Acupuncture reduces peripheral and brainstem cytokines in rats subjected to lipopolysaccharide-induced inflammation

Abstract

Background: Lipopolysaccharide (LPS) endotoxins are activators of innate immunity inducing infection and inflammatory responses. Anti-inflammatory drugs can have undesirable side effects. Acupuncture may be an alternative for the treatment of inflammatory processes. Objective: We investigated the potential anti-inflammatory effect of manual acupuncture (MA) at SP6 upon LPS-induced peritonitis in rats. Methods: Peritonitis was induced in rats with an intraperitoneal injection of LPS (0.002, 0.02, 0.2 or 2 µg/kg) in four experimental groups (n = 6 each). A fifth group was injected with sterile saline solution (saline group, n = 6). Four hours after the procedure, peritoneal fluid was collected to determine total cell counts for inflammatory cells, differential leukocyte counts and peritoneal capillary permeability. The LPS dose of 0.02 µg/kg was used in the subsequent experiments as it most successfully induced peritoneal inflammation. Subsequently, five experimental groups (n = 12 rats each) were used: (1) saline, (2) control (untreated LPS group), (3) indomethacin (LPS group treated with indomethacin), (4) NA (LPS group treated with MA at a location not corresponding to any traditional acupuncture point), and (5) SP6 (LPS group treated with verum MA at SP6). Ten minutes after MA or 30 min after indomethacin treatment, the rats received an intraperitoneal injection of LPS. After 4 h, total leukocyte and differential cell counts, myeloperoxidase (MPO) activity, vascular permeability and cytokine levels were evaluated in the peritoneal fluid. Cytokine levels were additionally evaluated in the brainstem. Results: SP6 MA and indomethacin treatments reduced inflammatory cell infiltration, vascular permeability and MPO activity in the LPS-exposed rats. Pre-treatment with indomethacin and SP6 MA decreased tumor necrosis factor (TNF)-α levels and preserved interleukin (IL)-10 in the peritoneal fluid. Indomethacin also reduced IL-6 in the peritoneal fluid. In the brainstem, indomethacin reduced IL-1β, IL-6, TNFα and IL-10, whereas SP6 MA reduced only TNFα and IL-6 levels. Conclusions: This study clearly demonstrates the anti-inflammatory effect of acupuncture, which we believe may involve the activation of anti-inflammatory neural reflexes in the regulation of peritonitis.

The Anti-Inflammatory Actions and Mechanisms of Acupuncture from Acupoint to Target Organs via Neuro-Immune Regulation

“… 28 In case of the peritonitis model, MA at SP6 reduces both TNF-α and IL-6 levels in the peritoneal fluid and brain stem, while MA at non-acupoints only partially prevents the increase of IL-6 in the brain stem, suggesting strong specificity of acupoints in the treatment of diseases. 29 In terms of the frequency of EA, it was found that 10 Hz or 30 Hz EA stimulation can significantly increase gastrointestinal peristalsis and reduce inflammation around POI, but 10 Hz was more effective, while 2 Hz or 100 Hz electrical stimulation did not produce any effect. 28 Although both 10 Hz and 100 Hz EA at ST36 was shown to regulate macrophage polarization and affect inflammatory factors release in colitis rats, only high-frequency stimulation increased Nrf2/HO-1 levels, suggesting that high-frequency EA stimulation exerts a therapeutic effect via the modulation of oxidative stress.…”

“… 28 MA at SP6 also down-regulates TNF-α and IL-6 in the peritoneal fluid, thereby upregulating IL-10 levels, inhibiting MPO activity, and treating the peritonitis model induced by lipopolysaccharide (LPS). 29 Liver ischemia-reperfusion (I/R) injury is a common clinical complication, and excessive inflammation is the key risk factor. EA at Hegu (LI4) is also reported to down-regulate TNF-α and IL-6 in serum and liver tissue, thereby inhibiting MPO activity and controlling excessive inflammatory response.…”

Acupuncture modulates immunity in sepsis: Toward a science-based protocol

“…The blood levels of proinflammatory factors such as TNF, IL-6, MCP-1 and INFγ in the acupuncture group were significantly reduced. The level of antiinflammatory factor IL-10 either increased (da Silva et al, 2011;Ramires et al, 2020) or did not change significantly (Song et al, 2012). It suggests that acupuncture does not simply suppress the immune response but modulates its balance.…”

“…The anti-inflammation effect of acupuncture is clear. A study (Ramires et al, 2020) showed that acupuncture obtained similar levels of effect as that of indomethacin (a classical nonsteroidal anti-inflammatory drug) in suppressing peripheral and brainstem cytokines. 2.…”

“…However according to the frequency effect (Chen et al, 2016), here we recommend using "alternating trains" of 2/15 Hz or 2/100 Hz, (100 Hz to enhance sympathoadrenal medullary reflex, Kim et al, 2008) for systemic effects, and "bursting trains" with high frequency (15-100 Hz) for local effects. If using the traditional manual acupuncture, we suggest mimicking the "alternating trains", applying a light or moderate stimulation (a slow rotation) of 2-5 min/10 min for 30 min, given that manual acupuncture can activate all groups of sensory nerve fibers (Kagitani et al, 2010) and a slow rotation of needle is efficient to induce anti-inflammatory effect (Lim et al, 2016;Ramires et al, 2020). 3) Daily dose and course of treatment: considering that the inhibitory effects of one treatment of EA on most inflammatory factors last for about 6 h (Song et al, 2012;Torres-Rosas et al, 2014), the daily dose we suggest is 2 times/day for patient with sepsis; one time/day for early stage of acute infection.…”