BMC Pharmacology[JOURNAL]
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200 papers
Effects of rasagiline, its metabolite aminoindan and selegiline on glutamate receptor mediated signalling in the rat hippocampus slice in vitro.
Dimpfel W, Hoffmann JA
BMC Pharmacol · 2011 Feb · PMID 21338509 · Full text
BACKGROUND: Rasagiline, a new drug developed to treat Parkinson's disease, is known to inhibit monoamine oxidase B. However, its metabolite R-(-)-aminoindan does not show this kind of activity. The present series of in v...
BACKGROUND: Rasagiline, a new drug developed to treat Parkinson's disease, is known to inhibit monoamine oxidase B. However, its metabolite R-(-)-aminoindan does not show this kind of activity. The present series of in vitro experiments using the rat hippocampal slice preparation deals with effects of both compounds on the pyramidal cell response after electric stimulation of the Schaffer Collaterals in comparison to selegiline, another MAO B inhibitor. METHOD: Stimulation of the Schaffer Collaterals by single stimuli (SS) or theta burst stimulation (TBS) resulted in stable responses of pyramidal cells measured as population spike amplitude (about 1 mV under control SS conditions or about 2 mV after TBS). RESULTS: During the first series, this response was attenuated in the presence of rasagiline and aminoindan-to a lesser degree of selegiline-in a concentration dependent manner (5-50 μM) after single stimuli as well as under TBS. During oxygen/glucose deprivation for 10 min the amplitude of the population spike breaks down by 75%. The presence of rasagiline and aminoindan, but rarely the presence of selegiline, prevented this break down. Following glutamate receptor mediated enhancements of neuronal transmission in a second series of experiments very clear differences could be observed in comparison to the action of selegiline: NMDA receptor, AMPA receptor as well as metabotropic glutamate receptor mediated increases of transmission were concentration dependently (0,3 - 2 μM) antagonized by rasagiline and aminoindan, but not by selegiline. On the opposite, only selegiline attenuated kainate receptor mediated increases of excitability. Thus, both monoamino oxidase (MAO) B inhibitors show attenuation of glutamatergic transmission in the hippocampus but interfere with different receptor mediated excitatory modulations at low concentrations. CONCLUSIONS: Since aminoindan does not induce MAO B inhibition, these effects must be regarded as being independent from MAO B inhibition. The results provide strong evidence for a neuroprotective activity of rasagiline and aminoindan in concert with an extended clinical indication into the direction of other diseases like Alzheimer's disease or stroke.
The boron-oxygen core of borinate esters is responsible for the store-operated calcium entry potentiation ability.
Dellis O, Mercier P, Chomienne C
BMC Pharmacol · 2011 Jan · PMID 21266088 · Full text
BACKGROUND: Store-Operated Calcium Entry (SOCE) is the major Ca2+ ion entry pathway in lymphocytes and is responsible of a severe combined immunodeficiency (SCID) when deficient. It has recently been observed or highligh...
BACKGROUND: Store-Operated Calcium Entry (SOCE) is the major Ca2+ ion entry pathway in lymphocytes and is responsible of a severe combined immunodeficiency (SCID) when deficient. It has recently been observed or highlighted in other cell types such as myoblasts and neurons, suggesting a wider physiological role of this pathway. Whereas Orai1 protein is considered to be the channel allowing the SOCE in T cells, it is hypothesized that other proteins like TRPC could associate with Orai1 to form SOCE with different pharmacology and kinetics in other cell types. Unraveling SOCE cell functions requires specific effectors to be identified, just as dihydropyridines were crucial for the study of Ca2+ voltage-gated channels, or spider/snake toxins for other ion channel classes. To identify novel SOCE effectors, we analyzed the effects of 2-aminoethyl diphenylborinate (2-APB) and its analogues. 2-APB is a molecule known to both potentiate and inhibit T cell SOCE, but it is also an effector of TRP channels and endoplasmic reticulum Ca2+-ATPase. RESULTS: A structure-function analysis allowed to discover that the boron-oxygen core present in 2-APB and in the borinate ester analogues is absolutely required for the dual effects on SOCE. Indeed, a 2-APB analogue where the boron-oxygen core is replaced by a carbon-phosphorus core is devoid of potentiating capacity (while retaining inhibition capacity), highlighting the key role of the boron-oxygen core present in borinate esters for the potentiation function. However, dimesityl borinate ester, a 2-APB analogue with a terminal B-OH group showed an efficient inhibitory ability, without any potentiating capacity. The removal or addition of phenyl groups respectively decrease or increase the efficiency of the borinate esters to potentiate and inhibit the SOCE. mRNA expression revealed that Jurkat T cells mainly expressed Orai1, and were the more sensitive to 2-APB modulation of SOCE. CONCLUSIONS: This study allows the discovery of new boron-oxygen core containing compounds with the same ability as 2-APB to both potentiate and inhibit the SOCE of different leukocyte cell lines. These compounds could represent new tools to characterize the different types of SOCE and the first step in the development of new immunomodulators.
Abstracts of the 16th Scientific Symposium of the Austrian Pharmacological Society (APHAR). Vienna, Austria. November 25-27, 2010.
Kargl J, Balenga N, Platzer W … +3 more , Martini L, Whistler J, Waldhoer M
BMC Pharmacol · 2010 · PMID 21092347 · Full text
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Pharmacokinetic and pharmacodynamic comparison of two "pegylated" interferon alpha-2 formulations in healthy male volunteers: a randomized, crossover, double-blind study.
García-García I, González-Delgado CA, Valenzuela-Silva CM … +11 more , Díaz-Machado A, Cruz-Díaz M, Nodarse-Cuní H, Pérez-Pérez O, Bermúdez-Badell CH, Ferrero-Bibilonia J, Páez-Meireles R, Bello-Rivero I, Castro-Odio FR, López-Saura PA, FarmaPEG Study Group
BMC Pharmacol · 2010 Nov · PMID 21092287 · Full text
BACKGROUND: Interferon (IFN) alpha conjugation to polyethylene glycol (PEG) results in a better pharmacokinetic profile and efficacy. The aim of this study was to compare the pharmacokinetic, pharmacodynamic and safety p...
BACKGROUND: Interferon (IFN) alpha conjugation to polyethylene glycol (PEG) results in a better pharmacokinetic profile and efficacy. The aim of this study was to compare the pharmacokinetic, pharmacodynamic and safety properties of a new, locally developed, 40-kDa PEG-IFN alpha-2b preparation with a reference, commercially available PEG-IFN alpha-2a in healthy male volunteers. METHODS: A randomized, crossover, double-blind study with a 3-weeks washout period, was done. A single 180 micrograms PEG-IFN alpha-2 dose was administered subcutaneously in both groups. Sixteen apparently healthy male subjects were included. Serum PEG-IFN concentration was measured during 336 hours by an enzyme immunoassay (EIA). Other clinical and laboratory variables were used as pharmacodynamic and safety criteria. RESULTS: The pharmacokinetic comparison by EIA yielded a high similitude between the formulations. In spite of a high subject variability, the parameters' mean were very close (in all cases p > 0.05): AUC: 53623 vs. 44311 pg.h/mL; Cmax: 333 vs. 271 pg/mL; Tmax: 54 vs. 55 h; half-life (t1/2): 72.4 vs. 64.8 h; terminal elimination rate (lambda): 0.011 vs. 0.014 h(-1); mean residence time (MRT): 135 vs. 123 h for reference and study preparations, respectively. There were no significant differences with respect to the pharmacodynamic variables either: serum neopterin and beta-2 microglobulin levels, stimulation of 2'5' oligoadenylate synthetase expression, and serum IFN antiviral activity. A strong Spearman's rank order correlation (p < 0.01) between the pharmacokinetic and pharmacodynamic concentration-time curves was observed. Both products caused similar leukocyte counts diminution and had similar safety profiles. The most frequent adverse reactions were leukopenia, fever, thrombocytopenia, transaminases increase and asthenia, mostly mild. CONCLUSIONS: Both formulations are fully comparable from the pharmacokinetic, pharmacodynamic, and safety profiles. Efficacy trials can be carried out to confirm clinical similarity.
Histopathology and biochemistry analysis of the interaction between sunitinib and paracetamol in mice.
Lim AY, Segarra I, Chakravarthi S … +2 more , Akram S, Judson JP
BMC Pharmacol · 2010 Oct · PMID 20950441 · Full text
BACKGROUND: Sunitinib, a tyrosine kinase inhibitor to treat GIST and mRCC may interact with paracetamol as both undergo P450 mediated biotransformation and P-glycoprotein transport. This study evaluates the effects of su...
BACKGROUND: Sunitinib, a tyrosine kinase inhibitor to treat GIST and mRCC may interact with paracetamol as both undergo P450 mediated biotransformation and P-glycoprotein transport. This study evaluates the effects of sunitinib-paracetamol coadministration on liver and renal function biomarkers and liver, kidney, brain, heart and spleen histopathology. ICR male mice (n = 6 per group/dose) were administered saline (group-A) or paracetamol 500 mg/kg IP (group-B), or sunitinib at 25, 50, 80, 100, 140 mg/kg PO (group-C) or coadministered sunitinib at 25, 50, 80, 100, 140 mg/kg PO and paracetamol IP at fixed dose 500 mg/kg (group-D). Paracetamol was administered 15 min before sunitinib. Mice were sacrificed 4 h post sunitinib administration. RESULTS: Group-A serum ALT and AST levels were 14.29 ± 2.31 U/L and 160.37 ± 24.74 U/L respectively and increased to 249.6 ± 222.7 U/L and 377.1 ± 173.6 U/L respectively in group-B; group-C ALT and AST ranged 36.75-75.02 U/L and 204.4-290.3 U/L respectively. After paracetamol coadministration with low sunitinib doses (group-D), ALT and AST concentrations ranged 182.79-221.03 U/L and 259.7-264.4 U/L respectively, lower than group-B. Paracetamol coadministration with high sunitinib doses showed higher ALT and AST values (range 269.6-349.2 U/L and 430.2-540.3 U/L respectively), p < 0.05. Hepatic histopathology showed vascular congestion in group-B; mild congestion in group-C (but lesser than in group-B and D). In group-D, at low doses of sunitinib, lesser damage than in group-B occurred but larger changes including congestion were observed at high sunitinib doses. BUN levels were higher (p < 0.05) for group-B (33.81 ± 5.68 mg/dL) and group-D (range 35.01 ± 6.95 U/L to 52.85 ± 12.53 U/L) compared to group-A (15.60 ± 2.17 mg/dL) and group-C (range 17.50 ± 1.25 U/L to 26.68 ± 6.05 U/L). Creatinine remained unchanged. Renal congestion and necrosis was lower in group-C than group-B but was higher in group-D (p > 0.05). Mild cardiotoxicity occurred in groups B, C and D. Brain vascular congestion occurred at high doses of sunitinib administered alone or with paracetamol. Hepatic and renal biomarkers correlated with histopathology signs. CONCLUSIONS: Paracetamol and sunitinib coadministration may lead to dose dependent outcomes exhibiting mild hepatoprotective effect or increased hepatotoxicity. Sunitinib at high doses show renal, cardiac and brain toxicity. Liver and renal function monitoring is recommended.
Protective efficacy of natansnin, a dibenzoyl glycoside from Salvinia natans against CCl4 induced oxidative stress and cellular degeneration in rat liver.
Srilaxmi P, Sareddy GR, Kavi Kishor PB … +2 more , Setty OH, Babu PP
BMC Pharmacol · 2010 Oct · PMID 20939865 · Full text
BACKGROUND: Carbon tetra chloride (CCl4), an industrial solvent, is a hepatotoxic agent and it is the well established animal model for free radical-induced liver injury. The present investigation was carried out to esta...
BACKGROUND: Carbon tetra chloride (CCl4), an industrial solvent, is a hepatotoxic agent and it is the well established animal model for free radical-induced liver injury. The present investigation was carried out to establish the protective effect of natansnin, a novel dibenzoyl glycoside from Salvinia natans against CCl4 induced oxidative stress and cellular degeneration in rat liver. RESULTS: CCl4 significantly increased the levels of lipid peroxides, oxidized glutathione and decreased the levels of reduced glutathione, SOD and CAT. CCl4 induce marked histopathological changes and increase in the levels of apoptotic proteins. CCl4 treatment significantly increased the levels of apoptotic proteins such as caspases-3, PARP, Bax, Bid and cytochrome C and also increased the levels of inflammatory mediators iNos and Cox-2. Natansnin treatment significantly decreased the levels of CCl4 induced apoptotic proteins and inflammatory mediators. Further natansinin treatment significantly inhibited the CCl4 induced apoptosis which was evident form the reduced TUNEL positive cells. CONCLUSIONS: In conclusion, our study demonstrated the protective effect of natansnin against CCl4 induced oxidative stress and cellular degeneration in rat liver tissue. This protective effect of natansnin can be correlated to its direct antioxidant effect.
Hematopoietic stem cells exhibit a specific ABC transporter gene expression profile clearly distinct from other stem cells.
Tang L, Bergevoet SM, Gilissen C … +4 more , de Witte T, Jansen JH, van der Reijden BA, Raymakers RA
BMC Pharmacol · 2010 Sep · PMID 20836839 · Full text
BACKGROUND: ATP-binding cassette (ABC) transporters protect cells against unrelated (toxic) substances by pumping them across cell membranes. Earlier we showed that many ABC transporters are highly expressed in hematopoi...
BACKGROUND: ATP-binding cassette (ABC) transporters protect cells against unrelated (toxic) substances by pumping them across cell membranes. Earlier we showed that many ABC transporters are highly expressed in hematopoietic stem cells (HSCs) compared to more committed progenitor cells. The ABC transporter expression signature may guarantee lifelong protection of HSCs but may also preserve stem cell integrity by extrusion of agents that trigger their differentiation. Here we have studied whether non-hematopoietic stem cells (non-HSCs) exhibit a similar ABC transporter expression signature as HSCs. RESULTS: ABC transporter expression profiles were determined in non-hematopoietic stem cells (non-HSCs) from embryonic, neonatal and adult origin as well as in various mature blood cell types. Over 11,000 individual ABC transporter expression values were generated by Taqman Low Density Arrays (TLDA) to obtain a sensitivity comparable with quantitative real-time polymerase chain reactions. We found that the vast majority of transporters are significantly higher expressed in HSCs compared to non-HSCs. Furthermore, regardless their origin, non-HSCs exhibited strikingly similar ABC transporter expression profiles that were distinct from those in HSCs. Yet, sets of transporters characteristic for different stem cell types could be identified, suggesting restricted functions in stem cell physiology. Remarkably, in HSCs we could not pinpoint any single transporter expressed at an evidently elevated level when compared to all the mature blood cell types studied. CONCLUSIONS: These findings challenge the concept that individual ABC transporters are implicated in maintaining stem cell integrity. Instead, a distinct ABC transporter expression signature may be essential for stem cell function. The high expression of specific transporters in non-HSCs and mature blood cells suggests a specialized, cell type dependent function and warrants further functional experiments to determine their exact roles in cellular (patho)physiology.
Beneficial effect of agmatine on brain apoptosis, astrogliosis, and edema after rat transient cerebral ischemia.
Wang CC, Chio CC, Chang CH … +2 more , Kuo JR, Chang CP
BMC Pharmacol · 2010 Sep · PMID 20815926 · Full text
BACKGROUND: Although agmatine therapy in a mouse model of transient focal cerebral ischemia is highly protective against neurological injury, the mechanisms underlying the protective effects of agmatine are not fully elu...
BACKGROUND: Although agmatine therapy in a mouse model of transient focal cerebral ischemia is highly protective against neurological injury, the mechanisms underlying the protective effects of agmatine are not fully elucidated. This study aimed to investigate the effects of agmatine on brain apoptosis, astrogliosis and edema in the rats with transient cerebral ischemia. METHODS: Following surgical induction of middle cerebral artery occlusion (MCAO) for 90 min, agmatine (100 mg/kg, i.p.) was injected 5 min after beginning of reperfusion and again once daily for the next 3 post-operative days. Four days after reperfusion, both motor and proprioception functions were assessed and then all rats were sacrificed for determination of brain infarct volume (2, 3, 5-triphenyltetrazolium chloride staining), apoptosis (TUNEL staining), edema (both cerebral water content and amounts of aquaporin-4 positive cells), gliosis (glial fibrillary acidic protein [GFAP]-positive cells), and neurotoxicity (inducible nitric oxide synthase [iNOS] expression). RESULTS: The results showed that agmatine treatment was found to accelerate recovery of motor (from 55 degrees to 62 degrees) and proprioception (from 54% maximal possible effect to 10% maximal possible effect) deficits and to prevent brain infarction (from 370 mm3 to 50 mm3), gliosis (from 80 GFAP-positive cells to 30 GFAP-positive cells), edema (cerebral water contents decreased from 82.5% to 79.4%; AQP4 positive cells decreased from 140 to 84 per section), apoptosis (neuronal apoptotic cells decreased from 100 to 20 per section), and neurotoxicity (iNOS expression cells decreased from 64 to 7 per section) during MCAO ischemic injury in rats. CONCLUSIONS: The data suggest that agmatine may improve outcomes of transient cerebral ischemia in rats by reducing brain apoptosis, astrogliosis and edema.
Salvianolic acid B functioned as a competitive inhibitor of matrix metalloproteinase-9 and efficiently prevented cardiac remodeling.
Jiang B, Chen J, Xu L … +6 more , Gao Z, Deng Y, Wang Y, Xu F, Shen X, Guo DA
BMC Pharmacol · 2010 Aug · PMID 20735854 · Full text
BACKGROUND: Infarct-induced left ventricular (LV) remodeling is a deleterious consequence after acute myocardial infarction (MI) which may further advance to congestive heart failure. Therefore, new therapeutic strategie...
BACKGROUND: Infarct-induced left ventricular (LV) remodeling is a deleterious consequence after acute myocardial infarction (MI) which may further advance to congestive heart failure. Therefore, new therapeutic strategies to attenuate the effects of LV remodeling are urgently needed. Salvianolic acid B (SalB) from Salviae mitiorrhizae, which has been widely used in China for the treatment of cardiovascular diseases, is a potential candidate for therapeutic intervention of LV remodeling targeting matrix metalloproteinase-9 (MMP-9). RESULTS: Molecular modeling and LIGPLOT analysis revealed in silico docking of SalB at the catalytic site of MMP-9. Following this lead, we expressed truncated MMP-9 which contains only the catalytic domain, and used this active protein for in-gel gelatin zymography, enzymatic analysis, and SalB binding by Biacore. Data generated from these assays indicated that SalB functioned as a competitive inhibitor of MMP-9. In our rat model for cardiac remodeling, western blot, echocardiography, hemodynamic measurement and histopathological detection were used to detect the effects and mechanism of SalB on cardio-protection. Our results showed that in MI rat, SalB selectively inhibited MMP-9 activities without affecting MMP-9 expression while no effect of SalB was seen on MMP-2. Moreover, SalB treatment in MI rat could efficiently increase left ventricle wall thickness, improve heart contractility, and decrease heart fibrosis. CONCLUSIONS: As a competitive inhibitor of MMP-9, SalB presents significant effects on preventing LV structural damage and preserving cardiac function. Further studies to develop SalB and its analogues for their potential for cardioprotection in clinic are warranted.
Quantitative in vitro and in vivo pharmacological profile of CE-178253, a potent and selective cannabinoid type 1 (CB1) receptor antagonist.
Hadcock JR, Carpino PA, Iredale PA … +12 more , Dow RL, Gautreau D, Thiede L, Kelly-Sullivan D, Lizano JS, Liu X, Van Deusen J, Ward KM, O'Connor RE, Black SC, Griffith DA, Scott DO
BMC Pharmacol · 2010 Aug · PMID 20712891 · Full text
BACKGROUND: Cannabinoid 1 (CB1) receptor antagonists exhibit pharmacological properties favorable for the treatment of obesity and other related metabolic disorders. CE-178253 (1-[7-(2-Chlorophenyl)-8-(4-chlorophenyl)-2-...
BACKGROUND: Cannabinoid 1 (CB1) receptor antagonists exhibit pharmacological properties favorable for the treatment of obesity and other related metabolic disorders. CE-178253 (1-[7-(2-Chlorophenyl)-8-(4-chlorophenyl)-2-methylpyrazolo[1,5-a]-[1,3,5]triazin-4-yl]-3-ethylaminoazetidine-3-carboxylic acid hydrochloride) is a recently discovered selective centrally-acting CB1 receptor antagonist. Despite a large body of knowledge on cannabinoid receptor antagonists little data exist on the quantitative pharmacology of this therapeutic class of drugs. The purpose of the current studies was to evaluate the quantitative pharmacology and concentration/effect relationships of CE-178253 based on unbound plasma concentration and in vitro pharmacology data in different in vivo preclinical models of FI and energy expenditure. RESULTS: In vitro, CE-178253 exhibits sub-nanomolar potency at human CB1 receptors in both binding (Ki = 0.33 nM) and functional assays (Ki = 0.07 nM). CE-178253 has low affinity (Ki > 10,000 nM) for human CB2 receptors. In vivo, CE-178253 exhibits concentration-dependent anorectic activity in both fast-induced re-feeding and spontaneous nocturnal feeding FI models. As measured by indirect calorimetry, CE-178253 acutely stimulates energy expenditure by greater than 30% in rats and shifts substrate oxidation from carbohydrate to fat as indicated by a decrease the respiratory quotient from 0.85 to 0.75. Determination of the concentration-effect relationships and ex vivo receptor occupancy in efficacy models of energy intake and expenditure suggest that a greater than a 2-fold coverage of the Ki (50-75% receptor occupancy) is required for maximum efficacy. Finally, in two preclinical models of obesity, CE-178253 dose-dependently promotes weight loss in diet-induced obese rats and mice. CONCLUSIONS: We have combined quantitative pharmacology and ex vivo CB1 receptor occupancy data to assess concentration/effect relationships in food intake, energy expenditure and weight loss studies. Quantitative pharmacology studies provide a strong a foundation for establishing and improving confidence in mechanism as well as aiding in the progression of compounds from preclinical pharmacology to clinical development.
Prediction of cytochrome P450 isoform responsible for metabolizing a drug molecule.
Mishra NK, Agarwal S, Raghava GP
BMC Pharmacol · 2010 Jul · PMID 20637097 · Full text
BACKGROUND: Different isoforms of Cytochrome P450 (CYP) metabolized different types of substrates (or drugs molecule) and make them soluble during biotransformation. Therefore, fate of any drug molecule depends on how th...
BACKGROUND: Different isoforms of Cytochrome P450 (CYP) metabolized different types of substrates (or drugs molecule) and make them soluble during biotransformation. Therefore, fate of any drug molecule depends on how they are treated or metabolized by CYP isoform. There is a need to develop models for predicting substrate specificity of major isoforms of P450, in order to understand whether a given drug will be metabolized or not. This paper describes an in-silico method for predicting the metabolizing capability of major isoforms (e.g. CYP 3A4, 2D6, 1A2, 2C9 and 2C19). RESULTS: All models were trained and tested on 226 approved drug molecules. Firstly, 2392 molecular descriptors for each drug molecule were calculated using various softwares. Secondly, best 41 descriptors were selected using general and genetic algorithm. Thirdly, Support Vector Machine (SVM) based QSAR models were developed using 41 best descriptors and achieved an average accuracy of 86.02%, evaluated using fivefold cross-validation. We have also evaluated the performance of our model on an independent dataset of 146 drug molecules and achieved average accuracy 70.55%. In addition, SVM based models were developed using 26 Chemistry Development Kit (CDK) molecular descriptors and achieved an average accuracy of 86.60%. CONCLUSIONS: This study demonstrates that SVM based QSAR model can predict substrate specificity of major CYP isoforms with high accuracy. These models can be used to predict isoform responsible for metabolizing a drug molecule. Thus these models can used to understand whether a molecule will be metabolized or not. This is possible to develop highly accurate models for predicting substrate specificity of major isoforms using CDK descriptors. A web server MetaPred has been developed for predicting metabolizing isoform of a drug molecule http://crdd.osdd.net/raghava/metapred/.
Use of silkworms for identification of drug candidates having appropriate pharmacokinetics from plant sources.
Asami Y, Horie R, Hamamoto H … +1 more , Sekimizu K
BMC Pharmacol · 2010 Jun · PMID 20537191 · Full text
BACKGROUND: We use silkworms to evaluate therapeutic effects of drug candidates. Our previous reports have revealed that there are common mechanisms of pharmacokinetics of chemicals in silkworms and mammals. In this repo...
BACKGROUND: We use silkworms to evaluate therapeutic effects of drug candidates. Our previous reports have revealed that there are common mechanisms of pharmacokinetics of chemicals in silkworms and mammals. In this report, we attempt to establish a method by using silkworms to identify chemicals from plant extracts which are absorbed from intestine and also stably exist in body fluids. RESULTS: Three compounds were detected in the silkworm hemolymph by HPLC analysis after midgut injection of acetone extracts of seihi, an herbal medicine obtained from orange peel. Analyses with MS and NMR revealed that the compounds were nobiletin, heptamethoxyflavone, and tangeretin. These compounds are reported to be stable in mammalian blood. The half-life of each of these compounds in the silkworm hemolymph was 18, 26 and 34 h, respectively. CONCLUSIONS: These findings suggest that silkworms can be used as a model animal to easily identify compounds with appropriate pharmacokinetic behavior.
An evaluation of R2 as an inadequate measure for nonlinear models in pharmacological and biochemical research: a Monte Carlo approach.
Spiess AN, Neumeyer N
BMC Pharmacol · 2010 Jun · PMID 20529254 · Full text
BACKGROUND: It is long known within the mathematical literature that the coefficient of determination R(2) is an inadequate measure for the goodness of fit in nonlinear models. Nevertheless, it is still frequently used w...
BACKGROUND: It is long known within the mathematical literature that the coefficient of determination R(2) is an inadequate measure for the goodness of fit in nonlinear models. Nevertheless, it is still frequently used within pharmacological and biochemical literature for the analysis and interpretation of nonlinear fitting to data. RESULTS: The intensive simulation approach undermines previous observations and emphasizes the extremely low performance of R(2) as a basis for model validity and performance when applied to pharmacological/biochemical nonlinear data. In fact, with the 'true' model having up to 500 times more strength of evidence based on Akaike weights, this was only reflected in the third to fifth decimal place of R(2). In addition, even the bias-corrected R(2)(adj) exhibited an extreme bias to higher parametrized models. The bias-corrected AICc and also BIC performed significantly better in this respect. CONCLUSION: Researchers and reviewers should be aware that R(2) is inappropriate when used for demonstrating the performance or validity of a certain nonlinear model. It should ideally be removed from scientific literature dealing with nonlinear model fitting or at least be supplemented with other methods such as AIC or BIC or used in context to other models in question.
Amphetamine dependence and co-morbid alcohol abuse: associations to brain cortical thickness.
Lawyer G, Bjerkan PS, Hammarberg A … +3 more , Jayaram-Lindström N, Franck J, Agartz I
BMC Pharmacol · 2010 May · PMID 20487539 · Full text
BACKGROUND: Long-term amphetamine and methamphetamine dependence has been linked to cerebral blood perfusion, metabolic, and white matter abnormalities. Several studies have linked methamphetamine abuse to cortical grey...
BACKGROUND: Long-term amphetamine and methamphetamine dependence has been linked to cerebral blood perfusion, metabolic, and white matter abnormalities. Several studies have linked methamphetamine abuse to cortical grey matter reduction, though with divergent findings. Few publications investigate unmethylated amphetamine's potential effects on cortical grey matter. This work investigated if amphetamine dependent patients showed reduced cortical grey matter thickness. Subjects were 40 amphetamine dependent subjects and 40 healthy controls. While all subjects were recruited to be free of alcohol dependence, structured clinical interviews revealed significant patterns of alcohol use in the patients. Structural magnetic resonance brain images were obtained from the subjects using a 1.5 Tesla GE Signa machine. Brain cortical thickness was measured with submillimeter precision at multiple finely spaced cortical locations using semi-automated post-processing (FreeSurfer). Contrast analysis of a general linear model was used to test for differences between the two groups at each cortical location. In addition to contrasting patients with controls, a number of analyses sought to identify possible confounding effects from alcohol. RESULTS: No significant cortical thickness differences were observed between the full patient group and controls, nor between non-drinking patients and controls. Patients with a history of co-morbid heavy alcohol use (n = 29) showed reductions in the superior-frontal right hemisphere and pre-central left hemisphere when compared to healthy controls (n = 40). CONCLUSIONS: Amphetamine usage was associated with reduced cortical thickness only in patients co-morbid for heavy alcohol use. Since cortical thickness is but one measure of brain structure and does not capture brain function, further studies of brain structure and function in amphetamine dependence are warranted.
BIAdb: a curated database of benzylisoquinoline alkaloids.
Singla D, Sharma A, Kaur J … +2 more , Panwar B, Raghava GP
BMC Pharmacol · 2010 Mar · PMID 20205728 · Full text
BACKGROUND: Benzylisoquinoline is the structural backbone of many alkaloids with a wide variety of structures including papaverine, noscapine, codeine, morphine, apomorphine, berberine, protopine and tubocurarine. Many b...
BACKGROUND: Benzylisoquinoline is the structural backbone of many alkaloids with a wide variety of structures including papaverine, noscapine, codeine, morphine, apomorphine, berberine, protopine and tubocurarine. Many benzylisoquinoline alkaloids have been reported to show therapeutic properties and to act as novel medicines. Thus it is important to collect and compile benzylisoquinoline alkaloids in order to explore their usage in medicine. DESCRIPTION: We extract information about benzylisoquinoline alkaloids from various sources like PubChem, KEGG, KNApSAcK and manual curation from literature. This information was processed and compiled in order to create a comprehensive database of benzylisoquinoline alkaloids, called BIAdb. The current version of BIAdb contains information about 846 unique benzylisoquinoline alkaloids, with multiple entries in term of source, function leads to total number of 2504 records. One of the major features of this database is that it provides data about 627 different plant species as a source of benzylisoquinoline and 114 different types of function performed by these compounds. A large number of online tools have been integrated, which facilitate user in exploring full potential of BIAdb. In order to provide additional information, we give external links to other resources/databases. One of the important features of this database is that it is tightly integrated with Drugpedia, which allows managing data in fixed/flexible format. CONCLUSIONS: A database of benzylisoquinoline compounds has been created, which provides comprehensive information about benzylisoquinoline alkaloids. This database will be very useful for those who are working in the field of drug discovery based on natural products. This database will also serve researchers working in the field of synthetic biology, as developing medicinally important alkaloids using synthetic process are one of important challenges. This database is available from http://crdd.osdd.net/raghava/biadb/.
Targeting ligand-gated ion channels in neurology and psychiatry: is pharmacological promiscuity an obstacle or an opportunity?
Bianchi MT, Botzolakis EJ
BMC Pharmacol · 2010 Mar · PMID 20196850 · Full text
BACKGROUND: The traditional emphasis on developing high specificity pharmaceuticals ("magic bullets") for the treatment of Neurological and Psychiatric disorders is being challenged by emerging pathophysiology concepts t...
BACKGROUND: The traditional emphasis on developing high specificity pharmaceuticals ("magic bullets") for the treatment of Neurological and Psychiatric disorders is being challenged by emerging pathophysiology concepts that view disease states as abnormal interactions within complex networks of molecular and cellular components. So-called network pharmacology focuses on modifying the behavior of entire systems rather than individual components, a therapeutic strategy that would ideally employ single pharmacological agents capable of interacting with multiple targets ("magic shotguns"). For this approach to be successful, however, a framework for understanding pharmacological "promiscuity"--the ability of individual agents to modulate multiple molecular targets--is needed. PRESENTATION OF THE HYPOTHESIS: Pharmacological promiscuity is more often the rule than the exception for drugs that target the central nervous system (CNS). We hypothesize that promiscuity is an important contributor to clinical efficacy. Modulation patterns of existing therapeutic agents may provide critical templates for future drug discovery in Neurology and Psychiatry. TESTING THE HYPOTHESIS: To demonstrate the extent of pharmacological promiscuity and develop a framework for guiding drug screening, we reviewed the ability of 170 therapeutic agents and endogenous molecules to directly modulate neurotransmitter receptors, a class of historically attractive therapeutic targets in Neurology and Psychiatry. The results are summarized in the form of 1) receptor-centric maps that illustrate the degree of promiscuity for GABA-, glycine-, serotonin-, and acetylcholine-gated ion channels, and 2) drug-centric maps that illustrated how characterization of promiscuity can guide drug development. IMPLICATIONS OF THE HYPOTHESIS: Developing promiscuity maps of approved neuro-pharmaceuticals will provide therapeutic class-based templates against which candidate compounds can be screened. Importantly, compounds previously rejected in traditional screens due to poor specificity could be reconsidered in this framework. Further testing will require high throughput assays to systematically characterize interactions between available CNS-active drugs and surface receptors, both ionotropic and metabotropic.
Mitochondria-targeted antioxidant effects of S(-) and R(+) pramipexole.
Ferrari-Toninelli G, Maccarinelli G, Uberti D … +2 more , Buerger E, Memo M
BMC Pharmacol · 2010 Feb · PMID 20137065 · Full text
BACKGROUND: Pramipexole exists as two isomers. The S(-) enantiomer is a potent D3/D2 receptor agonist and is extensively used in the management of PD. In contrast, the R(+) enantiomer is virtually devoid of any of the DA...
BACKGROUND: Pramipexole exists as two isomers. The S(-) enantiomer is a potent D3/D2 receptor agonist and is extensively used in the management of PD. In contrast, the R(+) enantiomer is virtually devoid of any of the DA agonist effects. Very limited studies are available to characterize the pharmacological spectrum of the R(+) enantiomer of pramipexole. RESULTS: Using differentiated SH-SY5Y neuroblastoma cells as an experimental model, here we show that S(-) and R(+) pramipexole are endowed with equipotent efficacy in preventing cell death induced by H2O2 and inhibiting mitochondrial reactive oxygen species generation. Both pramipexole enantiomers prevented mitochondrial ROS generation with a potency about ten times higher then that elicited for neuroprotection. CONCLUSIONS: These results support the concept of both S(-) and R(+) pramipexole enantiomers as mitochondria-targeted antioxidants and suggest that the antioxidant, neuroprotective activity of these drugs is independent of both the chiral 6-propylamino group in the pramipexole molecule and the DA receptor stimulation.
Antinociceptive effect of geranylgeraniol and 6alpha,7beta-dihydroxyvouacapan-17beta-oate methyl ester isolated from Pterodon pubescens Benth.
Spindola HM, Servat L, Denny C … +7 more , Rodrigues RA, Eberlin MN, Cabral E, Sousa IM, Tamashiro JY, Carvalho JE, Foglio MA
BMC Pharmacol · 2010 Jan · PMID 20055987 · Full text
BACKGROUND: Pterodon pubescens Benth seeds are commercially available in the Brazilian medicinal plant street market. The crude alcoholic extracts of this plant are used in folk medicine as anti-inflammatory, analgesic,...
BACKGROUND: Pterodon pubescens Benth seeds are commercially available in the Brazilian medicinal plant street market. The crude alcoholic extracts of this plant are used in folk medicine as anti-inflammatory, analgesic, and anti-rheumatic preparations. The aim of this study was to evaluate the contribution of geranylgeraniol (C1) and 6alpha, 7beta-dihydroxyvouacapan-17beta-oate methyl ester (C2) isolated from Pterodon pubescens Benth. to the antinociceptive activity of the crude extract. RESULTS: Compounds C1 and C2 demonstrated activity against writhing with intraperitoneal (i.p.) and oral (p.o.) routes, capsaicin (i.p. and p.o.), glutamate (i.p.), and in the hot-plate (p.o.) tests, demonstrating their contribution to the antinociceptive activity of crude Pterodon pubescens Benth extracts. The observed activity of compounds C1 and C2 may be related to vanilloid receptors VR1, and/or glutamate peripheral receptors. In hot-plate model, the antinociceptive activity was maintained when naloxone chloride (opioid antagonist) was administered prior to treatment with compounds suggesting that C1 and C2 (p.o.) do not exert their antinociceptive effects in the hot-plate test via opioid receptors. The findings presented herein also suggest that compounds within the crude Pterodon pubescens Benth. extract may exert a synergistic interactive effect, since the crude extract (300 mg x kg-1) containing lower concentrations of compounds C1 (11.5%- 34.6 mg x kg-1) and C2 (1.5% - 4.7 mg x kg-1) gave statistically the same effect to the pure compounds when tested separately (C1 = C2 = 300 mg.kg-1) in writhing experimental model with p.o. administration. Further studies will be undertaken to establish more specifically the mechanisms of action for compounds C1 and C2. Possible synergistic interactions will be evaluated employing the Isobole method. CONCLUSION: These results allowed us to establish a relationship between the popular use of Pterodon pubescens seeds for pain relief and the activity of two major compounds isolated from this species which demonstrated antinociceptive activity. Various "in vivo" experimental models corroborate the folk use of this species for different pain and inflammation disorders.
Divergence of allosteric effects of rapacuronium on binding and function of muscarinic receptors.
Jakubík J, Randáková A, El-Fakahany EE … +1 more , Dolezal V
BMC Pharmacol · 2009 Dec · PMID 20038295 · Full text
BACKGROUND: Many neuromuscular blockers act as negative allosteric modulators of muscarinic acetylcholine receptors by decreasing affinity and potency of acetylcholine. The neuromuscular blocker rapacuronium has been sho...
BACKGROUND: Many neuromuscular blockers act as negative allosteric modulators of muscarinic acetylcholine receptors by decreasing affinity and potency of acetylcholine. The neuromuscular blocker rapacuronium has been shown to have facilitatory effects at muscarinic receptors leading to bronchospasm. We examined the influence of rapacuronium on acetylcholine (ACh) binding to and activation of individual subtypes of muscarinic receptors expressed in Chinese hamster ovary cells to determine its receptor selectivity. RESULTS: At equilibrium rapacuronium bound to all subtypes of muscarinic receptors with micromolar affinity (2.7-17 microM) and displayed negative cooperativity with both high- and low-affinity ACh binding states. Rapacuronium accelerated [3H]ACh association with and dissociation from odd-numbered receptor subtypes. With respect to [35S]GTPgammaS binding rapacuronium alone behaved as an inverse agonist at all subtypes. Rapacuronium concentration-dependently decreased the potency of ACh-induced [35S]GTPgammaS binding at M2 and M4 receptors. In contrast, 0.1 microM rapacuronium significantly increased ACh potency at M1, M3, and M5 receptors. Kinetic measurements at M3 receptors showed acceleration of the rate of ACh-induced [35S]GTPgammaS binding by rapacuronium. CONCLUSIONS: Our data demonstrate a novel dichotomy in rapacuronium effects at odd-numbered muscarinic receptors. Rapacuronium accelerates the rate of ACh binding but decreases its affinity under equilibrium conditions. This results in potentiation of receptor activation at low concentrations of rapacuronium (1 microM) but not at high concentrations (10 microM). These observations highlight the relevance and necessity of performing physiological tests under non-equilibrium conditions in evaluating the functional effects of allosteric modulators at muscarinic receptors. They also provide molecular basis for potentiating M3 receptor-mediated bronchoconstriction.
Abstracts of the 15th Scientific Symposium of the Austrian Pharmacological Society (APHAR) joint meeting with the Hungarian Society of Experimental and Clinical Pharmacology (MFT) and the Slovenian Pharmacological Society (SDF). Graz, Austria. November 19-21, 2009.
BMC Pharmacol · 2009 Nov · PMID 19912617
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