Objective: To observe the effect of acupuncture on the expression of glial fibrillary acidic protein (GFAP) in hippocampus and prefrontal cortex and the level of serum interleukin 10 (IL-10) in rats with depression, so as to explore its mechanism underlying improvement of depression.
Methods: Thirty-two male SD rats were randomly divided into four groups: control, model, acupuncture, and medication (Fluoxetine, Flu) (n=8 rats in each). The depression model was established by using chronic restraint stress (constraint, fasting, water deprivation, etc.) combined with solitary raising for 28 days. Acupuncture was applied to "Baihui" (GV 20) and "Yintang" (GV 29), and bilateral "Sanyinjiao" (SP 6) for 20 min, once daily for 28 days. Fluoxetine (1.8 mg/kg) was given to rats of the medication group by gavage once every day for 28 days. Sucrose consumption test and open field test (crossing and rearing locomotion) were carried out to evaluate the behavioral changes. Western blot was used to detect the expression of GFAP in the hippocampus and prefrontal cortex, and the content of serum IL-10 was detected by enzyme linked immunosorbent assay (ELISA).
Results: After modeling, the sucrose consumption, the crossing numbers and rearing times, hippocampal GFAP protein expression and serum IL-10 content were significantly decreased and prefrontal GFAP protein expression was up-regulated markedly in the model group relevant to the control group (P<0.01). After the treatment, the decreased levels of sucrose consumption and crossing numbers, hippocampal GFAP protein expression and serum IL-10 content and the increased prefrontal GFAP protein expression were considerably suppressed in both medication and acupuncture groups compared with the model group (P<0.05, P<0.01). No significant differences were found between the acupuncture and medication groups in increasing the rats' locomotion, sucrose consumption, hippocampal GFAP protein expression (P>0.05) and in down-regulating prefrontal GFAP protein expression (P>0.05 ) except up-regulation of IL-10 level.
Conclusion: Acupuncture intervention plays a positive role in anti-depression in rats, which may be related to its effects in regulating the expression of GFAP in the hippocampal and prefrontal astrocytes, and in increasing the content of serum anti-inflammatory cytokine IL-10.
Keywords: Acupuncture; Chronic restraint stress; Depression; Glial fibrillary acidic protein; Interleukin-10.