bluuebunny/crossref_metadata_2025 huggingface dataset:
Arginine vasopressin release in response to the administration of 3,4-methylenedioxymethamphetamine (“ecstasy”): is metabolism a contributory factor?
Authors: Forsling Mary , Fallon John K , Kicman Andrew T , Hutt Andrew J , Cowan David A , Henry John A
Published: July 2003

The aim of this investigation was to examine the effect of 3,4-methylenedioxymethamphetamine (MDMA) administration on arginine vasopressin (AVP) release. (R,S)-MDMA (40 mg) was administered to eight normally hydrated healthy male volunteers (22–32 years) and blood samples were collected up to 24 h. Plasma was assayed for AVP and cortisol by radioimmunoassays, and for MDMA and the N-demethylated metabolite, MDA, by gas chromatography-mass spectrometry. Sodium concentrations and osmolality were also determined. Plasma AVP increased in all subjects after MDMA administration and a significant negative correlation was observed between concentrations of AVP and both single and total enantiomer MDMA at 1 h (r < −0.91, P < 0.01). This had disappeared by 2 h (P > 0.7). Compared with basal values, no significant change was observed for osmolality or cortisol at 1 h after drug administration. In conclusion, plasma AVP concentrations increase after MDMA administration, but the increase is not part of a generalized stress response since cortisol did not increase concurrently. A significant negative correlation between plasma MDMA and AVP was observed soon after administration. The possibility that a pharmacological effect of MDMA is primarily mediated via one or more metabolites, rather than by the parent drug, should be considered.
The effect of endotoxin on hepatocyte nuclear factor 1 nuclear protein binding: potential implications on CYP2E1 expression in the rat
Authors: Roe Amy L , Poloyac Samuel M , Howard Georgette , Shedlofsky Steven I , Blouin Robert A
Published: July 2003

The purpose of this study was to determine if changes in nuclear protein binding of hepatocyte nuclear factor 1 (HNF-1) occur after lipopolysaccharide (LPS) administration. In addition, the time-course of alterations in CYP2E1 regulation were evaluated. Rats were injected with 2.0 mg LPS and euthanized over a 72-h period. Nuclear protein binding to a consensus HNF-1 oligonucleotide was assessed by the electrophoretic mobility shift assay. CYP2E1 activity was analysed using chlorzoxazone as a substrate (6OH-CLZ), and CYP2E1 protein concentration was determined by enzyme-linked immunosorbent assay. Endotoxin treatment resulted in decreased nuclear protein binding to an HNF-1 element as early as 1 h after treatment and returned to control levels by 72 h. This reduced binding persisted for 24 h and returned to control values 48 h after LPS administration. In addition, the reduction in binding was primarily attributable to a HNF-1α immunoreactive protein. The observed reduction in HNF-1 binding was followed in the time-course by decreases in CYP2E1 activity and protein content with maximal decreases to 50 and 67% of control, respectively, at 48 h after LPS administration. Endotoxin is a potent inducer of the acute phase response (APR). The APR stimulation by endotoxin administration reduced HNF-1α binding and decreased the expression of CYP2E1 in the rat liver. The time-course of alterations in HNF-1 and CYP2E1 lend support to the possibility that HNF-1α may play a role in the down-regulation of genes that require HNF-1α for their constitutive expression. These data serve as an important precedent for future studies evaluating the direct association of decreased HNF-1α binding and reduced gene expression after LPS administration.
Antitumour activity and adverse reactions of combined treatment with chitosan and doxorubicin in tumour-bearing mice
Authors: Kimura Yoshiyuki , Sawai Naoki , Okuda Hiromichi
Published: July 2003

We examined the antitumour activity and adverse reactions, such as myelotoxicity, gastrointestinal toxicity and body-weight loss, of the cancer chemotherapy drug doxorubicin when given with chitosan in sarcoma 180-bearing mice. Intraperitoneally administered doxorubicin (5 mg kg−1) given on days 1 and 8 with or without orally administered chitosan (200, 400 and 800 mg kg−1 twice daily) inhibited tumour growth. The orally administered chitosan (400 and 800 mg kg−1 twice daily) prevented doxorubicin-induced body-weight loss and small-intestinal mucosal injury. Similarly, the reduction of leucocyte number induced by the intraperitoneally administered doxorubicin was restored to normal by the oral administration of chitosan (400 and 800 mg kg−1 twice daily). It seems likely that the mechanisms by which the orally administered chitosan protects against doxorubicin-induced gastrointestinal toxicity may be due to the formation of doxorubicin-chitosan complex in the small-intestinal mucosa through the diffusion of chitosan into the small-intestinal villi. In conclusion, our data suggest that the oral administration of chitosan prevents the gastrointestinal mucositis associated with doxorubicin therapy.
Immunomodulating activity of CVT-E002, a proprietary extract from North American ginseng (Panax quinquefolium)
Authors: Wang Meiqi , Guilbert Larry J , Ling Lei , Li Jie , Wu Yingqi , Xu Sharon , Pang Peter , Shan Jacqueline J
Published: July 2003

The activity of CVT-E002, an aqueous extract containing mainly oligosaccharides and polysaccharides from North American ginseng (Panax quinquefolium), as an immunobooster on murine spleen cells and peritoneal macrophages, was studied in-vitro. CVT-E002 stimulated the proliferation of normal mouse spleen cells, of which the major responding subpopulation was identified as B lymphocytes. CVT-E002 also activated peritoneal exudate macrophages leading to enhanced interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and nitric oxide (NO) production. In addition, CVT-E002 stimulated in-vivo immunoglobulin G (IgG) production in treated mice. These results identify some of the immunomodulating activities of CVT-E002 and suggest its use clinically for the modulation of immune responses.
Protective effects of cannabinoid receptor agonists against cocaine and other convulsant-induced toxic behavioural symptoms
Authors: Hayase Tamaki , Yamamoto Yoshiko , Yamamoto Keiichi
Published: July 2003

Based on the previously reported co-localization and relationship between cannabinoid and dopamine receptors, the effects of cannabinoid receptor agonists against cocaine-induced toxic behavioural symptoms, including convulsive seizures, were examined in mice. The anticonvulsant effect of several cannabimimetics against seizures induced by other convulsants was also compared. The cannabinoid receptor agonists CP 55940 ((-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)-cyclohexanol) and WIN 55212–2 ((R)-(+)-[2.3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone), and the endogenous cannabinoid anandamide were co-administered intraperitoneally with cocaine (75 mg kg−1) or other convulsants such as bicuculline, methyl 6,7-dimethoxy-4-ethyl-β-carboline-carboxylate (DMCM), l-glutamic acid and N-methyl-d-aspartate (NMDA). CP 55940 (2.5 mg kg−1) and anandamide (15 mg kg−1) significantly antagonized cocaine-induced lethality, and CP 55940 and WIN 55212–2 (2.5 mg kg−1) significantly attenuated the severity of cocaine-induced convulsive seizures. Furthermore, ataxic hyperactivity, which was observed only in the cocaine-treated group of mice and could be evaluated by their activity counts, was also depressed in the groups of mice co-treated with each of the three cannabinoid agonists. However, none of these agonists protected against bicuculline- or DMCM-induced lethality or convulsive seizures. In contrast, all of the cannabinoid agonists, most notably anandamide, antagonized both l-glutamic acid (2 g kg−1)- and NMDA (200 mg kg−1)-induced convulsive seizures. These data support the previously reported close correlation between dopamine and cannabinoid receptors, and between cannabinoid agonists, especially anandamide, and glutamate (NMDA) receptors. Furthermore, these results suggest a potential therapeutic role for cannabinoid agonists against cocaine- and other-convulsant-induced toxicities.
New insights into the mechanism of action of the anti-inflammatory triterpene lupeol
Authors: Fernández Maria Angeles , de las Heras Beatriz , Garcia Maria Dolores , Sáenz Maria Teresa , Villar Angel
Published: July 2003

The pentacyclic triterpene lupeol has been studied for its inhibitory effects on murine models of inflammation and peritoneal macrophage functions in-vitro. Lupeol (0.5 and 1 mg/ear) administered topically suppressed the mouse ear oedema induced by 12-O-tetradecanoyl-phorbol acetate (TPA), being less effective on ear oedema induced by arachidonic acid. Quantitation of the neutrophil specific marker myeloperoxidase demonstrated that its topical activity was associated with reduction in cell infiltration into inflamed tissues. When tested in-vitro, lupeol significantly reduced prostaglandin E2 (PGE2) production from A23187-stimulated macrophages, but failed to affect leukotriene C4 release. It was a weak inhibitor of nitrite release, but dose-dependently suppressed PGE2. Cytokine production (tumour necrosis factor-α and interleukin-1β) was inhibited in the range 10–100 μm in lipopolysaccharide-treated macrophages. This study demonstrated that lupeol possessed anti-inflammatory activity which was likely to depend on its ability to prevent the production of some pro-inflammatory mediators.
Effect of hyperprolactinaemia as induced by pituitary homografts under kidney capsule on gastric and duodenal ulcers in rats
Authors: Asad Mohammed , Shewade D G , Koumaravelou K , Abraham Benny K , Balasinor Nafisa , Ramaswamy S
Published: July 2003

The effect of hyperprolactinaemia, induced by two or four pituitary homografts under the kidney capsule, on gastric and duodenal ulcers has been studied. The acute gastric ulcer models used were pylorus ligation, indometacin-induced and ethanol-induced gastric ulcers. Chronic gastric ulcers were induced using acetic acid and duodenal ulcers by mercaptamine hydrochloride. After pylorus ligation, there was an approximate 30–40% increase in gastric secretion, a significant increase in total acidity (P < 0.01) and in the ulcer index (P < 0.01) in rats bearing pituitary homografts under the kidney capsule when compared with the sham-operated control. Hyperprolactinaemia did not affect the formation of ethanol-induced gastric ulcers but showed a 40% reduction in the development of indometacin-induced gastric ulcers. It also produced a 20% increase in the ulcer index in acetic acid-induced chronic gastric ulcers and a 30% increase in ulcer area in mercaptamine-induced duodenal ulcers. Our results showed that hyperprolactinaemia induced gastric acid secretion and thereby aggravated gastric and duodenal ulcers in rats. Hyperprolactinaemia did not affect gastric cytoprotection.
Response of MCF-7 human breast cancer cells to some binary mixtures of oestrogenic compounds in-vitro
Authors: Suzuki Takahiro , Ide Kunihito , Ishida Masaru
Published: July 2003

The effects of simultaneous administration of some binary mixtures of seven natural and synthetic oestrogenic substances (17β-estradiol, estrone, bisphenol A, butylbenzyl phthalate, endosulfan, methoxychlor and pentachlorophenol) on the cellular proliferation of human breast cancer MCF-7 cells in-vitro (a modified E-screen assay) have been measured. To assess the presence or absence of interactions of the two agents, the data were analysed on the basis of a graphical method in which the types and extents of interactions were described by response-surface diagrams. Of the nine combinations of the agents examined, synergistic interaction was evident for the combination of 17β-estradiol and bisphenol A, whereas the remaining eight combinations were weakly synergistic, additive and/or weakly antagonistic in the dose-range tested.
Riluzole suppresses post-sigh, but not spontaneous apnoeas during sleep in rats
Authors: Radulovacki Miodrag , Pavlovic Sasa , Rakic Andrei , Janelidze Marika , Shermulis Lisa , Carley David W
Published: July 2003

We conducted this experiment to determine the role of glutamate in the mechanism of sleep apnoeas by administering riluzole, a glutamate release inhibitor, to freely moving rats in which sleep-related apnoeas are physiological phenomena. Adult Sprague-Dawley rats were implanted with electrodes for electroencephalogram (EEG) and electromyogram (EMG) recording to monitor sleep and were placed inside a single-chamber plethysmograph to monitor respiration. Sleep and respiration were recorded for 6 h following intraperitoneal administration of 0.5, 5.0 and 10.0 mg kg−1 riluzole. Riluzole dose-dependently suppressed post-sigh apnoeas during rapid eye movement (REM) sleep but had no effect on sleep-related spontaneous apnoeas. The drug (5.0 and 10.0 mg kg−1) also dose-dependently reduced wakefulness and increased sleep. It appears that glutamate, an excitatory neurotransmitter, plays a role in the genesis of the post-sigh apnoeas during REM sleep.
Synthesis and preliminary behavioural evaluation in mice of new 3-aryl-3-pyrrol-1-ylpropanamides, analogues of FGIN-1–27 and FGIN-1–43
Authors: Guillon J , Boulouard M , Lelong V , Dallemagne P , Rault S , Jarry C
Published: July 2003

The 2-aryl-3-indoleacetamides FGIN-1–27 and FGIN-1–43 have already been characterized in-vitro as potent and specific ligands for the mitochondrial DBI receptor. This affinity was associated with psychotropic properties in several rodent behavioural tasks (in particular anxiolytic action) via enhancement of GABA transmission through neurosteroid production. The synthesis of new 3-aryl-3-pyrrol-1-ylpropanamides 1a-i, analogues of FGIN-1–27 and FGIN-1–43, is described in four steps starting from the corresponding arylaldehydes. Preliminary evaluation of these compounds in behavioural studies (spontaneous locomotor activity and anxiolytic activity) in mice was also undertaken.
Hepatoprotective activity of Trichilia roka on carbon tetrachloride-induced liver damage in rats
Authors: Germanò M P , D'Angelo V , Sanogo R , Morabito A , Pergolizzi S , De Pasquale R
Published: July 2003

Trichilia roka Chiov. (Meliaceae) is a tree widely distributed in tropical Africa. It has been used in Mali folk medicine for the treatment of various illnesses. A decoction of the roots is taken as a remedy for colds and pneumonia, and it is used as a diuretic and in hepatic disorders. We have evaluated the hepatoprotective effects of a decoction of Trichilia roka root on CCl4-induced acute liver damage in rats. Treatment with the decoction showed a significant protective action made evident by its effect on the levels of glutamate oxalacetate transaminase and glutamate pyruvate transaminase in the serum, on the protein content and lipid peroxidation levels in the liver homogenate. Histopathological changes produced by CCl4, such as necrosis, fatty change, ballooning degeneration and inflammatory infiltration of lymphocytes around the central veins, were clearly recovered by the treatment with Trichilia root decoction. On fractionating this extract into diethyl ether-soluble and water-soluble fractions, the activity was retained in the diethyl ether-soluble fraction. Moreover, the administration of decoction prevented a preferential deposition of collagen around the sinusoidal cell layer, which is responsible for the perisinusoidal fibrosis in the early stage of CCl4 damage. This study showed that treatment with Trichilia roka extracts or silymarin (as reference) appeared to enhance the recovery from CCl4-induced hepatotoxicity. The hepatoprotective properties of Trichilia roka may be correlated to polyphenol content of the decoction and its diethyl ether-soluble fraction.
Growth factor release from tissue engineering scaffolds
Authors: Whitaker M J , Quirk R A , Howdle S M , Shakesheff K M
Published: July 2003

Synthetic scaffold materials are used in tissue engineering for a variety of applications, including physical supports for the creation of functional tissues, protective gels to aid in wound healing and to encapsulate cells for localized hormone-delivery therapies. In order to encourage successful tissue growth, these scaffold materials must incorporate vital growth factors that are released to control their development. A major challenge lies in the requirement for these growth factor delivery mechanisms to mimic the in-vivo release profiles of factors produced during natural tissue morphogenesis or repair. This review highlights some of the major strategies for creating scaffold constructs reported thus far, along with the approaches taken to incorporate growth factors within the materials and the benefits of combining tissue engineering and drug delivery expertise.
Comparison of the lymphatic transport of a lipophilic drug from vehicles containing α-tocopherol and/or triglycerides in rats
Authors: Nielsen P B , Müllertz A , Norling T , Kristensen H G
Published: July 2003

The applicability of α-tocopherol as a lymphotropic carrier for a highly lipophilic drug has been evaluated. Transport to the intestinal lymph of the highly lipophilic model drug, Lu28–179, in rats after administration to the stomach in an α-tocopherol emulsion was compared with lymphatic transport after administration of a sesame oil emulsion and an α-tocopherol/sesame oil emulsion. Lymphatic transport of the triglycerides and of α-tocopherol was determined. A conscious rat model was used, and the mesenteric lymph was collected. There was no significant difference between the cumulative masses of triglyceride from the two emulsions containing triglyceride 24 h after administration. Administration of an α-tocopherol emulsion seemed to induce mobilization of endogenous triglyceride. The lymphatic transport of α-tocopherol was less than 1 mg 24 h after administration of both emulsions containing α-tocopherol. The absorption of Lu28–179 from the α-tocopherol emulsion was very low, with a lymphatic recovery of 0.05%. When administered in an α-tocopherol/sesame oil emulsion, the recovery of Lu28–179 increased sevenfold to 0.35%. However, after administration of Lu28–179 in a sesame oil emulsion, the lymphatic recovery increased a further 13-fold to 4.5%. In conclusion, the study showed that α-tocopherol did not promote lymphatic absorption of Lu28–179 and thus was not a good lymphotropic carrier, as compared with sesame oil. α-Tocopherol in combination with sesame oil was not a good lymphotropic carrier either. The non-absorbed α-tocopherol fraction in the intestine might be able to prevent the absorption of Lu28–179.
In-vitro nasal drug delivery studies: comparison of derivatised, fibrillar and polymerised collagen matrix-based human nasal primary culture systems for nasal drug delivery studies
Authors: Agu Remigius Uchenna , Jorissen Mark , Willems Tom , Augustijns Patrick , Kinget Renaat , Verbeke Norbert
Published: July 2003

The aim of this study was to establish a collagen matrix-based nasal primary culture system for drug delivery studies. Nasal epithelial cells were cultured on derivatised (Cellagen membrane CD-24), polymerised (Vitrogen gel) and fibrillar (Vitrogen film) collagen substrata. Cell morphology was assessed by microscopy. The cells were further characterised by measurement of ciliary beat frequency (CBF), transepithelial resistance (TER), permeation of sodium fluorescein, mitochondrial dehydrogenase (MDH) activity and lactate dehydrogenase (LDH) release upon cell exposure to sodium tauro-24, 25 dihydrofusidate (STDHF). Among the three collagen substrata investigated, the best epithelial differentiated phenotype (monolayer with columnar/cuboidal morphology) occurred in cells grown on Cellagen membrane CD-24 between day 4 and day 11. Cell culture reproducibility was better with Cellagen membrane CD-24 (90%) in comparison with Vitrogen gel (70%) and Vitrogen film (< 10%). TER was higher in cells grown on Vitrogen gel than on Cellagen membrane CD-24 and Vitrogen film. The apparent permeability coefficient (Papp × 10−7 cm s−1) of sodium fluorescein in these conditions was 0.45 ± 0.08 (Vitrogen gel) and 1.91 ± 0.00 (Cellagen membrane CD-24). Except for LDH release, CBF and cell viability were comparable for all the substrata. Based on MDH activity, LDH release, CBF, TER and permeation studies, Cellagen membrane CD-24- and Vitrogen gel-based cells were concluded to be functionally suitable for in-vitro nasal drug studies. Vitrogen film-based cultures may be limited to metabolism and cilio-toxicity studies.
Ursodeoxycholic acid action on the transport function of the small intestine in normal and cystic fibrosis mice
Authors: Hardcastle J , Hardcastle P T , Chapman J , Taylor C J
Published: July 2003

Ursodeoxycholic acid possesses choleretic and cytoprotective properties and in cystic fibrosis (CF) it is used to treat the hepatobiliary symptoms of the disease. This study investigated the effects of this bile acid on the transport function of the small intestine in normal and CF mice. The effects of ursodeoxycholic acid were monitored as changes in short-circuit current (SCC) in stripped sheets of small intestine from normal (Swiss MF1) and transgenic CF (Cftrtm2Cam) mice. In ileal sheets from Swiss MF1 mice, mucosal ursodeoxycholic acid caused a biphasic increase in SCC. The first phase was reduced by lowering the mucosal Na+ concentration, while the second phase was inhibited by Cl−-free conditions, serosal furosemide or mucosal diphenylamine-2-carboxylic acid (DPC), suggesting an initial Na+-dependent bile acid absorption followed by a stimulation of electrogenic Cl− secretion. Serosal application of ursodeoxycholic acid to the ileum and mucosal or serosal application to the mid-intestine and jejunum elicited a secretory response only. Secretion was Ca2+-dependent, but did not involve neural mechanisms. Mucosal mast cells, histamine and serotonin (5-HT) were implicated in the secretory response. Responses in tissues from transgenic wild-type mice were similar to those obtained with Swiss MF1 mice, but the secretory response to mucosal or serosal application of the bile acid was impaired in CF tissues. In ilea from CF mice the initial absorptive phase of the response to mucosal ursodeoxycholic acid was still observed. It is concluded that ursodeoxycholic acid induces secretion throughout the murine small intestine by a mechanism that involves degranulation of mucosal mast cells. In the ileum Na+-dependent absorption can also be detected. The secretory response is defective in CF intestine, but the absorptive effect is still present.
In-vitro activity and tissue distribution of new fluorinated meso-tetrahydroxyphenylporphyrin photosensitizers
Authors: Songca Sandile P
Published: July 2003

Tetra(hydroxyphenyl)porphyrins started to attract interest as potential photosensitizers for photodynamic therapy in the early eighties. Subsequently, a number of derivatives of these compounds have been studied. In 1997 we reported the synthesis of the fluorinated derivatives 5,10,15,20-tetrakis(2-fluoro-3-hydroxyphenyl)porphyrin (8), 5,10,15,20-tetrakis(2,4-difluoro-3-hydroxyphenyl)porphyrin (9), and 5,10,15,20-tetrakis(3,5-difluoro-4-hydroxyphenyl)porphyrin (10). We have measured their biological activity, using the MTT test, against cancer cell cultures in-vitro. The test showed that these compounds were as potent as 5,10,15,20-tetrakis(3-hydroxyphenyl)chlorin (5), one of the leading photosensitizers in photodynamic therapy. The highest photoactivity was shown by the meta-hydroxy compounds 8 and 9. The para-compound showed high toxicity in the dark. Distribution of these compounds between normal and cancer tissue was studied using 19F NMR spectroscopy. The highest cancer tissue localization was also shown by the meta-hydroxy compounds 8 and 9. The para compound showed poor localization in tumour tissue. This study has shown that 19F NMR spectroscopy can be used to estimate the tissue distribution of fluorinated tetrahydroxyphenylporphyrins in-vivo.
Effects of cholesterol and model transmembrane proteins on drug partitioning into lipid bilayers as analysed by immobilized-liposome chromatography
Authors: Lagerquist Caroline , Beigi Farideh , Karlén Anders , Lennernäs Hans , Lundahl Per
Published: July 2003

We have analysed how cholesterol and transmembrane proteins in phospholipid bilayers modulate drug partitioning into the bilayers. For this purpose we determined the chromatographic retention of drugs on liposomes or proteoliposomes entrapped in gel beads. The drug retention per phospholipid amount (the capacity factor Ks) reflects the drug partitioning. Cholesterol in the bilayers decreased the Ks value and hence the partitioning into the membrane in proportion to the cholesterol fraction. On average this cholesterol effect decreased with increasing temperature. Model transmembrane proteins, the glucose transporter GLUT1 and bacteriorhodopsin, interacted electrostatically with charged drugs to increase or decrease the drug partitioning into the bilayers. Bacteriorhodopsin proteoliposomes containing cholesterol combined the effects of the protein and the cholesterol and approached the partitioning properties of red blood cell membranes. For positively charged drugs the correlation between calculated intestinal permeability and log Ks was fair for both liposomes and bacteriorhodopsin-cholesterol proteoliposomes. Detailed modeling of solute partitioning into biological membranes may require an extensive knowledge of their structures.
Synthesis and in-vitro/in-vivo evaluation of orally administered entacapone prodrugs
Authors: Leppänen Jukka , Savolainen Jouko , Nevalainen Tapio , Forsberg Markus , Huuskonen Juhani , Taipale Hannu , Gynther Jukka , Männistö Pekka T , Järvinen Tomi
Published: July 2003

Entacapone is a new inhibitor of catechol-O-methyltransferase (COMT) that is used as an adjunct to l-dopa therapy in the treatment of Parkinson's disease. The bioavailability of orally administered entacapone is, however, relatively low (29–46%). In this study we have prepared more lipophilic acyl and acyloxyacyl esters, an acyloxy alkyl ether and an alkyloxycarbonyl ester of entacapone, and we have evaluated them as potential prodrugs to enhance the oral bioavailability of entacapone. All the derivatives fulfilled prodrug criteria and released entacapone in human serum in-vitro. The oral bioavailability of monopivaloyl (1a) and dipivaloyl (1b) esters of entacapone were investigated further in rats. The lipophilicity of 1b was high (log Papp 4.0 at pH 7.4) but its oral bioavailability was low (F = 0.6%), most probably due to its low aqueous solubility. The monopivaloyl ester of entacapone (1a) had a higher lipophilicity (log Papp 0.80) than entacapone (log Papp 0.18) at pH 7.4 while maintaining an aqueous solubility equal to entacapone. However, oral bioavailability was not increased when compared with the parent drug entacapone (F = 7.0% and 10.4%, respectively).
Comparison of vaginal aminopeptidase enzymatic activities in various animals and in humans
Authors: Acartürk Füsun , Parlatan Zehra I , Saracoĝlu Ömer F
Published: July 2003

The specific enzymatic activity of four different aminopeptidases (aminopeptidase N, leucine aminopeptidase, aminopeptidase A and aminopeptidase B) in vaginal homogenates from rabbit, rat, guinea-pig, sheep and humans was compared. The purpose of the study was to find an appropriate animal model that can be used in degradation studies of protein and peptide drugs. Different substrates were used as the relative specific substrates for the determination of aminopeptidase enzymatic activity: 4-methoxy-2-naphthylamide of l-alanine for amino-peptidase N, 4-methoxy-2-naphthylamide of l-leucine for leucine aminopeptidase, 4-methoxy-2-naphthylamide of l-glutamic acid for aminopeptidase A and 4-methoxy-2-naphthylamide of l-arginine for aminopeptidase B. The vaginal aminopeptidase enzymatic activity of different species was determined spectrofluorometrically. The inhibition of aminopeptidase activity in the presence of bestatin and puromycin inhibitors was also investigated. The results showed the presence of aminopeptidase enzymatic activity in all vaginal homogenates in the order: sheep > guinea-pig > rabbit ≥ human ≥ rat. Based on the results of the hydrolysis and inhibition of the 4-methoxy-2-naphthylamide substrates, it was difficult to have an exact decision on the aminopeptidase type in the vaginal homogenates from the species studied. It was found that the aminopeptidase activity in rat, rabbit and humans was not statistically different. Therefore, we suggest that rats and rabbits could be used as model animals for vaginal enzymatic activity studies and for determination of the degradation of protein and peptide drugs in the vagina.
Design, synthesis and biological testing of a novel series of anti-inflammatory drugs
Authors: Duffy Judith C , Dearden John C , Rostron Chris
Published: July 2003

Many of the non-steroidal anti-inflammatory drugs (NSAIDs) currently marketed produce severe gastro-toxic side effects. The benefits of producing NSAIDs without these side effects are obvious, particularly for patients requiring long-term therapy. The aim of this investigation was to produce novel NSAIDs, based on paracetamol, that exhibit little or no gastro-toxicity. The work covers design, synthesis and testing of 13 drug candidates. The analgesic and anti-inflammatory potencies of the drug candidates were measured using the mouse abdominal constriction assay and the carrageenan-induced rat paw oedema assay, respectively. The stomachs of the rats were examined post-mortem, to assess the gastro-toxicity of the drugs. Of the 13 compounds described herein, 11 were shown to possess analgesic activity at 2–10 times the potency of aspirin, while 8 demonstrated anti-inflammatory activity at 3–10 times the potency of aspirin. Significantly, all of the compounds showed very low gastro-toxicity when compared with aspirin. The results of this study indicate that it is possible to develop novel, potent NSAIDs based on the structure of paracetamol. These compounds have the advantage of demonstrating much lower gastro-toxicity than NSAIDs currently available. Drugs of this type may, in future, provide effective treatments for inflammatory disorders.
Ethnopharmacology of the Popoluca, Mexico: an evaluation
Authors: Leonti Marco , Vibrans Heike , Sticher Otto , Heinrich Michael
Published: July 2003

Medicinal plants are an essential part of indigenous pharmaceutical systems. We studied the medicinal plants used by the Popoluca of the Sierra Santa Marta (Eastern Mexico). This study is part of a series on the ethnopharmacology of various Macro-Mayan groups. During 16 months of ethnobotanical fieldwork, 614 taxa used medicinally and 4488 individual use-reports were documented. The data are analysed using the concept of the “healers' consensus” in order to identify culturally important medicinal plants. The medicinal uses of the plants were grouped into 13 illness categories. The responses for each species were summarized for each of the categories and were ordered by frequency of mention. The most frequently recorded medicinal plants of the Popoluca are Hamelia patens, used to stop bleeding from wounds, and Byrsonima crassifolia, used against diarrhoea. The high-ranked medicinal species were assessed pharmacognostically using published phytochemical and pharmacological data. Popoluca medicinal uses were fairly consistent with published data on active ingredients for those plants for which such data exist. However, data is still lacking for many other species. Toxicological studies are particularly scarce. This study will be used as a basis for subsequent studies on the pharmacology and phytochemistry of medicinal plant species.
Effects of the Class III antiarrhythmic agent dofetilide (UK-68,798) on L-type calcium current from rabbit ventricular myocytes
Authors: Paul A A , Leishman D J , Witchel H J , Hancox J C
Published: July 2003

The methanesulphonanilide agent dofetilide (UK-68,798) exerts Class III antiarrhythmic effects by inhibiting the cardiac rapid delayed rectifier potassium current (IKr) encoded by HERG. The aim of the present study was to determine whether dofetilide also exhibits Class IV (L-type calcium-channel blocking) effects. L-type calcium current (ICa,L) was measured from rabbit isolated ventricular myocytes, using the whole-cell patch-clamp technique under selective recording conditions. Positive control experiments demonstrated inhibition of ICa,L elicited by pulses to + 10 mV by both nifedipine and externally applied Ni2+ ions. Three concentrations of dofetilide were tested: 100 nm, 1 μm and 10 μm. ICa,L magnitude was not significantly reduced by any of the concentrations tested (P>0.05; n = minimum of seven cells per drug concentration). The inactivation time-course of ICa,L was also unaffected by 10 μm dofetilide. Heterologously expressed HERG current (IHERG) recorded from Chinese Hamster Ovary cells was extensively inhibited by 100 nm and 1 μm dofetilide, with inhibition at 1 μm not significantly different from 100% (P> 0.1). It is concluded that dofetilide produced no ICa,L blocking effects at concentrations up to and exceeding that required for maximal IHERG inhibition. The findings support the notion that dofetilide is a highly selective Class III antiarrhythmic agent, devoid of Class IV antiarrhythmic activity.
Cyclooxygenase-1 and cyclooxygenase-2 selectivity of non-steroidal anti-inflammatory drugs: investigation using human peripheral monocytes
Authors: Kato Miyako , Nishida Shinichi , Kitasato Hidero , Sakata Natsue , Kawai Shinichi
Published: July 2003

Since the pharmacological profiles of various non-steroidal anti-inflammatory drugs (NSAIDs) might depend on their differing selectivity for cyclooxygenase 1 (COX-1) and 2 (COX-2), we developed a new screening method using human peripheral monocytes. Monocytes from healthy volunteers were separated, and the cells were incubated with or without lipopoly-saccharide (LPS). Monocytes without LPS stimulation exclusively expressed COX-1 on Western blotting analysis, whereas LPS stimulation induced COX-2 expression. Unstimulated monocytes (COX-1) and LPS-stimulated monocytes (COX-2) were then used to determine the COX selectivity of various NSAIDs. The respective mean IC50 values for COX-1 and COX-2 IC50 (μm), and the COX-1/COX-2 ratio of each NSAID were as follows: celecoxib, 82, 6.8, 12; diclofenac, 0.076, 0.026, 2.9; etodolac, > 100, 53, > 1.9; ibuprofen, 12, 80, 0.15; indometacin, 0.0090, 0.31, 0.029; meloxicam, 37, 6.1, 6.1; 6-MNA (the active metabolite of nabumetone), 149, 230, 0.65; NS-398, 125, 5.6, 22; piroxicam, 47,25, 1.9; rofecoxib, > 100,25, > 4.0; S-2474, > 100,8.9, > 11; SC-560, 0.0048, 1.4, 0.0034. The percentage inhibition of COX-1 activity at the IC50 of COX-2 also showed a wide variation among these NSAIDs. The bioassay system using human monocytes to assess the inhibitory effects of various NSAIDs on COX-1 and COX-2 may become a clinically useful screening method.
Relationship between gamma-hydroxybutyrate plasma concentrations and its electroencephalographic effects in the rat
Authors: Van Sassenbroeck Diederik K , De Paepe Peter , Belpaire Frans M , Rosseel Marie-Thérèse , Martens Patrick , Boon Paul A , Buylaert Walter A
Published: July 2003

In view of the potential interest in an objective parameter for the depth of coma in intoxications with the recreational drug gamma-hydroxybutyrate (GHB), we have studied the relationship between the plasma concentrations and the electroencephalographic (EEG) changes induced by GHB in the rat. Fifteen rats randomly received either 150 (n = 3), 200 (n = 6) or 300 mg kg−1 (n = 6) GHB over 5 min, followed by a supramaximal dose of 450 mg kg−1 over 5 min at the end of the experiment. Plasma concentrations were determined with HPLC. The EEG was continuously recorded and the amplitude in the 15.5–30 Hz frequency band was quantified using aperiodic analysis. The plasma concentration-time profiles were fitted to a two-compartment model with Michaelis-Menten elimination. The pharmacokinetic parameters Vmax, Km and the apparent volume of distribution (Vd) proved to be independent of the dose and the mean pooled values were Vmax 2068 ± 140 μg mL−1 kg−1, Km 58 ± 16 μg mL−1 and Vd 476 ± 12 mL kg−1. The EEG amplitude in the 15.5–30 Hz frequency band displayed a monophasic inhibition and the effect-plasma concentration curve showed hysteresis. This hysteresis between EEG effect and plasma concentrations was minimized by simultaneous calculation of hypothetical effect-site concentrations and fitting the effect vs effect-site concentration curve to a sigmoid inhibitory Emax model. The descriptors of this Emax model (Emax, EC50, ke,0, γ and E0) were independent of the dose with an equilibration half-life t½ke,0 of 5.6 ± 0.3 min (mean value of the pooled results of the 5-min treatment groups). To investigate the origin of this hysteresis, a dose of 600 mg kg−1 GHB was infused over either 45 or 60 min each in three animals. The hysteresis was much less pronounced with 45 min than with 5 min and was absent with 60-min infusions. This indicated that the hysteresis was due to a distribution delay between the central compartment and the effect site. This study showed that the concentration-effect relationship of GHB could be characterized in individual rats using aperiodic analysis in the 15.5–30 Hz frequency band.
Enhancement of salivary secretion and neuropeptide (substance P, α-calcitonin gene-related peptide) levels in saliva by chronic anethole trithione treatment
Authors: Nagano Toshiaki , Takeyama Masaharu
Published: July 2003

Anethole trithione, a choleretic, has been reported to be effective in the treatment of dry mouth. We have examined the effects of chronic treatment with anethole trithione on salivary secretion, substance P immunoreactive substance (SP-IS) and α-calcitonin gene-related peptide immunoreactive substance (α-CGRP-IS) concentrations in human saliva. Anethole trithione caused significant increases of saliva SP-IS concentrations from the day 13 (25.3 ± 1.6 pg mL−1) to day 14 (25.8 ± 1.7 pg mL−1) compared with day 1 (19.9 ± 1.9 pg mL−1). Anethole trithione caused significant increase in saliva α-CGRP-IS concentration on day 14 (39.9 ± 4.7 pg mL−1) compared with day 1 (27.7 ± 4.7 pg mL−1). Anethole trithione significantly increased the sialosis volumes from day 11 to day 14 (1.6 ± 0.1–1.7 ± 0.2 mL) compared with the day 1 (1.2 ± 0.2 mL). Simple linear regression of the increase in sialosis volume with saliva SP-IS (r = 0.94) and α-CGRP-IS (r = 0.97) concentrations was found. These results demonstrated that chronic treatment with anethole trithione affected saliva SP-IS and α-CGRP-IS concentration in human saliva and sialosis volume.
Mechanism of AVP release and synthesis in chronic salt-loaded rats
Authors: Morita Masahiko , Kita Yasuhiro , Notsu Yoshitada
Published: July 2003

Arginine vasopressin (AVP) is involved in osmotic regulation in the brain and peripheral tissues. To elucidate the regulatory mechanism that involves AVP release in hyperosmolality, we investigated the regulation of the synthesis and release of AVP in chronic salt-loaded rats. In chronic salt-loaded rats, which were generated by free access to water containing 2% NaCl for 7 days, plasma osmolality was significantly increased compared with control value. When tested, the AVP content was significantly higher in plasma but lower in the pituitary and whole brain (hypothalamus, cortex and striatum) than in control rats. The expression of AVP mRNA in the brain was significantly up-regulated compared with that in control rats. These data lead to the suggestion that hyperosmolality stimulates AVP release from the brain and subsequently induces AVP synthesis in the brain. On the other hand, mRNA levels of vasopressin V1a receptor (V1aR), whose down-regulation is known to be a counteraction to the V1aR activation, was not changed in the brain, suggesting that the AVP seems not to interact with the V1aR in the brain. These results suggest that hyperosmosis promotes the release of AVP into plasma, the subsequent induction of AVP mRNA in the brain and its action on the peripheral tissues.
Anti-inflammatory effects of 5-aminosalicylic acid conjugates with chenodeoxycholic acid and ursodeoxycholic acid on carrageenan-induced colitis in guinea-pigs
Authors: Goto Michitaka , Okamoto Yasuhiro , Yamamoto Magobei , Aki Hatsumi
Published: July 2003

Two epimeric bile acid conjugates, 5-aminosalicylic acid-chenodeoxycholic acid (5-ASA-CDCA) and 5-aminosalicylic acid-ursodeoxycholic acid (5-ASA-UDCA), were synthesized to deliver 5-ASA to the large intestine by oral administration. The movement of the conjugates down the gastrointestinal tract and the anti-inflammatory effects on ulcerative colitis were investigated by administering the conjugates to guinea-pigs with an inflammatory bowel disease induced by 2% degraded carrageenan solution. The conjugates were protected from deconjugation in stomach and small intestine and reached the caecum and the colon, where 5-ASA was more easily liberated from 5-ASA-CDCA than from 5-ASA-UDCA. The conjugates at doses equivalent to 50 or 150 mg kg−1 5-ASA were orally administered once a day for 4 weeks from the 15th day after starting carrageenan treatment. The body weights and the bleeding scores of occult blood in faeces were measured during the experiment. The number of ulcers in the caecum and the colon were counted after killing the guinea-pigs at the end of the experiment. Rapid onset of efficacy was shown by a significant reduction in bleeding scores within a week after administration of the conjugates. Treatment with the lower dose of 5-ASA-CDCA showed a recovery of body weight and a significantly decreased number of ulcers in the caecum, and the ulcers in the colon had completely disappeared by the end of the experiment. There was a good correlation found between the number of ulcers in the caecum and the bleeding scores of occult blood in faeces. The findings indicate that both conjugates were sufficiently delivered to the large intestine without deconjugation and that the lower dose of 5-ASA-CDCA is enough for treatment of ulcerative colitis in colonic inflammatory bowel diseases.
In-vitro and in-vivo evaluation of a matrix-controlled bromocriptine mesilate-releasing vaginal ring
Authors: Acartürk Füsun , Altug Nesrin
Published: July 2003

The aim of this study was to evaluate the in-vitro release rates and in-vivo effectiveness of a controlled release, intravaginal dosage form of bromocriptine mesilate. The dimeticone (poly(dimethylsiloxane)) elastomer vaginal ring contained 3 mg bromocriptine mesilate and low molecular weight gelatin in a ratio of 1:3, and 10% propylene glycol. The daily release rate of the drug was designed to be 10% of the total administered dose and was confirmed with release experiments under sink conditions. The effect of the vaginal ring preparation on plasma prolactin level in the rabbit was investigated over a 10-day period. The results showed that the vaginal ring of bromocriptine mesilate significantly decreased the plasma prolactin level of the test group (P < 0.001–0.05) compared with the control and placebo groups. It was concluded that bromocriptine mesilate was effectively absorbed from rabbit vagina and that this controlled release intravaginal ring preparation of bromocriptine mesilate was effective in decreasing the plasma prolactin level in rabbits for ten days.
Identification of bacterial genes required for in-vivo survival
Authors: Tang C M , Bakshi S , Sun Y-H
Published: July 2003

Genetic approaches used for in-vivo studies of bacterial pathogenesis are providing insights into how bacteria disrupt host defences and exploit host molecules for their own advantage. Signature tagged mutagenesis (STM) provides a means of identifying the genes involved in the process of infection, particularly those genes that are important for bacterial proliferation in-vivo. In this review, the application of STM to the understanding of bacterial pathogenesis and findings from work on three human pathogens, Salmonella typhimurium, Mycobacterium tuberculosis and Neisseria meningitidis, are discussed. The next challenge is to understand how these and other genes influence the infective process at the molecular and cellular levels and to design novel interventions to block the progression of disease.
Investigation of the penetration behaviour of mycophenolate mofetil from a semisolid formulation into human skin ex-vivo
Authors: Jahn Konstanze , Fischer Anja , Neubert Reinhard H H , Wohlrab Johannes
Published: July 2003

Mycophenolate mofetil, the morpholinoethylester of mycophenolic acid, is an immuno-suppressant used in combination with ciclosporin (cyclosporin) and corticosteroids to prevent organ rejection after heart and kidney transplantations. The drug seems also to be effective in dermal diseases after systemic administration. However, up to date mycophenolate mofetil can be only systemically administered and this is associated with several side effects such as nausea, leucopenia, sepsis, and diarrhoea. The aim of this study was to develop a topical formulation containing mycophenolate mofetil and to investigate in-vitro release and penetration into human skin ex-vivo. HPLC was applied to quantify mycophenolate mofetil after release studies from semisolid formulations using a dodecanol-collodion membrane as a lipophilic acceptor. Penetration studies with an amphiphilic cream using excised human breast skin were carried out in Franz-type diffusion cells. Mycophenolate mofetil and its active metabolite mycophenolic acid were detected by HPLC-MS after microsectioning in different skin layers. In this study the penetration of mycophenolate mofetil from an amphiphilic cream into excised human skin was shown. Additionally, the enzymatic hydrolysis of penetrated mycophenolate mofetil into mycophenolic acid was proven even under ex-vivo conditions. In-vivo a higher extent of metabolism ofmycophenolate mofetil to mycophenolic acid would be expected because of the complete enzyme activity. This topical formulation might be a promising alternative to the usual systemic administration of mycophenolate mofetil in the treatment of skin diseases such as psoriasis.
Interpretation of mucoadhesive properties of polymer gel preparations using a tensile strength method
Authors: Hägerström Helene , Edsman Katarina
Published: July 2003

We have developed a new tensile strength method for assessing mucoadhesive properties of polymer gels utilising freshly excised porcine nasal mucosa and a texture analyser. In conjunction with this, we propose a method for interpreting the mucoadhesive properties that is based on reasoning about the locus of the failure of a mucoadhesive joint. This involves measuring the cohesiveness of the gel and the mucus layer, respectively, and comparing these results with those obtained from a mucoadhesion measurement. Linear polymers (sodium carboxymethylcellulose, poly(acrylic acid) and sodium hyaluronate) and a cross-linked polymer (poly(acrylic acid)) were used as model polymers in this study. It was shown that the withdrawal speed of the probe should be low, about 0.1 mm s−1, and that a contact time of 2 min was sufficient. In the mucoadhesion measurements there was no dependence of the results on the contact time in the interval 2–20 min. The tensile work appeared to be more applicable than the fracture strength for interpreting mucoadhesive properties. Furthermore, it was concluded that the interpretation procedure offers a good basis by which to assess whether the measured tensile work reflects a cohesive failure of the gel or a true interaction of the gel with the mucus layer.