RESUMO
Depression is a mental illness comorbid risk factor for glucose intolerance worldwide. Chaihu-shugan san, a 'Shu-Gan' formula in traditional Chinese medicine, is clinically used in the treatment of depression. The aim of this study was to investigate whether Chaihu-shugan san improved glucose tolerance with its antidepressant activity in rat model of depression and explore the mechanisms underlying its action on liver-brain inflammation axis. After 6 weeks of chronic unpredictable mild stress (CUMS) procedure, male Wistar rats were given Chaihu-shugan san water extract (925 and 1850â¯mg/kg) by gavage for the next 6 consecutive weeks. Sucrose consumption test was used to assess animal depressive-like behaviors. Oral glucose tolerance test (OGTT) was employed to define the status of glucose tolerance in rats. Serum alanine aminotransferase (ALT) and interleukin-1 beta (IL-1ß) were measured by commercial kits, respectively. Western blot was used to detect the expression of key proteins in inflammatory signaling cascades including toll-like receptor 4 (TLR4), myeloid differentiation protein 88 (MyD88), nuclear factor-kappa B (NF-κB), Nod-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), cysteinyl aspartate specific proteinase-1 (Caspase-1) and IL-1ß, as well as insulin signaling in liver and prefrontal cortex of rats. Immunohistochemical staining or immunofluorescence staining of NF-κB, and nuclear/cytoplasmic ratio of NF-κB by Western blot were used to describe its nuclear entry in liver and prefrontal cortex of rats. RT-qPCR and Western blot analysis, as well as microRNA-155 (miR-155) mimic or inhibitor transfection were used to explore possible association of MyD88 and miR-155. In this study, Chaihu-shugan san increased sucrose consumption and reduced serum glucose levels in CUMS rats, showing its antidepressant activity with glucose tolerance improvement. Chaihu-shugan san reduced serum levels of ALT and IL-1ß in this animal model. Furthermore, this formula inhibited hepatic and prefrontal cortical inflammatory response by suppressing TLR4/MyD88/NF-κB pathway and NLRP3 inflammasome activation, and improved insulin signaling in CUMS rats. More importantly, Chaihu-shugan san up-regulated miR-155 expression in liver and prefrontal cortex of CUMS rats. These results provide direct evidence that Chaihushugan San can ameliorate depressive-like behaviors by inhibiting liver-brain inflammation axis.
Assuntos
Intolerância à Glucose/complicações , Inflamação/tratamento farmacológico , Insulina/metabolismo , Fígado/metabolismo , Extratos Vegetais/uso terapêutico , Córtex Pré-Frontal/metabolismo , Transdução de Sinais , Estresse Psicológico/metabolismo , Alanina Transaminase/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Glicemia/metabolismo , Linhagem Celular , Doença Crônica , Depressão/tratamento farmacológico , Depressão/etiologia , Intolerância à Glucose/sangue , Intolerância à Glucose/genética , Inflamassomos/metabolismo , Inflamação/sangue , Inflamação/complicações , Inflamação/patologia , Interleucina-1beta/metabolismo , Fígado/efeitos dos fármacos , Fígado/fisiopatologia , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Extratos Vegetais/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Estresse Psicológico/sangue , Estresse Psicológico/complicações , Estresse Psicológico/genética , Água/químicaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Banxia-houpu decoction is a famous formula in traditional Chinese medicine (TCM) with the powerful anti-depressant activity. AIM OF THE STUDY: This study aimed to investigate the effect of Banxia-houpu decoction on glucose intolerance associated with anhedonia in chronic unpredictable mild stress (CUMS) rats, then to explore its underlying pharmacological mechanisms. MATERIALS AND METHODS: After 6-week CUMS procedure, male Wistar rats were given Banxia-houpu decoction (3.29 and 6.58g/kg, intragastrically) for 6 weeks. Sucrose solution consumption test was employed to evaluate the anhedonia behavior. Oral glucose tolerance test (OGTT) was used to determine glucose tolerance. Serum levels of corticosterone, corticotropin-releasing factor (CRF), insulin and interleukin-1 beta (IL-1ß) were measured by commercial enzyme-linked immunosorbent assay kits, respectively. Furthermore, the key proteins for insulin signaling, as well as nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, were analyzed by Western blot in periphery liver and brain regions hypothalamus, hippocampus and prefrontal cortex, respectively. RESULTS: Banxia-houpu decoction significantly increased sucrose solution consumption and decreased serum corticosterone and CRF levels in CUMS rats, further demonstrating its antidepressant activity. More importantly, Banxia-houpu decoction improved glucose tolerance in OGTT in this animal model. Furthermore, it protected against CUMS-induced insulin signaling impairment in the liver, as well as hypothalamus and prefrontal cortex in rats. Although without significant effect on serum IL-1ß levels, Banxia-houpu decoction inhibited NLRP3 inflammasome activation in the liver, hypothalamus, hippocampus and prefrontal cortex of CUMS rats, respectively. CONCLUSIONS: The present study demonstrates that Banxia-houpu decoction suppresses NLRP3 inflammasome activation and improves insulin signaling impairment in both periphery liver and brain regions in CUMS rats, possibly contributing to its anti-depressive effect with glucose tolerance improvement. These results may provide the evidence that Banxia-houpu decoction is a potential antidepressant with the advantage to reduce the risk of comorbid depression with type 2 diabetes mellitus.