bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Urinary Metabolites of Clemastine after Oral Administration to Man
Authors: Choi Man Ho , Jung Byung Hwa , Chung Bong Chul
Published: July 2003

The metabolism of clemastine, 2-{2-[1-(4-chlorophenyl)-1-phenylethoxy]ethyl}-1-methylpyrrolidine, has been studied in three adult male volunteers after a single oral dose of 20 mg as the fumarate. After enzymatic hydrolysis solvent extracts of urine were derivatized with N-methyl-N-trimethylsilyltrifluoroacetamide-ammonium iodide and analysed by gas chromatography-mass spectrometry. The structures of metabolites were determined on the basis of electron impact and chemical ionization mass spectra and the identities of some (e.g. carbinol, 4-chlorobenzophenone and 4-chlorophenylstyrene) were confirmed by use of authentic standards.

The principal route of metabolism of clemastine in man involves direct oxidation, O-dealkylation (fission of the ether bond), aromatic hydroxylation, aliphatic oxidation, alcoholic dehydration, and then enzymatic hydrolysis. Of the total amount of metabolites excreted in the urine 35% was carbinol (metabolite M3, major metabolite), 15% was M1, 17% was M2, 11% was M4, 9% was M5, 8% was M6 and 5% was M7.
Possible Influences of Ginseng on the Pharmacokinetics and Pharmacodynamics of Warfarin in Rats
Authors: Zhu M , Chan K W , Ng L S , Chang Q , Chang S , Li R C
Published: July 2003

We evaluated the significance of a reported clinical case of drug-drug interaction between ginseng and warfarin using a robust pharmacokinetic/pharmacodynamic approach in a rat model.

The influence of ginseng on the pharmacokinetics and pharmacodynamics of oral warfarin after a single dose (2 mg kg−1) and at steady state (0.2 mg kg−1 daily × 6 days) was studied in male Sprague-Dawley rats. Prothrombin time was employed as a pharmacodynamic index. Warfarin plasma concentration and vitamin K content in the ginseng extract were assessed by validated HPLC assays.

The pharmacokinetics of warfarin after a single dose were not altered in the presence of ginseng; peak plasma concentration (control 7.8 ± 0.5; ginseng 7.3 ± 2.5 μg mL−1), time to peak (control 2.6 ± 1.0; ginseng 3.1 ± 1.1h), elimination half-life (control 14.3 ± 5.8; ginseng 10.6 ± 3.1h), and oral clearance (control 17.5 ± 3.3; ginseng 20.2 ± 5.5 mL h−1) were not significantly different (P > 0–05). Similarly, alterations in the pharmacokinetics of warfarin were not detected under the multiple dosing paradigm. Under both dosing conditions, ginseng also showed no significant impact on the pharmacodynamics of warfarin as assessed by the area under the prothrombin time vs time curve (multiple dosing; control 3776 ± 619, ginseng 3830 ± 362 s h) and maximum prothrombin time (control 57.2 ± 11.8, ginseng 63.3 ± 9.1 s). Furthermore, the content of vitamin K was undetectable in the ginseng decoction.

In conclusion, current data obtained in the rat showed no significant impact of ginseng on the pharmacokinetics/pharmacodynamics of warfarin when they are concomitantly administered.
Forskolin Reverses Tachyphylaxis to the Bronchodilator Effects of Salbutamol: An In-vitro Study on Isolated Guinea-pig Trachea
Authors: Yousif Mariam H , Thulesius Olav
Published: July 2003

The objective of this study was to assess the relaxant responses of salbutamol, a β2 agonist, and forskolin, an activator of adenylate cyclase, and the possible role of forskolin in reversing tachyphylaxis to salbutamol.

The in-vitro bronchodilator effects of salbutamol and forskolin (10−9-10−5M) were tested on isolated guinea-pig tracheal rings precontracted with carbachol (10−7M). Both salbutamol and forskolin elicited concentration-dependent relaxation. Potency (EC50; the dose resulting in 50% relaxation) was determined from cumulative concentration-response curves. Salbutamol was more potent than forskolin in relaxing the tracheal preparations (-log molar EC50 7.68 ± 0.14 and 6.3 ± 0.17, respectively). Reproducible relaxant responses to salbutamol could be elicited after 24h incubation in Krebs solution. Tachyphylaxis to the relaxant effects of salbutamol was experimentally induced by incubation (24h) of the preparations in Krebs solution containing salbutamol (10−6, 3 × 10−6 or 10−5M). This pretreatment of the tissues resulted in a significant reduction in the potency of salbutamol. The potency of salbutamol was reduced to 6.85 ± 0.2, 6.8 ± 0.1 and 5.9 ± 0.27 after 24h incubation with salbutamol 10−6, 3 × 10−6 or 10−5M, respectively. The potency of salbutamol was increased from 7.35 ± 0.2 to 7.76 ± 0–28 by addition of forskolin (3 × 10−7M) under control conditions. Moreover, forskolin (3 × 10−7M) reversed the development of tachyphylaxis to salbutamol-induced relaxation in tissues pretreated with salbutamol. The potency of salbutamol was increased to 7.29 ± 0.41, 7.37 ± 0.17 and 7.23 ± 0.35 after the addition of forskolin (3 × 10−7M) to preparations pre-incubated (24h) with salbutamol 10−6, 3 × 10−6 or 10−5M respectively.

These results show that in guinea-pig tracheal ring preparations, forskolin shares with salbutamol the ability to relax airway smooth muscle and produces an apparent reversal of tachyphylaxis to the bronchodilator effects of salbutamol, particularly in the low concentration range. This effect could provide an alternative therapy for long term use, particularly with high doses of β2 agonists in bronchial asthma.
Characterization of Dopamine Receptor Subtypes Involved in Experimentally Induced Gastric and Duodenal Ulcers in Rats
Authors: Desai Jagruti K , Goyal Ramesh K , Parmar Narayan S
Published: July 2003

There are conflicting reports about the role of dopamine in gastric and duodenal ulcers. This investigation was undertaken to characterize the specific subtypes of dopamine receptor involved in gastric and duodenal ulceration.

Administration of dopamine D1 agonist fenoldopam and dopamine D2 antagonist sulpiride elicited a significant decrease in acid secretion, total acid output, pepsin output and histamine content in the gastric juice, and reduced ulcer-index values, in pylorusligated rats. However, dopamine D1 receptor antagonist SCH 39166 ((-)-trans-6,7, 7a,8,9,13b-hexahydro-3-chloro-2-hydroxy-N-methyl-5H-benzo (d) naptho - (2,1-b) azepine) and the D2 receptor agonist quinpirole led to significant augmentation of these parameters compared with respective controls. In the restraint plus water-immersion stress model the score for intraluminal bleeding and the cumulative gastric lesion length was significantly lower for rats treated with fenoldopam and sulpiride. The opposite effects were observed after pretreatment of rats with SCH 39166 and quinpirole. In the cysteamine-induced duodenal ulcer model the mean ulcer area and the score for intensity were significantly lower for fenoldopam and sulpiride and higher for SCH 39166 and quinpirole.

Our data suggest that the dopamine D1 and D2 receptors have opposite effects on gastric and duodenal ulcers. Whereas stimulation of dopamine D1 receptors inhibits the formation of gastric and duodenal ulcers, stimulation of dopamine D2 receptors has a pro-ulcerogenic effect.
Isolation, Purity Analysis and Stability of Hyperforin as a Standard Material from Hypericum perforatum L.
Authors: Orth H C J , Rentel C , Schmidt P C
Published: July 2003

In 1996 131.5 million daily doses of preparations containing extracts of Hypericum perforatum L. were prescribed in Germany for treating mild to moderately severe depressive disorders. New pharmacological and clinical results focus on hyperforin as the main active ingredient of the drug.

Hyperforin (C35H52O4) is one of the main components (2–4%) of the dried herb Hypericum perforatum L. It was isolated after six consecutive steps: extraction of deep-frozen blossoms (-20°C) with n-hexane by means of an Ultra Turrax at room temperature; separation of lipophilic substances on a silica gel column; purification of the relevant fraction by preparative HPLC; evaporation of the mobile phase under reduced pressure; removal of the remaining water by freeze-drying; and storage of hyperforin at −20°C under nitrogen. The identity and purity of the isolated substance were determined by highperformance thin-layer chromatography (HPTLC), high-performance liquid chromatography (HPLC) with diode-array and ultraviolet detection (DAD and UV), Fourier-transformed infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy, and liquid chromatography coupled with positive-ion electrospray-ionization tandem mass spectrometry (LC-ESI(+)-MS-MS). By use of these methods the purity of hyperforin was shown to be >99-9%. Peroxides present at each step of the isolation were detected by titration and by means of Merckoquant analytical peroxide test-strips. Elimination of the peroxides and stabilization of hyperforin was achieved by consistent protection from oxidation—the mobile phases were protected by use of ascorbic acid; evaporation and freeze-drying were performed under nitrogen; and the mobile phase used for preparative HPLC was sparged with helium. Stability testing was performed by HPLC—the samples were stored at −30°C in a normal atmosphere and at −20, 4, and 20°C in a normal atmosphere or under nitrogen. Results were compared with those obtained after storage under liquid nitrogen (-196°C).

Because of its high sensitivity to oxidation, hyperforin was more stable under nitrogen under all test conditions. There was no statistically significant difference between results obtained after 8 months at −20°C under nitrogen or at −30°C under a normal atmosphere and those from the reference sample stored under liquid nitrogen (-196°C). Despite this, because of the tendency of hyperforin to degrade, long-term storage at −70°C under nitrogen is recommended.
A Novel Image-analysis Technique for Measurement of Bacterial Cell Surface Tension
Authors: Hanlon G W , Olliff C J , Brant J A , Denyer S P
Published: July 2003

Cell-surface hydrophobicity is different for Staphylococcus epidermidis cells grown under different environmental conditions; this might influence attachment and colonization of surfaces. Although a wide variety of techniques has been employed to measure bacterial surface hydrophobicity, including contact angle determinations, adherence to hydrocarbons, hydrophobic-interaction chromatography and salt aggregation, many of these either require large numbers of cells or do not yield comparable quantitative data. This study describes a novel, quantitative method for the determination of bacterial surface tension on the basis of image analysis of cell-cell interactions.

S. epidermidis (strains 900 and 901) were suspended in different concentrations of propanol of known surface tension and examined by bright-field microscopy linked via a charge-couple device (CCD) camera to an image analyser. Frames were chosen randomly and the data recorded as a ratio of count/percentage coverage for each frame. The results showed that for strains 900 and 901 this ratio was maximum at surface tensions of 67 and 61 mN m−1 respectively. At these values of minimal interaction the surface tension of the liquid was equal to the bacterial cell surface tension. The results were in close agreement with those obtained from contact angles. The advantage of surface tension measurements is that, irrespective of the method used, the results generated are quantitative values and are therefore directly comparable.

The method reported is reliable, reproducible and is of particular value because the number of cells required is, typically, at least two orders of magnitude lower than is required for commonly used alternative methods.
Effect of the Chloroform Extract of Tanacetum vulgare and one of its Active Principles, Parthenolide, on Experimental Gastric Ulcer in Rats
Authors: Tournier Horacio , Schinella Guillermo , De Balsa Elba M , Buschiazzo Héctor , Mañez Salvador , De Buschiazzo Perla Mordujovich
Published: July 2003

This study examines the anti-ulcerogenic activity of a chloroform extract of Tanacetum vulgare and purified parthenolide, the major sesquiterpene lactone found in the extract.

Gastric ulcers induced by oral administration of absolute ethanol to rats were reduced dose-dependently by oral pretreatment of animals with the chloroform extract (2.5–80 mg kg−1) or parthenolide (5–40 mgkg−1). When administered 30 min before challenge with the alcohol the protection ranged between 34 and 100% for the extract and 27 and 100% for parthenolide. When the products were administered orally 24h before treatment with ethanol, 40 mg kg−1 of the extract and of the lactone reduced the mean ulcer index from 4.8 ± 0.3 for control animals to 1.4 ± 0.2 and 0.5 ± 0.1, respectively. The products also prevented alcohol-induced reduction of the number of sulphydryl groups within the gastric mucosa (50.6 ± 2.3 μg (mg protein)−1 for normal animals compared with 17.7 ± 3.0 μg (mg protein)−1 for alcohol-treated animals). Administration of the extract (80 mg kg−1) or parthenolide (40 mg kg−1) 24h before ethanol treatment restored the numbers of mucosal -SH groups to values near those found for normal animals.

These results suggest that the products assayed, in particular parthenolide, might find therapeutic application, although further work is required to establish their profit/risk ratio.
Lavender Oil Inhibits Immediate-type Allergic Reaction in Mice and Rats
Authors: Kim Hyung-Min , Cho Seong-Hoon
Published: July 2003

We studied the effects of lavender oil on mast cell-mediated immediate-type allergic reactions in mice and rats.

Lavender oil (1:500, 1:100, 1:10, 1:1, 1:0) inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80 in mice by both topical and intradermal application. Lavender oil (1:500, 1:100, 1:10, 1:1, 1:0) inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by both topical and intradermal application.

Lavender oil (1:500, 1: 100, 1: 10, 1:1, 1:0) also inhibited concentration-dependently the histamine release from the peritoneal mast cells by compound 48/80 or anti-DNP IgE. Moreover, lavender oil (1:1000, 1:100, 1:10, 1:0) had a significant inhibitory effect on anti-DNP IgE-induced tumour necrosis factor-α secretion from peritoneal mast cells.

These results indicate that lavender oil inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in-vivo and in-vitro.
Effects of Fosfomycin and Imipenem-Cilastatin on the Nephrotoxicity of Vancomycin and Cisplatin in Rats
Authors: Nakamura Tsutomu , Kokuryo Toshiyuki , Hashimoto Yukiya , Inui Ken-Ichi
Published: July 2003

The nephrotoxicity of vancomycin and cisplatin and the protective effects of fosfomycin and imipenem-cilastatin on renal function have been studied in rats. The renal clearance of vancomycin after the induction of renal dysfunction was also evaluated by calculating the glomerular filtration rate (GFR) and its secretory clearance.

Plasma concentrations of creatinine and urea nitrogen increased dose-dependently after vancomycin injection. No such increases were observed after co-treatment with fosfomycin or imipenem-cilastatin. Changes of N-acetyl-β-D-glucosaminidase activity in the urine of vancomycin-treated rats were not remarkable compared with those in cisplatin-treated animals. The reduced renal clearance of vancomycin in rats with acute renal failure induced by vancomycin was because of a decrease in both GFR and secretory clearance. However, the changes in GFR and secretory clearance were not proportional—the change in GFR was more pronounced than that of secretory clearance in the experimental groups. In addition, the renal clearance of vancomycin was maintained at the control level after co-administration of fosfomycin or imipenem-cilastatin with vancomycin.

These results suggest that vancomycin impairs glomerular filtration more markedly than renal tubular function as compared with cisplatin. Co-administration with fosfomycin or imipenem-cilastatin confers significant protection against the nephrotoxic effects of vancomycin.
A New Method for Monitoring the Contamination of Glycerol with Diethylene Glycol
Authors: Gomes M T S R , Veríssimo M I S , Oliveira J A B P
Published: July 2003

A quartz crystal microbalance has been used to check the purity of glycerol.

The experimental procedure involves no derivatization or other preliminary step except determination of water content. The protocol consists of the direct reading of the frequency of a quartz crystal with one face in contact with an aqueous solution of the glycerol to be tested.

The method is inexpensive, simple, rapid, and highly sensitive; diethylene glycol contamination at the 3.61% level could be detected.
Discovery of New Antimalarial Compounds by use of Molecular Connectivity Techniques
Authors: Gozalbes R , Gálvez J , Moreno A , García-Domenech R
Published: July 2003

Molecular connectivity has been applied to the search for new compounds with antimalarial activity. Linear discriminant analysis and connectivity functions were used to select several potentially suitable drugs which were tested for antimalarial properties by use of an in-vitro micro test which estimates parasite growth by measurement of incorporation of [3H]hypoxanthine.

Hexetidine stands out among the compounds selected. Activity assays were performed with Plasmodium falciparum passou and 3CD7 strains, for which the IC50 values (doses resulting in 50% inhibition) were 320 and 400 ng mL−1 respectively. These results are comparable with those obtained for quinine chlorhydrate (IC50 = 60 and 107.8 ng mL−1) and chloroquine sulphate (IC50 = 231 and 415 ng mL−1), the drugs used for reference.

These results demonstrate the usefulness of our topological approach for the selection and design of new lead drugs active against Plasmodium falciparum.
A New Insulin-mimetic Vanadyl Complex, (N-Pyridylmethylaspartate)oxovanadium(IV) with VO(N2O2) Coordination Mode, and Evaluation of its Effect on Uptake of D-Glucose by Ehrlich Ascites Tumour Cells
Authors: Tawa Riichi , Uchida Keiko , Taniyama Junko , Fujisawa Yae , Fujimoto Seiki , Nagaoka Takashi , Kanamori Kan , Sakurai Hiromu
Published: July 2003

Because it has been confirmed that the vanadyl(IV) ion and its complexes act as insulin mimetics, a new organic vanadyl complex, (N-pyridylmethylaspartate)oxovanadium (VOPASP) with VO(N2O2) coordination mode, was prepared. Development of a simple and rapid in-vitro assay is needed for recognition of potent insulin-mimetic complexes.

Treatment of Ehrlich ascites tumour cells with 2-deoxyglucose in the presence of vanadyl sulphate, or other vanadyl complexes with the same coordination mode (VOPASP, bis(picolinate)oxovanadium (VOPA) and bis(6-methyl picolinate)oxovanadium (VOMPA)), in the presence of 2-deoxy-D-[1-3H]glucose ([3H]deoxyglucose), resulted in concentration-dependent uptake of 2-deoxyglucose by the cells. The responses of the cells to the vanadyl complexes were reflected, in part, by results obtained from the free fatty acid-releasing assay using rat adipocytes.

These results show that the in-vitro assay with Ehrlich ascites tumour cells provides an accurate and rapid assessment of glucose uptake by the cells. The assay is proposed as a means of predicting the insulin-mimetic activity of the vanadyl complexes and for studying the mechanism of action of the complexes.
Inhibition by the Bioflavonoid Ternatin of Aflatoxin B1-induced Lipid Peroxidation in Rat Liver
Authors: Souza M F , Tomé A R , Rao V S N
Published: July 2003

Aflatoxin B1, a metabolite of Aspergillus flavus is a potent hepatotoxic and hepatocarcinogenic mycotoxin. Lipid peroxidation and oxidative DNA damage are the principal manifestations of aflatoxin B1-induced toxicity which could be mitigated by antioxidants. Many plant constituents, e.g. flavonoids, lignans and spice principles (capsaicin, curcumin, eugenol, etc.) have been reported to prevent liver damage associated with lipid peroxidation. In this study we investigated ternatin, a tetramethoxyflavone isolated from Egletes viscosa, for possible protection against liver injury induced by aflatoxin B1 in rats.

Seventy two hours after a single intraperitoneal dose of aflatoxin B1 (1 mg kg−1), the concentration of malondialdehyde, the product of lipid peroxidation in liver homogenates, and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly elevated (P < 0.01). Subcutaneous ternatin (25 mg kg−1) pretreatment greatly reduced aflatoxin B1-induced increases in the levels of serum enzymes (ALT from 5071 ± 763 to 293 ± 66 international unitsL−1 and AST from 4241 ± 471 to 449 ± 108 international units L−1) and elevated malondialdehyde levels (from 11.37 ± 1.27 to 0.79 ± 0.22 nmol (mg wet tissue)−1) in a manner similar to oral vitamin E (300 mg kg−1), a standard antioxidant. Further, histological changes induced by aflatoxin B1 such as hepatocellular necrosis and bile-duct proliferation were markedly inhibited in animals pretreated with ternatin or vitamin E.

These data provide evidence that ternatin inhibits lipid peroxidation and affords protection against liver damage induced by aflatoxin B1. Ternatin might, therefore, be a suitable candidate for the chemoprevention of aflatoxicosis associated liver cancer.
Cellular Uptake and Release of Two Contrasting Iron Chelators
Authors: Cable Hazel , Lloyd John B
Published: July 2003

Desferrioxamine and CP94 (1,2-diethyl-3-hydroxypyridin-4-one) are metal chelators used or proposed for use in the clinical treatment of iron overload. Recent data on their capacity to deplete intracellular iron led to the conjecture that the differences observed arose from the different membrane-penetration properties of the two compounds.

The time-course of accumulation and subsequent release of [14C]CP94 by the rat visceral yolk sac in-vitro was compared with that of [14C]desferrioxamine and for 125I-labelled poly(vinylpyrrolidone), a marker for fluid-phase endocytosis. The results indicate that [14C]CP94 crosses the plasma and lysosome membranes rapidly whereas [14C]desferrioxamine and 125I-labelled poly(vinylpyrrolidone) are effectively incapable of crossing these membranes, entering cells only by endocytosis.

It is concluded that although CP94 readily enters and leaves cells, desferrioxamine has the potential to accumulate to high concentration in the lysosomes and complex with intralysosomal iron. The results support and extend the proposed correlation between pharmacological activity and capacity for membrane penetration.
Inhibition by 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) of Responses to Nitric Oxide-donors in Rat Pulmonary Artery: Influence of the Mechanism of Nitric Oxide Generation
Authors: Homer Kerry L , Fiore Steven A , Wanstall Janet C
Published: July 2003

ODQ, (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of soluble guanylate cyclase) inhibits vasorelaxant responses to nitric oxide (NO)-donor drugs, but the extent of the inhibition varies depending on the NO donor studied. The purpose of this study was to test the hypothesis that these variations in the effects of ODQ reflect differences in the mechanisms whereby each NO donor generates NO.

On pulmonary artery preparations pre-contracted submaximally with phenylephrine, ODQ (3 μM) almost abolished the relaxant responses to glyceryl trinitrate, isosorbide dinitrate and nitroprusside; each of these drugs requires activation in the tissue (by enzymes or reducing agents) to generate NO. In contrast, ODQ (3 μM) caused a parallel shift in the concentration-relaxation curves to linsidomine (SIN-1), FK409, MAHMA NONOate and spermine NONOate (1.63 to 2.54 log units) with no depression in maximum response; each of these NO donors generates NO in the physiological bathing solution without requiring tissue activation. For the four drugs in this group, the effects of 10 μM ODQ were not significantly greater than the effects of 3 μM ODQ; thus there was an ODQ-resistant component to the response suggesting that part of the response involved a mechanism that was independent of soluble guanylate cyclase.

NO donors that require tissue activation probably generate NO within the smooth-muscle cell, whereas those that do not require tissue activation generate NO outside the cell. Hence it is concluded that the site of NO generation (intra- or extracellular) might determine whether or not there is an ODQ-resistant component in the relaxation response.
Alginate-Pectin-Poly-L-lysine Particulate as a Potential Controlled Release Formulation
Authors: Liu Ping , Krishnan T R
Published: July 2003

Drug delivery particulates were prepared using alginate, polylysine and pectin. Theophylline, chlorothiazide and indomethacin were used as the model drugs for in-vitro assessments, and mannitol was the model for assessing paracellular drug absorption across Caco-2 cell monolayers. Alginate and pectin served as the core polymers and polylysine helped to strengthen the particulates. Use of pectin specially helped in forming a more robust particulate that was more resistant in acidic pH and modulated the release profiles of the encapsulated model drugs in the alkaline pH. Alginate and pectin were also found to enhance the paracellular absorption of mannitol across Caco-2 cell monolayers by about three times. The release rate could be described as a first-order or square-root time process depending on the drug load.

Use of alginate-polylysine-pectin particulates is expected to combine the advantages of bioadhesion, absorption enhancement, and sustained release. This particulate system may have potential use as a carrier for drugs that are poorly absorbed after oral administration.
Formulation and Biological Activity of Antineoplastic Proteoglycans Derived from Mycobacterium vaccae in Chitosan Nanoparticles
Authors: Tian Xin-Xin , Groves Michael J
Published: July 2003

Although heat-killed suspensions of Mycobacterium vaccae have been tested clinically against tuberculosis and cancer, from a pharmaceutical perspective it would be advantageous to utilize isolated active components rather than the heat-degraded bacterial materials. In our laboratory we have isolated from M. vaccae a number of high-molecular-weight proteoglycans with considerable immunological and antineoplastic activity.

The structure of one of these, PS4A, obtained by extraction with boiling water, seems to consist of a basic unit with a 20-kDa protein core to which are attached glucans and O-methylated 4-kDa polysaccharides. The molecular weight is (approx.) 50 kDa, but because of self-association, that of the recovered high-molecular-weight fraction is greater than 150 kDa. A similar, but even larger, molecule (PS4α, MW ∼20 MDa) is obtained by cold extraction with 8 M urea. Both are active in-vivo against an S-180 murine sarcoma model but have no activity in-vitro, suggesting an antitumour effect involving activated macrophages. For this reason gelatin nanoparticles are unsuitable as a vehicle but chitosan seemed to be a promising alternative. In this report we describe the production of stable 600–700-nm diameter nanoparticles of chitosan without organic solvents. Adsorption and release of bovine serum albumin seemed to be affected by the charge of the two reactants and at high doses not all adsorbate was released. PS4A, because of structural and compositional differences, had to be loaded on to the chitosan by freeze drying a suspension of the nanoparticles in a solution of the drug. After a rapid (burst) release phase, the rate of release into water was steady for the next 4h, but not all the drug was released. In-vivo it was evident that PS4A and PS4α were equally active in solution or when formulated in the chitosan nanoparticles.

These results show that chitosan nanoparticles, readily prepared without the use of organic solvents, are a suitable vehicle for the delivery of these immunostimulants from M. vaccae; the formulations might find application as antitumour agents.
Improving the Oral Bioavailability of Albendazole in Rabbits by the Solid Dispersion Technique
Authors: Kohri Naonori , Yamayoshi Yasuko , Xin He , Iseki Ken , Sato Naoki , Todo Satoru , Miyazaki Katsumi
Published: July 2003

We have investigated the oral bioavailability of granules of albendazole, a drug used for treating echinococcosis in man, prepared by the solid dispersion technique.

Rapid dissolution and supersaturation were observed when hydroxypropylmethylcellulose and hydroxypropylmethylcellulose phthalate were used as carriers in the solid dispersion. They inhibited the crystallization of albendazole from the supersaturated solution and maintained an amorphous state for 8h. Gastric acidity-controlled rabbits were used to evaluate the variation in absorption after oral administration of the albendazole solid dispersion. For rabbits with low gastric acidity the bioavailability of orally administered albendazole in the granular form prepared by solid dispersion was more than three times that of albendazole in physical mixtures.

These results suggest that the bioavailability of albendazole in solid dispersions might be high even if there is a great variation in the gastric pH of patients.
Whole-body Autoradiography and Quantitative Organ-level Distribution Study of Deramciclane in Rats
Authors: Hazai István , Pátfalusi Márta , Klebovich Imre , ürmös Iván
Published: July 2003

The distribution of 3H-labelled deramciclane (EGIS-3886), a new 5-HT2 antagonist with anxiolytic activity, has been investigated by whole-body autoradiography and quantitative organ-level determination after intravenous and oral administration to male and female rats at a dose of 3 mg kg−1. Pregnant dams were also studied, but by autoradiography only. In the autoradiographic study 32 organs were investigated, while in the quantitative organ-level study the radioactivity in 15 organs were determined.

There are no sex differences in the distribution of deramciclane, absorption is rapid, elimination is comparatively fast, no specific organ is targeted, and the accumulation of the compound is very unlikely. Penetration of the blood-brain barrier was complete and extremely fast, a very important feature of a potential anxiolytic drug. There is no penetration of the foetus in pregnant dams.

The study demonstrated that deramciclane has advantageous pharmacokinetic properties in rats.
Insulin Lispro: In-vivo Potency Determination by Intravenous Administration in Conscious Rabbits
Authors: Lin Senshang , Wang Shun-Yung , Chen Eung-Cheng , Chien Yie W
Published: July 2003

Insulin lispro is a monomeric analogue of human insulin, produced by genetic engineering, and has been reported to have a more rapid absorption following subcutaneous injection than insulin. Since it has been shown to have a similar hypoglycaemic action to insulin in clinical studies and comparable properties in radioimmunoassay, the feasibility of using a bioassay which was designed originally for insulin, to measure insulin lispro potency was evaluated in this investigation.

A random-dose bioassay protocol, in which insulin lispro and two insulin standards were administered intravenously in a random sequence, was used and validated in nine conscious healthy rabbits. The decline in blood-glucose levels, following the intravenous injection of a dose of insulin or its lispro analogue, was monitored by a continuous glucose monitoring system. A glucose response curve was generated, from which various pharmacodynamic parameters were determined. Compared with the insulin standards, the potencies of insulin lispro determined from nadir, basal glucose normalized nadir, glycaemic reduction and ABGC (area of the blood-glucose response curve under baseline) were observed to have mean (95% confidence limits) values of 97.0 (69.5–124.6)%, 106-3 (72.4–140-2)%, 94.9 (51.8–138-0)% and 102.4 (76.3–128.5)%, respectively. In addition, the coefficients of variation for correspondent parameters were 36.9, 41.5, 59.1 and 33.2%, respectively.

The results indicated that the hypoglycaemic potency calculated from the ABGC values was the most accurate (102.4%) with the least coefficient of variation (33.2%). In conclusion, the potency of insulin lispro can be determined accurately from the ABGC values measured by the random-dose bioassay used.
Assessment of the Adrenergic Effects of Orphenadrine in Rat Vas Deferens
Authors: Pubill D , Canudas A M , Pallàs M , Sureda F X , Escubedo E , Camins A , Camarasa J
Published: July 2003

The peripheral adrenergic effects of orphenadrine, an antiparkinsonian drug, have been evaluated in the rat vas deferens to investigate whether these properties are the same as those of other phencyclidine ligands.

In the low micromolar range, orphenadrine enhanced electrically-evoked and exogenous noradrenaline contractile responses in the epididymal portion of rat vas deferens. It also induced spontaneous activity that was inhibited by prazosin (1 μM) but not by atropine (20 nM). It inhibited accumulation of [3H]noradrenaline in rat vas deferens (IC50 = 14.2 ± 2.3 μM). Orphenadrine competitively inhibited [3H]nisoxetine binding in rat vas deferens membranes (Ki = 1.05 ± 0.20 μM).

It can be concluded that orphenadrine, at low micromolar concentrations, interacts with the noradrenaline reuptake system inhibiting its functionality and thus potentiating the effect of noradrenaline.
Neuropsychopharmacological Profile of the Methanolic Fraction of Bryophyllum pinnatum Leaf Extract
Authors: Pal Siddhartha , Sen T , Chaudhuri A K Nag
Published: July 2003

Neuropharmacological studies were conducted in experimental animals (rats and mice) with the methanolic fraction of Bryophyllum pinnatum leaf extract.

The fraction produced alteration of behaviour pattern, caused dose-dependent potentiation of pentobarbitone sleeping time and had significant analgesic activity. Significant reduction of exploratory behaviour and loss of residual curiosity were among the effects observed with the fraction. The observations suggest that the methanolic fraction of Bryophyllum pinnatum possesses a potent CNS depressant action.
Simple O-Acylated Derivatives of Lysergol and Dihydrolysergol-I: Synthesis and Interaction with 5-HT2A, 5-HT2C and 5-HT1B Receptors, and α1 Adrenergic Receptors
Authors: Pertz Heinz H , Brown Anthony M , Gager Tracey L , Kaumann Alberto J
Published: July 2003

A series of simple O-acylated derivatives of the naturally occurring clavine alkaloids lysergol and dihydrolysergol-I were synthesized and tested in-vitro for their ability to interact with 5-HT2A receptors in rat tail artery, 5-HT2C receptors in piglet choroid plexus, 5-HT1B receptors in guinea-pig iliac artery and α1-adrenergic receptors in rat aorta.

In contrast to the classical ergoline 5-HT2A receptor antagonists methysergide and LY53857, the compounds produced competitive antagonism of the 5-HT response in rat tail artery. Affinities of ergolines 3–14 were higher (pA2 values of 7.33-8.40) than those of the parent alcohols lysergol (1) and dihydrolysergol-I (2), respectively. The introduction of an isopropyl substituent at the N(1) position of the compounds failed to enhance 5-HT2A receptor affinity. Compounds 3–14 exhibited lower affinities for α1-adrenergic receptors than for 5-HT2A receptors. In particular, those lysergol derivatives that had an isopropyl substituent at the N(1) position were highly specific 5-HT2A receptor antagonists (ratio 5-HT2A/α1 = 302–3548).

Selected derivatives of lysergol (3–5, 9–11) which were assayed for radioligand binding at 5-HT2C receptors in piglet choroid plexus had affinities that were similar to those found in rat tail artery. Additionally, lysergol and its N(1)-unsubstituted derivatives were found to be partial agonists (α of 0.2-0.4) for 5-HT2C receptor-mediated inositol phosphate accumulation in piglet choroid plexus. On the other hand, analogues with an isopropyl substituent at N(1) showed no measurable agonist activity. The observation that N(1)-unsubstituted derivatives of lysergol possessed agonist properties at 5-HT2C receptors whereas their agonist activity at 5-HT2A receptors was marginal (α of 0.05 for compound 3 at 1 μM) or not measurable, suggests that these compounds have different abilities to cause conformational change at the two receptor types. Selected derivatives of lysergol (3–5, 9.11) which were examined as ligands for 5-HT1B receptors in guinea-pig iliac artery caused insurmountable blockade of the contractile effect of 5-HT. N(1)-isopropyl derivatives had 30–50-fold lower affinities for 5-HT1B receptors of this tissue than their N(1)-unsubstituted analogues.

It is concluded that O-acylated derivatives of the clavine alkaloids lysergol and dihydrolysergol-I mimic therapeutically relevant ergolines due to the complexity of their pharmacological profile as partial agonists and antagonists at 5-HT2A, 5-HT2C and 5-HT1B receptors, and at α1-adrenergic receptors.
Inhibition by Leukotriene Inhibitors, and Calcium and Platelet-activating Factor Antagonists, of Acute Gastric and Intestinal Damage in Arthritic Rats and in Cholinomimetic-treated Mice
Authors: Rainsford K D
Published: July 2003

The leukotrienes, platelet activating factor and intracellular calcium have been implicated in the development of gastro-intestinal lesions induced by non-steroidal anti-inflammatory drugs (NSAIDs) but the relative significance of these inflammatory mediators in lesion formation has not been established in sensitive and specific models of gastro-intestinal ulceration. In the present study the effects of drugs affecting 5-lipoxygenase activity, the actions of platelet activating factor and intracellular calcium on the development of gastric and intestinal ulceration induced by NSAIDs were investigated in highly sensitive models of ulcerogenicity induced by treatment with either the cholinomimetic, acetyl-β-methyl choline chloride, in mice (gastric mucosal lesions) or adjuvant-induced polyarthritis in rats (gastric and intestinal mucosal lesions) as well as in normal mice (intestinal mucosal lesions).

The 5-lipoxygenase inhibitors, such as MK-886 (-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2-dimethylpropanoic acid), given at doses shown to reduce the indomethacin-induced increase in mucosal leukotriene B4 concentrations were found to partially prevent the development of gastric and intestinal lesion induced by indomethacin and gastric lesions from aspirin, but the same doses of MK-886 did not affect gastric lesions from diclofenac. Pretreatment with these inhibitors at both 3–5 h and 0-0.25 h was required to achieve protection against gastric mucosal damage from indomethacin. Immediate prior administration of platelet activating factor antagonists (e.g. WEB-2086) with the 5-lipoxygenase inhibitors did not affect gastric or intestinal lesions induced by indomethacin. The calcium antagonist, verapamil, was slightly protective against gastric and intestinal lesions induced by indomethacin. Gastric lesions were further prevented by combinations of a single dose of verapamil with a platelet activating factor antagonist but not combined with a 5-lipoxygenase inhibitor; other combinations of verapamil with lipoxygenase inhibitors or platelet-activating factor antagonists being without inhibitory effects on gastric or intestinal lesions compared with the drugs alone.

These results show that 5-lipoxygenase products and intracellular calcium play a major role in acute gastric and intestinal damage by the NSAIDs, but platelet-activating factor has little or no appreciable involvement.
Effects of an Essential Oil from the Bark of Croton cajucara Benth. on Experimental Gastric Ulcer Models in Rats and Mice
Authors: Hiruma-Lima C A , Gracioso J S , Nunes D S , Brito Arm Souza
Published: July 2003

Croton cajucara Benth. (Euphorbiaceae) is widely used in Amazonian folk medicine for the treatment of a wide range of gastrointestinal symptoms. The essential oil from its bark was investigated for acute toxicity in mice and for its ability to prevent the formation of ulceration of the gastric mucosa in different models of experimentally induced gastric ulcer in mice and rats.

When previously administered orally at a dose of 100mg kg-1, the essential oil significantly reduced (P < 0.01) the gastric injury induced by hypothermic restraint stress (48%), indomethacin (47%), ethanol (86%) and pylorus ligature models (87%) in rats. In the HCl/ethanol-induced gastric ulcer model in mice, at oral doses of 100 and 200mg kg-1 the essential oil from C. cajucara significantly reduced (P < 0.01) the formation of gastric lesions by 52% and 67%, respectively, when compared with the control group. In rats submitted to pylorus ligature, the essential oil given orally increased the volume of gastric juice when compared with the control group (P < 0.01). When the essential oil (100mg kg-1) was administered intraduodenally to mice, significant modifications were found in gastric parameters such as pH and total acid content after oil treatment. We observed significant changes (P < 0.01) in gastric juice parameters such as an increase in volume and a decrease in gastric acidity (pH and total acid content). The acute toxicologic effects of the essential oil from C. cajucara were assessed in mice. The LD50 values were 9.3g kg-1 by the oral route and 680mg kg-1 by the intraperitoneal route.

The good yield of essential oil obtained from dried C. cajucara bark (1%) as well as its anti-ulcerogenic activity and low toxicity suggest that pharmacological studies of this substance as a potential new anti-ulcerogenic drug are warranted.
Pharmacokinetics of BOF-4272, a Xanthine Oxidase Inhibitor, after Single Intravenous or Oral Administration to Male Mice and Rats
Authors: Naito Shinsaku , Nishimura Masuhiro , Nogawa Hiroyuki
Published: July 2003

BOF-4272, (±)-8-(3-methoxy-4-phenylsulphinylphenyl) pyrazolo [1,5-a]-1,3,5-triazine-4 (1H)-one), is a new drug intended for the treatment of hyperuricaemia. This report describes the detailed pharmacokinetics of BOF-4272 in mice and rats after intravenous or oral administration.

Plasma concentrations of BOF-4272 at 2.8h after intravenous administration were significantly higher in mice than in rats. Plasma concentrations of BOF-4272 after oral administration were significantly higher in fed mice than in fasted mice, but were similar in fasted and fed rats. The elimination half-life of the distribution phase (t1/2(α)) was similar in mice (0.158 h) and rats (0.210 h). The elimination half-life of the terminal elimination phase (t1/2(α)) in mice was 1.936 h, while that in rats was 0.742 h. The volume of the central compartment (V1) was almost the same in mice (415mL kg-1) and rats (440mL kg-1). However, the volume of the peripheral compartment (V2) in mice was 1068 mL kg-1, while that in rats was 92mL kg-1. The steady-state volume of distribution (Vss) was 2.8 times larger in mice than in rats. The area under the plasma concentration-time curve (AUC) in mice was 5332ngh mL-1, while that in rats was 3806ngh mL-1. The AUC0-24h after oral administration was 2.5 times greater in fed mice than in fasted mice, and was 1.4 times greater in fasted rats than in fed rats. The correlation coefficients of Cmax and AUC0-24h in both mice and rats after oral administration were greater than 0.997 in the dose range 1–125 mg kg-1, indicating that the linear range of absorption or elimination (or both) of BOF-4272 is very wide.

The results of the present study demonstrate that the mouse is a suitable animal species for evaluating the clinical pharmacokinetics of BOF-4272.
Fate of the Flavonoid Quercetin in Human Cell Lines: Chemical Instability and Metabolism
Authors: Boulton David W , Walle U Kristina , Walle Thomas
Published: July 2003

Although cell cultures are increasingly being used as models for studying the biological actions of flavonoids, no information on the fate, such as uptake and metabolism, exists for these natural products in these models.

This study examined the elimination of quercetin, one of the most abundant flavonoids, from the cultured human hepatocarcinoma cell line Hep G2 using [14C]-labelled compound with HPLC and LC/MS for structure characterization. These cells showed a 9.6-fold accumulation of quercetin and the formation of an O-methylated metabolite, isorhamnetin. However, a rapid elimination of quercetin, with no unchanged compound present beyond 8 h, was mainly due to oxidative degradation. The initial intermediate reaction appears to involve peroxidation, leading to a dioxetan, as evidenced by a 32-amu increase in the molecular ion by LC/MS. Subsequently, opening of the C-ring leads to the formation of carboxylic acids, the major one identified in this study as protocatechuic acid. A separate reaction results in a polymeric quercetin product which is highly retained on a reversed-phase C18 HPLC column.

It is postulated that these degradative and metabolic changes contribute to the multiple biological actions reported for quercetin, using cell culture models. Interestingly, part of the degradative pathway could be inhibited by including nontoxic concentrations of EDTA in the cell culture medium.
Effect of Acute Renal Failure on the Disposition of Cefoperazone
Authors: Katayama Hirokazu , Yasuhara Masato , Hori Ryohei
Published: July 2003

The effect of acute renal failure on the disposition of cefoperazone was investigated. Rats, 3 days after uranyl nitrate treatment, were used to model acute renal failure.

Although plasma-protein binding of cefoperazone decreased significantly in acute renal failure compared with control rats, the plasma clearance of total (bound plus unbound) drug after intravenous administration (50mg kg-1) did not differ significantly between the two groups (5.61 ± 2.37mL min-1 for control and 4.75 ± 2.82mL min-1 for acute renal failure). Consequently the plasma clearance of the unbound drug in acute renal failure (6.14 ± 1.16mL min-1) was significantly lower than in control rats (15.6 ± 3.7mL min-1, P < 0.025). Plasma clearance of the drug (both total and unbound) was also dependent on bile flow, and clearance of the unbound drug in acute renal failure rats was lower than in control rats with identical bile flow rates. To examine the mechanism of reduced unbound cefoperazone clearance, an in-vitro experiment using a simultaneous perfusion system of rat liver and kidney was performed. By changing perfusate plasma protein from bovine serum albumin to human serum albumin, the plasma clearance of the total cefoperazone changed to one-sixth in proportion to the unbound cefoperazone in the perfusate plasma. On the other hand, the plasma clearance of the total and unbound drug in acute renal failure rats decreased significantly compared with controls.

These results demonstrate that the plasma clearance of unbound cefoperazone, which is mainly eliminated by the liver, decreased in acute renal failure in rats, probably due to changes in hepatic transport.
First-degree Atrioventricular Block in Alprazolam Overdose Reversed by Flumazenil
Authors: Mullins Michael E
Published: July 2003

This report describes a case of alprazolam overdose associated with marked first-degree atrioventricular block reversed by flumazenil.

Animal and human evidence suggests activity of certain benzodiazepines at peripheral benzodiazepine receptors in the myocardium and elsewhere. Myocardial benzodiazepine receptor ligands appear to affect calcium-channel activity, which may explain the clinical findings. Benzodiazepines may behave like weak calcium-channel blockers.

This case raises the possibility of a potential role for flumazenil as an adjunct in the management of calcium-channel blocker toxicity.