N-acetylcysteine facilitates extinction of cued fear memory in rats via reestablishing basolateral amygdala glutathione homeostasis.

Individual differences in the development of uncontrollable fear in response to traumatic stressors have been observed in clinic, but the underlying mechanisms remain unknown. In the present study we first conducted a meta-analysis of published clinical data and found that malondialdehyde, an oxidative stress biomarker, was significantly elevated in the blood of patients with fear-related anxiety disorders. We then carried out experimental study in rats subjected to fear conditioning. We showed that reestablishing redox homeostasis in basolateral amygdale (BLA) after exposure to fear stressors determined the capacity of learned fear inhibition. Intra-BLA infusion of buthionine sulfoximine (BSO) to deplete the most important endogenous antioxidant glutathione (GSH) blocked fear extinction, whereas intra-BLA infusion of dithiothreitol or N-acetylcysteine (a precursor of GSH) facilitated extinction. In electrophysiological studies conducted on transverse slices, we showed that fear stressors induced redox-dependent inhibition of NMDAR-mediated synaptic function, which was rescued by extinction learning or reducing agents. Our results reveal a novel pharmacological strategy for reversing impaired fear inhibition and highlight the role of GSH in the treatment of psychiatric disorders.

S-methyl-L-cysteine Protects against Antimycin A-induced Mitochondrial Dysfunction in Neural Cells via Mimicking Endogenous Methionine-centered Redox Cycle.

Mitochondrial superoxide overproduction is believed to be responsible for the neurotoxicity associated with neurodegeneration. Mitochondria-targeted antioxidants, such as MitoQ, have emerged as potentially effective antioxidant therapies. Methionine sulfoxide reductase A (MsrA) is a key mitochondrial-localized endogenous antioxidative enzyme and it can scavenge oxidizing species by catalyzing the methionine (Met)-centered redox cycle (MCRC). In this study, we observed that the natural L-Met acted as a good scavenger for antimycin A-induced mitochondrial superoxide overproduction in PC12 cells. This antioxidation was largely dependent on the Met oxidase activity of MsrA. S-methyl-L-cysteine (SMLC), a natural analogue of Met that is abundantly found in garlic and cabbage, could activate the Met oxidase activity of MsrA to scavenge free radicals. Furthermore, SMLC protected against antimycin A-induced mitochondrial membrane depolarization and alleviated 1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity. Thus, our data highlighted the possibility for SMLC supplement in the detoxication of mitochondrial damage by activating the Met oxidase activity of MsrA.

Risk factors and clinical characteristics of tacrolimus-induced acute nephrotoxicity in children with nephrotic syndrome: a retrospective case-control study.

PURPOSE: Acute nephrotoxicity is a common adverse reaction of tacrolimus therapy; however, its risk factors in pediatric nephrotic syndrome (NS) remain to be evaluated. The objective of this study was to investigate the risk factors and characteristics of tacrolimus-induced acute nephrotoxicity in children with NS. METHODS: Past records of children with NS admitted to our hospital from 2014 to 2018 were reviewed. The incidence and characteristics of nephrotoxicity were analyzed. Multivariate logistic regression analysis was used to identify the risk factors of nephrotoxicity. A clinically applicable risk score was developed and validated. RESULTS: Tacrolimus-induced nephrotoxicity occurred in 25 of 129 patients, 13 patients were grade 1, and the renal function was recovered in 22 patients. Multivariate regression analysis showed that the maximum trough concentrations (C12h) of tacrolimus (OR, 1.48; 95% CI, 1.16 to 1.88; P < 0.001), huaiqihuang granules (OR, 0.095; 95% CI, 0.014 to 0.66; P = 0.017), and diarrhea (OR, 22.00; 95% CI, 1.58 to 306.92; P = 0.022) were independently associated with tacrolimus-induced nephrotoxicity. The maximum C12h were significantly higher in patients with nephrotoxicity (median 9.0 ng/ml) and the cut-off value for acute nephrotoxicity was 6.5 ng/ml. The area under the receiver operating characteristic curve was 0.821 for the proposed model based on the observations used to create the model and 0.817 obtained from k-fold cross-validation. CONCLUSIONS: High trough concentration of tacrolimus and diarrhea can potentiate the risk of tacrolimus-induced acute nephrotoxicity in children with NS, while huaiqihuang granules can protect this condition.

Rapid Antidepressant Effect of Hydrogen Sulfide: Evidence for Activation of mTORC1-TrkB-AMPA Receptor Pathways.

AIMS: We asked whether hydrogen sulfide (H2S), as the third gaseous mediator, provided fast antidepressant effect on major depressive disorders and underlying mechanisms. RESULTS: The decreased level of H2S was detected in the hippocampus of chronic unpredictable mild stress (CUMS)-treated rats. Acute administration of H2S either by H2S inhalation or by the donor NaHS produced a rapid antidepressant-like behavioral effect. Further investigation demonstrated that this effect of H2S was mediated by reversing the CUMS-induced decrease in dendritic spine density and required the activation of mammalian target of rapamycin (mTOR)C1 and neurotrophic TrkB receptors, which proceeded to increase synaptic protein expression, including postsynaptic density protein 95, synaptophysin, and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor GluR1/2 subunit. INNOVATION: This study provides the first direct evidence for detecting the decreased H2S in hippocampus of CUMS rats and the biological significance of H2S in treating major depression. CONCLUSION: Our data demonstrate that H2S activates mTORC1 signaling cascades and thereby produces fast-onset antidepressant effect. The study provides a profound insight into H2S or its donors as potent preventive and therapeutic agents for intervention of depression. Antioxid. Redox Signal. 27, 472-488.

Activity-Dependent Sulfhydration Signal Controls N-Methyl-D-Aspartate Subtype Glutamate Receptor-Dependent Synaptic Plasticity via Increasing d-Serine Availability.

AIMS: Reactive sulfur species, including hydrogen sulfide (H2S) and its oxydates, have been raised as novel redox signaling molecules. The present study aimed at examining whether endogenous sulfhydration signal is required for long-term potentiation (LTP), a cellular model for memory. RESULTS: In this study, we found that increased synaptic activity triggered sulfide generation and protein sulfhydration. Activity-triggered sulfide production was essential for N-methyl-D-aspartate subtype glutamate receptor (NMDAR)-dependent LTP via maintaining the availability of d-serine, a primary coagonist for synaptic NMDARs. Genetic knockdown of cystathionine ß-synthase, not cystathionine γ-lyase, impaired LTP. H2S increased NMDAR-dependent LTP via sulfhydration and disinhibition of serine racemase (SR), a main synthetase of d-serine. We found that polysulfides also increased NMDAR-dependent LTP and NMDAR activity. In aged rats, the level of H2S and SR sulfhydration decreased significantly. Exogenous supplement of H2S restored the sulfhydration of SR, followed by the improvement of age-related deficits in LTP. Furthermore, boost of H2S signal in vivo improves hippocampus-dependent memory. Innovation and Conclusion: Our results provide a direct evidence for the biological significance of endogenous sulfhydration signal in synaptic plasticity. Exogenous supplement of H2S could be considered as the new therapeutic approach for the treatment of neurocognitive dysfunction after aging. Antioxid. Redox Signal. 27, 398-414.

Dimethyl sulfide protects against oxidative stress and extends lifespan via a methionine sulfoxide reductase A-dependent catalytic mechanism.

Methionine (Met) sulfoxide reductase A (MsrA) is a key endogenous antioxidative enzyme with longevity benefits in animals. Only very few approaches have been reported to enhance MsrA function. Recent reports have indicated that the antioxidant capability of MsrA may involve a Met oxidase activity that facilities the reaction of Met with reactive oxygen species (ROS). Herein, we used a homology modeling approach to search the substrates for the oxidase activity of MsrA. We found that dimethyl sulfide (DMS), a main metabolite that produced by marine algae, emerged as a good substrate for MsrA-catalytic antioxidation. MsrA bounds to DMS and promoted its antioxidant capacity via facilitating the reaction of DMS with ROS through a sulfonium intermediate at residues Cys72, Tyr103, and Glu115, followed by the release of dimethyl sulfoxide (DMSO). DMS reduced the antimycin A-induced ROS generation in cultured PC12 cells and alleviated oxidative stress. Supplement of DMS exhibited cytoprotection and extended longevity in both Caenorhabditis elegans and Drosophila. MsrA knockdown abolished the cytoprotective effect and the longevity benefits of DMS. Furthermore, we found that the level of physiologic DMS was at the low micromolar range in different tissues of mammals and its level decreased after aging. This study opened a new window to elucidate the biological role of DMS and other low-molecular sulfides in the cytoprotection and aging.

Dimethyl sulfide, a metabolite of the marine microorganism, protects SH-SY5Y cells against 6-hydroxydopamine and MPP+-induced apoptosis / 中国药理学与毒理学杂志

Dimethyl sulfide (DMS) has been historically recognized as a metabolite of the marine microorganism or a disgusting component for the smell of halitosis patients. In our recent study, DMS has been identified as a cytoprotectant that protects against oxidative-stress induced cell death and aging. We found that at near- physiological concentrations, DMS reduced reactive oxygen species (ROS) in cultured PC12 cells and alleviated oxidative stress. The radical-scavenging capacity of DMS at near-physiological concentration was equivalent to endogenous methionine(Met)-centered antioxidant defense. Methionine sulfoxidereductase A (MsrA), the key antioxidant enzyme in Met-centered defense, bound to DMS and promoted its antioxidant capacity via facilitating the reaction of DMS with ROS through a sulfonium intermediate at residues Cys72, Tyr103, Glu115, followed by the release of dimethyl sulfoxide (DMSO). MTT assay and trypan blue test indicated that supplement of DMS exhibited cytopro?tection against 6-hydroxydopamine and MPP + induced cell apoptosis. Furthermore, MsrA knockdown abolished the cytoprotective effect of DMS at near- physiological concentrations. The present study reveals new insight into the potential therapeutic value of DMS in Parkinson disease.

Sulfite triggers sustained calcium overload in cultured cortical neurons via a redox-dependent mechanism.

Sulfite is a compound commonly used as preservative in foods and pharmaceuticals. Many studies have examined the neurotoxicity of sulfite, but its effect on neuronal calcium homeostasis has not yet been reported. Here, we observed the effect of sulfite on the cytosolic free calcium concentration ([Ca(2+)]i) in cultured cortical neurons using Fura-2/AM based calcium imaging technique. Sulfite (250-1000µM) caused a sustained increase in [Ca(2+)]i in the neurons via a dose-dependent manner. In Ca(2+)-free solution, sulfite failed to increase [Ca(2+)]i. After the depletion of the intracellular calcium store, the effect of sulfite on the [Ca(2+)]i was largely abolished. Pharmacological inhibition of phospholipase C (PLC)-inositol 1,4,5-triphosphate (IP3) signaling pathway blocked sulfite-induced increase of [Ca(2+)]i. Interestingly, antioxidants such as trolox and dithiothreitol, abolished the increase of [Ca(2+)]i induced by sulfite. Exposure to sulfite triggered generation of sulfur- and oxygen-centered free radicals in neurons and increased oxidative stress both in the cultured cortical neurons and the prefrontal cortex of rats. Furthemore, sulfite decreased cell viability in cultured cortical neurons via a calcium-dependent manner. Thus, our current study suggests that the redox-dependent calcium overload triggered by sulfite in cortical neuronsmay be involved in its neurotoxicity.

HFS-Triggered AMPK Activation Phosphorylates GSK3ß and Induces E-LTP in Rat Hippocampus In Vivo.

BACKGROUND: The AMP-activated protein kinase (AMPK) is a sensor of cellular energy and nutrient status, with substantial amount of cross talk with other signaling pathways, including its phosphorylation by Akt, PKA, and GSK3ß. AIMS: Various signaling pathways and energy-consuming transport of glutamate receptors subunits are required in synaptic plasticity. However, it is unknown which energy sensors integrate the signaling pathways in these processes. In this article, we elucidated the role of AMPK activation and GSK3ß phosphorylation after HFS during the inducement of early-phase long-term potentiation (E-LTP). METHODS: Synaptic LTP in vivo was induced by high-frequency stimulation (HFS at 200 Hz at a 5-s interval). In addition, phosphorylation of AMPK and glycogen synthase kinase 3ß (GSK3ß) were measured using Western blotting. The amount of hippocampal AMP, ADP and ATP was measured by HPLC. RESULTS: We showed that the phosphorylation of AMPK and GSK3ß was significantly increased by HFS in vivo. HFS-induced AMPK activation occurred via increased (AMP + ADP)/ATP ratio and activation of Ca(2+) /calmodulin-dependent kinase kinase beta (CaMKKß). Pharmacological inhibition of AMPK by compound C (CC) prevented HFS-induced inhibitory phosphorylation of GSK3ß and the induction of LTP in dentate gyrus (DG) area in vivo. CONCLUSIONS: Our findings reveal that HFS-triggered AMPK activation phosphorylates GSK3ß and induces E-LTP in vivo.

Propranolol decreases retention of fear memory by modulating the stability of surface glutamate receptor GluA1 subunits in the lateral amygdala.

BACKGROUND AND PURPOSE: Posttraumatic stress disorder (PTSD) is a mental disorder with enhanced retention of fear memory and has profound impact on quality of life for millions of people worldwide. The ß-adrenoceptor antagonist propranolol has been used in preclinical and clinical studies for the treatment of PTSD, but the mechanisms underlying its potential efficacy on fear memory retention remain to be elucidated. EXPERIMENTAL APPROACH: We investigated the action of propranolol on the retention of conditioned fear memory, the surface expression of glutamate receptor GluA1 subunits of AMPA receptors and synaptic adaptation in the lateral amygdala (LA) of rats. KEY RESULTS: Propranolol attenuated reactivation-induced strengthening of fear retention while reducing enhanced surface expression of GluA1 subunits and restoring the impaired long-term depression in LA. These effects of propranolol were mediated by antagonizing reactivation-induced enhancement of adrenergic signalling, which activates PKA and calcium/calmodulin-dependent protein kinase II and then regulates the trafficking of AMPA receptors via phosphorylation of GluA1 subunits at the C-terminus. Both i.p. injection and intra-amygdala infusion of propranolol attenuated reactivation-induced enhancement of fear retention. CONCLUSIONS AND IMPLICATIONS: Reactivation strengthens fear retention by increasing the level of noradrenaline and promotes the surface expression of GluA1 subunits and the excitatory synaptic transmission in LA. These findings uncover one mechanism underlying the efficiency of propranolol on retention of fear memories and suggest that ß-adrenoceptor antagonists, which act centrally, may be more suitable for the treatment of PTSD.

Methionine sulfoxide reductase A negatively controls microglia-mediated neuroinflammation via inhibiting ROS/MAPKs/NF-κB signaling pathways through a catalytic antioxidant function.

AIMS: Oxidative burst is one of the earliest biochemical events in the inflammatory activation of microglia. Here, we investigated the potential role of methionine sulfoxide reductase A (MsrA), a key antioxidant enzyme, in the control of microglia-mediated neuroinflammation. RESULTS: MsrA was detected in rat microglia and its expression was upregulated on microglial activation. Silencing of MsrA exacerbated lipopolysaccharide (LPS)-induced activation of microglia and the production of inflammatory markers, indicating that MsrA may function as an endogenous protective mechanism for limiting uncontrolled neuroinflammation. Application of exogenous MsrA by transducing Tat-rMsrA fusion protein into microglia attenuated LPS-induced neuroinflammatory events, which was indicated by an increased Iba1 (a specific microglial marker) expression and the secretion of pro-inflammatory cytokines, and this attenuation was accompanied by inhibiting multiple signaling pathways such as p38 and ERK mitogen-activated protein kinases (MAPKs) and nuclear factor kappaB (NF-κB). These effects were due to MsrA-mediated reactive oxygen species (ROS) elimination, which may be derived from a catalytic effect of MsrA on the reaction of methionine with ROS. Furthermore, the transduction of Tat-rMsrA fusion protein suppressed the activation of microglia and the expression of pro-inflammatory factors in a rat model of neuroinflammation in vivo. INNOVATION: This study provides the first direct evidence for the biological significance of MsrA in microglia-mediated neuroinflammation. CONCLUSION: Our data provide a profound insight into the role of endogenous antioxidative defense systems such as MsrA in the control of microglial function.

Pharmacokinetics of silybin nanoparticles in mice bearing SKOV-3 human ovarian carcinoma xenocraft.

The particle fabrication technique was used to fabricate monodisperse size and shape specific poly (lactide-co-glycolide) particles loaded with the silybin. Response surface methodology (RSM) using the central composite rotatable design (CCRD) model was used to optimize formulations of silybin nanoparticles. Further the optimized nanoparticles are characterized for particle size, zeta potential, surface morphology, entrapment efficiency, in-vitro drug release, silybin availability for tumor, plasma, lung, spleen, liver were determined. The significant findings were the optimal formulation of PLGA concentration 10 mg, PVA concentration 2000 and PET width of 6 gave rise to the EE of 88%, mean diameter of 223 nm and zeta potential of 25-mV. Release studies were investigated at pH 1.2 and pH 6.8. It was studied that lower the pH, faster the release of sylibin. The nanoparticles had~15-fold higher plasma exposure as measured by AUC contrasted to pure silybin. The nanoparticles had a 60% increase altogether tumor silybin presentation contrasted with pure silybin. Nanoparticles had higher silybin presentation in the spleen and liver contrasted with pure silybin suspension as expected for a nanoparticle formulation. The lung silybin presentation for the nanoparticle was additionally 2-fold higher than that of the pure silybin suspension. The results of pharmacokinetic parameters and oral bioavailability data exhibited that drug-nanoparticle complex could enhance the oral absorption of silybin and as well as the use of particles with smaller feature size may be preferred to decrease clearance by organs of the mononuclear phagocyte system.

Regulation of emotional memory by hydrogen sulfide: role of GluN2B-containing NMDA receptor in the amygdala.

As an endogenous gaseous molecule, hydrogen sulfide (H2 S) has attracted extensive attention because of its multiple biological effects. However, the effect of H2 S on amygdala-mediated emotional memory has not been elucidated. Here, by employing Pavlovian fear conditioning, an animal model widely used to explore the neural substrates of emotion, we determined whether H2 S could regulate emotional memory. It was shown that the H2 S levels in the amygdala of rats were significantly elevated after cued fear conditioning. Both intraamygdala and systemic administrations of H2 S markedly enhanced amygdala-dependent cued fear memory in rats. Moreover, it was found that H2 S selectively increased the surface expression and currents of NMDA-type glutamate receptor subunit 2B (GluN2B)-containing NMDA receptors (NMDARs) in lateral amygdala of rats, whereas blockade of GluN2B-containing NMDARs in lateral amygdala eliminated the effects of H2 S to enhance amygdalar long-term potentiation and cued fear memory. These results demonstrate that H2 S can regulate amygdala-dependent emotional memory by promoting the function of GluN2B-containing NMDARs in amygdala, suggesting that H2 S-associated signaling may hold potential as a new target for the treatment of emotional disorders. In our study, the effect of hydrogen sulfide (H2 S) on amygdala-mediated emotional memory was investigated. It was found that H2 S could enhance amygdala-dependent emotional memory and long-term potentiation (LTP) in rats by selectively increasing the function of GluN2B-containing NMDA receptors in the amygdala. These results suggest that H2 S-associated signaling may be a new target for the treatment of emotional disorders.

[Pharmacophore identification of novel dual-target compounds targeting AChE and PARP-1].

Multi-target drugs attract increasing attentions for the therapy of complicated neurodegenerative diseases. In this study, a computer-assisted strategy was applied to search for multi-target compounds by the pharmacophore matching. This strategy has been successfully used to design dual-target inhibitor models against both the acetylcholinesterase (AChE) and poly (ADP-ribose) polymerase-1 (PARP-1). Based on two pharmacophore models matching and physicochemical properties filtering, one hit was identified which could inhibit AChE with IC50 value of (0.337 +/- 0.052) micromol x L(-1) and PARP-1 by 24.6% at 1 micromol x L(-1).

Aggravation of seizure-like events by hydrogen sulfide: involvement of multiple targets that control neuronal excitability.

AIMS: Epileptic seizures are well-known neurological complications following stroke, occurring in 3% of patients. However, the intrinsic correlation of seizures with stroke remains largely unknown. Hydrogen sulfide (H2 S) is a gas transmitter that may mediate cerebral ischemic injury. But the role of H2 S in seizures has not been understood yet. We examined the effect of H2 S on seizure-like events (SLEs) and underlying mechanisms. METHODS AND RESULTS: Pentylenetetrazole (PTZ)- and pilocarpine-induced rat epileptic seizure models were tested. Low-Mg(2+) /high-K(+) - and 4-aminopyridine (4-AP)-induced epileptic seizure models were examined using patch-clamp recordings in brain slices. It was found that NaHS aggravated both PTZ- and pilocarpine-induced SLEs in rats, while both low-Mg(2+) /high-K(+) - and 4-AP-induced SLEs were also exacerbated by NaHS in brain slices, which may be due to its regulation on the voltage-gated sodium channel, N-methyl-D-aspartic acid receptor (NMDAR), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) function. Furthermore, these effects were reversed by blocking voltage-gated sodium channel, NMDAR, and AMPAR. CONCLUSIONS: These results suggest a pathological role of increased H2 S level in SLEs in vivo and in vitro. Enzymes that control H2 S biosynthesis could be interesting targets for antiepileptic strategies in poststroke epilepsy treatment.

A specific and rapid colorimetric method to monitor the activity of methionine sulfoxide reductase A.

Considerable evidence indicates that methionine sulfoxide (MetO) reductase A (MsrA) plays an important role in cytoprotection against oxidative stress and serves as a potential drug target. To screen for MsrA regulators, a rapid and specific assay to monitor MsrA activity is required. Most of current assays for MsrA activity are based on the reduction of radioactive substrates such as [3H]-N-acetyl-MetO or fluorescent derivatives such as dimethylaminoazo-benzenesulfonyl-MetO. However, these assays require extraction procedures and special instruments. Here, we developed a specific colorimetric microplate assay for testing MsrA activity quickly, which was based on the fact that MsrA can catalyze the reduction of methyl sulfoxides and simultaneously oxidize dithiothreitol (DTT), whose color can be produced by reacting with Ellman's reagent (dithio-bis-nitrobenzoic acid, DTNB). The corresponding absorbance change at 412nm was recorded with a microplate reader as the reaction proceeded. This method to monitor MsrA activity is easy to handle. Our findings may serve as a rapid method for the characterization of recombinant enzyme and for the screening of enzyme inhibitors, pharmacological activators, gene expression regulators and novel substrates.

Validation of the European Organization for Research and Treatment of Cancer cervical cancer module for Chinese patients with cervical cancer.

PURPOSE: The aim of our study was to assess, for the first time, the validity, reliability, and acceptability of the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life questionnaire (QLQ) cervical cancer module (CX24) in Chinese cervical cancer patients. PATIENTS AND METHODS: One hundred fifteen outpatients with cervical cancer in the First Affiliated Hospital of Xinxiang Medical University from May 2013 to July 2013 were included in this study. All participants self-administered the EORTC QLQ-CX24 and the core questionnaire (EORTC QLQ-C30), and the Karnofsky Performance Scale was performed to evaluate scores. Data were analyzed with Cronbach's α coefficient, Pearson correlation test, multitrait scaling analysis, and Mann-Whitney U test. RESULTS: Scale reliability was confirmed by Cronbach's α coefficients for internal consistency, which ranged from 0.71 to 0.82. Convergent and discriminant validity were confirmed by multitrait scaling analysis, which revealed three (3.4%) scaling errors for symptom experience scales and zero (0%) for body image as well as sexual/vaginal functioning scales. Higher missing value rate occurred in sexuality-related items. The clinical validity of the Chinese version of the EORTC QLQ-CX24 was demonstrated by the ability to discriminate among patients in different International Federation of Gynecology and Obstetrics stages. CONCLUSION: The EORTC QLQ-CX24 was proved to be a reliable and valid instrument with which to measure the quality of life in cervical cancer patients in the People's Republic of China.

The inhibitory effect of Binens bipinnata L. extract on U14 tumour in mice.

The objective of this paper was to study the in vitro and in vivo inhibitory effect of Bidens bipinnata L. extract on growth of cervical carcinoma U14 cells. MTT method was used to determine the inhibitory effect of Bidens bipinnata L. extract on U14 tumour cells, and the effects of Bidens bipinnata L. extract on inhibition rate of solid tumour and life prolongation rate of ascites tumour were observed through the establishment of two animal models of mouse cervical carcinoma U14 solid tumour and ascites tumour. In the in vitro MTT assay, the inhibition rate gradually increased with the increase of dose of Bidens bipinnata L. and the extension of time. Its inhibition rate was 70.44% at a concentration of 80µg/L. Solid tumour inhibition rates in the high- and low-dose groups and cisplatin group were 49.13%, 2.26% and 75.72% respectively; life prolongation rates in each ascites tumour group were 63.63%, 34.86% and 87.34% respectively. The Bidens bipinnata L. extract has a certain inhibitory effect on growth of mouse cervical carcinoma U14.

Orexin-A activates hypothalamic AMP-activated protein kinase signaling through a Ca²âº-dependent mechanism involving voltage-gated L-type calcium channel.

Hypothalamic AMP-activated protein kinase (AMPK) and orexins/hypocretins are both involved in the control of feeding behavior, but little is known about the interaction between these two signaling systems. Here, we demonstrated that orexin-A elicited significant activation of AMPK in the arcuate nucleus (ARC) of the hypothalamus by elevating cytosolic free Ca²âº involving extracellular calcium influx. Electrophysiological results revealed that orexin-A increased the L-type calcium current via the orexin receptor-phospholipase C-protein kinase C signaling pathway in ARC neurons that produce neuropeptide Y, an important downstream effector of orexin-A's orexigenic effect. Furthermore, the L-type calcium channel inhibitor nifedipine attenuated orexin-A-induced AMPK activation in vitro and in vivo. We found that inhibition of AMPK by either compound C (6-[4-[2-(1-piperidinyl)ethoxy]phenyl]-3-(4-pyridinyl)-pyrazolo[1,5-a]pyrimidine) or the ATP-mimetic 9-ß-D-arabinofuranoside prevented the appetite-stimulating effect of orexin-A. This action can be mimicked by nifedipine, the blocker of the L-type calcium channel. Our results indicated that orexin-A activates hypothalamic AMPK signaling through a Ca²âº-dependent mechanism involving the voltage-gated L-type calcium channel, which may serve as a potential target for regulating feeding behavior.

Resveratrol preconditioning increases methionine sulfoxide reductases A expression and enhances resistance of human neuroblastoma cells to neurotoxins.

Methionine sulfoxide reductases A (MsrA) has been postulated to act as a catalytic antioxidant system involved in the protection of oxidative stress-induced cell injury. Recently, attention has turned to MsrA in coupling with the pathology of Parkinson's disease, which is closely related to neurotoxins that cause dopaminergic neuron degeneration. Here, we firstly provided evidence that pretreatment with a natural polyphenol resveratrol (RSV) up-regulated the expression of MsrA in human neuroblastoma SH-SY5Y cells. It was also observed that the expression and nuclear translocation of forkhead box group O 3a (FOXO3a), a transcription factor that activates the human MsrA promoter, increased after RSV pretreatment. Nicotinamide , an inhibitor of silent information regulator 1 (SIRT1), prevented RSV-induced elevation of FOXO3a and MsrA expression, indicating that the effect of RSV was mediated by a SIRT1-dependent pathway. RSV preconditioning increased methionine sulfoxide(MetO)-reducing activity in SH-SY5Y cells and enhanced their resistance to neurotoxins, including chloramine-T and 1-methyl-4-phenyl-pyridinium. In addition, the enhancement of cell resistance to neurotoxins caused by RSV preconditioning can be largely prevented by MsrA inhibitor dimethyl sulfoxide. Our findings suggest that treatment with polyphenols such as RSV can be used as a potential regulatory strategy for MsrA expression and function.