RESUMO
BACKGROUND: Accumulating evidence demonstrates that traditional Chinese medicines that act on multiple targets could effectively treat various multi-etiological diseases, including cerebrovascular diseases, Alzheimer's disease (AD), Parkinson's disease (PD) and so on. Previous studies have shown that crocin richments (GJ-4), Gardenia jasminoides J.Ellis extract, provide neuroprotective effects on cognitive impairments in AD mouse models. However, the mechanism how GJ-4 improves cognition remains still unclear. PURPOSE: The aim of this study was to uncover the protective effects and underlying mechanism of GJ-4 on PrP-hAßPPswe/PS1ΔE9 (APP/PS1) transgenic mice. METHODS: APP/PS1 mice were given GJ-4 (10, 20, and 50 mg/kg), donepezil (5 mg/kg) and memantine (5 mg/kg) orally at eight months of age for 12 consecutive weeks. Morris water maze and novel object recognition were conducted to assess the cognitive ability of mice. The release of inflammatory cytokines was determined by RT-PCR assay, and the pathological features of neurons and microglia were assayed by immunohistochemistry and immunofluorescence assay. The expression of Aß-related proteins and signaling pathways were determined by Western blot. RESULTS: The behavioral results revealed that GJ-4 ameliorated the cognitive deficits of APP/PS1 mice measured by Morris water maze and novel object recognition tests. Mechanism studies indicated that GJ-4 significantly decreased ß-amyloid (Aß) level through reducing Aß production and promoting Aß degradation. It has been reported that Aß plaques trigger the hyper-phosphorylation of tau protein in APP/PS1 mice. Consistent with previous studies, hyper-phosphorylation of tau was also occurred in APP/PS1 mice in the present study, and GJ-4 inhibited Tau phosphorylation at different sites. Overwhelming evidence indicates that neuroinflammation stimulated by Aß and hyperphosphorylated tau is involved in the pathological progression of AD. We found that GJ-4 suppressed neuroinflammatory responses in the brain through regulating phosphatidylinositide 3-kinase/AKT (PI3K/AKT) signaling pathway activation, and subsequent expression of inflammatory proteins and release of inflammatory cytokines. CONCLUSION: Altogether, GJ-4 ameliorated cognition of APP/PS1 transgenic mice through multiple targets, including Aß, tau and neuroinflammation. This study provides a solid research basis for further development of GJ-4 as a potential candidate for the treatment of AD.
Assuntos
Disfunção Cognitiva , Medicamentos de Ervas Chinesas , Gardenia , Animais , Cognição , Disfunção Cognitiva/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Camundongos , Camundongos Transgênicos , Fosfatidilinositol 3-QuinasesRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Gardenia jasminoides J. Ellis (Fructus Gardenia) is a traditional Chinese medicine with diverse pharmacological functions, such as anti-inflammation, anti-depression, as well as improvement of cognition and ischemia brain injury. GJ-4 is a natural extract from Gardenia jasminoides J. Ellis (Fructus Gardenia) and has been proved to improve memory impairment in Alzheimer's disease (AD) mouse model in our previous studies. AIM OF THE STUDY: This study aimed to evaluate the therapeutic effects of GJ-4 on vascular dementia (VD) and explore the potential mechanisms. MATERIAL AND METHODS: In our experiment, a focal cerebral ischemia and reperfusion rat model was successfully developed by the middle cerebral artery occlusion and reperfusion (MCAO/R). GJ-4 (10 mg/kg, 25 mg/kg, 50 mg/kg) and nimodipine (10 mg/kg) were orally administered to rats once a day for consecutive 12 days. Learning and memory behavioral performance was assayed by step-down test and Morris water maze test. The neurological scoring test was performed to evaluate the neurological function of rats. 2,3,5-Triphenyltetrazolium chloride (TTC) staining and Nissl staining were respectively employed to determine the infarct condition and neuronal injury of the brain. Iba1 immunohistochemistry was used to show the activation of microglia. Moreover, the synaptic damage and inflammatory level were detected by Western blot. RESULTS: GJ-4 could significantly improve memory impairment, cerebral infraction, as well as neurological deficits of VD rats induced by MCAO/R. Further research indicated VD-induced neuronal injury was alleviated by GJ-4. In addition, GJ-4 could protect synapse of VD rats by upregulating synaptophysin (SYP) expression, post synaptic density 95 protein (PSD95) expression, and downregulating N-Methyl-D-Aspartate receptor 1 (NMDAR1) expression. Subsequent investigation of the underlying mechanisms identified that GJ-4 could suppress neuroinflammatory responses, supported by inhibited activation of microglia and reduced expression of inflammatory proteins, which ultimately exerted neuroprotective effects on VD. Further mechanistic study indicated that janus kinase 2 (JAK2)/signal transducer and activator of transcription 1 (STAT1) pathway was inhibited by GJ-4 treatment. CONCLUSION: These results suggested that GJ-4 might serve as a potential drug to improve VD. In addition, our study indicated that inhibition of neuroinflammation might be a promising target to treat VD.
Assuntos
Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Demência Vascular/prevenção & controle , Infarto da Artéria Cerebral Média/tratamento farmacológico , Janus Quinase 2/metabolismo , Transtornos da Memória/prevenção & controle , Memória/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Nootrópicos/farmacologia , Extratos Vegetais/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Fator de Transcrição STAT1/metabolismo , Animais , Encéfalo/enzimologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Demência Vascular/enzimologia , Demência Vascular/etiologia , Demência Vascular/psicologia , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Gardenia , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/enzimologia , Infarto da Artéria Cerebral Média/fisiopatologia , Mediadores da Inflamação/metabolismo , Masculino , Transtornos da Memória/enzimologia , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Ratos Sprague-Dawley , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/fisiopatologia , Transdução de Sinais , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Sinapses/patologiaRESUMO
The neuroprotective agent 3-hydroxymorphinan (3-HM) is a well-documented and highly safe therapeutic intervention for the inflammatory-related effects of Parkinson's disease (PD). However, the bioavailability of 3-HM is very low due to the rapid first-pass metabolism of the phenolic moiety. In the present study, we sought to improve the metabolic stability and overall pharmacokinetic profile of 3-HM. Based on an iterative design process that a suitably arranged heterocycle with an NH group would serve as the metabolically stable isostere of the phenolic group, we designed and synthesized two analogues of 3-HM. Benzimidazolone compound 8 (imidazolone-morphinan) was comparable in activity to 3-HM against lipopolysaccharide (LPS)-induced inflammatory responses in microglial BV2 cells and in vivo animal experiments (MPTP-induced PD mouse model). Moreover, the in vitro study showed that imidazolone-morphinan was non-toxic to microglia, indicating its high safety. Considering the favourable and unique preclinical profiles, compound 8 was nominated as a candidate for further clinical development.