A new systematic review and meta-analysis published in Frontiers in Cardiovascular Medicine reports that electroacupuncture preconditioning is associated with reduced myocardial injury and favorable changes in mitochondria-associated outcomes in animal models of myocardial ischemia-reperfusion injury (MIRI). The study, led by researchers from Guangzhou University of Chinese Medicine and affiliated institutions, synthesized data from 34 publications involving 586 animals. The findings suggest that electroacupuncture may mitigate oxidative stress and apoptosis in the heart following ischemia and reperfusion, although the evidence remains preclinical and hypothesis-generating. The authors emphasize that these results cannot establish mitochondrial protection as a causal mechanism, as other pathways may also contribute to the observed cardioprotective effects.
The research was designed to address a gap in the literature where no prior systematic review had quantitatively synthesized mitochondria-associated outcomes for acupuncture preconditioning in MIRI models. The authors searched eight databases from inception to 26 July 2026 for randomized controlled animal studies. Two independent reviewers screened the studies, assessed risk of bias using the SYRCLE tool, and extracted data. Graphical data were digitized by one reviewer and verified by another to ensure accuracy. The meta-analyses employed random-effects models with standardized mean differences (SMDs) and the Hartung-Knapp-Sidik-Jonkman adjustment to account for heterogeneity among the included studies.
The included studies predominantly utilized electroacupuncture, with 33 of the 34 publications employing this method and only one utilizing manual acupuncture. Thirty-three studies were pooled for quantitative analysis, while one study was synthesized qualitatively because its outcome direction could not be harmonized with the others. The primary outcomes evaluated were reactive oxygen species (ROS), malondialdehyde (MDA), adenosine triphosphate (ATP), Bax, B-cell lymphoma 2 (Bcl-2), and the apoptotic index (AI), in addition to infarct size. These markers are central to understanding mitochondrial dysfunction, which the authors note is a key factor in MIRI pathophysiology.
The meta-analysis found that acupuncture preconditioning was associated with significant reductions in infarct size, with a standardized mean difference of -2.69 (95% CI -3.57 to -1.82). The analysis also indicated reductions in markers of oxidative stress and apoptosis, including MDA (SMD -3.76), ROS (SMD -4.02), Bax (SMD -6.52), and the apoptotic index (SMD -6.36). Conversely, the intervention was associated with increases in ATP (SMD 3.21) and Bcl-2 (SMD 8.14), suggesting improved mitochondrial energy production and anti-apoptotic signaling. However, the authors highlight that heterogeneity remained high across most outcomes, with I-squared values ranging from 69.9% to 96.5%, indicating substantial variability in effect sizes among the included studies.
Subgroup analyses revealed significant effect modification only for Bcl-2, where both species and reperfusion duration influenced the outcome. The authors caution that extreme effect sizes for ROS, Bax, Bcl-2, and AI may be overestimated. Statistical tests for publication bias, including Egger’s test, did not indicate significant bias, although a trim-and-fill analysis rendered the ROS result non-significant. The certainty of evidence was assessed as moderate for most outcomes but low for Bax. These limitations underscore the need for further research to clarify the robustness of the observed associations.
The authors stress that the findings should not be generalized to acupuncture as a whole, given that only one study involved manual acupuncture. The evidence is preclinical and does not directly translate to human clinical applications. The study was registered in PROSPERO with the identifier CRD420261477352, ensuring transparency in the review process. The researchers conclude that while electroacupuncture preconditioning shows promise in reducing myocardial injury in animal models, sham-controlled studies are needed to further validate these effects and explore the underlying mechanisms.
By focusing on mitochondria-associated outcomes, the study provides a detailed quantitative synthesis that was previously lacking.
The publication, authored by Mingyi Du, Weiping Chen, Chen Jianan, Anran Liu, and Ye Taochun, is available in Frontiers in Cardiovascular Medicine.
Subject of Research: Systematic review of electroacupuncture effects on mitochondrial outcomes in animal myocardial ischemia-reperfusion models
Article Title: Electroacupuncture preconditioning and mitochondria-associated outcomes in animal models of myocardial ischemia-reperfusion injury: a systematic review and meta-analysis
Article References: Du, M., Chen, W., Chen, J., Liu, A., Jiang, J., & Ye, T. (2026). Electroacupuncture preconditioning and mitochondria-associated outcomes in animal models of myocardial ischemia-reperfusion injury: a systematic review and meta-analysis. Frontiers in Cardiovascular Medicine, 13, Article 1982708. https://doi.org/10.3389/fcvm.2026.1982708
Image Credits: AI Generated
DOI: 10.3389/fcvm.2026.1982708
Keywords: electroacupuncture, myocardial ischemia-reperfusion injury, mitochondrial dysfunction, systematic review, meta-analysis, cardioprotection, animal models, oxidative stress, apoptosis, preclinical research, preconditioning, mitochondria-associated
