Shen Yuan extract exerts a hypnotic effect via the tryptophan/5-hydroxytryptamine/melatonin pathway in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Sleep plays a critical role in several physiologic processes, and sleep disorders increase the risk of depression, dementia, stroke, cancer, and other diseases. Stress is one of the main causes of sleep disorders. Ginseng Radix et Rhizoma and Polygalae Radix have been reported to have effects of calming the mind and intensifying intelligence in Chinese Pharmacopoeia. Traditional Chinese medicine prescriptions composed of Ginseng Radix et Rhizoma and Polygalae Radix (Shen Yuan, SY) are commonly used to treat insomnia, depression, and other psychiatric disorders in clinical practice. Unfortunately, the underlying mechanisms of the SY extract's effect on sleep are still unknown.

AIM OF THE STUDY

This study aimed to investigate the hypnotic effect of the SY extract in normal mice and mice with chronic restraint stress (CRS)-induced sleep disorders and elucidate the underlying mechanisms.

MATERIALS AND METHODS

The SY extract (0.5 and 1.0 g/kg) was intragastrically administered to normal mice for 1, 14, and 28 days and to CRS-treated mice for 28 days. The open field test (OFT) and pentobarbital sodium-induced sleep test (PST) were used to evaluate the hypnotic effect of the SY extract. Liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay were utilized to detect the levels of neurotransmitters and hormones. Molecular changes at the mRNA and protein levels were determined using real-time quantitative polymerase chain reaction and Western blot analysis to identify the mechanisms by which SY improves sleep disorders.

RESULTS

The SY extract decreased sleep latency and increased sleep duration in normal mice. Similarly, the sleep duration of mice subjected to CRS was increased by administering SY. The SY extract increased the levels of tryptophan (Trp) and 5-hydroxytryptamine (5-HT) and the expression of tryptophan hydroxylase 2 (TPH2) in the cortex of normal mice. The SY extract increased the Trp level, transcription and expression of estrogen receptor beta and TPH2 in the cortex in mice with sleep disorders by decreasing the serum corticosterone level, which promoted the synthesis of 5-HT. Additionally, the SY extract enhanced the expression of arylalkylamine N-acetyltransferase, which increased the melatonin level and upregulated the expressions of melatonin receptor-2 (MT2) and Cryptochrome 1 (Cry1) in the hypothalamus of mice with sleep disorders.

CONCLUSIONS

The SY extract exerted a hypnotic effect via the Trp/5-HT/melatonin pathway, which augmented the synthesis of 5-HT and melatonin and further increased the expressions of MT2 and Cry1.

Anti-inflammatory effect and pharmacokinetics of dehydroandrographolide, an active component of Andrographis paniculata, on Poly(I:C)-induced acute lung injury

Acute lung injury (ALI) is a common and critical respiratory disorder caused by various factors, with viral infection being the leading contributor. Dehydroandrographolide (DAP), a constituent of the Chinese herbal plant Andrographis paniculata, exhibits a range of activities including anti-inflammatory, in vitro antiviral and immune-enhancing effects. This study evaluated the anti-inflammatory effects and pharmacokinetics (PK) profile of DAP in ALI mice induced by intratracheal instillation of Poly(I:C) (PIC). The results showed that oral administration of DAP (10-40 mg/kg) effectively suppressed the increase in lung wet-dry weight ratio, total cells, total protein content, accumulation of immune cells, inflammatory cytokines and neutrophil elastase levels in bronchoalveolar lavage fluid of PIC-treated mice. DAP concentrations, determined by an LC-MS/MS method, in plasma after receiving DAP (20 mg/kg) were unchanged compared to those in normal mice. However, DAP concentrations and relative PK parameters in the lungs were significantly altered in PIC-treated mice, exhibiting a relatively higher maximum concentration, larger AUC, and longer elimination half-life than those in the lungs of normal mice. These results demonstrated that DAP could improve lung edema and inflammation in ALI mice, and suggested that lung injury might influence the PK properties of DAP, leading to increased lung distribution and residence. Our study provides evidence that DAP displays significant anti-inflammatory activity against viral lung injury and is more likely to distribute to damaged lung tissue.

Interferon lambda in respiratory viral infection: immunomodulatory functions and antiviral effects in epithelium

Type III interferon (IFN-λ), a new member of the IFN family, was initially considered to possess antiviral functions similar to those of type I interferon, both of which are induced via the JAK/STAT pathway. Nevertheless, recent findings demonstrated that IFN-λ exerts a nonredundant antiviral function at the mucosal surface, preferentially produced in epithelial cells in contrast to type I interferon, and its function cannot be replaced by type I interferon. This review summarizes recent studies showing that IFN-λ inhibits the spread of viruses from the cell surface to the body. Further studies have found that the role of IFN-λ is not only limited to the abovementioned functions, but it can also can exert direct and/or indirect effects on immune cells in virus-induced inflammation. This review focuses on the antiviral activity of IFN-λ in the mucosal epithelial cells and its action on immune cells and summarizes the pathways by which IFN-λ exerts its action and differentiates it from other interferons in terms of mechanism. Finally, we conclude that IFN-λ is a potent epidermal antiviral factor that enhances the respiratory mucosal immune response and has excellent therapeutic potential in combating respiratory viral infections.

Melatonin-related dysfunction in chronic restraint stress triggers sleep disorders in mice

Stress may trigger sleep disorders and are also risk factors for depression. The study explored the melatonin-related mechanisms of stress-associated sleep disorders on a mouse model of chronic stress by exploring the alteration in sleep architecture, melatonin, and related small molecule levels, transcription and expression of melatonin-related genes as well as proteins. Mice undergoing chronic restraint stress modeling for 28 days showed body weight loss and reduced locomotor activity. Sleep fragmentation, circadian rhythm disorders, and insomnia exhibited in CRS-treated mice formed sleep disorders. Tryptophan and 5-hydroxytryptamine levels were increased in the hypothalamus, while melatonin level was decreased. The transcription and expression of melatonin receptors were reduced, and circadian rhythm related genes were altered. Expression of downstream effectors to melatonin receptors was also affected. These results identified sleep disorders in a mice model of chronic stress. The alteration of melatonin-related pathways was shown to trigger sleep disorders.

Protective effect of ginsenoside Rb1 against chronic restraint stress (CRS)-induced memory impairments in rats

Ginsenoside Rb1 (Rb1) is one of the most active components found in ginseng and provides important benefits to the central nervous system, especially for the improvement of learning and memory. Previous studies demonstrated that Rb1 protected against scopolamine-induced amnesia and exhibited memory-enhancing effects in the SAMP8 mouse model. However, the effects of Rb1 against chronic restraint stress (CRS)-induced cognitive impairments, especially the role of Rg1 on the performance of reward directed instrumental conditioning have not been investigated. In this study, rats were subjected to CRS (6 h/day) for 28 days. Thereafter, behavioural tests including reward-directed instrumental conditioning task (RICT) and the Morris water maze (MWM) task were conducted. Administered of Rb1 (6.75 and 13.5 mg/kg, i.p.) remarkably ameliorated the memory impairments caused by CRS as evident from the results of RICT and MWM task, and this effect was accompanied by noticeable alterations in the levels of oxidative markers (superoxide dismutase, catalase, and lipid peroxidation) in the hippocampus. Additionally, Rb1 reduced the ratio of Bax:Bcl-2 and the expression of cleaved caspase-3 and cleaved caspase-9, increased the levels of synaptophysin (SYP) and postsynaptic density 95 (PSD95) and activated the BDNF/TrkB pathway in the hippocampus. In summary, the present study demonstrated that Rb1 rescues cognitive deficits induced by CRS is partially mediated by antagonizing oxidative stress and apoptosis, improving synaptic plasticity and restoring the BDNF/TrkB signalling pathway. This newly discovered effect of Rb1 sheds light on its applications in the development of therapeutic interventions to alleviate the deleterious effects of chronic stress.

Dammarane sapogenins alleviates depression-like behaviours induced by chronic social defeat stress in mice through the promotion of the BDNF signalling pathway and neurogenesis in the hippocampus

Chronic social defeat stress (CSDS) is a widely used behavioural paradigm of psychosocial stress that can be used to research the pathogenesis of depression and seek antidepressant drugs. Dammarane sapogenins (DS), the deglycosylated product of ginsenosides, has a wide range of biological activities, including immunomodulatory, antifatigue, antitumour and antidepressant activities. However, whether DS has antidepressant-like effects in a CSDS mouse model remains unknown. Therefore, the present study was conducted to evaluate the antidepressant properties of DS in CSDS mice and its underlying mechanisms. The results showed that the oral administration of DS (40 and 80 mg/kg) increased the time spent in the interaction zone in the social interaction test and the sucrose intake in the sucrose preference test, decreased the latency in the novelty-suppressed feeding test, and reduced the immobility time in both the tail suspension test and forced swimming test. Biochemical analyses of brain tissue and serum showed that DS treatment significantly decreased serum corticosterone levels and enhanced brain monoamine neurotransmitter levels in CSDS mice. In addition, an impairment in hippocampal neurogenesis that paralleled a reduced BDNF level in the hippocampus was observed in the mice that were subjected with CSDS for 3 weeks, while treatment with DS reversed these changes. Moreover, DS treatment significantly upregulated BDNF, pTrkB/TrkB, pAkt/Akt, pPI3K/PI3K, pCREB/CREB, pERK1/2/ERK1/2 and pmTOR/mTOR protein expression in the hippocampus. In conclusion, our results showed that DS exerts antidepressant-like effects in mice with CSDS-induced depression, that the effects may be mediated by the normalization of monoamine neurotransmitter levels, the prevention of HPA axis dysfunction and the impairment of hippocampal neurogenesis, and that this occurs partly through the ability of DS to enhance BDNF expression by increasing the TrkB/CREB/ERK pathway and the PI3K/AKT/mTOR pathway.

[The classification and MR imaging of scapholunate ligament injuries]

Objective: To explore the MRI characteristics of injuries of scapholunate ligament (SLL), and provide imaging basis for the early diagnosis and treatment of the injuries. Methods: A total of 20 healthy volunteers without wrist injuries and 30 patients who complained dorsoradial-sided wrist pain and were highly suspected as the injury of SLL underwent the wrist magnetic resonance examination and X-ray examination in Beijing Jishuitan Hospital from January 2013 to September 2017.All subjects underwent anterior and lateral radiographs of the wrist joint and examination on coronal T(1)WI scan and PD-FS on 3 planes respectively in a prone position.Then the MRI characteristics of 20 healthy volunteers and 30 patients with SLL injuries that confirmed by operation were analyzed.According to the comparative analysis of normal anatomy and Geissler grades, the injuries were graded and MRI features of different types of injuries were analyzed.At last, imaging findings were compared with surgical results. Results: Twenty healthy volunteers without injuries showed mainly in low signal intensity on T(1)WI and PD-FS images.According to Geissler grades, there were 11 GradeⅠ injuries (5 had triangular fibrocartilage complex (TFCC) and SLL injuries and 1 had fracture of scaphoid and SLL injuries simultaneously), 8 GradeⅡ injuries (2 had TFCC and SLL injuries, 1 had TFCC, lunotriquetral ligament (LTL) and SLL injuries and 1 had distal radius fracture, TFCC and SLL injuries simultaneously), 7 Grade Ⅲ injuries (3 had TFCC and SLL injuries, 2 had fracture of scaphoid and SLL injuries and 1 had TFCC, LTL and SLL injuries simultaneously) and 4 Grade Ⅳ injuries (2 had TFCC and SLL injuries and 1 had fracture of scaphoid and SLL injuries simultaneously) among 30 patients.A tear can be confidently diagnosed when the ligament segment was absent or there was a fluidfilled discontinuity.A tear that involves 1 or 2 of the 3 segments (volar, proximal, or dorsal) of either the SLL was considered a partial tear, whereas a tear of all 3 segments was a complete tear. Conclusion: MRI can demonstrate the anatomy of interosseous ligaments accurately, evaluate and make the general grades of injuries.It is of significance for the early diagnosis and treatment protocols of the interosseous ligaments injuries.

[Huaier aqueous extract inhibits proliferation of human hepatoma SK-HEP-1 cells through up-regulation of autophagy]

The purpose of this study was to investigate the effect of Huaier on autophagy of human hepatoma SK-HEP-1 cells and the effect of autophagy on the proliferation of SK-HEP-1 cells. CCK-8 assay was used to evaluate the effect of Huaier on the proliferation of SK-HEP-1 cells under different concentrations and different times. Acridine orange staining was used to measure the effect of Huaier on the autolysosome formation in SK-HEP-1 cells. Immunofluorescence assay was applied to examine the effect of Huaier on the expression and distribution of autophagy marker LC3 in SK-HEP-1 cells. In addition， LC3 expression was also checked by immunoblot analysis in the presence of Huaier. At last， the effects of Huaier in combination with autophagy inhibitor bafilomycin A1 on the proliferation of SK-HEP-1 cells was detected by CCK-8 assay. The results showed that Huaier aqueous extract significantly inhibited the proliferation of human hepatoma SK-HEP-1 cells in a dose- and time-dependent manner. Huaier aqueous extract dramatically promoted the formation of autolysosome in SK-HEP-1 cells. Moreover， Huaier markedly increased the number and intensity of intracellular LC3 fluorescent puncta and up-regulated LC3-Ⅱ expression. These data indicated that Huaier evidently activated autophagy of SK-HEP-1 cells. Additionally， autophagy inhibition significantly attenuated the sensitivity of SK-HEP-1 cells to Huaier treatment. Therefore， autophagy activation is involved in the inhibitory effects of Huaier on the proliferation of human hepatoma SK-HEP-1 cells.

In-service light path PMD (polarization mode dispersion) monitoring by PMD compensation

We describe a novel method of measuring PMD (polarization mode dispersion) of an in-service DWDM system by PMD compensation. We successfully demonstrate the method in a 1500-km ultra-long haul DWDM test bed. We further verify the feasibility of the method for in-service light path PMD monitoring in a field trial in a revenue-generating route in Verizon Network, and obtain an accurate PMD value without impacting live network traffic. The discrepancy between the measured and expected PMD values is less than 6% for all cases tested.

Defects in ProTaper S1 instruments after clinical use: longitudinal examination

AIM

To evaluate defects in ProTaper shaping instrument S1 after a defined schedule of clinical use.

METHODOLOGY

Among all ProTaper files discarded from an endodontic clinic at a stomatological school in China over a period of 17 months, 122 S1 instruments were collected. They were ultrasonically cleaned, autoclaved and then examined in the laboratory. Any instrument separation was noted; the average length involved was determined. The 0.5 mm region on either side of this length of discarded but intact instruments was examined circumferentially by scanning electron microscope. The region adjacent to the broken end of the fractured instruments was also examined in the same way.

RESULTS

One specimen was lost during processing. Of the remaining 121 instruments, 27 were separated with a mean fracture length of 3.67 mm from the tip. Of these, two files showed macroscopically torsional fracture and the others showed signs of flexural fatigue. Only one file that had not fractured showed visible unwinding defects. Examination of the 3.1-4.1 mm region of other unfractured instruments revealed the presence of microcracks, surface debris, pitting and/or wear of their cutting edges. Some debris particles seemed to have been trapped in crack-like structures.

CONCLUSIONS

Multiple use of ProTaper S1 pre-disposed the instrument to microcrack formation and wear of the cutting edges. There was a low prevalence of plastic deformation and most ProTaper S1 instruments failed without discernible sign of unwinding of the flutes. Further studies should address the mode of failure and the role of debris particles in the fracture mechanism.

Low-power high-efficiency wavelength conversion based on modulational instability in high-nonlinearity fiber

Bandwidth and peak efficiency are enhanced for wavelength conversion based on induced modulation instability by use of dispersion-shifted fiber in which the nonlinearity (n(2)/A(eff)) is enhanced by a factor of ~4.5 over that of conventional dispersion-shifted fiber. We experimentally obtain a peak conversion efficiency as high as 28 dB over a 40-nm bandwidth with 600 mW of peak pump power. Considerations for further enhancement of fiber-based wavelength conversion are also discussed.