Drug addiction/dependence is defined as a chronically relapsing disorder that is characterized by compulsive drug taking, inability to limit intake, and intense drug cravings. The positive reinforcing/rewarding effects of drugs primarily depend on the mesocorticolimbic dopamine system innervating the nucleus accumbens while the craving for drugs is associated with activation of the prefrontal cortex. The chronic intake of drugs causes homeostatic molecular and functional changes in synapses, which may be critically associated with the development of drug dependence. Recent studies have demonstrated that various cytokines and proteinases are produced in the brain on treatment with drugs of abuse, and play a role in drug dependence. These endogenous modulators of drug dependence are classified into two groups, pro-addictive and anti-addictive factors. The former including basic fibroblast growth factor, brain-derived neurotrophic factor, tissue plasminogen activator, matrix metalloproteinase (MMP)-2 and MMP-9 act to potentiate the rewarding effects of drugs, while the latter such as tumor necrosis factor-α and glial cell line-derived neurotrophic factor reduce the reward. These findings suggest that an imbalance between pro-addictive and anti-addictive factors contributes to the development and relapse of drug dependence. Furthermore, targeting these endogenous modulators would provide new therapeutic approaches to the treatment of drug dependence.
The mitochondrial damage in the lung was assessed by examining the levels of reactive oxygen species (ROS), lipid peroxides, reduced glutathione, and the activities of isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, complexes I to IV, and cytochrome c. The oxidative phosphorylation (levels of adenosine triphosphatase) was evaluated for the assessment of mitochondrial functional capacity. We found significantly elevated levels of ROS, lipid peroxides, and decreased levels of mitochondrial enzymes in the mice administered with benzo[a]pyrene (B[a]p). Measurement of oxidative phosphorylation revealed a marked depletion in all the variables studied. Administration of crocetin prevented the structural and functional impairment of mitochondria upon administration to B[a]p. From the results, we suggest that administration of B[a]p induces damage to the lung mitochondria and crocetin protects the lung from damage by maintaining the structural and functional integrity of the mitochondrial membrane.
In this study, we examined the influence of finasteride (FIN), a 5α-reductase inhibitor, on the brain levels and metabolism of neurosteroids [allopregnanolone (AP), 3α-dihydroprogesterone (3α-DHP), progesterone (PROG), 20α-dihydroprogesterone and 11-deoxycorticosterone (DOC)] in rats exposed to immobilization stress. For this purpose, the sensitive, reproducible and accurate liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) methods that enable the quantification of trace amounts of brain neurosteroids were first developed. The animal study using these methods demonstrated that FIN dose-dependently inhibits the stress-induced elevation of the brain AP, a potent positive modulator of the γ-aminobutyric acid (GABA) type A receptors, and a 10 mg/kg dose of FIN can almost completely deplete AP in the brains. The study also found that the 20α-reduction of PROG is enhanced when its 5α-reduction pathway is inhibited in the brains. No change was found in the brain levels of 3α-DHP, another GABAergic neurosteroid, and DOC by the administration of FIN.
Mercuric chloride (HgCl2) is a widespread environmental toxin that affects mainly liver and kidney. The present study has been carried out to investigate the protective action of a protein (the CI protein) isolated from the herb, Cajanus indicus Spreng against HgCl2 induced renal and hepatic toxicities in mice. Intraperitoneal administration of HgCl2 at a dose of 5 mg/kg body weight for 1 d significantly reduced the activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Moreover, it also depleted the glutathione to oxidized glutathione (GSH/GSSG) ratio. In addition, HgCl2 increased the activities of serum marker enzymes (namely, glutamate pyruvate transaminase, GPT and alkaline phosphatase, ALP), creatinine, blood urea nitrogen and serum tumor necrosis factor alpha (TNF-α) level along with hepatic and renal lipid peroxidation. Besides, application of HgCl2 to hepatocytes increased reactive oxygen species production and reduced the total antioxidant activity of the treated hepatocytes. Treatment with the CI protein intraperitonealy at a dose of 2 mg/kg body weight before or after HgCl2 administration showed that it could scavenge free radicals in vitro and protect the alterations of the antioxidant molecules and the other parameters used in this particular study. Histological studies also revealed a milder lesion in kidney and liver samples of the CI protein treated mice compared to mice treated with HgCl2 alone. Effects of a known antioxidant N-acetylcysteine have been used to compare its action to that of the CI protein.
It is generally impossible to sort male and female sea urchins before they reach maturity, i.e., while they are still in the immature stage. The ribonuclease (RNase) activity of the gonads of immature stage sea urchins consistently shows a constant activity level. Comparison of the RNase activity of the gonads of mature male and female Hemicentrotus pulcherrimus and Anthocidaris crassispina species at pH 5.0 showed that while its mean specific activity in the immature stage of female H. pulcherrimus increased rapidly from 7.35 to 62.79 units/mg, its activity in male H. pulcherrimus decreased from 7.35 to 1.90 units/mg. The same phenomenon was observed in A. crassispina. Based on its optimal pH, substrate specificity, and heat stability the RNase that exhibited these changes was determined to be an enzyme of the RNase T2 type. This enzyme is also thought to exert an influence on sex determination in sea urchins.
Ym1 and Ym2 (Ym1/2) are chitinase-like proteins and we reported previously that IL-4 induced Ym1/2 in mouse bone marrow-derived mast cells. In the present study, ovalbumin-induced asthmatic mice were used to investigate the effect of glucocorticoids on Ym1/2 expression. Ym1/2 were highly induced in bronchoalveolar lavage fluid (BALF) and the lung. Ym1/2 expression was completely inhibited by dexamethasone (Dex) in BALF and weakly inhibited in the lung. Primary cultured macrophages were used to investigate the inhibition of Ym1/2 expression at the cellular level. Although Dex pretreatment inhibited the Ym1/2 expression level in an animal model, it did not reduce IL-4 induction of Ym1/2 expression in vitro. Next, we tested whether Dex blocks IL-4 induced STAT6 signaling and found that it had no inhibitory effect on the phosphorylation level of STAT6 in macrophages. The luciferase reporter assay also revealed that Dex did not inhibit IL-4 induction of Ym1/2 promoter activity. These results indicate that the inhibitory effect of Dex on Ym1/2 protein expression in the murine model of asthma does not involve the STAT6 signaling pathway.
A combination of purine and xanthine oxidase (XOD) dose-dependently elicited sustained contraction of porcine coronary arterial rings and resulted in increased concentrations of superoxide anions and hydrogen peroxide. These contractile responses appeared, with a delay, after the application of purine and XOD, used as a reactive oxygen species (ROS)-generating system. Coronary arteries precontracted with prostaglandin F2α failed to relax in response to substance P after exposing the arterial preparation to this ROS-generating system. The contractile response of the coronary artery to the ROS-generating system was almost completely inhibited by catalase (130 U/ml), and was partially inhibited by superoxide dismutase (60 U/ml), or mannitol (30 mM). A voltage-dependent L-type Ca2+ channel antagonist, nicardipine, had no effect on contraction. Dysfunction of endothelial cells was completely prevented by catalase, but not by superoxide dismutase or mannitol. These results suggest that superoxide anions, hydrogen peroxide and hydroxyl radicals might be involved in eliciting sustained, delayed-onset coronary artery contraction, which is not related to L-type Ca2+ channels. They also suggest that hydrogen peroxide might play a major role in endothelial dysfunction of the porcine coronary artery.
Carnitine is an essential cofactor in the transport of long-chain fatty acids into the mitochondrial matrix and plays an important role in energy production via β-oxidation. Vitamin C (VC) has long been considered a requirement for the activities of two enzymes in the carnitine biosynthetic pathway, i.e., 6-N-trimethyllysine dioxygenase and γ-butyrobetaine dioxygenase. Our present study using senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize VC in vivo, led to the conclusion that this notion is not true. After weaning at 40 d of age, SMP30/GNL KO mice were fed a diet lacking VC and carnitine, then given water containing 1.5 g/l VC (VC(+) mice) or no VC (VC(−) mice) for 75 d. Subsequently, total VC and carnitine levels were measured in the cerebrum, cerebellum, liver, kidney, soleus muscle, extensor digitorum longus muscle, heart, plasma and serum. The total VC levels in all tissues and plasma from VC(−) SMP30/GNL KO mice were negligible, i.e., <2% of the levels in SMP30/GNL KO VC(+) mice; however, the total carnitine levels of both groups were similar in all tissues and serum. In addition, carnitine was produced by incubated liver homogenates from the VC-depleted SMP30/GNL KO mice irrespective of the presence or absence of 1 mM VC. Collectively, these results indicate that VC is not essential for carnitine biosynthesis in vivo.
Juniperonic acid (Δ-5c,11c,14c,17c-20:4, JA) is a polymethylene-interrupted (PMI) fatty acid that occurs in Biota orientalis. In this study, we found that JA has an antiproliferative activity. Swiss 3T3 cells were preloaded with fatty acids before stimulation with bombesin, a mitogenic neuropeptide, and proliferation of the cells was assessed by [3H]thymidine incorporation. Preloading of linoleic acid (Δ-9c,12c-18:2) significantly enhanced bombesin-induced proliferation. In contrast, preloading of eicosapentaenoic acid (Δ-5c,8c,11c,14c,17c-20:5, EPA) suppressed proliferation. Likewise, cells preloaded with JA showed a significantly curtailed response to bombesin. The antiproliferative potency of JA was equivalent to that of EPA. Sciadonic acid (Δ-5c,11c,14c-20:3), an ω-6 analogue of JA did not show antiproliferative activity, suggesting the importance of the ω-3 double bond rather than the PMI structure. The EPA-like activity of JA may be involved in the pharmaceutical activity of biota seeds, a psychoactive Chinese traditional medicine.
Bovine pancreatic trypsin inhibitor (BPTI) is a natural non-specific serine protease inhibitor and possesses the ability to inhibit trypsin, chymotrypsin, plasmin and plasma kallikrein. The expression of BPTI in Escherichia coli and other systems has been reported. However, the preparation of recombinant BPTI (rBPTI) with correct N-terminus in Pichia pastoris has not been successful. A previous study showed that the preBPTI with the prepro leader sequence of alpha mating factor (AMF) was not processed into natural BPTI in P. pastoris. Now, we introduce a new method to prepare rBPTI, which carries a natural N-terminal amino acid residue, Arg-Pro-Asp, in P. pastoris using human serum albumin signal peptide corresponding to the pre sequence. The concentration of rBPTI in an 80 l fermentor reached 900 mg/l. We also explored a rapid and simple purification protocol for rBPTI and the purity of rBPTI reached 95—98% as evaluated by SDS-PAGE analysis. The sequencing results showed that the sequence of N-terminal 15 amino acids of rBPTI was consistent with that of natural BPTI. The inhibitory activity of rBPTI against trypsin was the same as natural BPTI and its Ki was 2.6±0.1×10−9. The therapeutic effect of rBPTI on acute pancreatitis was identified in rats.
Here, we confirmed that stable expression of B-cell lymphoma-xL (Bcl-xL) in N18TG neuroglioma cells could suppress c-Jun N-terminal protein kinase (JNK) activation, nuclear fragmentation, and cell death caused by etoposide treatment. Moreover, additional overexpression of JNK1 led to partially antagonize the antiapoptotic environment attained by Bcl-xL, implying that JNK1-involved pathway may play a role in down-regulation of the antiapoptotic effect of Bcl-xL. However, the antagonistic effect of JNK1 on the antiapoptotic action of Bcl-xL was significantly weaker than that on the action of Bcl-2. Interestingly, we found that overexpression of JNK1 led to increase of Bcl-xL expression. Thus, these results suggest that Bcl-xL and Bcl-2 may induce its antiapoptotic effect in a different mechanism, provoking the possibility of involvement of JNK1-involved pathway in Bcl-xL expression.
To examine the uptake of a recombinant human α-L-iduronidase (laronidase) by cultured fibroblasts from a patient with mucopolysaccharidosis I (MPS I) and its effect on the cleavage of accumulated substrates, we performed enzymological, Western blotting, immunocytochemical and morphological studies. Laronidase was incorporated into the MPS I cells dose-dependently mainly via mannose 6-phosphate (M6P) receptors. Then the incorporated enzyme was transported to lysosomes and processed to the mature form, the pathological changes of the cells being improved. Furthermore, we compared the uptake of laronidase by cultured mouse osteoblasts with that by cultured mouse fibroblasts. The enzyme was incorporated into the cultured mouse osteoblasts mainly via M6P receptors, although mannose (Man) receptors were partially involved in the uptake of the enzyme, as in the cultured fibroblasts. But the uptake by the former was apparently lower than that by the latter. The administration of a high dose of the enzyme or development of a recombinant α-L-iduronidase containing many M6P residues is required for further improvement of enzyme replacement therapy for skeletal disorders caused by MPS I.
Proteomics is a novel molecular profiling technology. It is mainly concerned with determining the structure, expression, localization, biochemical activity, interactions, and cellular roles of any proteins. Clinical research hopes to benefit from proteomics in the identification of new drug targets and the development of new diagnostic markers. Better to understand the mechanisms by which ascofuranone (AF), an isoprenoid antibiotic, regulates physiological or pathological events and induces responses in the pharmacological treatment of cancer, we performed differential analysis of the human osteosarcoma cells U2OS proteomes in response to this agent. The U2OS cell proteomes with and without treatment with AF were compared using two-dimensional electrophoresis, matrix-assisted laser desorption/ionization mass spectrometry, and bioinformatics. The largest differences in protein expression were observed for hydroxyindole O-methyltransferase, syntaxin-binding protein 1, the matrix metalloproteinase (MMP)-2, urokinase receptor, and endothelial protein C receptor. Changes in expression and activity of some selected proteins were confirmed by Western blotting, zymography, and reverse transcription-polymerase chain reaction analysis. In particular, we observed downregulated tumor growth related-proteins such as MMP-2 and endothelial protein C receptor. According to these results, AF might be useful as a potent chemotherapeutic agent.
The importance of microglial reactive oxygen species (ROS) signaling in neuroinflammatory processes has been well demonstrated; however, relatively little is known regarding the related mechanisms underlying these processes. Here, we show that ROS-dependent signal pathways that govern microglial phagocytosis are highly dependent upon nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) activation. Specifically, phagocytosis was greatly reduced by both antioxidant and Nox inhibitor treatments in lipopolysaccharide (LPS)-stimulated BV-2 microglia. Additionally, there was a marked reduction in intracellular ROS content. These results suggest that Nox is the main ROS source for LPS-induced microglial phagocytosis. More decisive evidence for the involvement of ROS in phagocytosis was obtained from an examination of phosphatidyl inositol 3-kinase (PI3-K) and p38 mitogen-activated protein kinase (MAPK) signal pathway activation under reduced ROS levels. These two kinases were activated by LPS treatment and inhibited by ROS neutralization and Nox inhibition. We conclude that microglial phagocytosis requires ROS-dependent PI3-K and p38 MAPK activation and that Nox-derived ROS functions as an upstream regulator of both PI3-K and p38 MAPK. These findings will provide a fundamental basis for a therapeutic modality in inflammation-mediated neurodiseases.
The role of AMP-activated protein kinase (AMPK) in adipocyte differentiation is not completely understood. Here we reported that an AMPK inhibitor, compound C, significantly inhibited adipogenic differentiation of 3T3-L1 cells in a dose dependent manner, and this inhibitory effect was primarily effective in the initial stage of differentiation. Compound C prevented the mitotic clonal expansion (MCE) of preadipocytes, probably by inhibiting expression of CCAAT/enhancer-binding protein (C/EBP)β and δ, and subsequently blocked the expression of C/EBPα and peroxisome proliferator-activated receptor (PPAR)γ and transcriptional activation of genes that produce the adipocyte phenotype. AMPK activity was also suppressed by compound C treatment during the early phase of adipogenic differentiation, which indicated that suppressed activation of AMPK by compound C may inhibit the MCE process of preadipocytes. Our results suggest that compound C might serve as a useful molecule in both basic and clinical research on adipogenesis and as a potential lead compound for the treatment of obesity.
Signal-transducing adaptor protein-2 (STAP-2) is a recently identified adaptor protein as a c-Fms/M-CSF receptor-interacting protein and constitutively expressed in macrophages. In our previous study, we examined the role of STAP-2 in the c-Fms/M-CSF receptor signaling using a murine macrophage tumor cells line, Raw264.7. Overexpression of STAP-2 in Raw264.7 cells markedly suppressed M-CSF-induced activation of extracellular signal regulated kinase and Akt. In addition, Raw264.7 overexpressing STAP-2 affected cell migration in wound-healing process. These results suggest that STAP-2 deficiency influences endogenous c-Fms/M-CSF receptor signaling. Here we show that loss of STAP-2 expression in knockout mouse macrophages results in marked enhancement of the c-Fms/M-CSF receptor signaling and wound-healing process. We therefore propose that STAP-2 acts as an endogenous regulator in normal macrophages functions.
We found that an extract from Laurus nobilis L. (Lauraceae) leaves showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). We purified two flavonoids as the effective compounds and identified them as kaempferol 3-O-α-L-(2″,4″-di-E-p-coumaroyl)-rhamnoside (C2) and kaempferol 3-O-α-L-(2″-Z-p-coumaroyl-4″-E-p-coumaroyl)-rhamnoside (C3). Both compounds showed strong antibacterial activity not only against MRSA but also against vancomycin-resistant enterococci (VRE). There was low or no antibacterial activity of C2 and C3 for Streptococcus pneumoniae, Pseudomonas aeruginosa and Serratia marcescens.
Indole-3-carbinol (I3C) is a natural compound found in a wide variety of plant food substances including members of the family Cruciferae with antioxidant and potential chemopreventive properties. In a previous study, I3C exhibited broad spectrum antibacterial activities. Particularly, it showed a more potent antibacterial activity against Gram-positive bacteria than Gram-negative bacteria. To elucidate this disparity of antibacterial activity between Gram-positive and Gram-negative bacteria, we investigated the actions of the efflux pumps and the lipopolysaccharide (LPS) barrier of the outer membrane of Gram-negative bacteria. The results showed that the antibacterial activity of I3C was affected by the barrier action of LPS in the outer membrane rather than by the efflux pumps. To assess its potential for combination therapy in treating bacterial infections, we investigated its synergy effects in combination with conventional antibiotics. The results demonstrated that I3C showed considerable synergistic activity in combination with ampicillin against drug-resistant isolates.
Histone deacetylase (HDAC) is a known modulator of gene transcription, and the immunosuppressive activity of HDAC inhibitors has been demonstrated in recent several reports. In this study, the HDAC inhibitor FR276457, a hydroxamic derivative, was found to have a similar inhibitory effect on all mammalian HDACs tested, but no isozyme selectivity. Both FR276457 and tacrolimus exerted an immunosuppressive effect on in vitro rat splenocyte proliferation stimulated with Concanavalin A. Next, the effect of FR276457 on allograft rejection when administered either as a monotherapy or in combination with tacrolimus was investigated in a rat heterotopic cardiac transplant model. Orally administered FR276457 prolonged the median survival times (MST) of the transplanted grafts in the vehicle group from 6 d to 17 or 21 d at doses of 20 or 40 mg/kg, respectively. Histopathological analysis showed the structures of the myocardium were not affected, but interstitial cellular infiltration could not be suppressed completely. Tacrolimus (0.032 mg/kg) prolonged allograft MST to 16 d. FR276457, when combined with tacrolimus, prevented allograft rejection at a dose lower than that of the monotherapy. The combination dose prolonged the MST in the groups treated with 10 and 20 mg/kg to >28 d, and cellular infiltration was suppressed completely. In conclusion, this study demonstrated that the oral administration of HDAC inhibitor FR276457 can prevent allograft rejection as a monotherapy, and has additive or synergistic effects when combined with tacrolimus.
Neurotrophic factors are essential to maintain and organize neurons functionally; thereby neurotrophic factor-like substances or their inducers are expected to be applied to the treatment of neurodegenerative diseases such as Alzheimer's disease. In the present study, we firstly examined the effects of ethanol extracts of four edible mushrooms, Hericium erinaceus (Yamabushitake), Pleurotus eryngii (Eringi), Grifola frondosa (Maitake), and Agaricus blazei (Himematsutake), on nerve growth factor (NGF) gene expression in 1321N1 human astrocytoma cells. Among the four mushroom extracts, only H. erinaceus extract promoted NGF mRNA expression in a concentration-dependent manner. In addition, secretion of NGF protein from 1321N1 cells was enhanced by H. erinaceus extracts, and the conditioned medium of 1321N1 cells incubated with H. erinaceus extract enhanced the neurite outgrowth of PC12 cells. However, hericenones C, D and E, constituents of H. erinaceus, failed to promote NGF gene expression in 1321N1 cells. The enhancement of NGF gene expression by H. erinaceus extracts was inhibited by the c-jun N-terminal kinase (JNK) inhibitor SP600125. In addition, H. erinaceus extracts induced phosphorylation of JNK and its downstream substrate c-Jun, and increased c-fos expression, suggesting that H. erinaceus promotes NGF gene expression via JNK signaling. Furthermore we examined the efficacy of H. erinaceus in vivo. ddY mice given feed containing 5% H. erinaceus dry powder for 7 d showed an increase in the level of NGF mRNA expression in the hippocampus. In conclusion, H. erinaceus contains active compounds that stimulate NGF synthesis via activation of the JNK pathway; these compounds are not hericenones.
The classic transient receptor potential channel (TRPC) is a candidate for Ca2+-permeable cation channel in mammalian cells. TRPC5 is desensitized rapidly after activation by G protein-coupled receptor. Here we investigate the mechanisms of desensitization of TRPC5 using patch-clamp recording. TRPC5 was initially activated by muscarinic stimulation using 50 μM carbachol (CCh) and decayed rapidly in the presence of CCh (desensitization). Intracellularly-applied phosphatidylinositol 4,5-bisphosphate (PIP2) slowed the rate of desensitization. In contrast, several other phosphoinositides, including PI(3,4)P2, PI(3,5)P2, PI(3,4,5)P3 and PI(4)P, had no effect on the desensitization of the TRPC5 current. This indicates that PIP2 attenuates the desensitization of the TRPC5 current in a highly selective manner. Neither wortmannin, an inhibitor of phosphatidylinositol 4-kinase, or poly-L-lysine (PLL), a scavenger of PIP2, had any effect on desensitization of the TRPC5 current. PIP2 breakdown appears to be a required step in the desensitization of TRPC5 current, but PIP2 depletion alone was insufficient for channel desensitization. TRPC5 was inhibited by cytochalasin D treatment. In mouse ileal myocytes, the desensitization of CCh-activated inward current (ICCh) also slowed in the presence of PIP2 in recording pipettes. These results indicate that PIP2 is involved in the desensitization of TRPC5 currents.
Tn-antigen (α-N-acetyl-galactosamine(GalNAc)-Ser/Thr) is a cancer-associated carbohydrate antigen expressed in various epithelial and hematological cancers, and although a number of anti-Tn IgG and IgM antibodies have been generated, they have not been fully validated for cancer immunotherapy. In this study, we generated a novel murine anti-Tn IgG1 monoclonal antibody, KM3413, by immunization of mucins purified from a culture supernatant of LS180: a human colon cancer cell line. The binding of KM3413 was detected against consecutive Tn-antigens (Tn3 and Tn2), but not against monovalent antigens (Tn1). The affinity (KD) of KM3413 was determined to be about 10−7 M with BIAcore. Cross-reactivity against type-A blood antigen, which shares a sugar residue, α-linked GalNAc, with Tn-antigen, was not detected. Next, we generated mouse-human chimeric IgG1 of KM3413 (cKM3413) and evaluated its anti-tumor activities against Jurkat: a human T-lymphoid leukemia cell line. In vitro assay revealed that cKM3413 induced antibody-dependent cellular cytotoxicity (ADCC) and direct killing activity with cross-link antibody. Furthermore, treatment of cKM3413 (1 or 10 mg/kg) showed significantly better survival of Jurkat-inoculated C.B-17/lcr-scid Jcl mice compared with controls using PBS treatment (p<0.001). These results suggest that humanized antibody against clustered Tn-antigens is a promising therapeutic antibody against Tn-positive cancers.
The present study was designed to investigate the modulatory effects of rottlerin on ischemia reperfusion induced myocardial injury. Isolated rat hearts were exposed to 30 min of global ischemia followed by 120 min of reperfusion using Langendorff apparatus. Myocardial injury was assessed in the terms of infarct size, release of lactate dehydrogenase (LDH), creatine kinase (CK) enzymes. Rottlerin, a selective PKCδ inhibitor, did not modulate ischemia-reperfusion (I/R) induced myocardial injury at low dose (3 μM). However, at moderate dose (6 μM) it significantly produced cardioprotective effects. On the contrary, rottlerin at high dose (12 μM) significantly enhanced I/R induced myocardial injury. However, administration of FR-167653 (1.1 μM, 2.2 μM), a selective p-38 mitogen activated protein kinase (p-38 MAPK) inhibitor, attenuated rottlerin (12 μM) mediated enhancement in I/R induced myocardial injury in a dose dependent manner. Per se administration of FR-167653 (1.1 μM, 2.2 μM) also attenuated I/R induced myocardial injury in a dose dependent manner. Pretreatment with rottlerin (6 μM) did not enhance the cardioprotective effects of FR-167653 (2.2 μM). It may be concluded that rottlerin mediated cardioprotective effects at moderate dose, possible due to inhibition of PKCδ; while at high dose it enhanced I/R induced myocardial injury which may be attributed to activation of p-38 MAPK.
Sanjoinine A is a component of the alkaloid fraction of Zizyphi Spinosi Semen. This experiment was performed to investigate whether sanjoinine A acts as an anticonvulsive in the N-methyl-D-aspartate (NMDA)-induced experimental seizure model. We also examined whether it protects against seizure-form electroencephalogram (EEG) alterations induced by NMDA in vivo and/or cell killing due to NMDA in cultured cerebellar granule cells. Administration of sanjoinine A increased the survival rate and the latency of seizure onset, and decreased the seizure scores and the weight-loss induced by NMDA in mice, in a dose-dependent manner. In addition, sanjoinine A blocked seizure-form EEG alterations induced by NMDA and inhibited NMDA-induced cell killing in cultured rat cerebellar granule cells, measured by both the trypan blue exclusion test and the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, sanjoinine A inhibited the elevation of intracellular calcium influx induced by NMDA, which was measured using a fluorescent dye, Furo 3-AM. It is suggested that sanjoinine A protects against NMDA-induced seizures by inhibiting intracellular calcium influx.
The present study was designed to investigate the possible role of opioids and KATP channels in ischemic postconditioning-induced reversal of global cerebral ischemia and reperfusion (I/R) induced neuronal injury. Mice were subjected to global ischemia by bilateral carotid artery occlusion for 10 min followed by reperfusion for 24 h, to produce neuronal injury. Ischemic postconditioning was induced by three episodes of carotid artery occlusion and reperfusion of 10 s each, immediately after global ischemia. Morphine postconditioning was induced by administration of morphine (5 mg/kg i.v.), 5 min prior to reperfusion. Naloxone (5 mg/kg i.v.), opioid receptor antagonist, and glibenclamide (5 mg/kg i.v.), KATP channel blocker were administered 10 min before global ischemia. Extent of cerebral injury was assessed by measuring cerebral infarct size using triphenyl tetrazolium chloride (TTC) staining. Short-term memory was evaluated using the elevated plus maze test, while degree of motor incoordination was evaluated using inclined beam-walking, rota-rod and lateral push tests. Bilateral carotid artery occlusion followed by reperfusion resulted in significant increase in infarct size, impairment in short-term memory and motor co-ordination. Ischemic/morphine postconditioning significantly attenuated I/R induced neuronal injury and behavioural alterations. Pretreatments with naloxone and glibenclamide attenuated the neuroprotective effects of ischemic/morphine postconditioning. It may be concluded that ischemic/morphine postconditioning protects I/R induced cerebral injury via activating opioid receptor and KATP channel opening.
Ginsenoside Rp1 (G-Rp1) is a novel ginseng saponin with a chemopreventive action. In this study, we examined the anti-metastatic activities of G-Rp1 using relevant in vitro assays and in vivo metastasis models. Using a U937 cell–cell adhesion assay, we found that exogenously added G-Rp1 down-regulates β1-integrin (CD29) activation at concentrations between 10 to 40 μM and suppresses the in vitro tube formation of human umbilical vein endothelial cells (HUVECs). Furthermore, this compound directly blocked cell viability of cancer cells such as A549 and HCT15 cells. In agreement with in vitro findings, G-Rp1 strongly inhibited the metastatic lung transfer of B16-F10 melanoma cells, which have a high surface level of β1-integrins, without altering body weight. Therefore, these results suggest that G-Rp1 may act as an anti-cancer agent by strongly inhibiting cell viability and metastatic processes, presumably by inhibiting the adhesion of tumor cells and vessel formation.
The barks and roots of Edgeworthia chrysantha LINDL., which have been used as the folk medicine “Zhu shima” in southern China due to their detumescence and acesodyne effects, were investigated for their anti-inflammatory and analgesic activities using a xylene-induced ear edema assay in mice and Freund's complete adjuvant-induced paw edema as inflammation models, and the acetic acid-induced writhing test as an analgesic model. Fractions effective in terms of anti-inflammatory and analgesic activities were obtained from E. chrysantha. The chloroform-soluble fraction (CHF) showed significant anti-inflammatory (p<0.01—0.001) and analgesic (p<0.01) effects. On further purification by silica gel, three major coumarins, edgeworin (EdN), edgeworosides A and C (EdeA and EdeC), were isolated from the chloroform fraction and both anti-inflammatory and analgesic activities were evaluated. EdN and EdeA had anti-inflammatory (p<0.05—0.01) and analgesic (p<0.001) effects, while EdeC only showed an analgesic effect. The results of this study thus demonstrated that the coumarins EdN, EdeA and EdeC in this plant may be active constituents that contribute to the anti-inflammatory and analgesic effects.
We have developed a novel method called loop-mediated isothermal amplification (LAMP) to detect Panax ginseng, the botanical source of Ginseng (Ginseng Radix), and to distinguish P. ginseng from Panax japonicus. Six allele-specific primers (two outer primers, two inner primers, and two loop primers) were designed based on the 18S ribosomal RNA gene sequence of P. ginseng, and LAMP was performed using those primers and total DNA extracted from P. ginseng as template. Amplifications were observed from approximately 30 min onwards at DNA concentrations of 0.5 to 10.0 ng. The presence of loop primers shortened the reaction time considerably. In contrast, in the reactions using total DNA from P. japonicus as template, no amplifications were observed. LAMP also enabled us to distinguish Ginseng from Japanese Ginseng (Panacis Japonici Rhizoma). LAMP was proven to be a rapid, highly sensitive, and specific method for the detection of P. ginseng and Ginseng.
The objective of the present study was to elucidate the beneficial properties of ampelopsine B (1) and ε-Viniferin (2), two oligostilbenes isolated from rhubarb, toward cardiovascular disease by protecting human lipoproteins against lipid peroxidation. In low density lipoprotein (LDL) oxidation, both 1 and 2 exert an inhibitory activity against Cu2+-, 2,2′-azobis-(2-amidinopropane) hydrochloride (AAPH)-induced, as exhibited by prolongation of lag time from 52 to 118 and 136 min, respectively, and also increasing the lag time 38 to 105 and 128 min in high density lipoprotein (HDL) oxidation for 1 and 2, respectively, at the concentration of 3.0 μM. In generation of thiobarbituric acid reactive subtances (TBARS), compounds 1 and 2 inhibited LDL oxidation mediated by either catalytic Cu2+ or thermo-labile radical initiator (AAPH) in a dose-dependent manner with IC50 values of 3.6 and 6.0 μM for 1, and 1.7 and 3.2 μM for 2, respectively. In addition, compounds 1—2 also showed strong ability to protect HDL oxidation induced by both Cu2+ and AAPH with low IC50 values. The results suggest that oligostilbenes 1—2 may have a role in preventing lipoprotein oxidation.
We examined the effect of 1-amino-3,5-dimethyladamantane (memantine) and (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801) on the inhibition of [3H]MK-801 binding to crude synaptic membranes of rat forebrains in the absence or presence of Ca2+. Ca2+ decreased the potency of memantine to inhibit [3H]MK-801 binding. The effect of Ca2+ was apparently competitive with memantine and was not annulled by the addition of Mg2+. Ca2+ slightly enhanced [3H]MK-801 binding, but showed no effect on the displacement of [3H]MK-801 binding by MK-801. The Ca2+-sensitive interaction of memantine with N-methyl-D-aspartate (NMDA) receptor-gated ion channels may provide a clue to understanding its voltage-dependent and clinically tolerated character.
The purpose of this research was to evaluate the effect of penetration enhancers on permeation kinetics of nitrendipine (NTP) through two different skin models. The permeation profile and related kinetics parameters such as activity parameter, diffusion parameter, lag time, relative activity parameter and relative diffusion parameter of NTP was determined in presence of some novel and widely accepted permeation enhancers. Among all the more pronounced enhancing effect was obtained with oleic acid (OA) as it presented the highest permeability coefficient. The enhancement was found to be increased in the following order: Dimethyl sulphoxide (DMSO)<Isopropyl myristate (IPM)<Sodium lauryl sulphate (SLS)<Tween 20 (T20)<Myristic acid (MA)<Lauric acid (LA)<Capric acid (CA)<Tween 80 (T80)<Span 80 (S80)<Thyme oil (TO)<Palmarosa oil (PA)<Petitlgrain oil (PT)<Basil oil (BO)<Oleic acid (OA). The increase in drug permeation was attributed mainly to the decrease in diffusion path length. Essential oils and surfactant (span 80) have shown relative activity parameter (Kr value) well above unity and relative diffusion parameter (Dr value) almost equal or less than unity, which would be attributed to gradual increase in membrane permeability leading to higher permeation. Oleic acid is effective for augmenting skin permeation of NTP, with potential application in transdermal delivery of the drug.
Microdialysis method (MD) is useful for sampling protein-unbound substances in vivo. Generally in the MD, a reference compound is used to correct differences in drug permeation clearance through a dialysis membrane in vivo and in vitro. No reference compound was, however, used for determination of a protein-unbound drug concentration in the epithelial lining fluid (ELF). In this study, we firstly examined the propriety of endogenous urea as a reference compound to determine the protein-unbound ulifloxacin concentrations in rat ELF by MD. Endogenous urea was used to correct differences in the permeation clearance in vivo and in vitro which reflect the differences in the extent of contact between a tip probe and ELF in vivo and in vitro. The results showed that our MD is applicable to determine the various concentrations of ulifloxacin and urea, and that we can use endogenous urea as a reference compound even if the extent of the contact between a tip of the probe and the ELF is small. In addition, use of urea concentrations does not affect drug distribution from plasma to ELF because we used endogenous urea. These results support usefulness of endogenous urea as a reference compound to determine protein-unbound drug concentration in ELF by MD. In addition, our results also suggest the existence of certain distribution mechanisms which cause the high penetration ulifloxacin into ELF. Our MD can help progress in pharmacokinetic-pharmacodynamic analysis of various antibiotics in the case where the concentrations in ELF are not equal to that in plasma.
This in vitro study aimed at investigating the possible radioprotective effects of natural substances propolis and quercetin on γ-irradiated human white blood cells. The levels of primary DNA damage were studied by the alkaline comet assay, while the cytogenetic damage was evaluated using the analysis of structural chromosome aberration and cytokinesis-block micronucleus assay. The results obtained by all endpoints indicate acceptable toxicity profiles of propolis and quercetin in vitro, and also confirmed their radioprotective abilities. Propolis was found to be more effective in diminishing the levels of primary and more complex cytogenetic DNA damage in gamma-irradiated white blood cells. Data gathered in present study support the use of propolis and quercetin as non-toxic protective substances. However, to clarify the underlying mechanisms of their cyto/radioprotective activities, additional studies are necessary at both in vitro and in vivo levels.
The inhibitory effects of three-component hybrid liposomes (HL) containing cationic lipids on the growth of human renal tumor cells were examined. Fifty percent inhibitory concentration of the three-component HL was remarkably reduced compared with that of dimyristoylphosphatidylcholine liposomes. The induction of apoptosis by the three-component HL without antitumor drugs was obtained for human renal tumor cells for the first time in this study.