Anti-inflammatory strategies for hepatic encephalopathy: preclinical studies / Estratégias anti-inflamatórias para encefalopatia hepática: estudos pré-clínicos

Abstract Hepatic encephalopathy (HE) is a potentially reversible neuropsychiatric syndrome. Often, HE causes cognitive and motor dysfunctions due to an acute or chronic insufficiency of the liver or a shunting between the hepatic portal vein and systemic vasculature. Liver damage induces peripheral changes, such as in the metabolism and peripheral inflammatory responses that trigger exacerbated neuroinflammation. In experimental models, anti-inflammatory strategies have demonstrated neuroprotective effects, leading to a reduction in HE-related cognitive and motor impairments. In this scenario, a growing body of evidence has shown that peripheral and central nervous system inflammation are promising preclinical targets. In this review, we performed an overview of FDA-approved drugs and natural compounds which are used in the treatment of other neurological and nonneurological diseases that have played a neuroprotective role in experimental HE, at least in part, through anti-inflammatory mechanisms. Despite the exciting results from animal models, the available data should be critically interpreted, highlighting the importance of translating the findings for clinical essays.

Resumo A encefalopatia hepática (EH) é uma síndrome neuropsiquiátrica potencialmente reversível. Muitas vezes a EH causa disfunções cognitivas e motoras devido à insuficiência do fígado ou por um desvio entre a veia porta hepática e a vasculatura sistêmica. O dano no fígado provoca alterações periféricas, como no metabolismo e nas respostas inflamatórias periféricas, que desencadeiam uma neuroinflamação exacerbada. Em modelos experimentais, estratégias anti-inflamatórias têm demonstrado efeitos neuroprotetores, levando a uma redução dos prejuízos cognitivos e motores relacionados à EH. Neste cenário, evidências crescentes têm mostrado a inflamação periférica e no sistema nervoso central como um promissor alvo pré-clínico. Nesta revisão, abordamos uma visão geral de drogas e compostos naturais aprovados pelo FDA para o uso no tratamento de outras doenças neurológicas e não neurológicas, que tiveram papel neuroprotetor na EH experimental, pelo menos em parte, através de mecanismos anti-inflamatórios. Apesar dos resultados empolgantes em modelos animais, os dados avaliados devem ser criticamente interpretados, destacando a importância da tradução dos achados para ensaios clínicos.

Doxycycline to treat levodopa-induced dyskinesias in Parkinson's disease: a preliminary study / Doxiciclina no tratamento das discinesias induzidas pela doença de Parkinson: um estudo preliminar

Abstract Background Levodopa-induced dyskinesia (LID) is a common motor complication of levodopa therapy in patients with Parkinson's disease (PD). Doxycycline is a widely used and inexpensive tetracycline with anti-inflammatory properties. Objective To evaluate the efficacy and safety of doxycycline in patients with PD and LID. Methods This was an open-label, uncontrolled, single-arm, single-center, phase 2 proof-of-concept study in patients with PD with functional impact of dyskinesia, which used levodopa three times daily, in a movement disorders clinic in Brazil. Participants were treated with doxycycline 200 mg/day for 12 weeks, with evaluations at baseline, week4, and week 12 of treatment. The primary outcome measure was the change from baseline in the Unified Dyskinesia Rating Scale (UDysRS) total score at week 12, evaluated by two blinded raters. Key secondary outcomes measures were OFF time and ON time with troublesome dyskinesia in the PD home diary. Results Eight patients with PD were treated and evaluated. Doxycycline 200 mg/day reduced the UDysRS total score at week 12, compared with baseline (Friedman χ2 = 9.6; p = 0.008). Further, doxycycline reduced the ON time with troublesome dyskinesia (Friedman χ2 = 10.8; p = 0.004) without worsening parkinsonism. There were no severe adverse events, and dyspepsia was the commonest event. Conclusion In this preliminary, open-label and uncontrolled trial, doxycycline was effective in reducing LID and safe after a 12-week treatment. Further well-designed placebo-controlled clinical trials with a longer duration and a larger number of participants are needed. Clinical trial registration https://ensaiosclinicos.gov.br, identifier: RBR-1047fwbf

Resumo Antecedentes A discinesia induzida por levodopa (DIL) é uma complicação motora comum da terapia com levodopa em pacientes com doença de Parkinson (DP). A doxiciclina é uma tetraciclina amplamente usada e barata, com propriedade anti-inflamatória. Objetivo Avaliar a eficácia e segurança da doxiciclina em pacientes com DP e DIL. Métodos Este foi um estudo aberto, não-controlado, de braço único, monocêntrico, fase 2 e de prova de conceito, em pacientes com DP e impacto funcional das discinesias, que usavam levodopa três vezes ao dia, em um ambulatório de distúrbios de movimento no Brasil. Os participantes foram tratados com doxiciclina 200 mg/dia por 12 semanas, com avaliações na base, na semana 4 e na semana 12 do tratamento. A medida de desfecho primário foi a mudança no escore total da Unified Dyskinesia Rating Scale (UDysRS) da base à semana 12, avaliada por dois avaliadores cegos. As medidas-chave de desfecho secundário fora o tempo em OFF e tempo em ON com discinesia problemática. Resultados Oito pacientes com DP foram tratados e avaliados. A doxiciclina 200 mg/dia reduziu o escore total da UDysRS na semana 12, comparado com a avaliação inicial (χ2 de Friedman = 9.6; p = 0.008). Além disso, a doxiciclina reduziu o tempo em ON com discinesia problemática (χ2 de Friedman = 10.8; p = 0.004) sem piorar o parkinsonismo. Não houve eventos adversos graves, e dispepsia foi o evento mais comum. Conclusão No presente estudo preliminar, aberto e não-controlado, a doxiciclina foi eficaz em reduzir as DIL e segura após tratamento por 12 semanas. Estudos clínicos bem-desenhados e placebo-controlados adicionais, com duração mais longa e maior número de participantes, são necessários.

Astragaloside IV alleviates stroke-triggered early brain injury by modulating neuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway

Purpose: Stroke is an acute cerebrovascular disease. Astragaloside IV (AS-IV) is an active ingredient extracted from Astragalus membranaceus with an established therapeutic effect on central nervous system diseases. This study examined the neuroprotective properties and possible mechanisms of AS-IV in stroke-triggered early brain injury (EBI) in a rat transient middle cerebral artery occlusion (MCAO) model. Methods: The neurological scores and brain water content were analyzed. 2,3,5-triphenyl tetrazolium chloride (TTC) staining was utilized to determine the infarct volume, neuroinflammatory cytokine levels, and ferroptosis-related genes and proteins, and neuronal damage and molecular mechanisms were evaluated by terminal deoxynucleotidyl transferase dutp nickend labeling (TUNEL) staining, western blotting, and real-time polymerase chain reaction. Results: AS-IV administration decreased the infarct volume, brain edema, neurological deficits, and inflammatory cytokines TNF-α, interleukin-1ß (IL-1ß), IL-6, and NF-κB, increased the levels of SLC7A11 and glutathione peroxidase 4 (GPX4), decreased lipid reactive oxygen species (ROS) levels, and prevented neuronal ferroptosis. Meanwhile, AS-IV triggered the Nrf2/HO-1 signaling pathway and alleviated ferroptosis due to the induction of stroke. Conclusion: Hence, the findings of this research illustrate that AS-IV administration can improve delayed ischemic neurological deficits and decrease neuronal death by modulating nuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway.

Cerebrolysin alleviates early brain injury after traumatic brain injury by inhibiting neuroinflammation and apoptosis via TLR signaling pathway

Purpose: Traumatic brain injury (TBI) is a major cause of death and disability. Cerebrolysin (CBL) has been reported to be anti-inflammatory by reducing reactive oxygen species (ROS) production. However, the neuroprotection of CBL in TBI and the potential mechanism are unclear. We aimed to investigate the neuroprotection and mechanisms of CBL in TBI. Methods: The TBI model was established in strict accordance with the Feeney weight-drop model of focal injury. The neurological score, brain water content, neuroinflammatory cytokine levels, and neuronal damage were evaluated. The involvement of the early brain injury modulatory pathway was also investigated. Results: Following TBI, the results showed that CBL administration increased neurological scores and decreased brain edema by alleviating blood­brain barrier (BBB) permeability, upregulating tight junction protein (ZO­1) levels, and decreasing the levels of the inflammatory cytokines tumor necrosis factor­α (TNF­α), interleukin­1ß (IL­1ß), IL­6, and NF­κB. The TUNEL assay showed that CBL decreased hippocampal neuronal apoptosis after TBI and decreased the protein expression levels of caspase­3 and Bax, increasing the levels of Bcl­2. The levels of Toll­like receptor 2 (TLR2) and TLR4 were significantly decreased after CBL treatment. In TBI patients, CBL can also decrease TNF­α, IL­1ß, IL­6, and NF­κB levels. This result indicates that CBL­mediated inhibition of neuroinflammation and apoptosis ameliorated neuronal death after TBI. The neuroprotective capacity of CBL is partly dependent on the TLR signaling pathway. Conclusions: Taken together, the results of this study indicate that CBL can improve neurological outcomes and reduce neuronal death against neuroinflammation and apoptosis via the TLR signaling pathway in mice.

Ulinastatin alleviates early brain injury after intracerebral hemorrhage by inhibiting oxidative stress and neuroinflammation via ROS/MAPK/Nrf2 signaling pathway

Purpose: Spontaneous intracerebral hemorrhage (ICH) is still a major public health problem, with high mortality and disability. Ulinastatin (UTI) was purified from human urine and has been reported to be anti-inflammatory, organ protective, and antioxidative stress. However, the neuroprotection of UTI in ICH has not been confirmed, and the potential mechanism is unclear. In the present study, we aimed to investigate the neuroprotection and potential molecular mechanisms of UTI in ICH-induced early brain injury in a C57BL/6 mouse model. Methods: The neurological score, brain water content, neuroinflammatory cytokine levels, oxidative stress levels, and neuronal damage were evaluated. Results: UTI treatment markedly increased the neurological score, alleviated brain edema, decreased the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6, and NF-κB, decreased the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and upregulated the levels of glutathione (GSH), superoxide dismutase (SOD), and Nrf2. This finding indicated that UTI-mediated inhibition of neuroinflammation and oxidative stress alleviated neuronal damage after ICH. The neuroprotective capacity of UTI is partly dependent on the ROS/MAPK/Nrf2 signaling pathway. Conclusions: UTI improves neurological outcomes in mice and reduces neuronal death by protecting against neural neuroinflammation and oxidative stress.

Genetic Propensity to Neuroinflammatory CNS Diseases in Korean Children: Molecular Typing of HLA Class II

PURPOSE: The study was aimed to investigate immunogenetic peculiarities of neuroinflammatory CNS diseases in Korean children. METHODS: A total of 16 children with neuroinflammatory CNS diseases(9 males and 7 females; mean age 7.5+/-4.2 years) were consecutively recruited. Genomic typings were performed on their HLA DRB/HLA DQB genes using PCR-SSOP/SSP techniques with Gel immunoelectrophoresis. RESULTS: The frequencies of HLA-DRB1*14(38%), HLA-DRB1*15(25%), HLA-DRB3* 02(50%), HLA-DQB1*05(56%) and DQB1*06(44%) were significantly increased compared with a control group. The frequencies of HLA-DRB1*15(50%) and HLA-DQB1*06(63%) were significantly increased in children with ADEM and HLA-DRB3*0202(100%), HLA- DRB1*1302(67%), HLA-DRB3*0301(67%), and HLA-DQB1*0301(67%) in children with multiple sclerosis. HLA-DRB1*1401, HLA-DRB3*0202, and HLA-DQB1*0502 were found in children with acute necrotizing encephalopathy. CONCLUSION:HLA-DRB1*14, HLA-DRB1*15, HLA-DRB3*02, HLA-DQB1*05 and DQB1*06 may be associated with the susceptibility to neuroinflammatory CNS diseases in Korean children. The frequencies of HLA-DRB1*1501, HLA-DRB5*0101, HLA-DRB3* 0301, and HLA-DQB1*0602 in Korean children with multiple sclerosis were not as high as those in western children. However, HLA-DRB3*0202 was seen in all the children with multiple sclerosis. Our data may provide further evidence that the immunogenetic backgrounds of neuroinflammatory CNS diseases in Korean children are distinctly different from those in Westerns. However, further studies are needed.

Molecular Analysis of HLA Class ll-Associated Susceptibility to Neuroinflammatory Diseases in Korean Children

The work was done to study immunogenetic peculiarities of neuroinflammatory diseases among Korean children. A total of 13 children with neuroinflammatory diseases (8 males and 5 females; mean age 4.6+/-2.6 yr) were consecutively recruited. Genomic typing was performed on their HLA DRB/HLA DQB genes using PCR-SSOP/ SSP techniques with gel immunoelectrophoresis. The frequencies of HLA-DR1* 15 in children with acute disseminated encephalomyelitis (ADEM) (31%) and DQB1* 06 in other neuroinflammatory diseases (38%) were significantly increased compared with control subjects. The frequencies of HLA-DRB3*0202 (100%), HLA-DRB1*1302 (67%), HLA-DRB3*0301 (67%), and HLA-DQB1*0301 (67%) were significantly increased in children with multiple sclerosis and the frequencies of HLA-DRB1*1501 (40%) and HLA-DRB5*0101 (40%) were significantly increased in children with ADEM. HLA-DRB1*1401, HLA- DRB3*0202, and HLA-DQB1*0502 were found in children with acute necrotizing encephalopathy. In conclusion, HLA-DR1*15 and DQB1*06 may be involved in susceptibility to inflammation in Korean children. The frequencies of HLA-DRB1*1501, HLA-DRB5*0101, HLA-DRB3*0301, and HLADQB1* 0602 were not as high in Korean children with multiple sclerosis as in western children. However, HLA-DRB3*0202 was seen in all children with multiple sclerosis. Our data may provide further evidence that the immunogenetic background of neuroinflammatory diseases in Korean is distinctly different from the ones in western countries. Further studies are necessary to confirm this finding.