bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Metabolite, an Oxepin Formed from Cannabidiol with Guinea-pig Hepatic Microsomes
Authors: Yamamoto I , Nagai K , Watanabe K , Matsunaga T , Yoshimura H
Published: April 2011

The metabolic formation of an oxepin derivative, 3-pentyl-6, 7, 7a, 8, 9, 11a-hexahydro-1, 7-dihydroxy-7, 10-dimethyldibenzo-[b,d]-oxepin, from cannabidiol was studied in-vitro using guinea-pig hepatic microsomes.

The hepatic microsomes catalysed the formation of the metabolite from cannabidiol and 8S, 9-epoxycannabidiol in the presence of an NADPH-generating system and 3, 3, 3-trichloropropene-1, 2-oxide. 8S, 9-Epoxycannabidiol was thought to be an intermediate in the formation of the metabolite, which was identified by gas chromatography-mass spectrometry. The metabolite synthesized from 8S, 9-epoxycannabidiol diacetate exhibited catalepsy, hypothermia and pentobarbitone-induced sleep prolongation in mice, although the pharmacological effect was less potent than that of Δ9-tetrahydrocannabinol.
Different Effects of Traditional Chinese Medicines Containing Similar Herbal Constituents on Prednisolone Pharmacokinetics
Authors: Homma Masato , Oka Kitaro , Ikeshima Ken , Takahashi Noriyuki , Niitsuma Tomoyuki , Fukuda Toshiaki , Itoh Hisao
Published: April 2011

Three major traditional Chinese medicines (TCM), Sho-saiko-To, Saiboku-To, and Sairei-To, consist of similar herbal prescriptions containing glycyrrhizin, which is a strong inhibitor of 11β-hydroxysteroid dehydrogenase. We performed cross-over open trials in healthy subjects to clarify prednisolone pharmacokinetics on co-administration of these preparations.

All subjects received a single oral dose of 10 mg prednisolone before oral treatment with one of the test preparations. After a 2-week wash-out interval, they received one of the test preparations for three days at daily doses of 7·5 or 9·0 g. On the third study day, 10 mg prednisolone was administered orally in combination with the test preparation. Area under the curves (AUC) of prednisolone before and after the treatment decreased from 0·94 to 0·78 mg h L−1 (P < 0·05) in the Sho-saiko-To group, increased from 0·92 to 1.06 mg h L−1 (P < 0·01) in the Saiboku-To group, and did not change in the Sairei-To group. AUC ratios of prednisone and prednisolone, which reflect the 11β-hydroxysteroid dehydrogenase activity, increased in the Sho-saiko-To group (P < 0·01), decreased in the Saiboku-To group (P < 0·01), and did not change in the Sairei-To group after the treatments. Similar results were observed in ratios of endogenous cortisone to cortisol.

Because of the equal glycyrrhizin content in all three preparations, it was unexpected that the 11β-hydroxysteroid dehydrogenase effect was different amongst the three groups. These observations suggest that some unknown metabolic enzyme modifiers, promoters or inhibitors, may be involved in these traditional treatments.
Ophthalmic Preservatives as Absorption Promoters for Ocular Drug Delivery
Authors: Sasaki Hitoshi , Nagano Toshiaki , Yamamura Kenzo , Nishida Koyo , Nakamura Junzo
Published: April 2011

The effects of ophthalmic preservatives on the drug permeability through isolated ocular membranes of albino rabbits were investigated using a two-chamber glass diffusion cell. Tilisolol and fluorescein isothiocyanate (FITC)-dextrans (average molecular weights 4400 and 9400 Da; FD-4 and FD-10, respectively) were used as model penetrants of ophthalmic β-blockers and peptide drugs. Preservatives significantly enhanced the corneal penetration of not only tilisolol but also FITC-dextrans. Especially, benzalkonium chloride increased the corneal permeability of FD-4 and FD-10 by 28·8 and 37·1 times, respectively. These results indicate the usefulness of ophthalmic preservatives as absorption promoters for the ocular delivery of β-blockers and hydrophilic macromolecules. Preservatives also enhanced the conjunctival permeability of tilisolol, FD-4 and FD-10. The promoting effect of preservatives on the conjunctival drug penetration was smaller than that on the corneal one. Preservative increased the ratio of corneal to conjunctival permeability of tilisolol, FD-4 and FD-10.

The different responses of corneal and conjunctival drug penetrations to ophthalmic preservatives may be useful to control the extent and pathway for the ocular and systemic absorptions of instilled drugs.
2-Heteroaryl 2-Substituted Phenylketone Derivatives and Their Inhibitory Activity on Platelet Aggregation
Authors: Hsu Ling-yih , Lee Chyuan-fang , Chou Tz-chong , Ding Yu-an
Published: April 2011

R 68070 and CV-4151 are two compounds possessing both thromboxane synthetase inhibitory activity and thromboxane receptor antagonist properties. 2-Heteroaryl 2-substituted phenylketone derivatives with a partial structural similarity to R 68070 and CV-4151, i.e. possessing a phenyl and a heteroaryl moiety, have been prepared and found to have antiplatelet activity. The compound 2-thienyl 2′-hydroxyphenyl ketone (4) was shown to completely inhibit platelet aggregation induced by arachidonic acid at a concentration of 5·0 μm. Structure-activity analysis indicated that the presence of a ketone group is an important requirement for this inhibitory activity. An o-hydroxyl substitution on the phenyl ring, and a 2-thienyl of heteroaryl ring might increase inhibitory activity.
The Effect of Moisture on the Heckel and Energy Analysis of Hydroxypropylmethylcellulose 2208 (HPMC K4M)
Authors: Nokhodchi Ali , Ford James L , Rowe Philip H , Rubinstein Michael H
Published: April 2011

The influence of moisture content on the Heckel analysis, energy analysis and strain-rate sensivity of hydroxyproplymethylcellulose 2208 (HPMC K4M) has been evaluated.

An increase in moisture content from 0 to 14.9% w/w decreased the mean yield pressure, probably due to a plasticizing effect of moisture which reduced the resistance of particles to deformation. For each moisture content (0, 2.2, 3.8, 5.9, 9.6 and 14.9% w/w), the initial relative density and the extrapolated density from the linear portion of the Heckel plot, tended to decrease with increasing compression speed. Minor changes were observed in the initial relative density due to changes in the moisture content. The strain-rate sensitivity increased from 21.6 to 50.7% as the moisture content increased from 0 to 14.9% w/w, indicating that the plasticity of HPMC increased with increase in moisture content, whereas increase in moisture content from 0 to 14.9% w/w decreased the plastic energy.

Increase in compression force or speed of compaction increased both the plastic and elastic energies. An increase in moisture content from 0 to 5.9% w/w slightly reduced the elastic energy but above 5.9% moisture content the elastic energy was unaffected by the moisture content.
Anti-inflammatory, Analgesic and Ulcerogenic Properties of S-(+)-Ibuproxam, Racemic Ibuproxam-β-cyclodextrin and S-(+)-Ibuproxam-β-cyclodextrin
Authors: Bole-Vunduk Breda , Verhnjak Katarina , Zmitek J
Published: April 2011

The anti-inflammatory, analgesic and gastric mucosal damage-inducing activities of S-(+)-ibuproxam, and S-(+)-ibuproxam-β-cyclodextrin, new propionic acid derivatives, and racemic ibuproxam-β-cyclodextrin were investigated in three animal models and compared with those of racemic ibuproxam, racemic ibuprofen and its optical enantiomer S-(+)-ibuprofen.

The anti-inflammatory activities of racemic ibuprofen, S-(+)-ibuprofen and racemic ibuproxam in carrageenan-induced paw oedema in rats were almost equipotent and slightly greater than those of S-(+)-ibuproxam and S-(+)-ibuproxam-β-cyclodextrin, and significantly greater than that of racemic ibuproxam-β-cyclodextrin. In abdominal constriction tests in mice, the analgesic effects of racemic ibuproxam, S-(+)-ibuproxam, racemic ibuproxam-β-cyclodextrin and S-(+)-ibuproxam-β-cyclodextrin were significantly less pronounced than those of racemic ibuprofen and S-(+)-ibuprofen. Ulcerogenic activity of S-(+)-ibuproxam-β-cyclodextrin in rats was found to be significantly weaker than that of racemic ibuproxam-β-cyclodextrin, racemic ibuproxam and S-(+)-ibuproxam and, most notably, weaker than those of racemic ibuprofen ans S-(+)ibuprofen.

These results indicate that S-(+)-ibuproxam-β-cyclodextrin could be a novel potent anti-inflammatory and analgesic agent with a therapeutic index more favourable than that of the classical non-steroid anti-inflammatory drugs ibuprofen and ibuproxam.
The Relaxant Effect of Extract of Phyllanthus urinaria in the Guinea-pig Isolated Trachea. Evidence for Involvement of ATP-sensitive Potassium Channels
Authors: Paulino Niraldo , Cechinel-Filho Valdir , Yunes Rosendo A , Calixto João B
Published: April 2011

This study analyses the relaxation induced by the hydroalcoholic extract of stems, leaves and roots from Phyllanthus urinaria (Euphorbiaceae) in the guinea-pig trachea (GPT) pre-contracted by carbachol.

The hydroalcoholic extract of P. urinaria (0.1–10 mg mL−1) caused a graded relaxation in GPT with or without epithelium, with mean EC50 values of 1.94 (1.41-2.67) and 2.00 (1.47-2.78) mg mL−1 and Emax of 717 mg (± 16) and 627 mg (± 12), respectively. The relaxation in response to hydroalcoholic extract, like that to cromakalim (EC50 3.57 (2.75-4.64 μM) in GPT without epithelium, was fully abolished in the presence of high KCl concentrations (80 mM), and was significantly attenuated by tetraethylammonium (10 or 30 mM) or glibenclamide (0.1 or 3 μM). However, the relaxation caused by the hydroalcoholic extract was unaffected by apamin (0.1 or 1.0 μM), nitro-L-arginine (L-NOARG, 100 μM), methylene blue (10 μM) or by calcitonin gene-related peptide (CGRP) (8–37) (a CGRP antagonist, 0.1 μM). Both propranolol (1 or 3 μM) and [D-p-Cl-Phe6,Leu17]VIP (a vasoactive intestinal peptide (VIP) receptor antagonist, 0.1 μM) produced a significant displacement to the right (about 2-fold) of the relaxation response to hydroalcoholic extract of P. urinaria.

Thus, the present results indicate that the ATP-activated potassium channels sensitive to glibenclamide, but not the small conductance calcium-activated potassium channels sensitive to apamin, largely contribute to the relaxation effect of the hydroalcoholic extract of P. urinaria in GPT. In addition, both β2 and VIP-mediated responses seem to account, at least in part, for the relaxation effect of the hydroalcoholic extract, as its relaxant response was partially attenuated by both propranolol and VIP receptor antagonist.
Reversible Inhibition of Cholinesterases by Opioids: Possible Pharmacological Consequences
Authors: Galli Alessandro , Ranaudo Esterina , Giannini Laura , Costagli Chiara
Published: April 2011

The inhibitory potency of opioids belonging to different structural categories on electric eel and rat brain acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BuChE) was investigated.

The phenylazepine meptazinol, the pyrrolo-[2,3-b]-indole derivative eseroline and the benzomorphan normetazocine were the most potent inhibitors of AChE among the compounds tested. These were followed by (-)-metazocine, N-allylnorcyclazocine, 3-(1,3-dimethyl-3-pyrrodinyl)-phenol, levallorphan, levorphanol and pentazocine. The opioids which inhibited horse serum BuChE were in order of potency: meptazinol, methadone, profadol, levallorphan and 1,2,3-trimethyl-3-(3-hydroxyphenyl)-piperidine. The results of this work appear consistent with the fact that the anticholinesterase activity of the opioids is not confined to specific structural categories, although conformationally constrained molecules, like those of morphinans, benzomorphans or pyrrolo-[2,3-b]-indoles, appear to favour affinity for AChE, whereas highly flexible molecules, like those of acyclic opioids, inhibit BuChE in a rather selective way. In all cases, the inhibitory action of opioids markedly differed from that of carbamates or organophosphorous compounds, in that it was time-independent and immediately reversible on dilution.

In general the anticholinesterase action of opioids does not seem to influence appreciably the pharmacological properties of the drugs since it is evidenced at drug doses higher than those which are analgesic. However, in the case of mixed agonist/antagonist opioids with rather weak analgesic activity, the enzyme inhibition caused by the levels of circulating drugs can be so marked as to exert also a cholinergic component of action.
Study of Interaction Effects of Polyacrylic Acid Polymers (Carbopol 940) on Antimicrobial Activity of Methyl Parahydroxybenzoate Against Some Gram-negative, Gram-positive Bacteria and Yeast
Authors: Scalzo Marcello , Orlandi Clelia , Simonetti Nicola , Cerreto Felice
Published: April 2011

Cosmetic or pharmaceutical formulations containing hydrophilic polymers of natural or synthetic origin, may be more exposed to successful microbial contamination because of a polymer-preservative interaction. The experimental data reported in this paper relate to the possible interference of Carbopol 940 with methyl parahydroxybenzoate.

Results show that this hydrophilic polymer, widely employed in many formulations, exerts, on the contrary, an interesting synergism on microbicidal activity of the preserving agent against E. coli and P. Aeruginosa.

A reduction in microbicidal activity against S. aureus and C. albicans is observed for a polymer concentration higher than that needed for anti-Gram-negative synergy.
Influence of pH on Skin Permeation of Amino Acids
Authors: Hatanaka Tomomi , Kamon Toshihiko , Uozumi Chisato , Morigaki Setsuko , Aiba Tetsuya , Katayama Kazunori , Koizumi Tamotsu
Published: April 2011

Skin permeation of amino acids through excised rat skin was measured at various pH values.

The permeabilities varied with the donor pH and amino acid, indicating that each ionic species of amino acid may have a different permeability. The permeability coefficient of each ion was estimated from the permeability-pH profiles using the dissociation constants. The estimated values for mono-cation and uncharged zwitterion were not dependent on the lipophilicity but on the size of the amino acid, suggesting a porous mechanism of transport. The permeability coefficient was highest for di-cation, followed by mono-cation, positively charged, uncharged and negatively charged zwitterions. The electrical potential difference across the skin was too small to affect the permeation of ions.

The permselective property of skin thus seems to be determined by the difference of diffusivity in aqueous pores of skin due to the hydration of ions and other factors.
Immunological Detection of Type II Collagen Degradation: Use in the Evaluation of Anti-arthritic Therapies
Authors: Chichester C O , Barrach H-J , Srinivas G R , Mitchell P
Published: April 2011

Propagated Swarm rat chondrosarcoma cells, rabbit chrondrocytes (from articular cartilage of knee, shoulder and hip joints), and bovine nasal cartilage explant cultures were studied. Type II collagen (CII) and its peptide fragments were quantitated in cell medium and cell layer separately, using two previously developed assays; one assay employed a monoclonal antibody, C4F6, that reacts specifically with triple helical CII and the other assay used an antibody, E1E5, that reacts specifically with a peptide of CII.

A time-dependent increase in the content of CII and CII-derived peptides was observed in both rat and rabbit cultures. In both culture systems the majority of the native type II collagen is found associated with the cell layer (97% in rat cultures and 73% in rabbit cultures), while the major part of the CII peptides is found in the media (73% in rat cultures, 88% in the rabbit cultures). The concentration of peptides in the media reaches approximately 2 μg mL−1 in both chondrocyte monolayer cultures after 4 days.

The CII peptide assay employing E1E5 was well suited to quantitate articular cartilage collagen degradation in explant culture. Thus it can be used to evaluate potential therapeutic agents that can modify or inhibit cartilage degradation. The assay has the added potential that it could be used in-vivo to evaluate the effectiveness of potential metalloproteinase inhibitors in animal models of osteoarthritis or in clinical trials.
Preoperative Lymph-node Staining with Liposomes Containing Patent Blue Violet. A Clinical Case Report
Authors: Pump B , Hirnle P
Published: April 2011

A case study is reported using patent blue violet entrapped in liposomes to localize lymph nodes before surgery.

Liposomes containing 44 mg patent blue violet were injected into foot lymphatics of a patient due to undergo retroperitoneal staging-lymphonodectomy. Lymph nodes were readily visualized and removed, and urine and serum was collected for assay of the dye. The maximum concentration of patent blue violet in serum was 2.7 μg mL−1, 1.5 h after the termination of the injection; almost no dye was detectable by the time of the operation 24 h later.

In the first urine sample (2 h after the termination of the injection) the concentration of patent blue violet was 1.3 μg mL−1, and subsequently diminished, with the last urine sample to contain detectable dye being collected 20 h later. A total of 0.8 mg dye (2% of the injected amount) was excreted in the urine suggesting 10% of the circulating amount of dye was renally excreted.

Endolymphatic injection of patent blue violet simplifies the often difficult process of finding the lymph nodes and additionally reduces side-effects. All surgery cases demanding a radical lymphonodectomy may profit, including testicular or bladder cancers and many gynaecological tumours.
Suppression of Adjuvant Arthritis in Rats by Oral Administration of Type II Collagen in Combination with Type I Interferon
Authors: Yoshino Shin
Published: April 2011

The oral administration of 3 μg but not 300 μg of type II collagen (CII) significantly suppressed adjuvant arthritis in rats that was induced by immunization with Mycobacterium tuberculosis. Feeding 5000 units of type I interferon was also effective in downregulating the disease. More suppression of adjuvant arthritis was observed when both CII and interferon were orally given. Delayed-type hypersensitivity responses to M. tuberculosis were inhibited in interferon-but not in CII-fed animals. There were no delayed responses to CII in M. tuberculosis-immunized rats fed either CII or interferon. However, the delayed response to M. tuberculosis plus CII was significantly reduced by CII as well as interferon given orally. Feeding both CII and interferon was more effective in suppressing the delayed responses to M. tuberculosis plus CII. A similar suppression was observed in proliferative responses of lymph-node cells to M. tuberculosis, CII, or M. tuberculosis plus CII in-vitro.

These results suggest that the suppression of adjuvant arthritis by oral administration of CII is due to tolerance to CII in which a bystander suppression mechanism appears to be involved. Orally administered interferon seems to suppress nonspecifically cellular immune responses. The oral administration of CII in combination with interferon may be a novel way to treat T cell-mediated diseases.
The Disposition of Aspirin and Salicylic Acid in the Isolated Perfused Rat Liver: the Effect of Normal and Retrograde Flow on Availability and Mean Transit Time
Authors: Mellick George D , Roberts Michael S
Published: April 2011

The effect of changing the direction of perfusate flow from anterograde to retrograde on the disposition of acetylsalicylic acid (aspirin) and salicylic acid was studied in the single pass in-situ perfused rat liver. Mixtures of aspirin, [14C]salicylic acid and the inert reference solute [3H]sucrose were administered as boluses into the liver using red blood cell and albumin-free perfusate media at a flow rate of 30 mL min−1/liver. Hepatic availability (F), mean transit time (MTT) and normalized variance (CV2) for aspirin, preformed [14C]salicylic acid, salicylic acid produced from aspirin in the liver and [3H]sucrose were deduced from the outflow concentration profiles using statistical moment analysis.

The values for F, MTT and CV2 for the solutes under anterograde perfusion were: aspirin (0.73 ± 0.04, 15.13 ± 2.01 s, 0.33 ± 0.09, n = 5), preformed [14C]salicylic acid (1.05 ± 0.06, n=12, 43.19 ± 2.21 s, 1.08 ± 0.08, n = 5), salicylic acid from aspirin (0.33 ± 0.05, 42.82 ± 9.16 s, 0.73 ± 0.10, n = 5) and [3H]sucrose (1.05 ± 0.05, 16.88 ± 0.77 s, 0.74 ± 0.10, n = 5). The corresponding values for retrograde perfusions were: aspirin (0.73 ± 0.02, 17.41 ± 3.06 s, 0.32 ± 0.09, n = 5), preformed [14C]salicylic acid (1.14 ± 0.02, 44.42 ± 3.16 s, 0.95 ± 0.07, n = 5), salicylic acid from aspirin (0.33 ± 0.09, 36.47 ± 10.28 s, 0.58 ± 0.05, n = 5) and sucrose (1.01 ± 0.04, 18.08 ± 1.61 s, 0.76 ± 0.15, n = 5).

No significant differences in F or MTT were apparent between anterograde and retrograde perfusions for all solutes. The MTT and CV2 data for [14C]salicylic acid and salicylic acid produced from aspirin is suggestive of a permeability limitation for salicylic acid transport.
Alterations in Renal Uptake Kinetics of the Xanthine Derivative Enprofylline in Endotoxaemic Mice
Authors: Nadai Masayuki , Hasegawa Takaaki , Wang Li , Haghgoo Soheila , Okasaka Toshiki , Nabeshima Toshitaka , Kato Nobuo
Published: April 2011

The pharmacokinetics and renal uptake of enprofylline, which is primarily excreted into the urine by an active tubular secretion mechanism, were investigated in endotoxaemic mice by lipopolysaccharide isolated from Klebsiella pneumoniae.

Lipopolysaccharide (1 mg kg−1) was infused 2 h before starting the examination, thereby inducing a decrease in the systemic clearance and an increase in the steady-state volume of distribution of enprofylline while inducing no changes in the urinary recovery (> 90%). The protein binding of enprofylline significantly decreased in the presence of lipopolysaccharide. Both the systemic clearance for unbound enprofylline and glomerular filtration rate decreased in the treated mice. A nonlinear relationship was found in both groups between the steady-state unbound plasma concentration and renal uptake of enprofylline after constant infusion for 1 h. The renal uptake rate of enprofylline decreased in the treated mice. Lipopolysaccaharide caused increases in the apparent maximum capacity for renal uptake (Vmax) from 17.3 to 32.2 μg h−1 g−1 of kidney and in the Michaelis–-Menten constant (Km) from 2.7 to 21.7 μg mL−1 and decrease in the nonsaturable uptake rate constant (Kd) from 0.87 to 0.43 mL h−1 g−1 of kidney.

These results indicate that lipopolysaccharide decreases the renal tubular secretion of enprofylline by inducing a decrease in the renal uptake ability.
Kinetics of Bupivacaine After Nicorandil Treatment in Mice
Authors: Gantenbein Manon , Attolini Laurence , Bruguerolle Bernard
Published: April 2011

Previous studies have reported interactions between potassium-channel agonists and bupivacaine. This study was designed to document possible changes in the pharmacokinetic behaviour of bupivacaine and its main metabolite, N-desbutylbupivacaine, in mice after a single 1 mg kg−1 intraperitoneal injection of nicorandil.

The kinetic variables of bupivacaine were determined after a single 20 mg kg intraperitoneal dose of bupivacaine in controls (group 1) and in nicorandil-treated mice (group 2). The maximal concentration in the serum (Cmax 0.618 ± 0.051 vs 0.408 ± 0.041 μg mL−1 for group 1 vs 2, P = 0.01) and the area under the concentration curve (AUC 1.039 ± 0.051 vs 0.758 ± 0.072 μg mL−1 h for group 1 vs 2, P = 0.013) of bupivacaine were significantly lower in nicorandil-treated mice, while CL (0.579 ± 0.025 vs 0.815 ± 0.079 for group 1 vs 2, P = 0.022) and Vd (0.506 ± 0.054 vs 0.981 ± 0.117 for group 1 vs 2, P = 0.1006) were increased in nicorandil-treated animals. The ratio of AUC for N-desbutylbupivacaine to AUC for bupivacaine, which may partially indicate the rate of metabolism, was higher in the presence of nicorandil (1.142 ± 0.017 compared with 0.877 ± 0.013, P = 0.0001).

Our data may indicate an increased metabolism of bupivacaine in nicorandil-treated mice. These results do not explain the previously reported enhanced anaesthetic activity of bupivacaine in the presence of nicorandil, but may participate, at least in part, in the relative protective effect of nicorandil against the previously reported bupivacaine-induced toxicity.
Molecular Biological Analysis of the Effects of Ginsenoside-Rb2 on Albumin mRNA in Streptozotocin-induced Diabetic Rats
Authors: Yokozawa Takako , Yasui Teruhito , Oura Hikokichi
Published: April 2011

The mechanisms of the mRNA synthesis-promoting action of ginsenoside-Rb2, were investigated at the gene level.

Rot analysis suggested that the previously reported increase in RNA polymerase activity as a result of administration of ginsenoside-Rb2 might be because of its effect on a specific gene. In this regard, albumin mRNA, which is expressed specifically in the liver, was assayed by northern blot hybridization using albumin cDNA in normal rats, diabetic control rats and diabetic rats given ginsenoside-Rb2. When the level of albumin mRNA in normal rats was set at 100, the level was reduced markedly to 32 in diabetic control rats. In contrast, in diabetic rats given ginsenoside-Rb2 the level was 0.54, significantly higher (69%) than that in diabetic rats given no ginsenoside-Rb2. In addition, poly(A)+RNA was purified from total RNA and subjected to hybridization, and poly(A)+RNA bands with different charges were measured by densitometry. The results of the measurement revealed changes dependent on the charge, and this was confirmed by autoradiography.

We found no significant difference in the transcription activity of albumin mRNA, however, it showed only a tendency to increase. This suggests that ginsenoside-Rb2 has some effect on post-transcriptional regulation of the stability of mRNA itself. The results of Rot analysis suggest that ginsenoside-Rb2 affects a specific gene alone.
Time-dependent Densification Behaviour of Cyclodextrins
Authors: Muñoz-Ruiz Angel , Paronen Petteri
Published: April 2011

Understanding of volume reduction mechanisms is a valuable aid in the development of robust cyclodextrin tablet formulations. The particle and powder properties of α-, β-, γ-and hydroxypropyl (HP) -β-cyclodextrins and their behaviour under compression were examined.

The cyclodextrins studied showed big differences in particle-size distribution and particle shape. The highest densification on tapping was found for cyclodextrins having the smallest particle size. Cyclodextrins were compressed using single-sided saw-tooth displacement-time profiles at rates of 3 and 300 mm s−1 with a compaction simulator. The densification of the powders was examined by Heckel treatment, using the tablet-indie and ejected-tablet methods. The cyclodextrins were denser at the beginning of the tableting process (at low pressures) if high rather than low velocity was used. Ranking according to their tendency toward total deformation and permanent plastic deformation was: HP-β-cyclodextrin > β-cyclodextrin > γ-cyclodextrin > α-cyclodextrin. The ranking order in strain-rate sensitivity (SRS) of total deformation was HP-β-cyclodextrin γ-cyclodextrin ≥ α-cyclodextrin ≥ β-cyclodextrin. On the basis of the yield pressure values and the Heckel plot profiles, all the cyclodextrins were highly prone to plastic deformation. Cyclodextrins showed time-dependent consolidation behaviour manifested as increased yield pressure with decreased contact time.

A ratio was defined between the SRS of fast elastic recovery and total elastic recovery. The two materials with high ratios, HP-β-cyclodextrin and β-cyclodextrin, were especially prone to fast elastic recovery with increasing punch velocities; γ-cyclodextrin and α-cyclodextrin had low values and were less prone. On the basis of this parameter it might be possible to categorize pharmaceutical materials according to capping tendency.
The Preparation of Norfloxacin-loaded Liposomes and their In-vitro Evaluation in Pig's Eye
Authors: Lin Hung-Hong , Ko Shiu-Man , Hsu Li-Ren , Tsai Yi-Hung
Published: April 2011

The effectiveness of norfloxacin as an antibacterial agent in ophthalmology is limited by poor drug delivery and limited ocular bioavailability. Liposomes containing norfloxacin have been prepared from different phospholipids using a novel technique with an encapsulation efficiency sixteen times greater than that of a conventional film method. The in-vitro release of the norfloxacin and the transcorneal characteristics of the liposomes have been evaluated. Differential scanning calorimetry was used to determine the interaction occurring between liposomes and cornea.

The release of liposome-entrapped norfloxacin was affected by the pH of the environment. In the in-vitro corneal perfusion studies, norfloxacin-loaded liposome was transferred through the cornea at a slower rate than was the free drug. Norfloxacin-loaded liposomes were accumulated primarily in the cornea. The drug corneal retention of the lipids increased in the order dirnyristoyl-L-α-phosphatidylcholine < dipalmitoyl-L-α-phospha-tidylcholine < distearoyl-L-α-phosphatidylcholine. In the corneal drug-elimination study, liposomal norfloxacin increased the loading of the drug in cornea; the maximum value of the loading occurred 5 h after dosing. The drainage of liposomes from the cornea was somewhat slower than the solution form.

Accumulation of norfloxacin in the cornea was greater for the liposome-entrapped drug. The results suggest that norfloxacin-loaded liposomes are absorbed by the cornea via endocytosis.
The Sources of Ca2+ for Muscarinic Receptor-induced Contraction in the Rat Ileum
Authors: Elorriaga Martin , Anselmi Elsa , Hernandez Jose M , D'Ocon Pilar , Ivorra Dolores
Published: April 2011

The contractile responses obtained by activation of different muscarinic receptor subtypes in the longitudinal muscle of the rat ileum and especially the responses of this muscle to acetylcholine in a Ca2+-free medium have been investigated.

In Ca2+-containing solution, acetylcholine elicited similar concentration-dependent contractile responses in the duodenum, jejunum and ileum strips of the rat intestine. The response to a maximal concentration of the agonist (1 μM) consisted of a rapid phasic response followed by a slower tonic one. Nifedipine completely relaxes or inhibits the sustained response and only partially diminishes the phasic one, which suggests that the phasic contraction depends on the release of internal Ca2+ as well as Ca2+ entry from the extracellular space through voltage-dependent Ca2+ channels, but that the tonic contraction only depends on the influx of the external ion. In Ca2+-free medium, acetylcholine (1 μM) induced phasic contractions that depend on the release of this ion from internal stores.

Participation of different subtypes of receptors (M1, M2 and M3) in these responses depends on the inhibitory action shown by methoctramine, 4−DAMP and atropine but not by pirenzepine in two different experimental models.
The Synthesis and Some Pharmacological Actions of the Enantiomers of the K+-Channel Blocker Cetiedil
Authors: Roxburgh Craig J , Ganellin C Robin , Shiner Mark A R , Benton David C H , Dunn Philip M , Ayalew Yeshi , Jenkinson Donald H
Published: April 2011

Cetiedil ((±)-2−cyclohexyl-2-(3−thienyl)ethanoic acid 2-(hexahydro-1H-azepin-1−yl) ethyl ester) possesses anti-sickling and analgesic, antispasmodic, local anaesthetic and vasodilator activities. A total synthesis and circular dichroism spectra of the enantiomers of cetiedil is described, together with a comparison of their effectiveness as blockers of the Ca2+-activated K+ permeability of rabbit erythrocytes; the contractile response of intestinal smooth muscle to acetylcholine; the Ca2+-dependent contraction of depolarized intestinal muscle; and the cell volume-sensitive K+ permeability (Kvol) of liver cells.

The enantiomers did not differ substantially in their ability to block the Ca2+-activated K+ permeability of rabbit red cells or in their effectiveness as blockers of the contractile response of depolarized smooth muscle to externally applied Ca2+. There was a clear difference in the muscarinic blocking activity of the enantiomers, as assessed by inhibition of the contractile response of intestinal smooth muscle to acetylcholine; (+)-cetiedil was 7.7 ± 0.2 (s.d.) times more active than the (–-) form. The enantiomers also differed in their potency as blockers of the increase in membrane conductance which occurs when liver cells swell. The concentration of (+)-cetiedil needed to reduce the conductance increase by 50% was 2.04 ± 0.54 (s.d.) μM; (–-)-cetiedil was 2.6 ± 0.8 (s.d.) times less active (IC50 of 5.2 ± 1.2 μM).

Differences in the biological actions of the enantiomers of cetiedil indicate that a more extensive study could be rewarding in relation to the use of the enantiomers both in therapeutics and in the study of K+ channels.
Antibacterial Activity of Xanthones from Guttiferaeous Plants against Methicillin-resistant Staphylococcus aureus
Authors: Iinuma Munekazu , Tosa Hideki , Tanaka Toshiyuki , Asai Fujio , Kobayashl Yasuko , Shimano Ryoyu , Miyauchi Ken-Ichi
Published: April 2011

Extracts of Garcinia mangostana (Guttiferae) showing inhibitory effects against the growth of S. aureus NIHJ 209p were fractionated according to guidance obtained from bioassay and some of the components with activity against methicillin-resistant Staphylococcus aureus (MRSA) were characterized.

One active isolate, α-mangostin, a xanthone derivative, had a minimum inhibitory concentration (MIC) of 1.57−12.5 μg mL−1. Other related xanthones were also examined to determine their anti-MRSA activity. Rubraxanthone, which was isolated from Garcinia dioica and has a structure similar to that of α-mangostin, had the highest activity against staphylococcal strains (MIC = 0.31−1.25 μg mL−1), an activity which was greater than that of the antibiotic vancomycin (3.13−6.25 μg mL−1). The inhibitory effect against strains of MRSA of two of the compounds when used in conjunction with other antibiotics was also studied. The anti-MRSA activity of α-mangostin was clearly increased by the presence of vancomycin; this behaviour was not observed for rubraxanthone.

The strong in-vitro antibacterial activity of xanthone derivatives against both methicillin-resistant and methicillin-sensitive Staphylococcus aureus suggests the compounds might find wide pharmaceutical use.
Influence of Pentobarbitone on In-vivo Local Disposition of Diclofenac in Rat Liver
Authors: Tabata Kenji , Yamaoka Kiyoshi , Yasui Hiroyuki , Fukuyama Takako , Nakagawa Terumichi
Published: April 2011

Because the liver is the main organ eliminating many drugs from the body and because pentobarbitone and other analogues can inhibit biliary secretion, the influence of pentobarbitone on hepatic local disposition of diclofenac has been investigated. Diclofenac was infused into the portal and femoral veins of non-anaesthetized rats (group A) and rats anaesthetized with pentobarbitone (group B) and the plasma concentration of diclofenac and the total amount of diclofenac excreted in the bile (in both cases intact diclofenac plus its glucuronide) were simultaneously monitored by HPLC at appropriate time intervals. The time-courses of plasma concentration and amount excreted in the bile were evaluated by moment analysis with trapezoidal integration. The hepatic recovery ratio (FH) was calculated by comparing the area under the curve (AUC) of plasma concentration after intravenous infusion with that after intraportal infusion. The mean biliary transit time (tb) was estimated by subtracting the mean residence time (MRT) of the plasma data from the mean biliary residence time (MRTb) of the biliary excretion data. The FH values of diclofenac were 0.664 in group A and 0.643 in group B. The biliary excretion ratio (Fb) of total diclofenac after intravenous administration was 27.0% in group A and 14.1% in group B. The t̄b values for total diclofenac were estimated to be 0.192 h (intravenous) and 0.159 h (intraportal) in group A, and 0.174 h and 0.238 in group B. Analysis of variance showed that differences among these four t̄b values were insignificant at the 5% level. The differences in the mean residence time (MRT), total clearance (CL) and distribution volume at steady state (VSS) were insignificant between groups A and B.

Whereas total and the hepatic clearance of diclofenac were not affected by pentobarbitone, biliary clearance was extensively reduced. It took a relatively long time for diclofenac to move from the sinusoid into the bile and the time was not affected by pentobarbitone.
Influence of Fatty Acids on the Binding of Warfarin and Phenprocoumon to Human Serum Albumin with Relation to Anticoagulant Therapy
Authors: Vorum Henrik , Honoré Bent
Published: April 2011

Warfarin and phenprocoumon binding to human serum albumin was studied by equilibrium dialysis.

The first stoichiometric binding constant was 1.89 × 105 M−1 for warfarin and 2.40 × 105 M−1 for phenprocoumon. The affinity of warfarin was markedly increased on addition of up to 3 mol mol−1 albumin of palmitic, stearic, oleic or linoleic acids with energetic couplings for co-binding of one molecule of each of the fatty acids and one molecule of warfarin of 0.9, 1.1, 0.7 and 0.6 kJ mol−1, respectively. The affinity of phenprocoumon was only increased slightly on addition of palmitate with an energetic coupling of 0.3 kJ mol−1.

Six consecutive serum samples were obtained from each of 14 patients undergoing surgery. The serum affinity of the drugs varied considerably corresponding to free drug concentrations between 0.7 and 2.7% for warfarin and between 0.8 and 4.9% for phenprocoumon. The affinity of warfarin but not of phenprocoumon was correlated to the increasing plasma fatty acid concentration. Anticoagulant therapy with phenprocoumon may thus be less sensitive than warfarin to changes in the fatty acid concentration of plasma.
Local Tolerance of Subcutaneous Injections
Authors: Fransson J , Espander-Jansson A
Published: April 2011

Human insulin-like growth factor I (hIGF-I) has several possible clinical applications. Because subcutaneous administration of the drug can cause pain, local tolerance to injection of different formulations with or without hIGF-I has been investigated in man using isotonic saline solution as reference.

The formulations, made isotonic with NaCl, ranged in pH from 6 to 7 with phosphate buffer concentrations of 5 to 50 mM. The local tolerance after injection was assessed as injection pain on a visual analogue scale, pain duration and local tolerance (redness, paleness and oedema). The discomfort at the injection site was lowest with 10 mM phosphate, pH 7. Injection of buffer at pH 6 (50 mM phosphate) caused significantly more pain than using 10 mM phosphate, whereas the pain at pH 6 using 10 mM phosphate did not differ significantly from that experienced on injection of the solution at pH 7 using either 10 or 50 mM phosphate. hIGF-I itself did not seem to cause pain.

We concluded that for subcutaneous injections at non-physiological pH, the buffer strength should be kept as low as possible to avoid pain upon injection. We also hypothesize that when a non-physiological pH must be used for stability reasons, a lower buffer strength enables more rapid normalization of the pH at the injection site.
In-vitro Metabolism of YM17E, an Inhibitor of Acyl Coenzyme A: Cholesterol Acyltransferase, by Liver Microsomes in Man
Authors: Uchida Taisuke , Watanabe Takashi , Van Hoogdalem Ewoud J , Higuchi Saburo
Published: April 2011

Because YM17E (1,3-bis[[1-cycloheptyl-3-(p-dimethylaminophenyl)ureido]methyl]benzene dihydrochloride) inhibits acyl coenzyme A:cholesterol acyltransferase (ACAT) it has potential application in the treatment of hypercholesterolaemia. In man and animals YM17E is extensively metabolized, via N-demethylation, to five active metabolites (M1, M2-a, M2-b, M3 and M4). The main objectives of this study were to examine inhibition of YM17E metabolism by the products and identify the cytochrome P450 isoforms in liver microsomes which catalyse in-vitro YM17E metabolism in man.

In microsomes in man, N-demethylation of YM17E to M1 occurred enzymatically; for up to 45 s the rate was linearly proportional to the microsomal protein concentration. This reaction was inhibited by metabolites M2-a, M2-b, M3 and M4. Further, N-demethylation of [14C]-YM17E was also inhibited by its product, M1. These results showed that primary metabolism of YM17E was inhibited by its products, and supported the finding that the non-linear increase in plasma concentration of the parent drug and metabolites observed in an in-vivo study was due to inhibition by these products. Metabolic activity in microsomes from ten individual human livers demonstrated that YM17E N-demethylase activity correlated closely with testosterone 6β-hydroxylase activity. When cytochrome P450 isozyme-specific substrates and chemical inhibitors were used to inhibit YM17E N-demethylase activity, CYP3A-specific substrate and inhibitors such as nifedipine, ketoconazole and triacetyloleandomycin strongly inhibited this activity, whereas CYP1A-specific substrate or inhibitor, ethoxyresorufin and α-naphthoflavone, inhibited weakly. Other CYP inhibitors, in contrast, had few or no effects. An inhibition study using anti-rat CYP1A1, CYP2B1, CYP2C11, CYP2E1 and CYP3A2 antibodies demonstrated that only anti-rat CYP3A2 antibody inhibited YM17E metabolism, to 40% of control level, with no other antibodies showing an inhibitory effect. Of seven cDNA-expressed P450 isoforms in man (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2D6, CYP2E1 and CYP3A4), CYP3A4, CYP2D6 and CYP1A2 isozyme exhibited substantial catalytic activity of N-demethylation of YM17E.

These results indicate the predominant role of CYP3A4 in liver metabolism of YM17E in man.
Role of Na+/K+ ATPase on the Relaxation of Rabbit Ear and Femoral Arteries
Authors: GarcíA-Villalón A L , Monge L , García J L , Fernández N , Gómez B , Diéuez G
Published: April 2011

The role of Na+/K+ ATPase in vascular relaxation has been studied by determining its inhibitory effects on 2-mm segments from rabbit central ear and femoral arteries, mounted for isometric tension recording.

Acetylcholine (10-8-10-4 M), the nitric oxide donor sodium nitroprusside (10-8-3 × 10-4 M), the potassium channel agonist cromakalim (10-8-3 × 10-5 M), histamine (10-8-10-4 M) in the presence of the H1 antagonist chlorpheniramine (10-5 M), and papaverine (10-6-3 × 10-4 M) all produced arterial relaxation in ear and femoral arteries precontracted with endothelin 1. Addition of potassium (6 × 10-3- 1.2 × 10-2 M) caused relaxation of the same arteries preincubated in potassium-free medium.

Ouabain (10-5 M) an inhibitor of Na+/K+ ATPase, reduced the relaxation of ear arteries, but not of femoral arteries, in response to acetylcholine; it also reduced the response to sodium nitroprusside, cromakalim or histamine, and abolished the relaxation to potassium, but did not modify the response to papaverine, in both types of artery.

These results suggest that Na+/K+ ATPase might play a role in the relaxation of ear and femoral arteries to nitrovasodilators, to potassium channel openers and to activation of histamine receptors, and that Na+/K+ ATPase might play a role in the cholinergic relaxation of ear, but not femoral arteries, suggesting that the mechanism of cholinergic relaxation might differ in each type of artery.
Nicotinic Acid Transport Mediated by pH-dependent Anion Antiporter and Proton Cotransporter in Rabbit Intestinal Brush-border Membrane
Authors: Takanaga Hitomi , Maeda Hiroshi , Yabuuchi Hikaru , Tamai Ikumi , Higashida Haruhiro , Tsuji Akira
Published: April 2011

In order to determine whether the vitamin nicotinic acid is absorbed via an anion antiporter, intestinal epithelial cell membrane transport mechanisms for nicotinic acid were characterized using isolated rabbit jejunal brush-border membrane vesicles.

The uptake of nicotinic acid by the membrane vesicles showed an overshoot phenomenon in the presence of an outwardly directed bicarbonate gradient or an inwardly directed proton gradient and the uptakes were two times and six times greater, respectively, than that in the absence of any ion gradient. The bicarbonate-dependent initial uptake of nicotinic acid was increased at acidic pH, showing pH-dependent transport activity. An inhibitor of anion transport, 4,4′-diisothiocyanostilbene-2,2′-disulphonic acid, specifically reduced bicarbonate-dependent transport of nicotinic acid. The initial uptakes of nicotinic acid via the anion antiporter and the proton cotransporter were specifically inhibited by monocarboxylic acids such as acetic acid, benzoic acid, D- and L-lactic acid, pravastatin and valproic acid, but not by di- or tricarboxylic acids, bile acids or amino acids. Nicotinic acid uptake activity was, furthermore, expressed in a Xenopus laevis oocyte system after injection of messenger RNA (mRNA) derived from rabbit intestinal epithelial cells.

These observations demonstrate that nicotinic acid is absorbed by two independent active transport mechanisms from small intestine, i.e. a proton cotransporter and an anion antiporter. The pH-dependence observed in the intestinal absorption of nicotinic acid might, therefore, be ascribed partly to pH-sensitive and partly to carrier-mediated transport mechanisms in the brush-border membrane.
Simple HPLC Determination of the Concentrations of Epiroprim in the Serum and Brains of Mice
Authors: Lee How Sung , Chang Hernan R , Khoo Yok Moi
Published: April 2011

Epiroprim, an analogue of trimethoprim, has been shown to potentiate the efficacy of dapsone in experimental parasitic infections. A simple and accurate HPLC method has been developed to estimate epiroprim in serum and brain

Blood and brains from mice were sampled 0, 30, 75, 120 and 240 min after 50 or 100 mg kg−1 oral gavage. The drug and added internal standard metoprine in serum and brain supernatant were isolated by solid-phase extraction (Supelclean LC-SCX). The HPLC system consisted of a 150 × 4.6 mm Hypersil 5 μm ODS column. The mobile phases contained various proportions of acetonitrile, methanol and phosphate buffer (0.1 M). Peaks were detected by UV absorbance at 210 run. Serum concentrations (mean ± s.e.m.) of epiroprim were highest at 30 min for both 50 and 100 mg kg−1 doses, 173 ± 20 and 207 ± 25 ng mL−1, respectively, falling to 8 ± 5 and 18 ±6 ng mL−1, respectively, at 240 min. Epiroprim concentrations in the brain correlated well with those in the serum, with levels of 223 ±69 and 265 ±21 ng g−1 falling to 10 ± 10 and 31 ± 11 ng g−1, respectively.

Epiroprim is rapidly absorbed and distributed to the brain.