Abstract: BACKGROUND: Shujin Jiannao Prescription is an empirical formula for the treatment of cerebral palsy in Dongzhimen Hospital, Beijing University of Chinese Medicine, with clear clinical efficacy, but the specific mechanism needs to be elucidated.
OBJECTIVE: To explore the possible mechanism of Shujin Jiannao Prescription in treating cerebral palsy. 
METHODS: Sixty-four 7-day-old Sprague-Dawley rats were randomly divided into a normal group (n=12) and a model group (n=52). An animal model was established by the Rice-Vannucci method. After successful modeling, 52 model rats were randomly divided into control model group (n=12), minocycline group, and the low-, medium-, and high-dose groups of the Shujin Jiannao Prescription (n=10 per group). Rats in the minocycline group were given 40 mg/kg•d 
minocycline by gavage; rats in the low-, medium, and high-dose groups were given 4, 8, and 16 g/kg•d Shujin Jiannao Prescription granules by gavage, respectively; and rats in the normal group and control model group were given an equal dose of normal saline by gavage. Medication in each group was given once a day for 1 week. The rats in each group were evaluated behaviorally using suspension test, abnormal involuntary movement score, and Bederson score. The pathological changes of the cerebral cortex were observed by hematoxylin-eosin staining. The levels of tumor necrosis factor α, interleukin 1β, and interleukin 10 in the cerebral cortex were determined using ELISA. The positive expressions of Janus kinase 2 (JAK2), phosphorylated Janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in the cerebral cortex were detected using immunohistochemistry. The protein expression levels of JAK2, p-JAK2, and p-STAT3 were detected using western blot. 
RESULTS AND CONCLUSION: Compared with the normal group, the suspension test score and involuntary movement score were decreased in the control model group (P < 0.01 or P < 0.05). The pathological results showed structural disruption of nerve cells, formation of large numbers of vacuoles, cell swelling, and increased intercellular space in the control model group. In addition, the expressions of tumor necrosis factor α and interleukin 1β in the cerebral cortex were significantly increased (P < 0.01), the expression of interleukin 10 was decreased (P < 0.05), and the protein expressions of JAK2, p-JAK2, and p-STAT3 in the cerebral cortex were significantly increased (P < 0.01) in the control model group compared with the normal group. Compared with the model group, minocycline and Shujin Jiannao Prescription at each dose could improve the behavioral indexes of rats (P < 0.01 or P < 0.05) and ischemic-hypoxic pathological changes were attenuated, with only a small amount of necrotic nerve cells and a few vacuoles, and reduced intercellular space. Moreover, the expressions of tumor necrosis factor α and interleukin 1β in the cerebral cortex were decreased in each drug group compared with the control model group (P < 0.05), while the protein expressions of JAK2, p-JAK2, and p-STAT3 in the cerebral cortex were significantly decreased (P < 0.01). The most obvious improvement was observed in the high-dose Shujin Jiannao Prescription group. To conclude, Shujin Jiannao Prescription can inhibit inflammation in the cerebral cortex of rats with hypoxic-ischemic brain injury. The mechanism may be related to the regulation of the JAK2/STAT3 signaling pathway.

Key words: cerebral palsy, Shujin Jiannao Prescription, inflammation, JAK2/STAT3 signaling pathway