Effect of “lumbar three needles” on expression of oxidative stress factors in rats with multifidus muscles injury / 中国组织工程研究

ABSTRACT

BACKGROUND: Posterior lumbar spine surgery is currently the main surgical approach for many surgical operations such as discectomy and spinal canal decompression. However, 10%-40% of patients with posterior lumbar spine surgery can have low back pain and related dysfunctions soon after surgery, which is related to excessive stretching or blunt injury to the paraspinal muscles such as the multifidus muscle during the operation. OBJECTIVE: To explore the effect of “Lumbar Three Needles” on the expression of oxidative stress factors, including malondialdehyde, reactive oxygen species, superoxide dismutase, glutathione peroxidase and phosphorylated protein kinase B, in rats with multifidus muscles injury. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into control group, model group and “Lumbar Three Needles” group, with 8 rats in each group. An animal model of multifidus muscles injury was made by intramuscular injection of 0.5% bupivacaine hydrochloride in the model and treatment groups in control and “Lumbar Three Needles” group, while normal saline was injected in the control group. No acupuncture intervention was given in the control group and model group, while Dachangshu, Shenshu and Weizhong acupoints were electroacupunctured in the “Lumbar Three Needles” group. Needles were then stimulated electrically using a Han's Acupoint Nerve Stimulator with density wave, frequency of 2 Hz/10 Hz and continuous current of 1 mA for 20 minutes, once daily for 7 days in total. The multifidus muscle was stained with hematoxylin-eosin staining to observe morphological changes, and kits were used to observe the expression of malondialdehyde, reactive oxygen species, superoxide dismutase, and glutathione peroxidase, while western blot was applied to observe the expression of phosphorylated protein kinase B. The study protocol was approved by the Animal Ethic Committee of Guangdong Second Traditional Chinese Medicine Hospital with an approval No. 048617. RESULTS AND CONCLUSION: Hematoxylin-eosin staining results indicated that the muscle fibers were partially fixed in the model group and there were still a lot of macrophages after 7 days of intervention. Compared with the model group, more newborn muscle fibers and fewer macrophages could be seen in the “Lumbar Three Needles” group. After intervention, the cross-sectional area of the multifidus muscles in the “Lumbar Three Needles” group was significantly bigger than that in the model group (P < 0.01). The expression levels of malondialdehyde and reactive oxygen species in the model group were significantly increased compared with the control group (P < 0.01) and “Lumbar Three Needles” group (P < 0.01). The expression of superoxide dismutase, glutathione peroxidase and phosphorylated protein kinase B in the “Lumbar Three Needles” group was significantly higher than that in the model group (P < 0.01 or P < 0.05). Therefore, “Lumbar Three Needles” can significantly decrease the oxidative stress level after multifidus muscle injury, which may be related to the improvement of phosphorylated protein kinase B.