Phenylephrine Attenuated Sepsis-Induced Cardiac Inflammation and Mitochondrial Injury Through an Effect on the PI3K/Akt Signaling Pathway.

OBJECTIVE: To investigate whether phenylephrine (PE) inhibits sepsis-induced cardiac dysfunction, cardiac inflammation, and mitochondrial injury through the PI3K/Akt signaling pathway. METHODS: A rat model of sepsis was established by cecal ligation and puncture. PE and/or wortmannin (a PI3K inhibitor) were administered to investigate the role of PI3K/Akt signaling in mediating the effects of PE on inhibiting sepsis-induced cardiac dysfunction, cardiac inflammation, and mitochondrial injury. Hematoxylin-eosin staining, echocardiography, and Langendorff system were used to examine the myocardial injury and function. The concentrations of TNF-α and IL-6 were analyzed by enzyme-linked immunosorbent assay. Intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), myeloperoxidase, mitochondria-related fusion/fission proteins, and PI3K/Akt signaling pathway-associated proteins were analyzed by Western blotting. RESULTS: PE improved the cardiac function and survival in septic rats. PE decreased TNF-α, IL-6, ICAM-1, VCAM-1, and myeloperoxidase contents in the myocardium of septic rats. Meanwhile, PE increased the fusion-related proteins and decreased the fission-related proteins in the myocardial mitochondria of septic rats. On the other hand, PE activated the PI3K/Akt signaling pathway in the cecal ligation and puncture-treated rats, and all the protective effects of PE were abolished by wortmannin. CONCLUSIONS: PE attenuated sepsis-induced cardiac dysfunction, cardiac inflammation, and mitochondrial injury through the PI3K/Akt signaling pathway.

Ginsenosides from stems and leaves of ginseng prevent ethanol-induced lipid accumulation in human L02 hepatocytes.

OBJECTIVE: To investigate the effect of ginsenosides from stems and leaves of ginseng on ethanol-induced lipid deposition in human L02 hepatocytes. METHODS: L02 cells were exposed to ethanol for 36 h and treated with or without ginsenosides. The viability of L02 cells was evaluated by methylthiazolyldiphenyl-tetrazolium bromide assay and the triglyceride (TG) content was detected. Lipid droplets were determined by oil red O staining. Intracellular reactive oxygen species (ROS) production and the mitochondrial membrane potential were tested by flow cytometry. The ATP level was measured by reverse phase high performance liquid chromatography. The expression of cytochrome p450 2E1 (CYP2E1) and peroxisome proliferator-activated receptor α (PPARα) was detected by reverse transcriptase-polymerase chain reaction and Western blotting, respectively. RESULTS: Ethanol exposure resulted in the increase of TG level, lipid accumulation and ROS generation, and the decrease of mitochondrial membrane potential and ATP production in the cells. However, ginsenosides significantly reduced TG content (9.69±0.22 µg/mg protein vs. 4.93±0.49 µg/mg protein, P<0.01), and ROS formation (7254.8±385.7 vs. 5825.2±375.9, P<0.01). Meanwhile, improvements in mitochondrial membrane potential (10655.33±331.34 vs. 11129.52±262.35, P<0.05) and ATP level (1.20±0.18 nmol/mg protein vs. 2.53±0.25 nmol/mg protein, P<0.01) were observed by treatment with ginsenosides. Furthermore, ginsenosides could down-regulate CYP2E1 expression (P<0.01) and upregulate PPARα expression (P<0.01) in ethanol-treated cells. CONCLUSIONS: Ginsenosides could prevent ethanol-induced hepatocyte steatosis in vitro related to the inhibition of oxidative stress and the improvement of mitochondrial function. In addition, the modulation of CYP2E1 and PPARα expression may also play an important role in the protective effect of ginsenosides against lipid accumulation.

From the Cover: Exposing Imidacloprid Interferes With Neurogenesis Through Impacting on Chick Neural Tube Cell Survival.

As a neonicotinoid pesticide, imidacloprid is widely used to control insects in agriculture and fleas on domestic animals. However, it is not known whether imidacloprid exposure negatively affects neurogenesis during embryonic development. In this study, using a chick embryo model, we investigated the effects of imidacloprid exposure on neurogenesis at the earliest stage and during late-stage embryo development. Exposing HH0 chick embryos to imidacloprid in EC culture caused neural tube defects (NTDs) and neuronal differentiation dysplasia as determined by NF/Tuj1 labeling. Furthermore, we found that F-actin accumulation on the apical side of the neural tube was suppressed by exposure to imidacloprid, and the expression of BMP4 and Shh on the dorsal and ventral sides of the neural tubes, respectively, were also reduced, which in turn affects the dorsolateral hinge points during bending of the neural plate. In addition, exposure to imidacloprid reduced cell proliferation and increased cell apoptosis, as determined by pHIS3 labeling and TUNEL staining, respectively, also contributing to the malformation. We obtained similar results in late-stage embryos exposed to imidacloprid. Finally, a bioinformatics analysis was employed to determine which genes identified in this study were involved in NTDs. The experimental evidence and bioinformatics analysis suggested that imidacloprid exposure during chick embryo development could increase the risk of NTDs and neural dysplasia.

Effects of Senegenin against hypoxia/reoxygenation-induced injury in PC12 cells.

OBJECTIVE: To investigate the effect and the potential mechanism of Senegenin (Sen) against injury induced by hypoxia/reoxygenation (H/R) in highly differentiated PC12 cells. METHODS: The cultured PC12 cells were treated with H/R in the presence or absence of Sen (60 µmol/L). Four groups were included in the experiment: control group, H/R group, H/R+Sen group and Sen group. Cell viability of each group and the level of lactate dehydrogenase (LDH) in culture medium were detected for the pharmacological effect of Sen. Hoechst 33258 staining and annexin V/propidium iodide double staining were used to analyze the apoptosis rate. Moreover, mitochondrial membrane potential (△Ψm), reactive oxygen species (ROS) and intracellular free calcium ([Ca(2+)]i) were measured by fluorescent staining and flow cytometry. Cleaved caspase-3 and activity of NADPH oxidase (NOX) were determined by colorimetric protease assay and enzyme linked immunosorbent assay, respectively. RESULTS: Sen significantly elevated cell viability (P<0.05), decreased the leakage of LDH (P<0.05) and apoptosis rate (P<0.05) in H/R-injured PC12 cells. Sen maintained the value of △Ψm (P<0.05) and suppressed the activity of caspase-3 (P<0.05). Moreover, Sen reduced ROS accumulation P<0.05) and [Ca(2+)]i increment (P<0.05) by inhibiting the activity of NOX (P<0.05). CONCLUSION: Sen may exert cytoprotection against H/R injury by decreasing the levels of intracellular ROS and [Ca(2+)]i, thereby suppressing the mitochondrial pathway of cellular apoptosis.

Angiogenesis is repressed by ethanol exposure during chick embryonic development.

It is now known that excess alcohol consumption during pregnancy can cause fetal alcohol syndrome to develop. However, it is not known whether excess ethanol exposure could directly affect angiogenesis in the embryo or angiogenesis being indirectly affected because of ethanol-induced fetal alcohol syndrome. Using the chick yolk sac membrane (YSM) model, we demonstrated that ethanol exposure dramatically inhibited angiogenesis in the YSM of 9-day-old chick embryos, in a dose-dependent manner. Likewise, the anti-angiogenesis effect of ethanol could be seen in the developing vessel plexus (at the same extra-embryonic regions) during earlier stages of embryo development. The anti-angiogenic effect of ethanol was found associated with excess reactive oxygen species (ROS) production; as glutathione peroxidase activity increased while superoxide dismutase 1 and 2 activities decreased in the YSMs. We further validated this observation by exposing chick embryos to 2,2'-azobis-amidinopropane dihydrochloride (a ROS inducer) and obtained a similar anti-angiogenesis effect as ethanol treatment. Semiquantitative reverse transcription-polymerase chain reaction analysis of the experimental YSMs revealed that expression of angiogenesis-related genes, vascular endothelial growth factor and its receptor, fibroblast growth factor 2 and hypoxia-inducible factor, were all repressed following ethanol and 2,2'-azobis-amidinopropane dihydrochloride treatment. In summary, our results suggest that excess ethanol exposure inhibits embryonic angiogenesis through promoting superfluous ROS production during embryo development.

Ginsenoside Rg1 relieves tert-Butyl hydroperoxide-induced cell impairment in mouse microglial BV2 cells.

Microglial activation plays an important role in neurodegenerative diseases associated with oxidative stress. tert-Butyl hydroperoxide (t-BHP), an analog of hydroperoxide, mimics the oxidative damage to microglial cells. It has been reported that ginsenoside Rg1 (G-Rg1), an active ingredient of Panax ginseng, has anti-stress and anti-inflammatory properties. The present study aims to investigate the ability of G-Rg1 to decrease the t-BHP-mediated cell damage of BV2 microglial cells. We performed flow cytometry assays to facilitate the detection of reactive oxygen species as well as Western blotting analyses and immunofluorescence assays using specific antibodies, such as antibodies against phospho-mitogen-activated protein kinases (p-MAPKs), phospho-nuclear factor-κB (p-NF-κB), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), Caspase-3, autophagy marker light chain 3 (LC3), and Becline-1. We found that treatment with 50 µM G-Rg1 protected microglial cells against oxidative damage induced by 10 µM t-BHP.

Daucosterol protects neurons against oxygen-glucose deprivation/reperfusion-mediated injury by activating IGF1 signaling pathway.

We previously reported that daucosterol (a sterolin) up-regulates the expression of insulin-like growth factor I (IGF1)(1) protein in neural stem cells. In this study, we investigated the effects of daucosterol on the survival of cultured cortical neurons after neurons were subjected to oxygen and glucose deprivation and simulated reperfusion (OGD/R)(2), and determined the corresponding molecular mechanism. The results showed that post-treatment of daucosterol significantly reduced neuronal loss, as well as apoptotic rate and caspase-3 activity, displaying the neuroprotective activity. We also found that daucosterol increased the expression level of IGF1 protein, diminished the down-regulation of p-AKT(3) and p-GSK-3ß(4), thus activating the AKT(5) signal pathway. Additionally, it diminished the down-regulation of the anti-apoptotic proteins Mcl-1(6) and Bcl-2(7), and decreased the expression level of the pro-apoptotic protein Bax(8), thus raising the ratio of Bcl-2/Bax. The neuroprotective effect of daucosterol was inhibited in the presence of picropodophyllin (PPP)(9), the inhibitor of insulin-like growth factor I receptors (IGF1R)(10). Our study provided information about daucosterol as an efficient and inexpensive neuroprotectants, to which the IGF1-like activity of daucosterol contributes. Daucosterol could be potentially developed as a medicine for ischemic stroke treatment.

Daucosterol promotes the proliferation of neural stem cells.

Neural stem cells (NSCs) are self-regenerating cells, but their regenerative capacity is limited. The present study was conducted to investigate the effect of daucosterol (a sterolin) on the promotion of NSC proliferation and determine the corresponding molecular mechanism. Results of cell counting kit-8 (CCK-8) assay showed that daucosterol significantly increased the quantity of viable cells and the effectiveness of daucosterol was similar to that of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Flow cytometry detection of CFSE-labeled (CFSE, carboxyfluorescein diacetate succinimidyl ester) NSCs showed that Div Index (or the average number of cell divisions) and % Divided (or the percentage of cells that divided at least once) of the cells were increased, indicating that daucosterol increased the percentage of NSCs re-entering the cell cycle. mRNA microarray analysis showed that 333 genes that are mostly involved in the mitotic cell cycle were up-regulated. By contrast, 627 genes that are mostly involved in differentiation were down-regulated. In particular, insulin-like growth factor I (IGF1) was considered as an important regulatory gene that functionally promoted NSC proliferation, and the increased expression of IGF1 protein was validated by ELISA. In addition, the phosphorylation of AKT was increased, indicating that the proliferation-enhancing activity of daucosterol may be involved in IGF1-AKT pathway. Our study provided information about daucosterol as an efficient and inexpensive growth factor alternative that could be used in clinical medicine and research applications.

Berberine inhibits norepinephrine-induced apoptosis in neonatal rat cardiomyocytes via inhibiting ROS-TNF-α-caspase signaling pathway.

OBJECTIVE: To determine the effect of berberine (Ber) on norepinephrine (NE)-induced apoptosis in neonatal rat cardiomyocytes. METHODS: The cultured neonatal rat cardiomyocytes were treated with NE in the presence or absence of Ber. The activity of lactate dehydrogenase (LDH) in the culture medium was examined, and apoptosis of cardiomyocytes was assessed by Hoechst 33258, isothiocyanate (FITC)-conjugated annexin-V, and propidine iodide (PI) staining. In addition, the activities of caspases-2 and-3 were measured by a fluorescent assay kit. The level of secreted tumor necrosis factor α (TNF-α) and production of intracellular reactive oxygen species (ROS) were also determined. RESULTS: NE at a concentration of 50 µ mol/L induced an obvious increase in the activity of LDH in the culture medium (P<0.05), which was inhibited by coincubation with 0.5, 1.0, or 2.0 µ mol/L Ber (P<0.05). Ber also significantly attenuated NE-induced apoptosis in a dose-dependent manner (P<0.01). Moreover, Ber at a dose of 2 µ mol/L markedly decreased the ROS and TNF-α productions (P <0.05) and inhibited the activation of caspases-2 and -3 in cardiomyocytes exposed to NE (P<0.05)h. CONCLUSION: The present study suggested that Ber could reduce NE-induced apoptosis in neonatal rat cardiomyocytes through inhibiting the ROS-TNF-α-caspase signaling pathway.

Luteolin reduces primary hippocampal neurons death induced by neuroinflammation.

OBJECTIVES: This study examined whether luteolin may exert an anti-inflammatory effect in microglia and may be neuroprotective by regulating microglia activation. METHODS: We treated BV2 microglia with 1.0 µg/ml lipopolysaccharide (LPS) after incubation with luteolin for 1 hour, the nitric oxide (NO) levels were determined by a Griess reaction, the inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-alpha), and interleukin 1beta (IL-1beta) mRNA expression were determined by real-time PCR analysis, the iNOS and COX-2 protein induction were determined by Western blot analysis, and the levels of prostaglandin E(2) (PGE(2)), TNF-alpha, and IL-1beta were determined by enzyme-linked immunosorbent assay (ELISA) kits. Rat primary hippocampal neurons were co-cultured with LPS-activated BV2 microglia with 20 µM luteolin for 24 hours, the hippocampal neurons viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the number of apoptotic hippocampal neurons was determined by immunofluorescence detection. RESULTS: Luteolin significantly inhibited the expression of iNOS and COX-2 in LPS-induced BV2 microglia. Moreover, the compound down-regulated the proinflammatory cytokines (TNF-alpha and IL-1beta) as well as the production of NO and PGE(2) in these cells. When hippocampal neurons were co-cultured with LPS-stimulated BV2 microglia, the administration of 20 µM luteolin increased the neurons viability and reduced the number of apoptotic neurons. CONCLUSION: These data demonstrate that anti-inflammatory activity of luteolin in microglia contributes to its neuroprotective effect and suggest that it may have a potential therapeutic application in the treatment of neurodegenerative diseases.

Luteolin inhibits microglial inflammation and improves neuron survival against inflammation.

Microglia activation is one of the causative factors for neuroinflammation, which results in brain damage during neurodegenerative disease. Accumulating evidence has shown that the flavonoid luteolin (Lut) possesses potent anti-inflammatory properties; however, its effect on microglia inhibition is currently unknown. Moreover, it is not clear whether Lut also has indirect neuroprotective effects by reducing inflammatory mediators and suppressing microglia activation. In this study, we examined the effects of Lut on lipopolysaccharide (LPS)-induced proinflammatory mediator production and signaling pathways in murine BV2 microglia. In addition, we cocultured microglia and neurons to observe the indirect neuroprotective effects of Lut. Lut inhibited the LPS-stimulated expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), and interleukin-1ß (IL-1ß) as well as the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)). Moreover, Lut blocked LPS-induced nuclear factor kappa B (NF-κB) activation. Preincubation of microglia with Lut diminished the neurotoxic effects, owing to the direct anti-inflammatory effects of the compound. Taken together, our findings suggest that Lut may have a potential therapeutic application in the treatment of neuroinflammatory disorders.

Pretreatment with berberine and yohimbine protects against LPS-induced myocardial dysfunction via inhibition of cardiac I-[kappa]B[alpha] phosphorylation and apoptosis in mice.

Myocardial dysfunction is a common complication in sepsis and significantly contributes to the mortality of patients with septic shock. Our previous study demonstrated that pretreatment with berberine (Ber) protected against the lethality induced by LPS, which was enhanced by yohimbine, an [alpha]2-adrenergic receptor antagonist, and Ber combined with yohimbine also improved survival in mice subjected to cecal ligation and puncture. However, no studies have examined whether Ber and yohimbine reduce LPS-induced myocardial dysfunction. Here, we report that pretreatment with Ber, Ber combined with yohimbine, or yohimbine significantly reduced LPS-induced cardiac dysfunction in mice. LPS-provoked cardiac apoptosis, I-[kappa]B[alpha] phosphorylation, IL-1[beta], TNF-[alpha], and NO production were attenuated by pretreatment with Ber and/or yohimbine, whereas cardiac Toll-like receptor 4 mRNA expression, malondialdehyde content, and superoxide dismutase activity were not affected. These data demonstrate for the first time that pretreatment with Ber and/or yohimbine prevents LPS-induced myocardial dysfunction in mice through inhibiting myocardial apoptosis, cardiac I-[kappa]B[alpha] phosphorylation, and TNF-[alpha], IL-1[beta], and NO production, suggesting that activation of [alpha]2-adrenergic receptor in vivo may be responsible at least in part for LPS-induced cardiac dysfunction, and Ber in combination with yohimbine may be a potential agent for preventing cardiac dysfunction during sepsis.

In vitro anti-viral activity of the total alkaloids from Tripterygium hypoglaucum against herpes simplex virus type 1.

Herpes simplex virus type 1 (HSV-1) is a commonly occurring human pathogen worldwide. There is an urgent need to discover and develop new alternative agents for the management of HSV-1 infection. Tripterygium hypoglaucum (level) Hutch (Celastraceae) is a traditional Chinese medicine plant with many pharmacological activities such as anti-inflammation, anti-tumor and antifertility. The usual medicinal part is the roots which contain about a 1% yield of alkaloids. A crude total alkaloids extract was prepared from the roots of T. hypoglaucum amd its antiviral activity against HSV-1 in Vero cells was evaluated by cytopathic effect (CPE) assay, plaque reduction assay and by RT-PCR analysis. The alkaloids extract presented low cytotoxicity (CC(50) = 46.6 µg/mL) and potent CPE inhibition activity, the 50% inhibitory concentration (IC(50)) was 6.5 µg/mL, noticeably lower than that of Acyclovir (15.4 µg /mL). Plaque formation was significantly reduced by the alkaloids extract at concentrations of 6.25 µg/mL to 12.5 µg/mL, the plaque reduction ratio reached 55% to 75 which was 35% higher than that of Acyclovir at the same concentration. RT-PCR analysis showed that, the transcription of two important delayed early genes UL30 and UL39, and a late gene US6 of HSV-1 genome all were suppressed by the alkaloids extract, the expression inhibiting efficacy compared to the control was 74.6% (UL30), 70.9% (UL39) and 62.6% (US6) respectively at the working concentration of 12.5 µg/mL. The above results suggest a potent anti-HSV-1 activity of the alkaloids extract in vitro.

Glycine inhibits the LPS-induced increase in cytosolic Ca2+ concentration and TNFalpha production in cardiomyocytes by activating a glycine receptor.

AIM: Previous studies have demonstrated that glycine (GLY) markedly reduces lipopolysaccharide (LPS)-induced myocardial injury.However, the mechanism of this effect is still unclear. The present study investigated the effect of GLY on cytosolic calcium concentration([Ca2+]c) and tumor necrosis factor-alpha (TNFalpha) production in cardiomyocytes exposed to LPS, as well as whether the glycine-gated chloride channel is involved in this process. METHODS: Neonatal rat cardiomyocytes were isolated, and the [Ca2+]c and TNFalpha levels were determined by using Fura-2 and a Quantikine enzyme-linked immunosorbent assay, respectively. The distribution of the GLY receptor and GLY-induced currents in cardiomyocytes were also investigated using immunocytochemistry and the whole-cell patch-clamp technique, respectively. RESULTS: LPS at concentrations ranging from 10 ng/mL to 100 microg/mL significantly stimulated TNFalpha production. GLY did not inhibit TNFalpha production induced by LPS at concentrations below 10 ng/mL but did significantly decrease TNFalpha release stimulated by 100 microg/mL LPS and prevented an LPS-induced increase in [Ca2+]c, which was reversed by strychnine, a glycine receptor antagonist. GLY did not block the isoproterenol-induced increase in [Ca2+]c, but did prevent the potassium chloride-induced increase in [Ca2+]c in cardiomyocytes.Strychnine reversed the inhibition of the KCl-stimulated elevation in [Ca2+]c by GLY. In chloride-free buffer, GLY had no effect on the dipotassium hydrogen phosphate-induced increase in [Ca2+]c. Furthermore, GLY receptor alpha1 and beta subunit-immunoreactive spots were observed in cardiomyocytes, and GLY-evoked currents were blocked by strychnine. CONCLUSION: Cardiomyocytes possess the glycine-gated chloride channel, through which GLY prevents the increase in [Ca2+]c and inhibits the TNFalpha production induced by LPS at high doses in neonatal rat cardiomyocytes.

[Therapeutic effect of intravenous high-dose vitamin C on implanted hepatoma in rats].

OBJECTIVE: To study the therapeutic effect of intravenous high-dose vitamin C on implanted hepatoma in rats. METHODS: The rats bearing implanted Walker-256 hepatoma were treated with high-dose vitamin C at 2.83 and 5.65 g/kg intravenously, and the general condition, liver functions (A/G, ALT, AST, GGT), tumor volume, and tumor growth of the rats were evaluated. RESULTS: The A/G of the rats treated with 2.83 g/kg vitamin C was significantly higher, but the ALT and GCT were significantly lower than those of the model rats (P<0.05 or 0.01). The ALT level in rats with 5.65 g/kg vitamin C treatment was significantly lower than that of the model rats (P<0.05). The tumor necrosis rate was significantly higher in rats with 2.83 g/kg vitamin C treatment than in the model rats (P<0.05). CONCLUSION: Intravenous administration of 2.83 g/kg vitamin C can promote the necrosis and apoptosis of hepatoma Walker256 cells in rats and protect the liver function of the tumor-bearing rats.

[Influence of different treatment patterns on cost-effectiveness in treatment of acute myocardial infarction].

OBJECTIVE: To investigate the influences of different treatment patterns on the cost-effectiveness in treating acute myocardial infarction (AMI). METHODS: Data about referral of AMI patients who called for help because of chest pain to the nearby hospitals from October 2003 to December 2005 were collected from the Guangzhou 120 Call Center. All these patients were followed up 6 months after discharge to survey the cost during hospitalization, major treatment, prognosis (death, re-infarction, stroke etc. ), and secondary prevention for coronary heart disease. We used SF-36 scale was used to quantify the health status. RESULTS: 101 AMI patients referred to grade 2 A hospitals (Group A) and 137 patients referred to grade 3 A hospitals (Group B) were successfully followed up. The cost during hospitalization of Group B was (33965 +/- 963) yuan RMB, significantly higher than that of Group A (18943 +/- 893) yuan, P = 0.021). 11 patients of Group B died, and 5 patients suffered from stroke with the mortality and stroke rate both significantly lower than those of Group A (18/101 and 12/101, P = 0.022, P = 0.015). There was no significant difference in the re-infarction rate between the 2 groups. The scores in physical function, general health status, vitality, social function, role-emotional, mental health of Group B were all significantly higher than those of Group A (all P < 0.05) , however, there were not significant differences in body pain and role-physical between these 2 groups. The smoking cessation rate, specialist outpatient department follow-up rate, statins use rate of Group B were significantly higher than those of Group A (P = 0.017, P = 0.016, P = 0.038). CONCLUSION: The 120-grade 3 A hospital CCU pattern is more cost-effective in treatment of AMI.

Curcumin improves learning and memory ability and its neuroprotective mechanism in mice.

BACKGROUND: Increasing evidence suggests that many neurons may die through apoptosis in Alzheimer's disease (AD). Mitochondrial dysfunction has been implicated in this process of neuronal cell death. One promising approach for preventing AD is based upon anti-apoptosis to decrease death of nerve cells. In this study, we observed the memory improving properties of curcumin in mice and investigated the neuroprotective effect of curcumin in vitro and in vivo. METHODS: The mice were given AlCl(3) orally and injections of D-galactose intraperitoneally for 90 days to establish the AD animal model. From day 45, the curcumin group was treated with curcumin for 45 days. Subsequently, the step-through test, neuropathological changes in the hippocampus and the expression of Bax and Bcl-2 were carried out to evaluate the effect of curcumin on the AD model mice. In cultured PC12 cells, AlCl(3) exposure induced apoptosis. The MTT assay was used to measure cell viabilities; flow cytometric analysis to survey the rate of cell apoptosis; DNA-binding fluorochrome Hoechst 33258 to observe nuclei changes in apoptotic cells and Western blot analysis of Bax, Bcl-2 to investigate the mechanisms by which curcumin protects cells from toxicity. RESULTS: Curcumin significantly improved the memory ability of AD mice in the step-through test, as indicated by the reduced number of step-through errors (P < 0.05) and prolonged step-through latency (P < 0.05). Curcumin also attenuated the neuropathological changes in the hippocampus and inhibited apoptosis accompanied by an increase in Bcl-2 level (P < 0.05), but the activity of Bax did not change (P > 0.05). AlCl(3) significantly reduced the viability of PC12 cells (P < 0.01). Curcumin increased cell viability in the presence of AlCl(3) (P < 0.01). The rate of apoptosis decreased significantly in the curcumin group (P < 0.05) when measured by flow cytometric analysis. Curcumin protected cells by increasing Bcl-2 level (P < 0.05), but the level of Bax did not change (P > 0.05). CONCLUSIONS: This study demonstrates that curcumin improves the memory ability of AD mice and inhibits apoptosis in cultured PC12 cells induced by AlCl(3). Its mechanism may involve enhancing the level of Bcl-2.

Berberine inhibits cytosolic phospholipase A2 and protects against LPS-induced lung injury and lethality independent of the alpha2-adrenergic receptor in mice.

Acute lung injury is still a significant clinical problem having a high mortality rate despite significant advances in antimicrobial therapy and supportive care made in the past few years. Our previous study demonstrated that berberine (Ber) remarkably decreased mortality and attenuated the lung injury in mice challenged with LPS, but the mechanism behind this remains unclear. Here, we report that pretreatment with Ber significantly reduced pulmonary edema, neutrophil infiltration, and histopathological alterations; inhibited protein expression and phosphorylation of cytosolic phospholipase A2; and decreased thromboxane A2 release induced by LPS. Yohimbine, an alpha2-adrenergic receptor antagonist, did not antagonize these actions of Ber. Furthermore, pretreatment with Ber decreased TNF-alpha production and mortality in mice challenged with LPS, which were enhanced by yohimbine, and Ber combined with yohimbine also improved survival rate in mice subjected to cecal ligation and puncture. Taken together, these observations indicate that Ber attenuates LPS-induced lung injury by inhibiting TNF-alpha production and cytosolic phospholipase A2 expression and activation in an alpha2-adrenoceptor-independent manner. Berberine combined with yohimbine might provide an effective therapeutic approach to acute lung injury during sepsis.

Neutral sulfate berberine modulates cytokine secretion and increases survival in endotoxemic mice.

AIM: Berberine is thought to be an immunomodulator, so the present study aimed to investigate the effect of berberine on mortality, lung and intestine injury in endotoxemic mice, and the mechanism of its action. METHODS: Mice were challenged with lipopolysaccharide (LPS, 28 mg/kg, ip), and neutral sulfate berberine was administrated intragastrically. Mortality was monitored every 12 h, and histology of the lungs and intestine as well as the plasma tumor necrosis factor-alpha (TNF-alpha), interferon- gamma (IFN-gamma), interleukin-12 (IL-12), IL-10, and nitric oxide (NO) levels were examined. RESULTS: Pretreatment with 50 mg/kg neutral sulfate berberine once a day for 5 days significantly decreased the mortality rate and attenuated tissue injury of the lungs and small intestine in mice challenged with LPS. LPS stimulated a marked increase in plasma levels of TNF-alpha, IFN- gamma, IL-12, IL-10, and NO. The administration of berberine significantly reduced plasma TNF-alpha, IFN- gamma, and NO levels, but did not suppress plasma IL-12 levels in mice exposed to LPS. Furthermore, pretreatment with neutral sulfate berberine augmented IL-10 secretion stimulated by LPS in mice. CONCLUSION: Pretreatment with neutral sulfate berberine attenuates tissue injury and improves survival in endotoxemic mice, which may be mediated, at least in part, by the inhibition of pro-inflammatory mediator production and upregulation of IL-10 release. These findings might provide a new strategy for the treatment of endotoxemia.

Effects of neutral sulfate berberine on LPS-induced cardiomyocyte TNF-alpha secretion, abnormal calcium cycling, and cardiac dysfunction in rats.

AIM: To evaluate the effect of neutral sulfate berberine on cardiac function, tumor necrosis factor alpha (TNF-alpha) release, and intracellular calcium concentration ([Ca(2+)]i) in cardiomyocytes exposed to lipopolysaccharide (LPS). METHODS: Primary cultured rat cardiomyocytes were prepared from ventricles of 3-4-day old Sprague-Dawley rats. TNF-alpha concentrations in cell-conditioned media were measured by using a Quantikine enzyme-linked immunosorbent assay kit, and cardiomyocyte [Ca(2+)]i was measured by using Fura-2/AM. The isolated rat hearts were perfused in the Langendorff mode. RESULTS: LPS at doses of 1, 5, 10, and 20 microg/mL markedly stimulated TNF-alpha secretion from cardiomyocytes, and neutral sulfate berberine inhibited LPS-induced TNF-alpha production. Intracellular calcium concentration was significantly decreased after LPS stimulation for 1 h, and increased 2 h after LPS treatment. Pretreatment with neutral sulfate berberine reversed the LPS-induced [Ca(2+)]i alterations, although neutral sulfate berberine did not inhibit a rapid increase in cardiomyocyte [Ca(2+)]i induced by LPS. Perfusion of isolated hearts with LPS (100 microg/mL) for 20 min resulted in significantly impaired cardiac performance at 120 min after LPS challenge: the maximal rate of left ventricular pressure rise and fall (+/-dp/dt(max)) decreased compared with the control. In contrast, +/-dp/dt(max) at 120 min in hearts perfused with neutral sulfate berberine (1 micromol/L) for 10 min followed by 20 min LPS (100 microg/mL) was greater than the corresponding value in the LPS group. CONCLUSION: Neutral sulfate berberine inhibits LPS-stimulated myocardial TNF-alpha production, impairs calcium cycling, and improves LPS-induced contractile dysfunction in intact heart.