Alleviating Mechanical Allodynia and Modulating Cellular Immunity Contribute to Electroacupuncture’s Dual Effect on Bone Cancer Pain

• Published in: Integrative cancer therapies Vol. 17; no. 2; pp. 401 - 410
• Main Authors: Liang, Yi, Du, Jun-Ying, Fang, Jun-Fan, Fang, Ruo-Yi, Zhou, Jie, Shao, Xiao-Mei, Jiang, Yong-Liang, Chen, Yi-Tian, Fang, Jian-Qiao
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.06.2018; SAGE PUBLICATIONS, INC; SAGE Publishing
• Subjects: Acupuncture; Analgesics; Animals; Bone cancer; Bone Neoplasms - immunology; Cancer Pain - immunology; CD3 antigen; CD3 Complex - immunology; CD4 antigen; CD4-Positive T-Lymphocytes - immunology; CD8 antigen; CD8-Positive T-Lymphocytes - immunology; Cell growth; Cell proliferation; Cell Proliferation - physiology; Cell-mediated immunity; Concanavalin A; Electroacupuncture; Electroacupuncture - methods; Enzyme-linked immunosorbent assay; Female; Flow cytometry; Humans; Hyperalgesia - immunology; Immunity, Cellular - immunology; Immunomodulation; Inoculation; Interleukin 2; Lymphocytes; Lymphocytes T; Mammary gland; Mechanical stimuli; Morphine; Naloxone; Opioids; Pain perception; Rats; Rats, Sprague-Dawley; Spleen; Tibia; cellular immunity; analgesia; bone cancer pain; naloxone; mechanical allodynia; electroacupuncture; morphine
• ISSN: 1534-7354; 1552-695X
• DOI: 10.1177/1534735417728335

Hypothesis: Electroacupuncture (EA) has been used as an alternative analgesic therapy for hundreds of years, yet its analgesic potency and therapeutic advantage against bone cancer pain (BCP) in comparison with morphine remains unclear. This study aimed to investigate the effects of EA on mechanical allodynia and cellular immunity of BCP rats, and to further explore the potential mechanism. Methods: The BCP model was established by implanting Walker 256 mammary gland carcinoma cells into the left tibia of adult female Sprague-Dawley rats. EA (dilatational wave, 2/100 Hz, 0.5 mA–1mA–1.5 mA for 10 minutes each intensity) was applied bilaterally to Zusanli (ST 36) and Kunlun (BL 60) for 30 minutes. Both EA stimulation and morphine (10 mg/kg, intraperitoneally) was given once every other day. Naloxone (0.3 mg/kg, intraperitoneally) was injected at 30 minutes prior to EA. Mechanical allodynia were demonstrated by paw withdrawal thresholds (PWTs) which measured by dynamic plantar aesthesiometer. T cell proliferation, percentage of CD3+, CD4+ and CD8+ T lymphocytes in spleen as well as expression of interleukin-2 (IL-2) in plasma were detected by WST-8, flow cytometry, and enzyme-linked immunosorbent assay technique, respectively. Results: An intratibial inoculation of Walker 256 mammary gland carcinoma cells significantly decreased PWTs to mechanical stimuli. EA stimulation alleviated mechanical allodynia in BCP rats, and the analgesic potency of EA was weaker than that of morphine. In contrast to morphine, EA stimulation of BCP rats increased splenic concanavalin A (Con A)-induced T cell proliferation and plasma IL-2 content, as well as increased the percentages of splenic CD3+CD4+ and CD3+CD8+ T cell subsets. Moreover, both the analgesic effect and the partial immunomodulation of EA were suppressed by an intraperitoneal injection of naloxone. Conclusion: EA could significantly alleviate BCP-induced mechanical allodynia. Although the analgesic effect of EA was weaker than that of morphine, EA had an immunomodulation effect on cellular immunity. Both analgesic and immunomodulatory effect of EA might share the same mechanism via the opioid-mediated pathway, which needs further investigation.