[Influence of electroacupuncture stimulation on serum and hepatic interleukin-18 expression in nonalcoholic fatty
Li Wang1, Biao Gong, Li-Li Zhu
1College of Chinese Medicine, Chongqing Medical University, Chongqing 400016, China. wlkate@163.com
Objective:
To observe the effect of electroacupuncture (EA) stimulation of "Zusanli" (ST 36), etc. on serum sugar and insulin contents, serum and liver interleukin-18 (IL-18) levels in nonalcoholic fatty liver disease (NAFLD) rats, so as to study its mechanism underlying improvement of NAFLD.
Methods:
Forty-four SD rats were randomized into normal control, model, EA and non-acupoint groups, with 11 rats in each group. EA (2 Hz, 1.5 V) was applied to bilateral "Zusanli" (ST 36), "Fenglong" (ST 40), "Sanyinjiao" (ST 6) and "Taichong" (LR 3) and non-acupoint (proximal 1/3 of the tail) for 15 min, once daily for 4 weeks. IL-18 contents of serum and liver tissue were assayed by using double antibody sandwich enzyme linked immunosorbent assay (ELISA), fasting blood sugar (FBS) content was measured by enzymatic colorimetric method, and fasting insulin (FINS) level assayed by radioimmunoassay. H. E. staining of the liver tissue sections was used to display pathological changes.
Results:
Compared with the normal control group, serum FBS and FINS contents, serum and hepatic IL-18 levels and fasting insulin resistance index (FIRI) in the model group were significantly increased (P < 0.01). While compared with the model group, the levels of serum FBS, FINS, FIRI and IL-18 as well as hepatic IL-18 content in the EA group were markedly decreased (P < 0.05). The fatty degeneration in hepatic tissue was relieved. No significant changes of the five indexes mentioned above were found in the non-acupoint group (P > 0.05). H. E. staining of the liver tissue showed that in the model group, the hypatocyte was clearly increased in the size, with different degrees of fatty degeneration or necrosis, and inflammatory cell infiltration. These changes were relatively milder in the EA group rather than in the non-acupoint group.
Conclusion:
EA stimulation of "Zusanli" (ST 36), "Fenglong" (ST 40), etc. can suppress NAFLD induced upregulation of blood sugar, serum insulin, insulin resistance in- dex and serum and hepatic IL-18 levels in fatty liver rats, which may contribute to its effect in relieving polysaccharide attack induced liver damage.
