The effect of in situ cadmium contamination on some biomarkers in Cerastoderma glaucum

The present study was designed to detect in situ effects of cadmium on marine organisms Cerastoderma glaucum from the gulf of Gabès (Tunisia). Six sampling stations were chosen: one site, relatively far from known local source of pollution, was considered as uncontaminated site and five sites clearly exposed to anthropogenic impact. Metallothionein like protein (MTLP) and sub-cellular metal partitioning were measured in cockles (C. glaucum) gills and digestive gland. Various biomarkers were also measured, including malondialdehyde (MDA) in the digestive gland and acetylcholinesterase activity (AChE) in the remainder. The health status of the cockles was assessed by using the condition index (CI). Significant differences between sites were noted for Cd concentrations, (CI) and also for the three studied biomarkers. Significant higher biomarkers response was measured in cockles from stations located in the northern part of the gulf, which are exposed directly to industrial and urban effluents, whereas the response of most biomarkers was minimal at the reference station. Positive and significant correlations were observed between MTLP and Cd concentrations in the digestive gland and in the gills. However, it must be noted that these correlations were more significant in the digestive gland, suggesting that compared to the gills, the digestive gland of C. glaucum is more suitable for monitoring metal pollution. The subcellular distribution of Cd showed that the soluble fraction was the major compartment for Cd storage, a pattern which is due to the role of MTLP in Cd detoxication. But at the most contaminated site (EH), cadmium in the digestive gland was preferentially accumulated in the insoluble fraction (P1) suggesting that the MTLP capacity in binding metals was not sufficient to avoid the binding of Cd to the insoluble fraction. Furthermore, the MTLP concentrations in the cockles from this site are lower than expected. So in highly polluted sites, MTLP in C. glaucum should not be used as a useful biomarker for metal pollution. The lipid peroxidation as presented by malondialdehyde levels, and MT-like protein concentrations increased in cockles exposed to cadmium contamination. We can, therefore, hypothesize that Cd could induce MTLP synthesis and MDA increase. While AChE had distinct and specific pattern showing that cadmium is not the only factor of the inhibition of cholinesterase activity. There are other polluting inputs engendering this inhibition.     

Modulatory effect of phytoglycoprotein (38?kDa) on cyclin D1/CDK4 in BNL CL.2 cells induced by N-methyl-N′-nitro-N-nitrosoguanidine

In the developmental stages of cancer, cell transformation occurs after the promotion stage and is a marker of cancer progression. This cell transformation is related to abnormal proliferation during the cancer initiation stage. The purpose of this study was to evaluate the effect of Styrax japonica Siebold et al. Zuccarin (SJSZ) glycoprotein on cell transformation in murine embryonic liver cells (BNL CL.2) following N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) treatment. To determine abnormal proliferation during the initiation stage, intracellular reactive oxygen species (ROS), phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), activities of cell cycle-related factors [cyclin D1/cyclin dependent kinase (CDK) 4], cell cycle inhibitors (p53, p21, and p27), nuclear factor (NF)-κB, and proliferating cell nuclear antigen (PCNA) were evaluated using Western blot analysis and real-time PCR. Our study demonstrated that SJSZ glycoprotein (50 μg/ml) reduces foci formation with combined treatment [MNNG and 12-O-tetradecanoyl phorbol-13-acetate] of BNL CL.2 cells. With regard to proliferation-related signals, our finding indicated that SJSZ glycoprotein (50 μg/ml) diminished the production of intracellular ROS, activity of phosphorylated ERK, p38 MAPK, NF-κB (p50 and p65), PCNA, and cyclin D1/CDK4 in MNNG-induced BNL CL.2 cells. Taken together, these results lead us to speculate that SJSZ glycoprotein can inhibit abnormal cell proliferation at the initiation stage of hepatocarcinogenesis.     

Inhibitory effect of(-),( )clausenamide on acetylcholinesterase in vitro

用Ｅｌｍａｎ比色法测定乙酰胆碱酯酶（ＡＣｈＥ）的活性，观察（－），（＋）黄皮酰胺对小鼠脑组织海马，前脑皮层和红细胞膜ＡＣｈＥ活性的影响，以探索药物作用机制并比较左右旋体黄皮酰胺作用的异同．结果表明：（－），（＋）黄皮酰胺对海马和皮层ＡＣｈＥ均有抑制作用，（－）黄皮酰胺对小鼠脑皮层和海马ＡＣｈＥ抑制的ＩＣ５０（９５％可信限）值分别为０．３１（０．２７－０．３６）和０．３３（０．２８－０．３９）ｍｍｏｌ·Ｌ－１；（＋）黄皮酰胺对小鼠脑皮层和海马ＡＣｈＥ抑制的ＩＣ５０（９５％可信限）值分别为０．７１（０．５３－０．９４）和０．７７（０．５５－１．０７）ｍｍｏｌ·Ｌ－１．（－），（＋）黄皮酰胺对红细胞膜ＡＣｈＥ的抑制作用是可逆性的，抑制特点属于竞争与非竞争混合型抑制，（－）黄皮酰胺的Ｋｉ值为０．２６ｍｍｏｌ·Ｌ－１，Ｋｉ′值为１．２０５ｍｍｏｌ·Ｌ－１；（＋）黄皮酰胺Ｋｉ值为０．７２ｍｍｏｌ·Ｌ－１，Ｋｉ′值为１．８５６ｍｍｏｌ·Ｌ－１．提示：（－）黄皮酰胺作用强于（＋）黄皮酰胺．黄皮酰胺的抑制ＡＣｈＥ作用存在手性选择性．     

Cellular glutathione content modulates the effect of andrographolide on β-naphthoflavone-induced CYP1A1 mRNA expression in mouse hepatocytes

We previously reported that andrographolide (Andro), a major bioactive constituent of Andrographis paniculata, synergistically enhanced the inducible expression of CYP1A1 mRNA. In this study, although the synergism was confirmed at 24h after the start of treatment with Andro and β-naphthoflavone (βNF), a CYP1A inducer, the expression was profoundly suppressed at an earlier phase, namely at 6-12h, when the βNF-induced expression peaked. Although oxidized glutathione (GSSG) levels were higher in co-treated cells at 6 and 24h, levels of reactive oxygen species varied depending on the treatment period and species, indicating no relation to the synergistic expression of CYP1A1 mRNA. Glutathione (GSH) and N-acetyl-l-cysteine (NAC) significantly enhanced the βNF-induced expression, and partly reversed the suppressive effect of Andro in the early phase. At 24h, the addition of GSH or NAC had no effect on βNF-induced CYP1A1 mRNA expression, but significantly reduced the synergistic effect of Andro. The synergistic effect was enhanced by l-buthionine-(S,R)-sulfoximine, a GSH depleter. Furthermore, H(2)O(2) and ascorbic acid further modified the profile of synergism of Andro on βNF-inducible CYP1A1 mRNA expression. These results suggest that GSH status might be involved in βNF-induced CYP1A1 mRNA expression, and the interaction of Andro with GSH might modulate the expression.     

AMPA-receptor activation is involved in the antiamnesic effect of DM 232 (unifiram) and DM 235 (sunifiram)

DM 232 and DM 235 are novel antiamnesic compounds structurally related to ampakines. The involvement of AMPA receptors in the mechanism of action of DM 232 and DM 235 was, therefore, investigated in vivo and in vitro. Both compounds (0.1 mg/kg^–1 i.p.) were able to reverse the amnesia induced by the AMPA receptor antagonist NBQX (30 mg/kg^–1 i.p.) in the mouse passive avoidance test. At the effective doses, the investigated compounds did not impair motor coordination, as revealed by the rota rod test, nor modify spontaneous motility and inspection activity, as revealed by the hole board test. DM 232 and DM 235 reversed the antagonism induced by kynurenic acid of the NMDA-mediated release of [³H]NA in the kynurenate test performed in rat hippocampal slices. This effect was abolished by NBQX. DM 232 increases, in a concentration dependent manner, excitatory synaptic transmission in the rat hippocampus in vitro. These results suggest that DM 232 and DM 235 act as cognition enhancers through the activation of the AMPA-mediated neurotransmission system.     

Regulating effect of carbonic anhydrase (CA) inhibitor on aquaporin-1 (AQP1) water channel gene expression in rat kidney

AIM: To investigate whether the aquaporin-1 (AQR-1) geneexpression can be regulated by acetazolamide, a carboincanhydrase inhibitor in rat kidney. Carbonic anhydrase inhibitor isone of the diuretics with the site of action on renal proximaltubules. And AQP-1 wate channel is located on the epithelialcells of the renal proximal tubules with the function of facilitatingwater transport across proximal tubules epithelia. METHODS:The kidneys were excised from immature (20 d) female rat at     

Effect of cadmium on cortisol production and 11β-hydroxysteroid dehydrogenase 2 expression by cultured human choriocarcinoma cells (JEG-3)

Cadmium is a toxicant with known carcinogenic and endocrine disruptor effects. We have previously reported that prenatal exposure to cadmium may induce low birth weight which is associated to increased foetal exposure to glucocorticoids; both signals constitute “hallmarks” of developmental programming. Since the effect of cadmium on the glucocorticoid system of placental carcinogenic cells is unknown, in the present work, we studied the effect of acute low dose of cadmium on cortisol production and 11β-HSD2 expression and activity by cultured human choriocarcinoma cells (JEG-3). In addition, it was also evaluated whether those effects were related to the methylation index of the HSD11B2 gene, which can be regulated by epigenetic mechanisms. Cells were incubated with low cadmium dose (0.5 and 1 μM) for 24 h and viability (MTT), cortisol production (EIA), 11β-HSD2 expression (qRT-PCR) and activity (radioassay), and methylation index of the HSD11B2 gene were determined.Results show lower cortisol concentrations in the incubation media of exposed cells, which were associated to increased 11β-HSD2 expression and activity and to a lower methylation index of the gene. These results suggest that cadmium-induced endocrine disruptor effects on JEG-3 cells could be mediated by changes in the methylation status of some target genes.     

Neuroprotective effect of sinapic acid in a mouse model of amyloid β1-42 protein-induced Alzheimer's disease

Sinapic acid (SA) is a phenylpropanoid compound with anti-inflammatory and neuroprotective activities. The neuroprotective effects of SA in a mouse model of amyloid β (Aβ)_1-42 protein-induced Alzheimer's disease (AD) were investigated. Mice received a bilateral injection of Aβ_1-42 protein into the hippocampus to verify the efficacy of SA. Mice were treated with SA (10 mg/kg/day, p.o.) for 7 days beginning immediately after Aβ_1-42 protein injection, and an acquisition trial of the passive avoidance task was conducted 1 h after the last administration of SA. Retention trial was conducted 24 h after the acquisition trial, and mice were sacrificed for immunohistochemistry immediately after the retention trial. SA rescued neuronal cell death in the hippocampal CA1 region and also attenuated the increase of iNOS expression, glial cell activations and nitrotyrosine expressions induced by Aβ_1-42 protein. SA significantly attenuated memory impairment in the passive avoidance task. These results suggest that SA ameliorated Aβ_1-42 protein-related pathology including neuronal cell death and cognitive dysfunction via its anti-oxidative and anti-inflammatory activities, and may be an efficacious treatment for AD.     

Characterization of the hepatic cellular uptake of α(1) -acid glycoprotein (AGP), part 1: a peptide moiety of human AGP is recognized by the hemoglobin β-chain on mouse liver parenchymal cells

Human α(1) -acid glycoprotein (AGP), a serum glycoprotein, is known to have anti-inflammatory activity. We recently reported that AGP was mainly incorporated into the liver in mice via a receptor-mediated pathway, although the mechanism for this was largely unknown. The objective of this study was to identify the specific cellular surface protein that recognizes the peptide moiety of AGP. Pharmacokinetic studies of (111) In-AGP and (111) In -recombinant glycan-deficient AGP (rAGP) in mice demonstrated that both AGPs are mainly distributed to the liver and kidney, but hepatic and renal uptake clearance of rAGP was higher than that for AGP. Hepatic uptake of rAGP was inhibited in the presence of 100-fold excess of unlabeled AGP, indicating that the hepatic uptake of rAGP shared a common route with that of AGP and that it recognized the peptide moiety of AGPs. In ligand blotting analyses using crude cellular membrane fraction of mice liver, a band corresponding to a 16 kDa protein was observed to bind to both AGPs. Interestingly, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry MALDI-TOF-MS and western blotting analyses indicated that this 16 kDa protein is the hemoglobin β-chain (HBB). It, therefore, appears that HBB is associated with the hepatic uptake of AGP via a direct interaction with its peptide moiety.     

Dibenzofuran induces oxidative stress,disruption of trans-mitochondrial membrane potential (ΔΨm) and G1 arrest in human hepatoma cell line

Dioxins are a class of extremely toxic environmentally persistent pollutant, comprised of halogenated dibenzo-p-dioxins, dibenzofurans and biphenyls. Despite significant human exposure via multiple routes, very little is known about toxicity induced by dibenzofuran (DF). Current study shed lights on the potential toxicity mechanism of DF using human hepatoma cell line (HepG2). It was observed that the exposure to DF potentiate oxidative stress, apoptosis and necrosis at 10 μM within 8 h in HepG2 cells. Interestingly, when we pre-incubated the cells with α-NF (1 nM) for 12 h, an aromatic hydrocarbon receptor antagonist, the IC₅₀ of DF increased by 14 folds indicating the cytoprotective ability of α-NF from DF induced toxicity. Furthermore, three additional metabolites were observed while studying the metabolic profile of DF in HepG2 cells with and without pre-incubation with α-NF using chromatography–mass spectroscopy (GC–MS). Of these, two metabolites were characterized as dihydroxylated derivative of DF and third metabolite was characterized as quinone derivative of DF. By flow cytometry and confocal laser microscopy analysis we followed the ROS formation after DF (10 μM) exposure for 3 h. Significantly low ROS was generated in cells which were pre-incubated with α-NF than cells which were not pre-incubated with α-NF underlining the importance of metabolism in DF toxicity. The same pattern of protection was consistent while measuring mitochondrial membrane potential (MMP), i.e., less MMP dip was observed in ‘with α-NF pre-incubated and DF (10 μM) exposed cells’ than ‘without α-NF pre-incubated but DF exposed cells’. In cell cycle studies, it was confirmed that cell population of HepG2 at G1 stage progressively increased in number (∼74%) within 24 h. Thus, DF and its metabolites induce significantly higher cytotoxicity after metabolism in HepG2 cells than its parent compound (DF) by ROS formation, MMP dip and impaired cell cycle.     

Apoptotic effect of Aralia echinocaulis extract on fibroblast-like synoviocytes in rats with adjuvant-induced arthritis via inhibiting the Akt/Hif-1α signaling pathway in vitro

Aralia echinocaulis is used for the treatment of rheumatoid arthritis by Tujia Minority in China. A previous study demonstrated that A. echinocaulis had a significant anti-arthritic effect on adjuvant arthritis (AA) rats in vivo. However, it remains unclear whether A. echinocaulis can induce the apoptosis of fibroblast-like synoviocytes (FLS) from AA rats and the underlying mechanism is unknown. In this paper, CCK-8 assay, Hoechst staining and flow cytometry were used to evaluate the apoptotic effect of an A. echinocaulis ethanol extract (AEE) on AA FLS. Western blotting analysis was performed to measure the protein expression levels of Bcl-2, Bax, cleaved caspase-3, Akt, p-Akt, and Hif-1α. The results revealed that AEE could inhibit FLS proliferation in a dose and time-dependent manner. After treatment with AEE, AA FLS displayed the classical apoptotic morphology, and the apoptosis rates were significantly increased. Furthermore, we found that AEE increased the protein levels of Bax, cleaved caspase 3, and decreased the protein levels of Bcl-2, Hif-1α and p-Akt, without affecting total Akt levels. Collectively, these results suggested that the apoptosis inducing effect of AEE on AA FLS was related to the regulation of the expression of apoptosis-related proteins and the inhibition of the Akt/Hif-1α signaling pathway.     

Inhibitory effect of antisense oligodeoxynucleotide to p44/p42 MAPK on angiotensin Ⅱ-induced hypertrophic response in cultured neonatal rat cardiac myocyte

AIM: To explore the inhibitory effect of antisense oligonucleotide (ODN) to mitogen activated protein kinase (MAPK) on cardiomyocyte hypertrophy induced by angiotensin Ⅱ (Ang Ⅱ). METHODS: A 17-mer phosphorothioate protected antisense ODN directed against the initiation of translation sites of the p42 and p44 MAPK isoforms by liposomal transfection was applied to inhibit the translation of p44/p42 MAPK mRNA. The sense and random ODNs to p44/p42MAPK were used as sequence controls. Neonatal cardiac myocytes were exposed to Ang Ⅱ (10 nmol/L) for 5 min and then harvested in lysis buffer for the measurement of the activity and the phosphorylated protein content of p44/p42MAPK that were tested by P-81 phosphocellulose filter paper method and Western blotting, respectively. The     

Differential effects of systemically administered nor-binaltorphimine (nor-BNI) on κ-opioid agonists in the mouse writhing assay

The opioid antagonist effects of systemically administered nor-binaltorphimine (nor-BNI) were evaluated against the kappa agonists CI-977, U69,593, U50,488, ethylketocyclazocine (EKC), Mr2034 and bremazocine, the mu agonist morphine and the alkaloid delta agonist BW-373U86 in the acetic acid-induced writhing assay in mice. All eight agonists completely and dose-dependently inhibited writhing. Antagonism of CI-977 was apparent 1 h after administration of 32 mg/kg nor-BNI, peaking after 4 h and was maintained for at least 4 weeks; no antagonist effects of nor-BNI were apparent after 8 weeks. Nor-BNI (32 mg/kg) caused little or no antagonism of morphine or BW-373U86 at 1 h and none at 24 h after nor-BNI administration. Subsequently, dose-effect curves for CI-977, U50,488, U69,593, EKC, Mr2034 and bremazocine were determined 24 h after pretreatment with 3.2, 10 and 32 mg/kg nor-BNI. Pretreatment with 3.2 mg/kg nor-BNI produced significant antagonism of all six kappa agonists, suggesting that their antinociceptive effects were mediated at least in part by nor-BNI-sensitive kappa receptors. At higher doses, nor-BNI dose-depend-ently shifted the agonist dose-effect curves of CI-977, U50,488, U69,593 and bremazocine, but not those of EKC and Mr2034, suggesting that the latter compounds may be producing effects via nor-BNI-insensitive receptors. Mu receptor involvement was demonstrated following a 24 h pretreatment with 32 mg/kg-FNA in combination with nor-BNI, which significantly increased the degree of antagonism of Mr2034 and EKC from that seen with nor-BNI alone. Hence, SC administered nor-BNI selectively antagonized agonist activity mediated through kappaopioid receptors without differentiating between kappa subtypes. Nor-BNI also enabled the mu agonist activity of proposed kappa agonists to be measured.A preliminary report of these findings was made at the International Narcotic/Research/Conference in Keystone, CO, June, 1992. This work was supported by USPHS grant DA 00254. Animals used in these studies were maintained in accordance with the University Committee on Use and Care of Animals, University of Michigan, and guidelines of the Committee on Care and Use of Laboratory Animal Resources, National Research Council (Department of Health, Education and Welfare, Publication No. (NIH) 85-23, revised 1983)     

The effect of C-terminal fragment of ANF-ANF(24–28)OH on the cardiovascular system in rat

1. The effect of C-terminal fragment of ANF-ANF(24–28)OH on the cardiovascular system was investigated in rats2. _{In vivo} this pentapeptide caused the fall of systolic and diastolic blood pressure.3. ANF(24–28)OH increased cardiac contraction amplitude and changed coronary outflow in vitro.4. These experiments showed that the shorter fragment of ANF containing five amino acids: Asn24-Ser25-Phe26-Arg27-Tyr28-COOH is a bioactive substance.     

Essential role of ICAM-1/LFA-1 interaction in synergistic effect of IL-18 and IL-12 on IFN-γ production in human PBMC

IL-18 (0-100 ng/ml) specifically upregulated ICAM-1 expression on monocytes in human PBMC as demonstrated in our previous study. In the present study, we examined whether the synergistic upregulation of ICAM-1 occurred after the stimulation with the combination of IL-18 and IL-12 and whether the synergistic production of IFN-gamma was dependent on the interaction between ICAM-1 on monocytes and LFA-1 on NK/T cells. The effect of IL-12 on ICAM-1 expression on monocytes was marginal even at the highest concentration (100 ng/ml). However, in the presence of IL-12 (100 ng/ml), the expression of ICAM-1 induced by IL-18 was significantly enhanced as compared with that obtained by IL-18 alone. In addition to the expression of ICAM-1 on monocytes, IFN-gamma production was synergistically stimulated by IL-18 and IL-12. Anti-ICAM-1 and anti-LFA-1 Abs exhibited significant inhibitory effect on enhanced production of IFN-gamma by the combination of two cytokines, in particular, anti-ICAM-1 showing the complete inhibition. These results as a whole indicated that synergistic effect of IL-18 and IL-12 on IFN-gamma production in human PBMC is ascribed to the synergism of the effect of two cytokines on ICAM-1 expression on monocytes and that the subsequent ICAM-1/LFA-1 interaction plays an important role in the enhanced production of IFN-gamma.     

Inhibitory effect of siRNA complexes with polyamidoamine dendrimer/α-cyclodextrin conjugate (generation 3, G3) on endogenous gene expression

In the present study, we prepared the small interfering RNA (siRNA) complexes with polyamidoamine (PAMAM) dendrimer (G3) conjugate with α-cyclodextrin (α-CDE (G3)), and examined the physicochemical properties, serum resistance, in vitro RNAi effects on endogenous gene expression, cytotoxicity, interferon response, hemolytic activity, cellular association and intracellular distribution. In addition, these results were compared to the siRNA complexes with the commercial transfection reagents such as linear polyethyleneimine (PEI), Lipofectamine?2000 (L2) and RNAiFect? (RF). α-CDE (G3) interacted with siRNA, and suppressed siRNA degradation by serum. The siRNA complex with α-CDE (G3) showed the potent RNAi effects against Lamin A/C and Fas expression with negligible cytotoxicity and hemolytic activity, compared to those of the transfection reagents in Colon-26-luc cells and NIH3T3-luc cells. Cell-death patterns induced by siRNA polyplexes with α-CDE (G3) and PEI were different from siRNA lipoplexes with L2 and RF. α-CDE (G3) delivered fluorescent-labeled siRNA to cytoplasm, not nucleus, after transfection in NIH3T3-luc cells. Taken together, α-CDE (G3) could be potentially used as a siRNA carrier to provide the RNAi effect on endogenous gene expression with negligible cytotoxicity.     

CTB glycoprotein (75 kDa) inhibits IgE releasing,TNF-α and IL-6 expressed by bisphenol A in vivo and in vitro

Cudrania tricuspidata Bureau (CTB) has been used to treat allergies and inflammatory disease as folk medicine in Korea. The objective of this study is to determine whether a glycoprotein isolated from CTB (75 kDa) has a preventive potential of allergic inflammation caused by bisphenol A (BPA) in BALB/c mice and RBL-2H3 cells. Production of immunoglobulin (Ig) E and releasing of β-hexosaminidase and histamine at treatment of CTB glycoprotein (5–10 mg/kg, BW) were evaluated in mice serum. Activation of extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinase (MAPK), activator protein (AP)-1, expressions of pro-inflammatory cytokines, nitric oxide (NO) production and cyclooxygenase (COX)-2 were assessed in RBL-2H3 cells. In the results, CTB glycoprotein (10 mg/kg, BW) inhibited the production of IgE and releasing of β-hexosaminidase and histamine. Also, the CTB glycoprotein (100 μg/ml) blocked phosphorylation of ERK1/2 and p38 MAPK, and the activation of AP-1, while it inhibited the NO production, activities of COX-2, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, but not IL-1β. Taken together, the results of this study indicated that the CTB glycoprotein modulates the expression of allergic inflammation-related factors via the suppression of MAPK/AP-1 activation.     

Anti-inflammatory effects of higenamine (Hig) on LPS-activated mouse microglia (BV2) through NF-κB and Nrf2/HO-1 signaling pathways

Microglia are the most widely equipped protective cells in the brain and play a pivotal role in the development of neurological diseases. Inflammatory response and oxidative stress are critical risk factors in the activation of microglia which may cause various neurological diseases. Higenamine (Hig), a plant-based alkaloid and isolated from Aconite tuber, exhibits various properties and is mainly applied to treat heart failure. In addition, Hig expresses potential protective effects for neurodegenerative diseases. However, the effects and mechanisms of Hig on lipopolysaccharide (LPS) activated mouse microglia has not been fully explored. Therefore, we evaluated the anti-inflammatory effects of Hig on LPS-activated BV2 microglia and revealed the underlying mechanisms. Our data showed that Hig significantly inhibited the production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), reactive oxygen species (ROS) as well as NO (mediated by iNOS) and PGE₂ (mediated by COX2) in LPS-activated BV2 cells. Then we found that Hig suppressed NF-κB signaling pathway by inhibiting nuclear translocation of NF-κB/p65 subunit as well as degradation and phosphorylation of IκBα in cytoplasm, and the effect of Hig was intimately related to NF-κB inhibitor BAY-11-7082. Furthermore, we found that the anti-inflammatory effect of Hig were accompanied by the promotion of heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor-2 (Nrf2) expression, which was partly reversed by protoporphyrin (SnPP) and Nrf2 siRNA, respectively. Taken together, our results demonstrated that Hig expressed significant anti -inflammatory and -oxidative effects by inhibiting NF-κB and activating Nrf2/HO-1 signaling pathways.     

Piperacillin enhances the inhibitory effect of tazobactam on β-lactamase through inhibition of organic anion transporter 1/3 in rats

To assess the mechanism of the pharmacokinetic interaction between piperacillin and tazobactam, renal excretion and pharmacokinetic studies of piperacillin/tazobactam were investigated in normal and bacteremia rats. A bacteremia model was established to investigate the pharmacokinetic properties of piperacillin and tazobactam under different conditions. Renal slices were taken to examine the uptake of piperacillin and tazobactam. Pharmacokinetic studies of β-lactamase in rats were performed to study the contribution of rOat1/3 to the inhibition of tazobactam on β-lactamase. The AUC (from 2.93 ± 0.58 to 6.52 ± 1.44 mg·min/ml) and the plasma clearance (CL_P) (from 2.41 ± 1.20 to 0.961 ± 0.212 ml/min/kg) of tazobactam were both altered after the intravenous coadministration of piperacillin and tazobactam in the bacteremia rats. The renal clearance (CL_R) of tazobactam decreased from 1.30 ± 0.50 to 0.361 ± 0.043 ml/min/kg. In summary, there was a beneficial interaction between piperacillin and tazobactam mediated by rOat1 and rOat3. Piperacillin enhances the inhibitory effect of tazobactam on β-lactamase through the inhibition of rOat1 and rOat3 in rats. The contribution rate of rOat1/3 for the synergistic effect was 20% when the two drugs were coadministered.