Background: Heat therapy (HT) and electroacupuncture (EA) are widely utilized pain relief methods, but the analgesic mechanisms of their combined application remain unclear. Methods: In acetic acid (AA)-induced writhing test and complete Freund’s adjuvant (CFA)-induced inflammatory pain tests, mice received one of three treatments: EA at bilateral ST36, HT via a 45 °C heating pad, or the combination (EA + HT). To probe underlying pathways, separate groups were pretreated with caffeine, DPCPX (a selective adenosine A₁ receptor antagonist), or naloxone (an opioid receptor antagonist). Spinal expression of glial fibrillary acidic protein (GFAP) and phosphorylated p38 (p-p38) was examined by Western blot and immunofluorescence. Results: Both EA and HT individually reduced AA-induced writhing, with the combination (EA + HT) exhibiting the greatest analgesic effect. EA’s analgesic effect was reversed by caffeine and DPCPX and partially by naloxone, while HT’s effect was reversed by caffeine and DPCPX but was unaffected by naloxone. AA injection elevated spinal p-p38 and GFAP expression, which were attenuated by either EA or HT, with the most substantial suppression observed in the EA + HT group. In the CFA model, both treatments alleviated mechanical allodynia, while the combined treatment resulted in significantly greater analgesia compared to either treatment alone. Conclusions: EA combined with HT synergistically enhances analgesia in both AA and CFA pain models, accompanied by reduced spinal inflammation and astrocyte activation. EA’s analgesic effects appear to involve adenosine A₁ receptor pathways and, to a lesser extent, opioid receptor mechanisms, whereas HT’s effects involve adenosine A₁ receptor pathways.

Radiotherapy and chemotherapy can impair salivary gland (SG) function, which causes xerostomia and exacerbate other side effects of chemotherapy and oral infection, reducing patients’ quality of life. This animal study aimed to assess the efficacy of electroacupuncture (EA) as a means of preventing xerostomia induced by 5−fluorouracil (5−FU). A xerostomia mouse model was induced via four tail vein injections of 5−FU (80 mg/kg/dose). EA was performed at LI4 and LI11 for 7 days. The pilocarpine-stimulated salivary flow rate (SFR) and salivary glands weight (SGW) were recorded. Salivary immunoglobulin A (SIgA) and lysozyme were determined via enzyme-linked immunosorbent assay (ELISA). SG was collected for hematoxylin and eosin staining to measure acini number and acinar cell size. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and aquaporin 5 (AQP5) mRNA expressions in SG were quantified via RT-qPCR. 5−FU caused significant decreases in SFR, SGW, SIgA, lysozyme, AQP5 expression, and acini number, while TNF-α and IL-1β expressions and acinar cell size were significantly increased. EA treatment can prevent 5−FU damage to the salivary gland, while pilocarpine treatment can only elevate SFR and AQP5 expression. These findings provide significant evidence to support the use of EA as an alternative treatment for chemotherapy-induced salivary gland hypofunction and xerostomia.

Background: Neuropathic pain (NP) is a debilitating chronic condition driven by maladaptive neuroimmune interactions in the spinal cord, with microglia playing a central pathological role. Electroacupuncture (EA) has shown analgesic effects in clinical and preclinical studies, but the microglia-centered mechanisms underlying these effects remain incompletely integrated. This review aims to provide a comprehensive mechanistic synthesis of how EA modulates microglia-associated neuroinflammatory pathways in neuropathic pain. Methods: This systematic search-narrative review used systematic search and screening procedures to identify English-language animal studies published between 2015 and 2025 in PubMed, CINAHL, Web of Science, and Cochrane Library. Twenty-six animal studies investigating EA effects on microglia-associated signaling pathways in neuropathic pain models met the inclusion criteria. Because of substantial heterogeneity in neuropathic pain models, EA parameters, molecular endpoints, and behavioral outcomes, findings were synthesized narratively, and no meta-analysis was performed. Results: The reviewed evidence revealed four convergent mechanistic categories through which EA modulates microglial activity: (1) attenuation of purinergic microglial activation via downregulation of IRF8, P2X4R, P2X7R; (2) suppression of innate immune sensing and inflammasome pathways, including TLR4/MyD88/NF-κB and NLRP3 signaling; (3) inhibition of downstream inflammatory amplification through p38 MAPK, PI3K/AKT, and COX-2 pathways; and (4) promotion of pro-resolution mechanisms involving IL-10/β-endorphin, PD-L1, GRK2/TREM2/DAP12, α7nAChR, GLP-1R, and GABAergic signaling. Conclusions: The available preclinical evidence suggests that EA modulates multiple microglia-associated pathways, attenuating inflammatory signaling while enhancing selected pro-resolution mechanisms. These findings provide a mechanistic framework for understanding EA-induced analgesia in neuropathic pain and highlight microglial signaling networks as important targets for future experimental and translational investigation.