8-O-acetyl shanzhiside methylester protects against sleep deprivation-induced cognitive deficits and anxiety-like behaviors by regulating NLRP3 and Nrf2 pathways in mice.

Sleep deprivation (SD) is prevalent throughout the world, which has negative effects on cognitive abilities, and causing mood alterations. 8-O-acetyl shanzhiside methylester (8-OaS), a chief component in Lamiophlomis rotata (L. rotata) Kudo, possesses potent neuroprotective properties and analgesic effects. Here, we evaluated the alleviative effects of 8-OaS on memory impairment and anxiety in mice subjected to SD (for 72-h). Our results demonstrated that 8-OaS (0.2, 2, 20 mg/kg) administration dose-dependently ameliorated behavioral abnormalities in SD mice, accompanied with restored synaptic plasticity and reduced shrinkage and loss of hippocampal neurons. 8-OaS reduced the inflammatory response and oxidative stress injury in hippocampus caused by SD, which may be related to inhibition of NLRP3 inflammasome-mediated inflammatory process and activation of the Nrf2/HO-1 pathway. SD also led to increases in the expressions of TLR-4/MyD88, active NF-κB, pro-IL-1ß, TNFα and MDA, as well as a decrease in the level of SOD in mice hippocampus, which were reversed by 8-OaS administration. Moreover, our molecular docking analyses showed that 8-OaS also has good affinity for NLRP3 and Nrf2 signaling pathways. These results suggested that 8-OaS could be used as a novel herbal medicine for the treatment of sleep loss and for use as a structural base for developing new drugs.

Scutellarin ameliorates the stress-induced anxiety-like behaviors in mice by regulating neurotransmitters.

Anxiety disorders are a common frequently psychiatric symptom in patients that lead to disruption of daily life. Scutellarin (Scu) is the main component of Erigeron breviscapus, which has been used as a neuroprotective agent against glutamate-induced excitotoxicity. However, the potential effect of Scu on the stress-related neuropsychological disorders has not been clarified. In this study, Anxiety-like behavior was induced by acute restraint stress in mice. Scu were injected intraperitoneally (twice daily, 3 days). Results showed that Scu exhibited good protective activity on mice by decreasing transmitter release levels. Restraint stress caused significant anxiety like behavior in mice. Treatment of Scu could significantly improve the moving time of open arms in Elevated Plus Maze and central time on open field test. Scu treatment suppressed action potential firing frequency, restored excessive presynaptic quantal release, and down-regulated glutamatergic receptor expression levels in the prefrontal cortex (PFC) of stressed mice. GABAA Rα1 and GABAA γ2 expression in the brain PFC tissues of mice were nearly abrogated by Scu treatment. In stress-induced anxiety mice, stress can increase the frequency of mini excitatory postsynaptic currents (mEPSC), which can be reversed by Scu treatment. Therefore, Scu has a potent anxiolytic activity and may be valuable for the treatment of stress-induced anxiety disorders.

Gastrodin relieved complete Freund's adjuvant-induced spontaneous pain by inhibiting inflammatory response.

The analgesic effects of gastrodin (GAS), an active component derived from the Chinese herb Tian ma (Gastrodia elata Blume), on chronic inflammatory pain of mice and the involved molecular mechanisms were investigated. GAS significantly attenuated mice chronic inflammatory pain induced by hindpaw injection of complete Freund's adjuvant (CFA) and the accompanying anxiety-like behaviors. GAS administration reduced CFA-induced up-regulation of GluR1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, GluN2A- and GluN2B-containing N-methyl-d-aspartate (NMDA) receptors, and Ca2+/calmodulin-dependent protein kinase II-alpha (CaMKII-α) in the anterior cingulate cortex (ACC). The GluN2A and GluN2B subunits of NMDA receptors, the GluR1 type of AMPA receptor, and CaMKII-α are key molecules responsible for neuroplasticity involved in chronic pain and the accompanying anxiety. Moreover, GAS administration reduced the activation of astrocyte and microglia and the induction of TNF-α and IL-6 in the ACC of the CFA-injected mice. Therefore, GAS administration relieved chronic pain, exerted anxiolytic effects by regulating neuroplasticity molecules, and attenuated the inflammatory response by reducing the induction of TNF-α and IL-6 in the ACC of the CFA-injected mice.

Silibinin Prevents Autophagic Cell Death upon Oxidative Stress in Cortical Neurons and Cerebral Ischemia-Reperfusion Injury.

Neuronal apoptosis and oxidative stress are involved in most of the neurodegenerative diseases, promoting neuron survival is critical for therapy. Silibinin (SLB), which is derived from the seeds of Silybinisus laborinum L., has been widely used as an antioxidant. Here we tested the neuroprotective effects of SLB and the involved molecular mechanisms. We demonstrated that SLB promoted neuron viability upon hydrogen peroxide (H2O2) challenge and reduced hypoxia/ischemia injury in the middle cerebral artery occlusion (MCAO) mouse model. SLB reversed the decreased level of procaspase-3 and balanced Bcl-2 and Bax expression upon H2O2 insult to inhibit cell apoptosis. Furthermore, SLB suppressed the activation of autophagy by decreasing microtubule-associated protein 1 light chain 3 (LC3-II) and Beclin-1 levels under oxidative stress accordingly. SLB phosphorylated protein kinase B (Akt-1) at Ser473 in a time- and dose-dependent manner. The inhibitor for phosphoinositide-3-kinase (PI3K) wortmannin abrogated SLB-induced phosphorylation of Akt-1 and mTOR, decreased the suppression of autophagy, and therefore abolished SLB-mediated neuroprotection. All the data suggested that SLB protected neurons by inhibiting both the mitochondrial and autophagic cell death pathways. This study opens new avenues for the use of SLB in treatment of central nervous system (CNS) diseases in which oxidative stress plays a major role in disease pathogenesis. Given that it occurs naturally with low toxicity and pleiotropic effects that benefit the nervous system, SLB acts potentially as a novel therapy for ischemic injury.

Validation of HPLC method for the determination of polydatin in giant knotweed rhizome.

An HPLC method has been developed to determine polydatin in giant knotweed rhizome. In order to systematically validate the method, specificity, precision, linearity of reference solution and test solution, repeatability, reproducibility, accuracy, stability and robustness were measured. In the robustness test, a one-variable-at-a-time procedure was applied to evaluate the influence of slight variations in method factors, including the flow rate, the column temperature, the extraction time, and etc., on the assay result of polydatin. No significant differences were found when the process parameters changed during the experimental domain. And system suitability test limits were defined based on the robustness test. Results showed that the developed method was accurate, reproducible and robust.

Neuroprotective effects of oxymatrine against excitotoxicity partially through down-regulation of NR2B-containing NMDA receptors.

Oxymatrine (OMT) is a major bioactive component derived from Sophora flavescens Ait (kushen), which is widely used in Chinese medicine. Recent studies have shown that it has neuroprotective effects; however, its underlying mechanisms remain unclear. We focus on the mechanisms of pharmacologic action in OMT by detecting its pharmacological properties against focal cerebral ischemia in vivo and NMDA-induced neurotoxicity in vitro. OMT prevented cerebral ischemic injury in mice induced via a 2 h middle cerebral artery occlusion and a 24 h reperfusion, in vivo. In vitro cultured neurons challenged with N-methyl-D-aspartate (NMDA, 200 µM) for 30 min showed significant decrease in the viability of neurons; however, OMT was able to protect neurons against induced neurotoxicity via NMDA exposure. Western blot analysis revealed that OMT decreased the expression of Bax and repaired the balance of pro- and anti-apoptotic proteins. Furthermore, OMT significantly reversed the up-regulation of NR2B and inhibited the calcium overload in the cultured neurons after challenging the NMDA. OMT showed partial protection in the cortical neurons via down-regulation of NR2B containing NMDA receptors and up-regulation of Bcl-2 family. Our results provide new insights into the development of natural therapeutic anti-oxidants against ischemia.