Potential neuroprotective of trans-resveratrol a promising agent tempeh and soybean seed coats-derived against beta-amyloid neurotoxicity on primary culture of nerve cells induced by 2-methoxyethanol / Potencial neuroprotetor do agente trans-resveratrol em cascas de sementes de soja e tempê derivadas da neurotoxicidade beta-amiloide na cultura primária de células nervosas induzidas pelo 2-metoxietanol

Resveratrol, a natural polyphenol found in tempeh, has not been investigated especially in vitro as a neuroprotective agent against 2-methoxyethanol (2-ME)-induced beta-amyloid cytotoxicity. Beta amyloid peptides (Aß) could initiate neurotoxic events and neuron-inflammatory response via microglial activation. However, it remains unknown whether the neurotoxic effect of beta-amyloid and/or associated with the potential of 2-ME to induce neurotoxic effects on primary culture of nerve cells induced by 2-ME. This study investigated potential neuroprotective of trans-resveratrol a promising agent tempeh and soybean seed coats-derived against betaamyloid cytotoxicity on primary culture of nerve cells induced by 2-methoxyethanol. Biotium and MTT assays were used to analyze neurons, which were isolated from the cerebral cortex of fetal mice at gestation day 19 (GD-19). A standard solution of 2-methoxyethanol was dosed at 10 µL. The cultured cells were randomly divided into the following groups: (1) 2-ME group + resveratrol standard, (2) 2-ME group + resveratrol isolated from tempeh, (3) 2-ME group + resveratrol isolated from soybean seed coats, and (4) the control group, without the addition of either 2-ME or resveratrol. Exposure of the primary cortical neuron cells to beta-amyloid monoclonal antibody pre-incubated for 24 h with 10 µL of 4.2 µg/mL resveratrol and 7.5 mmol/l 2-methoxy-ethanol additions. Here, we report that the addition of 2-ME and resveratrol (standard and isolated from tempeh) of cell culture at concentrations of 1.4, 2.8 and 4.2 µg/mL showed that the majority of neurons grew well. In contrast, after exposure to 2-ME and Beta-amyloid, showed that glial activated. These findings demonstrate a role for resveratrol in neuroprotective-neurorescuing action.

O resveratrol, um polifenol natural encontrado em tempê, não foi investigado apenas in vitro como agente neuroprotetor contra a citotoxicidade beta-amiloide induzida por 2-metoxietanol (2-ME). Os peptídeos betaamiloides (Aß) podem iniciar eventos neurotóxicos e resposta inflamatória dos neurônios via ativação microglial. No entanto, permanece desconhecido se o efeito neurotóxico do peptídeo beta-amiloide associado ao potencial do 2-ME causa efeitos neurotóxicos na cultura primária de células nervosas induzidas pelo 2-ME. Este estudo investigou o potencial neuroprotetor do agente trans-resveratrol em cascas de sementes de soja e tempê derivadas da citotoxicidade beta-amiloide na cultura primária de células nervosas induzidas pelo 2-metoxietanol. Ensaios de biotium e MTT foram utilizados para analisar os neurônios isolados do córtex cerebral de camundongos fetais no dia da gestação 19 (GD-19). As células cultivadas foram divididas aleatoriamente nos seguintes grupos: (1) grupo 2-ME + padrão de resveratrol; (2) grupo 2-ME + resveratrol isolado de tempê; (3) grupo 2-ME + resveratrol isolado de cascas de sementes de soja; e (4) grupo controle, sem a adição de 2-ME ou resveratrol. Houve exposição das células primárias dos neurônios corticais ao anticorpo monoclonal beta-amiloide pré-incubado por 24 horas, com 10 µL de 4,2 µg/mL de resveratrol, e adições de 7,5 mmol/l de 2-metoxietanol. A adição de 2-ME e resveratrol (padrão e isolado do tempê) da cultura de células nas concentrações de 1,4, 2,8 e 4,2 µg/mL mostrou que a maioria dos neurônios cresceu bem. Por outro lado, após a exposição ao 2-ME e beta-amiloide, a glia foi ativada. Esses achados demonstram um papel do resveratrol na ação neuroprotetora e de neurorresgate.

Ginsenoside Rg_1 protects PC12 cells against Aβ-induced injury through promotion of mitophagy by PINK1/parkin activation / 中国中药杂志

Amyloid β-protein(Aβ) deposition in the brain is directly responsible for neuronal mitochondrial damage of Alzheimer's disease(AD) patients. Mitophagy, which removes damaged mitochondria, is a vital mode of neuron protection. Ginsenoside Rg_1(Rg_1), with neuroprotective effect, has displayed promising potential for AD treatment. However, the mechanism underlying the neuroprotective effect of Rg_1 has not been fully elucidated. The present study investigated the effects of ginsenoside Rg_(1 )on the autophagy of PC12 cells injured by Aβ_(25-35) to gain insight into the neuroprotective mechanism of Rg_1. The autophagy inducer rapamycin and the autophagy inhi-bitor chloroquine were used to verify the correlation between the neuroprotective effect of Rg_1 and autophagy. The results showed that Rg_1 enhanced the viability and increased the mitochondrial membrane potential of Aβ-injured PC12 cells, while these changes were blocked by chloroquine. Furthermore, Rg_(1 )treatment increased the LC3Ⅱ/Ⅰ protein ratio, promoted the depletion of p62 protein, up-regulated the protein levels of PINK1 and parkin, and reduced the amount of autophagy adaptor OPTN, which indicated the enhancement of autophagy. After the silencing of PINK1, a key regulatory site of mitophagy, Rg_1 could not increase the expression of PINK1 and parkin or the amount of NDP52, whereas it can still increase the LC3Ⅱ/Ⅰ protein ratio and promote the depletion of OPTN protein which indicated the enhancement of autophagy. Collectively, the results of this study imply that Rg_1 can promote autophagy of PC12 cells injured by Aβ, and may reduce Aβ-induced mitochondrial damage by promoting PINK1-dependent mitophagy, which may be one of the key mechanisms of its neuroprotective effect.

Ursolic acid attenuates beta-amyloid-induced memory impairment in mice / Ácido ursólico atenua a perda de memória induzida por beta-amilóide em ratos

ABSTRACT Objective Increasing evidence demonstrates that oxidative stress and inflammatory are involved in amyloid β (Aβ)-induced memory impairments. Ursolic acid (UA), a triterpenoid compound, has potent anti-inflammatory and antioxidant activities. However, it remains unclear whether UA attenuates Aβ-induced neurotoxicity. Method The aggregated Aβ25-35 was intracerebroventricularly administered to mice. Results We found that UA significantly reversed the Aβ25-35-induced learning and memory deficits. Our results indicated that one of the potential mechanisms of the neuroprotective effect was attenuating the Aβ25-35-induced accumulation of malondialdehyde (MDA) and depletion of glutathione (GSH) in the hippocampus. Furthermore, UA significantly suppressed the upregulation of IL-1β, IL-6, and tumor necrosis-α factor levels in the hippocampus of Aβ25-35-treated mice. Conclusion These findings suggest that UA prevents memory impairment through amelioration of oxidative stress, inflammatory response and may offer a novel therapeutic strategy for the treatment of Alzheimer’s disease.

RESUMO Objetivo Há evidências crescentes de que o estresse oxidativo e a inflamação estão envolvidos na perda de memória induzida pelo peptídeo beta-amilóide (βA). O ácido ursólico (AU), um composto triterpenóide, apresenta atividades anti-inflamatórias e antioxidantes potentes. Entretanto, não se sabe ainda se o AU atenua a neurotoxicidade induzida pelo βA. Método O agregado βA 25-35 foi administrado aos ratos por via intracerebroventricular. Resultados Observou-se que o AU reverteu significativamente os déficits de aprendizado e de memória induzidos pelo βA 25-35. Portanto, um dos potenciais mecanismos do efeito neuroprotetor seria a atenuação do acúmulo de malondialdeído e a depleção de glutationa no hipocampo induzidos pelo βA 25-35. Além disso, o AU suprimiu significativamente a supra regulação dos níveis de IL-1β, IL-6 e do fator de necrose tumoral α no hipocampo dos ratos tratados com βA 25-35. Conclusão Esses achados sugerem que o AU previne a perda de memória através da melhora do estresse oxidativo e da resposta inflamatória, podendoproporcionar uma nova estratégia terapêutica para o tratamento da doença de Alzheimer.

Early phase of amyloid beta42-induced cytotoxicity in neuronal cells is associated with vacuole formation and enhancement of exocytosis

Amyloid beta (Abeta) neurotoxicity is believed to play a critical role in the pathogenesis of Alzheimer's disease (AD) mainly because of its deposition in AD brain and its neuronal toxicity. However, there have been discrepancies in Abeta-induced cytotoxicity studies, depending on the assay methods. Comparative analysis of Abeta42-induced in vitro cytotoxicity might be useful to elucidate the etiological role of Abeta in the pathogenesis of AD. In this study, MTT, CCK-8, calcein-AM/EthD-1 assays as well as thorough microscopic examinations were comparatively performed after Abeta42 treatment in a neuronal precursor cells (NT2) and a somatic cells (EcR293). Extensive formation of vacuoles was observed at the very early stage of Abeta42 treatment in both cells. Early observation of Abeta42 toxicity as seen in vacuole formation was also shown in MTT assay, but not in CCK-8 and calcein-AM/EthD-1 assays. In addition, Abeta42 treatment dramatically accelerated MTT formazan exocytosis, implying its effect on the extensive formation of cytoplasmic vacuoles. Abeta42 seems to cause indirect inhibition on the intracellular MTT reduction as well as vacuole formation and exocytosis enhancement. Following the acute cellular dysfunction induced by Abeta42, the prolonged treatment of micromolar concentration of Abeta42 resulted in slight inhibition on redox and esterase activity. The early Abeta42-induced vacuolated morphology and later chronic cytotoxic effect in neuronal cell might be linked to the chronic neurodegeneration caused by the accumulation of Abeta42 in AD patients' brain.

Oligodendrocytes damage in Alzheimer's disease: Beta amyloid toxicity and inflammation

Research on Alzheimer's disease (AD) focuses mainly on neuronal death and synaptic impairment induced by â-Amyloid peptide (Aâ), events at least partially mediated by astrocyte and microglia activation. However, substantial white matter damage and its consequences on brain function warrant the study of oligodendrocytes participation in the pathogenesis and progression of AD. Here, we analyze reports on oligodendrocytes' compromise in AD and discuss some experimental data indicative of Aâ toxicity in culture. We observed that 1 ìM of fibrilogenic Aâ peptide damages oligodendrocytes in vitro; while pro-inflammatory molecules (1 ìg/ml LPS + 1 ng/ml IFNã) or the presence of astrocytes reduced the Ab-induced damage. This agrees with our previous results showing an astrocyte-mediated protective effect over Aâ-induced damage on hippocampal cells and modulation of the activation of microglial cells in culture. Oligodendrocytes protection by astrocytes could be, either by reduction of Aâ fibrilogenesis/deposition or prevention of oxidative damage. Likewise, the decrease of Aâ-induced damage by proinflammatory molecules could reflect the production of trophic factors by activated oligodendrocytes and/or a metabolic activation as observed during myelination. Considering the association of inflammation with neurodegenerative diseases, oligodendrocytes impairment in AD patients could potentiate cell damage under pathological conditions.

The effect of beta-amyloid on neurons and the influence of glucocorticoid and age on such effect / 华中科技大学学报（医学）（英德文版）

To explore the relationship between beta-amyloid (A beta) and the pathogenesis of Alzheimer disease (AD), after injection of beta-amyloid into the rat brain, the apoptosis of nerve cells and acetylcholine (Ach) content in rat hippocampus were examined by employing TUNEL technique and base hydroxylamine colorimetry respectively. The influence of age and glucocorticoid on the neurotoxic effect of A beta was also analyzed. A beta peptide could strongly induce the apoptosis of neurons in hippocampus, cortex and striate body (P < 0.05 or P < 0.01). In addition, the senility and glucocorticoid pre-treatment could enhance the toxic effect of A beta (P < 0.05 or P < 0.01). It is concluded that A beta may play an important role in the pathogenesis of Alzheimer disease via its induction of apoptosis of neurons and by decreasing the content of the Ach.