Hongshi Li1, Zexu Gu2, Li'an Wu3, Liang Xia4, Kecheng Zhou5, Lingling E1, Dongsheng Wang1, Junping Kou6, Hongchen Liu7. 1. Institute of Stomatology, Chinese People's Libecation Army General Hospital, Beijing 100853, China. 2. Department of Orthodontic Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China. 3. Department of Paediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China. 4. Department of Psychology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China. 5. Department of Chinese Compound Prescription, China Pharmaceutical University, Nanjing, Jiangsu 210038, China. 6. State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210038, China. 7. Institute of Stomatology, Chinese People's Libecation Army General Hospital, Beijing 100853, China. Email: liuhongchen301@hotmail.com.
Abstract
BACKGROUND: The pain caused by orthodontic treatment has been considered as tough problems in orthodontic practice. Danggui-shaoyao-san (DSS) is a traditional Chinese medicine (TCM) prescription which has long been used for pain treatment and possesses antioxidative, cognitive enhancing and antidepressant effects. We raise the hypothesis that DSS exerts analgesic effect for orthodontic pain via inhibiting the activations of neuron and microglia. METHODS: DSS was given twice a day from day 5 prior to experimental tooth movement (ETM). Directed face grooming and vacuous chewing movements (VCM) were evaluated. Immunofluorescent histochemistry and Western blot analysis were used to quantify the Iba-1 (microglia activation) and Fos (neuronal activation) expression levels in the trigeminal spinal nucleus caudalis (Vc). RESULTS: ETM significantly increased directed face grooming and VCM which reached the peak at post-operative day (POD) 1 and gradually decreased to the baseline at POD 7. However, a drastic peak increase of Fos expression in Vc was observed at 4 hours and gradually decreased to baseline at POD 7; while the increased Iba-1 level reached the peak at POD 1 and gradually decreased to baseline at POD 7. Furthermore, pre-treatment with DSS significantly attenuated the ETM induced directed face grooming and VCM as well as the Fos and Iba-1 levels at POD 1. CONCLUSION: Treatment with DSS had significant analgesic effects on ETM-induced pain, which was accompanied with inhibition of both neuronal and microglial activation.
BACKGROUND: The pain caused by orthodontic treatment has been considered as tough problems in orthodontic practice. Danggui-shaoyao-san (DSS) is a traditional Chinese medicine (TCM) prescription which has long been used for pain treatment and possesses antioxidative, cognitive enhancing and antidepressant effects. We raise the hypothesis that DSS exerts analgesic effect for orthodontic pain via inhibiting the activations of neuron and microglia. METHODS: DSS was given twice a day from day 5 prior to experimental tooth movement (ETM). Directed face grooming and vacuous chewing movements (VCM) were evaluated. Immunofluorescent histochemistry and Western blot analysis were used to quantify the Iba-1 (microglia activation) and Fos (neuronal activation) expression levels in the trigeminal spinal nucleus caudalis (Vc). RESULTS: ETM significantly increased directed face grooming and VCM which reached the peak at post-operative day (POD) 1 and gradually decreased to the baseline at POD 7. However, a drastic peak increase of Fos expression in Vc was observed at 4 hours and gradually decreased to baseline at POD 7; while the increased Iba-1 level reached the peak at POD 1 and gradually decreased to baseline at POD 7. Furthermore, pre-treatment with DSS significantly attenuated the ETM induced directed face grooming and VCM as well as the Fos and Iba-1 levels at POD 1. CONCLUSION: Treatment with DSS had significant analgesic effects on ETM-induced pain, which was accompanied with inhibition of both neuronal and microglial activation.