ABSTRACT
OBJECTIVE To study the effects of Yishen daluo decoction on inflammatory factors and cyclic adenosine monophosphate（cAMP）/protein kinase A （PKA）/cAMP response element binding protein （CREB） signal pathway in experimental autoimmune encephalomyelitis （EAE） model mice by inhibiting the expressions of β-arrestin1， and to explore the mechanism of Yishen daluo decoction in the treatment of EAE. METHODS Sixty mice were randomly divided into normal group， model group， TCM group （Yishen daluo decoction 20 g/kg）， positive control group （prednisone acetate 3.9 mg/kg）， β-arrestin1 siRNA adeno- associated virus （AAV-β） group， AAV-β+TCM group， with 10 mice in each group. Except for normal group， EAE model was made in other groups. AAV-β group and AAV-β+TCM group were injected with AAV-β via tail vein to interfere with the expression of β -arrestin1 protein. Starting from the 8th day of modeling， they were given corresponding drug solution/normal saline intragastrically， once a day， for consecutive 14 days. The neurological function score of mice was detected； the pathological and morphological changes were observed in the brain and spinal cord tissues of mice； the serum levels of inflammatory factors [interleukin-2 （IL-2）， IL-23， interferon-γ （IFN-γ）] in mice were determined； the expressions of β-arrestin1， cAMP， PKA and CREB in brain and spinal cord were detected. RESULTS Compared with normal group， neurological function scores， serum levels of inflammatory factors， and protein expressions of β-arrestin1 in brain and spinal cord were significantly increased （P＜0.05 or P＜ 0.01）； protein expressions of PKA， CREB and cAMP in brain and spinal cord were decreased significantly（P＜0.05 or P＜0.01）. The deep staining of cellular shrinkage and aggregation of inflammatory cells were observed in most neurons of the brain and spinal cord， with varying degrees of demyelinating. Compared with model group， the neurological function scores， pathological changes in brain and spinal cord tissues， and most indicators （except for CREB and cAMP proteins in the brain tissue of AAV-β group） were significantly reversed （P＜0.05 or P＜0.01）.Compared with AAV- β group， the neurological function scores， the levels of IFN-γ in serum and β-arrestin1 in spinal cord were significantly decreased （P＜0.05 or P＜0.01）， PKA and cAMP in brain and spinal cord tissues were significantly increased in AAV- β +TCM group （P＜0.05 or P＜0.01）. CONCLUSIONS Yishen daluo decoction can inhibit the expression of β-arrestin1 in the central nervous system thus activating the cAMP/PKA/CREB signaling pathway， relieving nervous system inflammation， and ultimately alleviates the symptoms of EAE.