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.

Undescribed diphenyl ethers betaethrins A-I from a desert plant endophytic strain of the fungus Phoma betae A.B. Frank (Didymellaceae).

Ten diphenyl ethers (DPEs), including nine undescribed analogs named betaethrins A-I, were isolated from the desert plant endophytic fungus Phoma betae A.B. Frank (Didymellaceae). Their structures were determined mainly by NMR, HR-ESI-MS spectral and X-ray diffraction experiments. Betaethrins D-I possessed different fatty acid chains connected with the B-ring, which was the first report in all DPEs. The shielding effect of the B-ring on H-6 (A-ring) in methyl barceloneate, betaethrin A and betaethrins D-F (asterric acid analogs) was first observed and analyzed, which could differentiate the 1H-NMR chemical shift values of H-4/H-6 without the assistance of 3-OH. An empirical rule was then suggested: the steric hindrance between the A- and B-rings in asterric acid analogs might prevent these two aromatic rings from rotating freely, which led to the 1H-NMR chemical shift value of H-6 being in the high field zone due to the shielding effect of the B-ring on H-6. Based on the empirical rule, the chemical shift values of the A-ring in methyl barceloneate were revised. The possible biosynthesis of these isolates was postulated. Betaethrin H showed moderate cytotoxicity against MCF-7 and HepG2 cancer cell lines. Betaethrins A-F, H and I displayed strong antioxidant activities. These results further implied that endophytic fungi from unique environments, such as desert plants, with few chemical studies are an important resource of undescribed and bioactive metabolites.

Chronic restraint stress induced changes in colonic homeostasis-related indexes and tryptophan-kynurenine metabolism in rats.

Chronic stressors represented risk factors for the etiology or exacerbation of several gastrointestinal diseases. The goal of the present study was to examine whether chronic restraint stress (CRS) could initiate and aggravate colonic inflammation, integrity damage and metabolic disturbance of rats. Firstly, increased inflammatory cytokines (interferon-γ (IFN-γ), tumor necrosis factor-α(TNF-α) and interleukin-10(IL-10)) and decreased tight junction (TJ) proteins (occludin and zonula occludins-1 (ZO-1)) in rat colon were observed. Secondly, untargeted metabolomics based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass (UPLC-Q-TOF/MS) revealed that TRP metabolism was the most prominently affected. Thirdly, quantification of TRP and its metabolites via prominence ultrafast liquid chromatography coupled with a QTRAP 5500 mass (UFLC-QTRAP-5500/MS) showed that TRP, kynurenine (KYN), kynurenic acid (KA) and 3-hydroxykynurenine (3-HK) were significantly increased. At the same time, 5-hydroxytryptamine (5-HT) was unchanged and 5-hydroxyindolacetic acid (5-HIAA) was significantly decreased in the colon of CRS rats. Besides, TRP metabolic enzyme changes were with the same trends as the corresponding metabolites. Thus, our data showed that CRS could initiate colonic inflammation, integrity damage and colonic metabolism disturbance, especially TRP-KYN metabolism pathway of rats, which may provide an experimental background for future research on stress-related gastrointestinal dysfunction. SIGNIFICANCE: Chronic exposure to psychological stress could induce metabolic imbalance of the body, and stressful life events were intimately correlated with frequent relapses in patients with intestinal disorders. The present study showed that chronic restraint stress (CRS) could initiate and aggravate colonic inflammation, integrity damage and metabolic disturbance, especially tryptophan-kynurenine metabolism of rats. Tryptophan-kynurenine pathway may be involved in the initiation and development of diseases induced by chronic stress. This research may shed light on future research on stress-related gastrointestinal dysfunction.

Enhancing in vivo oral bioavailability of cajaninstilbene acid using UDP-glucuronosyl transferase inhibitory excipient containing self-microemulsion.

Cajaninstilbene acid (CSA) exerts wide pharmacological activities, such as anti-inflammation, hypoglycaemic activity, analgesic effect and cognition improvement. However, it underwent severe phase II metabolism mediated by UDP-glucuronosyltransferase (UGT) in the gastrointestinal (GI) tract after oral administration, affecting its oral bioavailability. In the present study, we utilize UGT inhibitory excipient containing self-microemulsion (SME) delivery system to reduce the production of glucuronide metabolites and increase its oral bioavailability. The present results showed that although similar properties in physiochemical, cytotoxicity, cellular uptake, absorption and transport across rat everted gut sacs between SME-1 (inhibitory excipient containing SME) and SME-2 (control SME, without inhibitory excipient), an improved absolute bioavailability of 57.3 % was conferred by SME-1, significantly higher than the value of 35.4 % by SME-2 and 34.0 % by free CSA. Noticeably, the significantly lower AUC value of CSA glucuronide was determined in rats treated with SME-1 than those either treated with SME-2 or free CSA. Thus, the ability of SME-1 to enhance oral bioavailability of CSA is mainly attributed to the inhibition of phase II metabolism in the GI tract.

Protective effects of Myrica rubra flavonoids against hypoxia/reoxygenation-induced cardiomyocyte injury via the regulation of the PI3K/Akt/GSK3ß pathway.

Myrica rubra is well known for its delicious taste and high nutritional value. The present study investigated the potential protective effects and mechanisms of M. rubra flavonoids (MRF) extract on isoproterenol (ISO)­induced myocardial injury in rats and hypoxia/reoxygenation (H/R) injury in H9c2 cardiomyocytes. An in vivo study revealed that MRF decreased serum cardiac enzyme levels, ameliorated pathological heart alterations and increased the antioxidant potential. The in vitro investigation demonstrated that MRF inhibited cell death, reactive oxygen species (ROS) accumulation, mitochondrial membrane depolarization, apoptosis rate and caspase­3 activation and enhanced the Bcl­2/Bax ratio during H/R injury. These effects were accompanied by the phosphorylation of protein kinase B (Akt) and glycogen synthase kinase (GSK)­3ß. Further mechanism studies demonstrated that LY294002, a specific inhibitor of phosphoinositide 3­kinase (PI3K), abolished the MRF­mediated cardioprotection against H/R­induced apoptosis and ROS overproduction. Collectively, these results suggested that MRF exerts cardioprotective effects by attenuating oxidative damage and cardiomyocyte apoptosis most likely via a PI3K/Akt/GSK3ß­dependent mechanism.

Plasma and brain pharmacokinetics of ganoderic acid A in rats determined by a developed UFLC-MS/MS method.

Ganoderic acid A (GAA), an active triterpenoid of the traditional Chinese herbal medicine Lingzhi, has been reported to exhibit antinociceptive, antioxidative, and anti-cancer activities. The present study aims to establish a sensitive and rapid UPLC-MS/MS method for studying the plasma and brain pharmacokinetics of GAA in rats. The analytes were separated on a C18 column eluted with a gradient mobile phase consisting of acetonitrile and 0.1% aqueous formic acid at 0.3mL/min. The eluate was monitored by a mass detector using an MRM (m/z, 515.3-285.1) model in negative electrospray ionization. The calibration curve showed good linearity (r2>0.99), with limits of detection and quantification of 0.25 and 2.00 nmol/L, respectively. The intra- and inter-day precision and accuracy were less than 9.99% and ranged from 97.45% to 114.62%, respectively. The extraction recovery from plasma was between 92.89% and 98.87%. GAA was found to be stable in treated samples at room temperature (22°C) for 12h and in plasma at -20°C for 7d. The developed method was successfully applied to a pharmacokinetic study of GAA in rats. GAA could be rapidly absorbed into the circulation (Tmax, 0.15h) and eliminated relatively slowly (t1/2, 2.46h) after orally dosing, and could also be detected in the brain lateral ventricle (Tmax, 0.25h and t1/2, 1.40h) after intravenously dosing. The absolute oral bioavailability and brain permeability of GAA were estimated to be 8.68% and 2.96%, respectively.

Effects of phenolic constituents of daylily flowers on corticosterone- and glutamate-treated PC12 cells.

BACKGROUND: Daylily flowers, the flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-You-Cao in Chinese, meaning forget-one's sadness plant. However, the major types of active constituents responsible for the neurological effects remain unclear. This study was to examine the protective effects of hydroalcoholic extract and fractions and to identify the active fractions. METHODS: The extract of daylily flowers was separated with AB-8 resin into different fractions containing non-phenolic compounds, phenolic acid derivatives and flavonoids as determined using UPLC-DAD chromatograms. The neuroprotective activity was measured by evaluating the cell viability and lactate dehydrogenase release using PC12 cell damage models induced by corticosterone and glutamate. The neurological mechanisms were explored by determining their effect on the levels of dopamine (DA), 5-hydroxy tryptamine (5-HT), γ-aminobutyric acid (GABA), noradrenaline (NE) and acetylcholine (ACh) in the cell culture medium measured using an LC-MS/MS method. RESULTS: Pretreatment of PC12 cells with the extract and phenolic fractions of daylily flowers at concentrations ranging from 0.63 to 5 mg raw material/mL significantly reversed corticosterone- and glutamate-induced neurotoxicity in a dose-dependent manner. The fractions containing phenolic acid derivatives (0.59% w/w in the flowers) and/or flavonoids (0.60% w/w) exerted similar dose-dependent neuroprotective effect whereas the fractions with non-phenolic compounds exhibited no activity. The presence of phenolic acid derivatives in the corticosterone- and glutamate-treated PC12 cells elevated the DA level in the cell culture medium whereas flavonoids resulted in increased ACH and 5-HT levels. CONCLUSION: Phenolic acid derivatives and flavonoids were likely the active constituents of daylily flowers and they conferred a similar extent of neuroprotection, but affected the release of neurotransmitters in a different manner.

Myricitrin attenuates endothelial cell apoptosis to prevent atherosclerosis: An insight into PI3K/Akt activation and STAT3 signaling pathways.

Blood vessel endothelial dysfunction induced by oxidized low-density lipoprotein (ox-LDL) has been implicated in the pathogenesis of atherosclerosis and vasculopathy. The ox-LDL-elicited reactive oxygen species (ROS) release has been assumed to serve a critical function in endothelial damage. Myricitrin (from Myrica cerifera) is a natural antioxidant that has strong anti-oxidative, anti-inflammatory, and anti-nociceptive activities. However, the protective effect of myricitrin on ROS-induced endothelial cell injury and its related molecular mechanisms have never been investigated. This study demonstrates that myricitrin can inhibit ox-LDL-induced endothelial apoptosis and prevent plaque formation at an early stage in an atherosclerotic mouse model. The administration of myricitrin in vivo decreases the thickness of the vascular wall in the aortic arch of ApoE-/- mice. In vitro study shows that ox-LDL-induced human umbilical vein endothelial cell apoptosis can be reduced upon receiving myricitrin pre-treatment. Treatment with myricitrin significantly attenuated ox-LDL-induced endothelial cell apoptosis by inhibiting LOX-1 expression and by increasing the activation of the STAT3 and PI3K/Akt/eNOS signaling pathways. At the same time, our result demonstrates that myricitrin treatment optimizes the balance of pro/anti-apoptosis proteins, including Bax, Bad, XIAP, cIAP-2, and survivin. Our study suggests that myricitrin treatment can effectively protect cells from ox-LDL-induced endothelial cell apoptosis, which results in reduced atherosclerotic plaque formation. This result indicates that myricitrin can be used as a drug candidate for the treatment of cardiovascular diseases.

Tenuifolin, a secondary saponin from hydrolysates of polygalasaponins, counteracts the neurotoxicity induced by Aß25-35 peptides in vitro and in vivo.

Alzheimer's disease (AD) is associated with damage to hippocampal neurons and declines in cognitive functions. The accumulation of amyloid peptides is regarded as a crucial event in the initiation of AD. The neurotoxicity induced by Aß25-35 peptides was used to screen for cytoprotective factors in vitro, and the cognitive deficits induced by the injection of Aß25-35 into the hippocampus were used to evaluate effect on learning and memory. Our previous study revealed that hydrolysate of polygalasaponins (HPS) clearly improve the cognitive deficits induced by the injection of Aß25-35 in mice, but the potential active constituent of HPS remains unclear. The purposes of this study were to separate and purify the secondary saponins of HPS, screen for neuroprotective effects of the constituents in vitro, and to evaluate the effect of cognition in vivo. Various chromatographic methods were used to separate and purify the HPS. The neuroprotective effects were examined in Aß25-35-damage-induced PC12 cells. The protective effect of tenuifolin on the cognitive impairments induced by Aß25-35 injection was assessed using the Morris water maze and step-through passive avoidance tests. Tenuifolin and fallaxsaponin A were isolated from the HPS. Tenuifolin possessed neuroprotective effects against Aß25-35-induced apoptosis in PC12 cells and significantly improved the cognitive deficits induced by the intrahippocampal injection of Aß25-35 in mice. Thus, tenuifolin is one of the active constituents of HPS against the neurotoxicity induced by Aß25-35 peptides in vitro and in vivo.

Cajaninstilbene acid prevents corticosterone-induced apoptosis in PC12 cells by inhibiting the mitochondrial apoptotic pathway.

BACKGROUND/AIMS: Cajaninstilbene acid (3-hydroxy-4-prenyl-5-methoxystilben-2 -carboxylic acid, CSA), a natural stilbene isolated from the leaves of Cajanus cajan, has attracted considerable attention for its wide range of pharmacological activities. This study investigated whether CSA protects against corticosterone (CORT)-induced injury in PC12 cells and examined the potential mechanisms underlying this protective effect. METHODS: Cell viability and cytotoxicity were detected using a 3-(4,5-desethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) assay kit, respectively. PC12 cell apoptosis was measured using Hoechst 33342 staining and a DNA fragmentation assay kit, and intracellular Ca(2+) concentrations were assessed by fluorescent labelling. Next, the mitochondrial permeability transition pores (mPTPs) and mitochondrial membrane potentials (∆Ψm) were detected using a colorimetric mPTP detection kit and a 5,5',6,6'-tetrachloro-1,1',3,3'- tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) kit, respectively. Finally, cytochrome c, caspase-3 and inhibitor of caspase-activated deoxyribonuclease (ICAD) expression levels were monitored by western blot analysis. RESULTS: Treatment with 100 µmol/l CORT induced cytotoxicity in PC12 cells. However, CSA dose-dependently increased cell viability and decreased LDH release as well as CORT-induced apoptosis. Mechanistically, compared with the CORT-treated group, CSA strongly attenuated intracellular Ca(2+) overload and restored mitochondrial functions, including mPTPs and ∆Ψm. Furthermore, the down-regulation of cytochrome c and ICAD protein expression and the blockage of caspase-3 activity were observed upon CSA treatment. CONCLUSIONS: In summary, our data are the first to show that the in vitro antidepressant-like effect of CSA may be attributed to the cytoprotection of neurons and that such neuroprotective mechanisms are correlated with intracellular Ca(2+) homeostasis and mitochondrial apoptotic pathways.

Saikosaponin D acts against corticosterone-induced apoptosis via regulation of mitochondrial GR translocation and a GR-dependent pathway.

Saikosaponin D is an agonist of the glucocorticoid receptor (GR), and our preliminary study showed that it possesses neuroprotective effects in corticosterone-treated PC12 cells. However, further proof is required, and the molecular mechanisms of this neuroprotection remain unclear. This study sought to further examine the cytoprotective efficiency and potential mechanisms of action of Saikosaponin D in corticosterone-treated PC12 cells. The cells were treated with 250 µM corticosterone in the absence or presence of Saikosaponin D for 24 h; cell viability was then determined, and Hoechst 33342/propidium iodide (PI) and annexin/PI double staining, and TUNEL staining were performed. Next, mPTP, MMP, [Ca(2+)]i, translocation of the GR to the nucleus and Western blot analyses for caspase-3, caspase-9, cytochrome C, GR, GILZ, SGK-1, NF-Κb (P65), IκB-α, Bad, Akt, Hsp90 and HDAC-6 were investigated. The neuroprotective effects of Saikosaponin D were further confirmed by Hoechst 33342/PI, annexin/PI and TUNEL staining assays. These additional data suggested that Saikosaponin D partially reversed the physiological changes induced by corticosterone by inhibiting the translocation of the GR to the mitochondria, restoring mitochondrial function, down-regulating the expression of pro-apoptotic-related signalling events and up-regulating anti-apoptotic-related signalling events. These findings suggest that SSD exhibited its anti-apoptotic effects via differential regulation of mitochondrial and nuclear GR translocation, partial reversal of mitochondrial dysfunction, inhibition of the mitochondrial apoptotic pathway, and selective activation of the GR-dependent survival pathway.

[Protect effects and the underlying mechanisms of myricitrin against vascular endothelial cells apoptosis induced by oxidative stress].

This study is to report the study of protective effects of myricitrin against oxidative stress-induced apoptosis of vascular endothelial cells and the investigation of the possible mechanisms of action of myricitrin. The model of H2O2-induced apoptosis of vascular endothelial cells was used to determine the protective effects of myricitrin. The levels of LDH, MDA and the activities of SOD, NO were measured using the respective kits. The H2O2-induced apoptosis of vascular endothelial cells was detected using MTT reduction, TUNEL assay, JC-1 and ROS staining. The activation of Caspase-3 was also measured by fluorometry. The expression of apoptosis-related proteins was determined with Western blotting assay. Myricitrin had significant protective effects against H2O2-induced apoptosis of vascular endothelial cells in a time- and dose-dependent manner. The results show that myricitrin could attenuate H2O2-induced decrease in the activities of SOD (P < 0.01). Myricitrin could decrease the levels of LDH, MDA and increase cell viability and the mitochondrial membrane potential (P < 0.01). Myricitrin had protective effects in a dose-dependent manner between 32 micromol x L(-1) to 64 micromol x L(-1). Myricitrin pretreatment could attenuate H2O2-induced increase of p-ERK. Moreover, myricitrin pretreatment could up-regulate the expression of the anti-apoptotic protein Bcl-2, down-regulate the expression of the pro-apoptotic protein Bax, and decrease the expression of Caspase-3, 9. In conclusion, myricitrin had significant protective effects against H2O2-induced apoptosis of vascular endothelial cells. Myricitrin can enhance the activities of anti-oxidative enzymes and decrease the production of free radicals. The possible mechanisms of action of myricitrin are due to myricitrin-mediated inhibition of phosphorylation of the apoptosis signaling pathways-related kinase ERK, up-regulation of the expression of the anti-apoptotic protein, and down-regulation of the expression of the pro-apoptotic protein.

Inhibitory effects of myricitrin on oxidative stress-induced endothelial damage and early atherosclerosis in ApoE-/- mice.

Atherosclerosis (AS) is a state of heightened oxidative stress characterized by lipid and protein oxidation in vascular walls. Oxidative stress-induced vascular endothelial cell (VEC) injury is a major factor in the pathogenesis of AS. Myricitrin, a natural flavonoid isolated from the root bark of Myrica cerifera, was recently found to have a strong antioxidative effect. However, its use for treating cardiovascular diseases, especially AS is still unreported. Consequently, we evaluated the cytoprotective effect of myricitrin on AS by assessing oxidative stress-induced VEC damage. The in vivo study using an ApoE-/-mouse model of AS demonstrated that myricitrin treatment protects against VEC damage and inhibits early AS plaque formation. This effect is associated with the antioxidative effect of myricitrin, as observed in a hydrogen peroxide (H2O2)-induced rat model of artery endothelial injury and primary cultured human VECs. Myricitrin treatment also prevents and attenuates H2O2-induced endothelial injury. Further investigation of the cytoprotective effects of myricitrin demonstrated that myricitrin exerts its function by scavenging for reactive oxygen species, as well as reducing lipid peroxidation, blocking NO release, and maintaining mitochondrial transmembrane potential. Myricitrin treatment also significantly decreased H2O2-induced apoptosis in VECs, which was associated with significant inhibition of p53 gene expression, activation of caspase-3 and the MAPK signaling pathway, and alteration of the patterns of pro-apoptotic and anti-apoptotic gene expression. The resulting significantly increased bcl-2/bax ratio indicates that myricitrin may prevent the apoptosis induced by oxidative stress injury.

Neuroprotective effects of total saikosaponins of Bupleurum yinchowense on corticosterone-induced apoptosis in PC12 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Bupleurum yinchowense Shan et Y. Li, a well-known medicinal plant in China, was originally documented in the "Shennong's Herbal", which is the oldest Chinese materia medica monographs. It has the action of soothing liver and relieving constraint for improving symptoms of emotional instability such as depression, anxiety and phobia. The in vivo experiment of our previous study has showed an efficacy of Total Saikosaponins (TSS) from Bupleurum yinchowense in acute stress and chronic unpredictable mild stress models. Nevertheless, there are no studies on the cytoprotection and potential mechanisms of TSS on corticosterone-induced apoptosis in PC12 cells. The present study focuses on cytoprotection against corticosterone-induced neurotoxicity in PC12 cells and its underlying molecule mechanisms of the antidepressant-like effect of TSS. MATERIALS AND METHODS: The PC12 cells were treated with 250 µM corticosterone in the absence or presence of different concentrations of TSS for 24 h, then the cell viability, lactate dehydrogenase (LDH) release, Hoechst 33342 and propidium iodide (PI) double staining and the DNA fragmentation of the apoptotic PC12 cells were determined. The mitochondrial permeability transition pore (mPTP), mitochondrial membrane potential (MMP), intracellular Ca(2+) ([Ca(2+)]i) concentration and western blot analysis of caspase-3, glucose-regulated protein 78 (GRP78), growth arrest and DNA damage inducible proteins 153 (GADD-153), X-box DNA-binding protein-1 (XBP-1), Bax, Bcl-2 were investigated. RESULTS: Pretreatment of PC12 cells with TSS (3.125, 6.25, 12.5, 25 µg/ml) partly reversed corticosterone-induced neurotoxicity in a dose dependent manner. TSS (25 =g/ml) reversed the increase of dead cells in the Hoechst 33342 stain, the accumulation in LDH leakage and the number of TUNEL positive cells induced by corticosterone to PC12 cells. Moreover, the cytoprotection of TSS was proved to be associated with the homeostasis of intracellular Ca(2+), the stabilization of ER stress via the down-regulation of GRP78, GADD-153, XBP-1, and the restoration of mitochondrial function, which included mPTP, MMP and caspase-3 activity. Furthermore, TSS (25 µg/ml) markedly ameliorated up-regulation of Bax and down-regulation of Bcl-2 in corticosterone-induced PC12 cells. CONCLUSION: The result depicted that antidepressant-like effect of TSS in vivo may be associated with the cytoprotection of neuron, and the neuroprotective mechanisms were correlated with inhibiting the ER stress and the mitochondrial apoptotic pathways.

[Neuroprotective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells].

This study is to investigate the protective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells. While PC12 cells were exposed to 100 micromol x L(-1) corticosterone for 48 h, cell survival rate was reduced and lactate dehydrogenase (LDH) release increased. In parallel, corticosterone caused significant elevations of DNA fragmentation, [Ca2+]i and caspase-3 activity. However, when the PC12 cells were incubated with longistyline A (4.0, 8.0 and 16.0 micromol x L(-1)) in the presence of 100 micromol x L(-1) corticosterone for 48 h, the effects were evidently alleviated, but dose-dependent manner was not obvious. In summary, longistyline A could generate a neuroprotective effect against corticosterone-induced neurotoxicity in PC12 cells possibly by decreasing [Ca2+]i and caspase-3 activity.

Cytotoxicity of cycloartane triterpenoids from aerial part of Cimicifuga foetida.

Our previous study had demonstrated cytotoxicity of EtOAc fraction from aerial part of Cimicifuga foetida on various cancer cell lines. In the present study, we investigated the cytotoxicity of five cycloartane triterpenoids isolated from the EtOAc fraction. Compounds (1,2,3) showed moderate cytotoxic activity on R-HepG2 cells and drug resistant sub line R-HepG2 but exhibited less toxicity against primary cultured normal mouse hepatocytes. Compounds (4) and (5) were inactive on all tested cell lines.

[Studies on new trierpenoid constituents from the Rhizoma of Cimicifuga foetida].

OBJECTIVE: To find new active constituents from Rhizome of Cimicifuga foetida. METHOD: Various column chromatographic techniques were employed for isolation and purification. The structures were elucidated on the basis of spectral and chemical evidences. RESULT: Four triterpenoid compounds were isolated and identified as 7,8-didehydro-27-deoxyactein(1), 24-O-acetylshengmanol-3-O-beta-D-xyl (23R, 24R)[2], cimigenol(3), cimigenol-3-O-beta-D-xyl(4). CONCLUSION: Compound 1 is a new compound, 2-4 were obtained from this medicinal material for the first time. The antiosteoporosis activity screening in vitro(by the method of SRB) indicates that Compounds 1, 2 and 4 can promote the proliferation for rat Osteoblastoma cell line (UMR106) at the concentration of 10(-9) kg.L-1.