). CONCLUSION: EA of BL18 and GB34 points has a protective effect on ischemic liver injury in rats with HIRI, which may be associated with its functions in inhibiting the migration and release of HMGB1 from the nucleus to the cytoplasm and in down-regulating the expression of inflammatory factors.