Antidepressive effects of ginsenoside Rg1 via regulation of HPA and HPG axis.

Background: Hypothalamic-pituitary-adrenal (HPA) axis hyperactivity is a well-established pathological feature of major depression, accompanied by the persistent increase of glucocorticoid level and the dysfunction of hypothalamic-pituitary-gonadal (HPG) axis. Ginsenoside Rg1 (Rg1) is one of the most active ingredients of Panax ginseng, which has various biological activity.

Objective: This study aimed to investigate the antidepressive effects of Rg1 and elucidate its impact on neuroendocrine system.

Recent advances in the study of (-)clausenamide: chemistry, biological activities and mechanism of action.

Clausenamide (clau) is one of seven novel compounds isolated from Clausena lansium (Lour) skeels. Clau is unusual in that it contains 4 chiral centers yielding 8 pairs of enantiomers. After identification of the configuration of these enantiomers, the synthesis of 16 enantiomers, including optically active clau and (+) and (-)clau was carried out.

Post-trial anatomical frame alignment procedure for comparison of 3D joint angle measurement from magnetic/inertial measurement units and camera-based systems.

Magnetic and inertial measurement units (MIMUs) have been widely used as an alternative to traditional camera-based motion capture systems for 3D joint kinematics measurement. Since these sensors do not directly measure position, a pre-trial anatomical calibration, either with the assistance of a special protocol/apparatus or with another motion capture system is required to establish the transformation matrices between the local sensor frame and the anatomical frame (AF) of each body segment on which the sensors are attached. Because the axes of AFs are often used as the rotational axes in the joint angle calculation, any difference in the AF determination will cause discrepancies in the calculated joint angles.

Investigation of a passive inter-limb device on step-to-step transition of human walking.

In walking like an inverted pendulum, the step-to-step transition period requires a substantial amount of simultaneous positive and negative mechanical work to redirect the center of mass between steps and it was considered as a major determinant of gait in terms of metabolic expenditure. In the current study, we developed a passive inter-limb device that transfers energy between the legs during the step-to-step transition period. By effectively transferring the energy dissipated at heel-strike from the leading leg to the trailing leg which is performing push-off, we hypothesize that the mechanical cost of transport (COT) will be reduced.

Development of an energy harvesting backpack and performance evaluation.

A biomechanical energy harvesting backpack that generates electrical energy during human walking is presented. This device differs from previous designs because it integrates motion from both lower limbs into a single mechanical drive train. The energy harvesting backpack produced an average of 15 W of electricity during walking at a speed of 1.

Concurrent validation of Xsens MVN measurement of lower limb joint angular kinematics.

This study aims to validate a commercially available inertial sensor based motion capture system, Xsens MVN BIOMECH using its native protocols, against a camera-based motion capture system for the measurement of joint angular kinematics. Performance was evaluated by comparing waveform similarity using range of motion, mean error and a new formulation of the coefficient of multiple correlation (CMC). Three dimensional joint angles of the lower limbs were determined for ten healthy subjects while they performed three daily activities: level walking, stair ascent, and stair descent.

Stereoselective excretion and first-pass metabolism of clausenamide enantiomers.

Stereoselective differences in pharmacokinetics between clausenamide (CLA) enantiomers have been found after intravenous and oral administration of each enantiomer to rats. The differences could be associated with excretion and first-pass metabolism of two enantiomers. The data from this study demonstrated that (-)CLA was mainly excreted in feces with 13.

Estimation of spatio-temporal parameters for post-stroke hemiparetic gait using inertial sensors.

This paper represents the first step in developing an inertial sensor system that is capable of assessing post-stroke gait in terms of walking speed and temporal gait symmetry. Two inertial sensors were attached at the midpoint of each shank to measure the accelerations and angular velocity during walking. Despite the abnormalities in hemiparetic gait, the angular velocity of most of the testing subjects (12 out of 13) exhibited similar characteristics as those from a healthy population, enabling walking speed estimation and gait event detection based on the pendulum walking model.

Activation of ERK1/2-CREB pathway during potentiating synaptic transmission of (-)clausenamide in rat dentate gyrus.

To investigate the signal mechanism of (-)clausenamide ((-)-3-hydroxy-5-(hydroxy-phenyl-methyl)-1-methyl-4-phenyl-pyrrolidin-2-one, 1) and for understanding its effect on synaptic transmission, electrophysiological recording was done for basal synaptic transmission determination. Western blot analysis was employed to examine the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and cAMP responsive element-binding protein (CREB). Immunohistochemistry and tissue in situ hybridization were applied to detect the expression of Zif268.

Lower-limb-driven energy harvesting: preliminary analysis.

In this paper, we present a new lower limb driven biomechanical energy harvester and its preliminary performance analysis. An estimate of the mechanical available power, estimated user felt resistance, and preliminary testing were conducted in this study. The estimated total available mechanical power and user felt resistance are based on the kinematic motion data and the mathematical model of the energy harvester prototype.

[Regulation of microglia on neurogenesis in adult mammals].

Adult neurogenesis had been confirmed in rodents and other mammals for decades. The mechanisms underlying neurogenesis have been investigated extensively in recent years. Microglial cells, an immuno-cell in the central nervous system, have been found playing important roles in modulating the process of adult neurogenesis.

[Salvianolic acid B alleviate the disruption of blood-brain barrier in rats after cerebral ischemia-reperfusion by inhibiting MAPK pathway].

The aim of the study is to investigate the effect of salvianolic acid B (SalB) on blood-brain barrier (BBB) in rats after cerebral ischemia-reperfusion, and to illustrate its possible mechanisms. Cerebral ischemia-reperfusion was induced by middle cerebral artery occlusion in rats. The break-down of BBB was indicated by extravasations of immunoglobulin (IgG) monitored with immunohistochemistry.

Inhibitory effect of ginsenoside Rg1 on lipopolysaccharide-induced microglial activation in mice.

Microglial activation plays a pivotal role in the pathogenesis of neurodegenerative diseases by producing various pro-inflammatory cytokines and nitric oxide (NO). In the paper, the anti-inflammatory effect of ginsenoside Rg1 was investigated in mice intracerebroventricular injected of lipopolysaccharide (LPS). NO and tumor necrosis factor (TNF)-α production in both cerebral cortex and hippocampus decreased at dose-dependent manner by oral administration with Rg1.

Protective effect of (-)clausenamide against Abeta-induced neurotoxicity in differentiated PC12 cells.

The neurotoxicity of aggregated beta-amyloid (Abeta) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease (AD). In the present study, we investigated the effect of (-)clausenamide ((-)Clau), an aqueous extract of leaves of Clausena lassium (lour) skeel, on the neurotoxicity of Abeta(25-35). The viability of differentiated PC12 cells was determined by MTT assay.

Protective role of PI3-kinase/Akt/eNOS signaling in mechanical stress through inhibition of p38 mitogen-activated protein kinase in mouse lung.

Aim: To test the hypothesis that PI3K/Akt/eNOS signaling has a protective role in a murine model of ventilation associated lung injury (VALI) through down-regulation of p38 MAPK signaling.

Methods: Male C57BL/J6 (wild-type, WT) or eNOS knockout mice (eNOS(-/-)) were exposed to mechanical ventilation (MV) with low (LV(T), 7 mL/kg) and high tidal volume (HV(T), 20 mL/kg) for 0-4 h. A subset of WT mice was administered the specific inhibitors of PI3K (100 nmol/L Wortmannin [Wort], ip) or of p38 MAPK (SB203580, 2 mg/kg, ip) 1 h before MV.

New achievements in ginseng research and its future prospects.

In recent decades, scientists in Asian and Western countries have been paying great attention to ginseng research. Today, more than 200 ginsenosides and non-saponin constituents have been isolated and identified. Ginsenosides show biological activities only after being deglycosylated by intestinal bacteria.

Improvement of memory in mice and increase of hippocampal excitability in rats by ginsenoside Rg1's metabolites ginsenoside Rh1 and protopanaxatriol.

Ginsenoside Rg1 has been reported to improve cognitive function in many memory-impaired animal models. However, little is known about the bioactivity of its metabolites in the central nervous system in vivo. In the present study, we employed the step through test and electrophysiological approach to investigate the effects of ginsenoside Rg1's primary metabolite ginsenoside Rh1 and end metabolite protopanaxatriol (Ppt) on learning and memory as well as hippocampal excitability.

Ginsenoside Rg1 activated CaMKIIalpha mediated extracellular signal-regulated kinase/mitogen activated protein kinase signaling pathway.

Aim: We carried out this study to investigate the effect of ginsenoside Rg1 on the extracellular signal-regulated kinase/mitogen activated protein kinase (ERK/ MAPK) pathway for understanding its effect on synaptic platicity.

Methods: Western blotting and immunostaining were used to examine the phosphorylation of ERK1/2, CaMKIIalpha and cAMP response element binding protein (CREB) in PC12 cells and synaptosomes. The confocal microscopy and fluorescent indicator Fluo-3 was applied to observe the intracellular calcium ion flux.

Comparison of the pharmacological effects of Panax ginseng and Panax quinquefolium.

Medical application of Panax ginseng was first found in "Shen-Nong Herbal Classic"around 200 AD Panax quinquefolium was first introduced in "Essential of Materia Medica" in 1694 in China. The most important bioactive components contained in P ginseng and P quinquefolium are ginseng saponins (GS). The contents of ginsenoside Rb1, Re, and Rd in P quinquefolium are higher than they are in P ginseng.

Stereoselective plasma protein binding and target tissue distribution of clausenamide enantiomers in rats.

Stereoselective differences in pharmacokinetics between clausenamide (CLA) enantiomers have been found after intravenous and oral administration of each enantiomer to rats. The differences could be associated with protein binding of CLA enantiomers. By equilibrium dialysis methods, the binding of CLA enantiomers to rat plasma protein was investigated.

[Protective effect of (-) clausenamide against neurotoxicity induced by okadaic acid and beta-amyloid peptide25-35].

This study is to investigate the protective effect of (-) clausenamide against the neurotoxicity of okadaic acid in SH-SY5Y cell line, and injection beta-amyloid peptide25-35 (Abeta25-35) to the cerebral ventricle in ovariectomy (OVX) rats. MTT assay, LDH assay, and Hoechst 33258 staining were used to detect the effect of (-) clausenamide on the toxicity of okadaic acid in SH-SY5Y cell line. The animal model was induced by ovariectomized and injection of Abeta25-35 in the cerebroventricle of rats.

[Effect of salvianolic acid B on neural cells damage and neurogenesis after brain ischemia-reperfusion in rats].

This study is to observe the effect of salvianolic acid B (Sal B) on neural cells damage and neurogenesis in sub-granular zone (SGZ) and sub-ventricular zone (SVZ) after brain ischemia-reperfusion (I/R) in rats. A modified middle cerebral artery occlusion (MCAO) model of focal cerebral ischemia-reperfusion was used. The rats were divided into four groups: sham control group, ischemia-reperfusion group, Sal B 1 and 10 mg x kg(-1) groups.

[The mechanism of ginsenosides Rg1 and Rb1 promoting glutamic acid release from PC12 cells].

Aim: To study the mechanism of ginsenosides Rg1 and Rb1 promoting glutamic acid release from PC12 cells.

Methods: The amount of glutamic acid released from PC12 cells was measured by high performance liquid chromatography (HPLC). The effect of Rg1 and Rb1 on the phosphorylation of synapsins was detected with immunofluorescent staining and Western blotting.