ABSTRACT
Neuroinflammation is a key factor in cognitive dysfunction and neurodegenerative diseases such as Alzheimer's disease (AD), so inhibiting neuroinflammation is considered as a potential treatment for AD. Epigallocatechin-3-gallate (EGCG), a polyhydroxyphenol of green tea, has been found to exhibit anti-oxidative, anti-inflammatory and neuroprotective effects. The aim of this study was to investigate the inhibitory effect of EGCG on inflammation and its mechanism. In this study, BV2 cells were simultaneously exposed to lipopolysaccharides (LPS) and the amyloid-ß oligomer (AßO) to induce inflammatory microenvironments. Inflammatory cytokines and NLRP3 inflammasome-related molecules were detected by RT-PCR and Western Blot. The results show that EGCG inhibits LPS/AßO-induced inflammation in BV2 cells through regulating IL-1ß, IL-6, and TNF-α. Meanwhile, EGCG reduces the activation of the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome and levels of intracellular ROS in BV2 cells treated with LPS/AßO by affecting the mitochondrial membrane potential (MMP). Further research found that EGCG inhibited MMP through regulating thioredoxin-interacting protein (TXNIP) in LPS/AßO-induced neuroinflammation. In conclusion, EGCG may alleviate LPS/AßO-induced microglial neuroinflammation by suppressing the ROS/ TXNIP/ NLRP3 pathway. It may provide a potential mechanism underlying the anti-inflammatory properties of EGCG for alleviating AD.
Subject(s)
Amyloid beta-Peptides , Carrier Proteins , Catechin , Lipopolysaccharides , NLR Family, Pyrin Domain-Containing 3 Protein , Neuroinflammatory Diseases , Reactive Oxygen Species , Signal Transduction , Catechin/analogs & derivatives , Catechin/pharmacology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Lipopolysaccharides/toxicity , Animals , Amyloid beta-Peptides/toxicity , Mice , Reactive Oxygen Species/metabolism , Carrier Proteins/metabolism , Signal Transduction/drug effects , Neuroinflammatory Diseases/drug therapy , Neuroinflammatory Diseases/metabolism , Cell Line , Thioredoxins/metabolism , Microglia/drug effects , Microglia/metabolismABSTRACT
People of all ages could suffer from sleep disorders, which are increasingly recognized as common manifestations of neurologic disease. Acorus tatarinowii is a herb that has been used in traditional medicine to promote sleep. ß-asarone, as the main component of volatile oil obtained from Acorus tatarinowii, may be the main contributor to the sleeping-promoting efficacy of Acorus tatarinowii. In the study, adult male C57BL/6 mice were administered ß-asarone at 12.5 mg/kg, 25 mg/kg, and 50 mg/kg. Behavioral experiments showed that ß-asarone at 25 mg/kg could significantly improve sleep duration. It was also observed that the proportion of NREM (Non-Rapid Eye Movement) sleep increased considerably after administration of ß-asarone. In the PVN (paraventricular nucleus of hypothalamus) region of the hypothalamus, it was observed that the glutamate content decreased after ß-asarone treatment. At the same time, the expression of VGLUT2 (vesicular glutamate transporters 2) decreased while the expression of GAD65 (glutamic acid decarboxylase 65) and GABARAP (GABA Type A Receptor-Associated Protein) increased in the hypothalamus, suggesting that ß-asarone may suppress arousal by reducing glutamate and promoting transformation of glutamate to the inhibitory neurotransmitter GABA (γ-aminobutyric acid). This study is the first to focus on the association between ß-asarone and sleep, shedding perspectives for pharmacological applications of ß-asarone and providing a new direction for future research.