[Exploring the effect of acupuncture at the "Qiaomai" points on the immune function of central and peripheral macrophages in insomnia rats based on the "Defense Qi Theory"].

OBJECTIVES: To observe the effect of acupuncture at the "Qiaomai" points on the immune function activity of central and peripheral macrophages in insomnia rats, so as to explore its underlying therapeutic mechanisms.

METHODS: SD rats were randomly divided into 4 groups (blank group, model group, Western medicine group, and acupuncture group), with 10 rats in each group. An insomnia rat model was established by intraperitoneal injection of para-chlorophenylalanine suspension for 2 d. After successful modeling, the Western medicine group was given diazepam at a dose of 1 mg/kg by gavage, while the acupuncture group was treated with the "Zhaohai" (KI6) and "Shenmai" (BL62) acupuncture technique for 15 min per session. All interventions were administered once daily for a total of 7 d. The general condition of the rats was observed, and their body weight was recorded before modeling, before intervention, and after intervention. The threshold dose of pentobarbital sodium in sleep experiment before and after treatment were also recorded. The thymus index and spleen index were calculated. Flow cytometry was used to determine the CD68+, CD86+, and CD163+ positive cells in peripheral blood. Immunohistochemistry was used to detect the expression levels of ionized calcium-binding adapter molecule 1 (Iba-1), inducible nitric oxide synthase (iNOS), and arginase-1 (Arg-1) in hippocampal tissue. The BioLegend LEGENDplex™ multiplex assay was used to measure the levels of 6 inflammatory factors in the plasma of peripheral blood, including tumor necrosis factor-α (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin(IL)-12, IL-1β, IL-1α and IL-6.

RESULTS: Compared to the blank group, the model group rats exhibited lethargy, rough fur, reduced food intake, decreased daytime sleep, increased daytime activity, and weight loss (P<0.01). Sleep latency was prolonged (P<0.01) and sleep duration was shortened (P<0.01). Spleen index and thymus index were reduced (P<0.01). The proportions of CD68+ and CD68++CD86+ cells in peripheral blood were decreased (P<0.01). The positive expressions of Iba-1 and iNOS in hippocampal tissue were decreased (P<0.01). The plasma levels of GM-CSF, IL-1α, IL-1β, IL-6, IL-12, and TNF-α in peripheral blood were lower (P<0.01). Compared to the model group, the Western medicine group and the acupuncture group rats showed improved general condition, increased food intake, increased daytime sleep, reduced daytime activity, and increased body weight (P<0.01, P<0.05). Sleep latency was shortened (P<0.01) and sleep duration was extended (P<0.01). The proportion of CD68++CD86+ cells in peripheral blood was increased(P<0.05, P<0.01). Additionally, compared to the model group, the acupuncture group showed higher spleen index and thymus index (P<0.01, P<0.05);the proportion of CD68+ cells in peripheral blood was increased (P<0.01);the positive expressions of Iba-1 and iNOS in hippocampal tissue were elevated (P<0.05);and the plasma levels of IL-1α, IL-1β, IL-6, IL-12, TNF-α, and GM-CSF were higher (P<0.01, P<0.05). Compared with the Western medicine group, the acupuncture group showed higher spleen index and thymus index (P<0.05). The proportions of CD68+ and CD68++CD86+ cells in peripheral blood were increased (P<0.05, P<0.01). The plasma levels of IL-1α, IL-1β, IL-6, IL-12, TNF-α, and GM-CSF were increased (P<0.05, P<0.01).

CONCLUSIONS: Acupuncture at the "Qiaomai" points can improve the sleep quality of insomnia rats, potentially by promoting macrophage proliferation and their transformation into M1-type macrophages, thereby increasing the levels of inflammatory factors related to sleep regulation and enhancing the immune function activity of central and peripheral macrophages.