Discovery of novel ketoxime ether derivatives with potent FXR agonistic activity, oral effectiveness and high liver/blood ratio.

The farnesoid X receptor (FXR) is a promising therapeutic target for nonalcoholic steatohepatitis (NASH) and other bile acid related diseases because it plays a critical role in fibrosis, inflammation and bile acid homeostasis. Obeticholic acid (OCA), a FXR agonist which was synthesized from chenodeoxycholic acid, showed desirable curative effects in clinical trials. However, the pruritus which was the main side effect of OCA limited its further applications in NASH. Although pruritus was also observed in the clinical trials of non-steroidal FXR agonists, the proportion of patients with pruritus was much smaller than that of OCA. Thus, we decided to develop non-steroidal FXR agonists and discovered a series of novel FXR agonists which were synthesized from GW4064 by replacing the stilbene group with ketoxime ether. Encouragingly, in the following biological tests, our target compounds 13j and 13z not only showed potent FXR agonistic activities in vitro, but also effectively promoted the expression of target genes in vivo. More importantly, in the pharmacokinetic experiments, compounds 13j and 13z displayed high liver/blood ratio characteristics which were helpful to reduce the potential side effects which were caused by prolonged systemic activation of FXR. In summary, our compounds were good choices for the development of non-steroidal FXR agonists and were deserved further investigation.

Acute Toxicity of Gambierone and Quantitative Analysis of Gambierones Produced by Cohabitating Benthic Dinoflagellates.

Understanding the toxicity and production rates of the various secondary metabolites produced by Gambierdiscus and cohabitating benthic dinoflagellates is essential to unravelling the complexities associated with ciguatera poisoning. In the present study, a sulphated cyclic polyether, gambierone, was purified from Gambierdiscus cheloniae CAWD232 and its acute toxicity was determined using intraperitoneal injection into mice. It was shown to be of low toxicity with an LD50 of 2.4 mg/kg, 9600 times less toxic than the commonly implicated Pacific ciguatoxin-1B, indicating it is unlikely to play a role in ciguatera poisoning. In addition, the production of gambierone and 44-methylgambierone was assessed from 20 isolates of ten Gambierdiscus, two Coolia and two Fukuyoa species using quantitative liquid chromatography-tandem mass spectrometry. Gambierone was produced by seven Gambierdiscus species, ranging from 1 to 87 pg/cell, and one species from each of the genera Coolia and Fukuyoa, ranging from 2 to 17 pg/cell. The production of 44-methylgambierone ranged from 5 to 270 pg/cell and was ubiquitous to all Gambierdiscus species tested, as well as both species of Coolia and Fukuyoa. The relative production ratio of these two secondary metabolites revealed that only two species produced more gambierone, G. carpenteri CAWD237 and G. cheloniae CAWD232. This represents the first report of gambierone acute toxicity and production by these cohabitating benthic dinoflagellate species. While these results demonstrate that gambierones are unlikely to pose a risk to human health, further research is required to understand if they bioaccumulate in the marine food web.

Sodium Butyrate Downregulates Implant-Induced Inflammation in Mice.

Sodium butyrate (NaBu), a histone deacetylase inhibitor, has shown to exert beneficial actions attenuating inflammation in a number of intestinal and extra-intestinal diseases. However, the effects of NaBu on persistent inflammatory processes as in a response to implantation of foreign material have not been investigated. Synthetic matrix of polyether-polyurethane sponge was implanted in mice's subcutaneous layer of the dorsal region, and the animals were treated daily with oral administration of NaBu (100 mg/kg). After 7 days, the implants were removed and processed for assessment of inflammatory markers. Butyrate treatment caused a significant attenuation of neutrophil and macrophage infiltration in implants, which was reflected by the reduction of myeloperoxidase and N-acetyl-ß-D-glucosaminidase activities, respectively. Similar reduction was observed in intra-implants nitrite levels of NaBu-treated mice. NaBu treatment was also able to decrease mast cell recruitment/activation and the levels of CXCL1, CCL2, IL-6, TNF-ɑ, and TGF-ß1 in the implants but did not alter the levels of IL-10. In addition, NaBu administration decreased the concentration of proteins p65 and p50 in the nucleus as compared with the cytoplasm by western blot analysis. This result suggests that treatment with NaBu inhibited the NF-κB pathway. The circulating levels of TNF-ɑ and TGF-ß1 were also attenuated by NaBu. Persistent inflammation at sites of implanted devices very often impairs their functionality; therefore, our findings suggest that NaBu holds potential therapeutic value to control this adverse response to biomedical implants.

Preparation and Characterization of Cellulose Ether Liposomes for the Inhibition of Prion Formation in Prion-Infected Cells.

Prion accumulation in the brain and lymphoreticular system causes fatal neurodegenerative diseases. Our previous study revealed that cellulose ethers (CE) have anti-prion activities in vivo and in prion-infected cells when administered at high doses. This study aims to improve the bioavailability of a representative CE using a liposomal formulation and characterized CE-loaded liposomes in cultured cells. The liposomal formulation reduced the EC50 dose of CE by <1/200-fold in prion-infected cells. Compared to empty liposomes, CE-loaded liposomes were taken up much more highly by prion-infected cells and less by macrophage-like cells. Phosphatidylserine modification reduced the uptake of CE-loaded liposomes in prion-infected cells and did not change the anti-prion activity, whereas increased the uptake in macrophage-like cells. Polyethylene glycol modification reduced the uptake of CE-loaded liposomes in both types of cells and reduced the anti-prion activity in prion-infected cells. These results suggest that a liposomal formulation of CE is more practical than unformulated CE and showed that the CE-loaded liposome uptake levels in prion-infected cells were not associated with anti-prion activity. Although further improvement of the stealth function against phagocytic cells is needed, the liposomal formulation is useful to improve CE efficacy and elucidate the mechanism of CE action.

Cu nanoparticles constrain segmental dynamics of cross-linked polyethers: a trade-off between non-fouling and antibacterial properties.

Copper has a strong bactericidal effect against multi-drug resistant pathogens and polyethers are known for their resistance to biofilm formation. Herein, we combined Cu nanoparticles (NPs) and a polyether plasma polymer in the form of nanocomposite thin films and studied whether both effects can be coupled. Cu NPs were produced by magnetron sputtering via the aggregation in a cool buffer gas whereas polyether layers were synthesized by Plasma-Assisted Vapor Phase Deposition with poly(ethylene oxide) (PEO) used as a precursor. In situ specific heat spectroscopy and XPS analysis revealed the formation of a modified polymer layer around the NPs which propagates on the scale of a few nanometers from the Cu NP/polymer interface and then transforms into a bulk polymer phase. The chemical composition of the modified layer is found to be ether-deficient due to the catalytic influence of copper whereas the bulk polymer phase exhibits the chemical composition close to the original PEO. Two cooperative glass transition phenomena are revealed that belong to the modified polymer layer and the bulk phase. The former is characterized by constrained mobility of polymer segments which manifests itself via a 30 K increase of dynamic glass transition temperature. Furthermore, the modified layer is characterized by the heterogeneous structure which results in higher fragility of this layer as compared to the bulk phase. The Cu NPs/polyether thin films exhibit reduced protein adsorption; however, the constrained segmental dynamics leads to the deterioration of the non-fouling properties for ultra-thin polyether coatings. The films are found to have a bactericidal effect against multi-drug resistant Gram-positive Methicillin-Resistant Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa.

Dose- and time-dependent pharmacokinetics of apigenin trimethyl ether.

Apigenin trimethyl ether (5,7,4'-trimethoxyflavone, ATE), one of the key polymethoxyflavones present in black ginger (rhizome of Kaempferia parviflora) possesses various health-promoting activities. To optimize its medicinal application, the pharmacokinetics of ATE was assessed in Sprague-Dawley rats with emphases to identify the impacts from dose and repeated dosing on its major pharmacokinetic parameters. Plasma ATE levels were monitored by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Upon single intravenous administration (2 mg/kg), plasma levels of ATE declined through an apparent first-order process while dose-escalation to 4 and 8 mg/kg led to its non-linear disposition, which could be described by the Michaelis-Menten model. Similarly, dose-dependent oral pharmacokinetics was confirmed and when the dose was escalated from 5 to 15 and 45 mg/kg, much longer mean residence time (MRT0→last), higher dose-normalized maximal plasma concentration (Cmax/Dose) and exposure (AUC/Dose) were observed at 15 and/or 45 mg/kg. One-week daily oral administration of ATE at 15 mg/kg caused its accelerated elimination and the plasma exposure (AUC) after intravenous (2 mg/kg) and oral administration (15 mg/kg) dropped ~40 and 60%, respectively. As ATE displayed both dose- and time-dependent pharmacokinetics, caution is needed in the medicinal applications of ATE and/or black ginger.

Synthesis, anticancer evaluation and pharmacokinetic study of novel 10-O-phenyl ethers of dihydroartemisinin.

Twenty hybrid compounds, tethering dihydroartemisinin (DHA) with diaryl-pyrazoline/diaryl-pyrazole through ether linkage, were synthesized based on hybridization strategy and assessed for their anticancer activity. The representative compound 6f exhibited significantly elevated antiproliferative activity compared with DHA against a panel of cancer cell lines. Unexpected sensitivity of 6f in Adriamycin-resistant MCF-7 cells (MCF-7/Adr) inspired subsequent research on anticancer activity of these DHA derivatives against breast cancer cell lines. All the novel compounds exhibited potent activity in three breast cancer cells including MDA-MB-231, MCF-7 and MCF-7/Adr. Most of them exerted almost 10-fold higher potency in MCF-7/Adr than in MCF-7 and MDA-MB-231 cells. Compound 5f, the most potent compound against MCF-7/Adr (GI50 = 18 nM), was used for mechanism research which revealed that compound 5f arrested MCF-7 and MCF-7/Adr cells in G0/G1 phase with decreased levels of cyclin D1 and increased levels of p27. Preliminary pharmacokinetic properties of 5f and 6f were investigated in rats after a single intravenous administration. The high sensitivity of MCF-7/Adr indicates that these compounds have potential to be developed as therapeutic agents to treat drug-resistant cancer.

In vitro Controlled Release of two new Tuberculocidal Adamantane Aminoethers from Solid Pharmaceutical Formulations (II).

The aim of the present investigation was to develop matrix tablet formulations for the in vitro controlled release of two new tuberculocidal adamantane aminoethers (compounds III and IV), congeneric to the adamantane derivative SQ109, which is in final clinical trials, and aminoethers (I) and (II), using carefully selected excipients, such as polyvinylpyrrolidone, sodium alginate and lactose. The tablets were prepared using the direct compression method and dissolution experiments were conducted using the US Pharmacopoeia type II apparatus (paddle method) in gastric and intestinal fluids. The results suggest that both analogues, albeit more lipophilic than SQ109, and aminoethers (I) and (II), have the requisite in vitro release characteristics for oral administration. In conclusion, these formulations merit further assessment by conducting in vivo studies, at a later stage.

Triazolopyridine ethers as potent, orally active mGlu2 positive allosteric modulators for treating schizophrenia.

Triazolopyridine ethers with mGlu2 positive allosteric modulator (PAM) activity are disclosed. The synthesis, in vitro activity, and metabolic stability data for a series of analogs is provided. The effort resulted in the discovery of a potent, selective, and brain penetrant lead molecule BMT-133218 ((+)-7m). After oral administration at 10mg/kg, BMT-133218 demonstrated full reversal of PCP-stimulated locomotor activity and prevented MK-801-induced working memory deficits in separate mouse models. Also, reversal of impairments in executive function were observed in rat set-shifting studies at 3 and 10mg/kg (p.o.). Extensive plasma protein binding as the result of high lipophilicity likely limited activity at lower doses. Optimized triazolopyridine ethers offer utility as mGlu2 PAMs for the treatment of schizophrenia and merit further preclinical investigation.

Bursaphelenchus xylophilus is killed by homologues of 2-(1-undecyloxy)-1-ethanol.

2-(1-Undecyloxy)-1-ethanol, monochamol, is a male-produced aggregation pheromone of the Monochamus species, which are efficient vectors of the pine wood nematode (PWN), Bursaphelenchus xylophilus, which cause devastating damage to pines worldwide. The nematicidal activity of synthetic monochamol and its homologues (ROEtOH: R = C7-C13) were investigated to find potential alternatives to the currently used PWN control agents abamectin and emamectin. Compounds with C7-C13 chain length alkyl groups exhibited 100% nematicidal activity at a concentration of 1000 mg/L. At a concentration of 100 mg/L, 2-(1-nonyloxy)-1-ethanol (C9OEtOH), 2-(1-decyloxy)-1-ethanol (C10OEtOH), 2-(1-undecyloxy)-1-ethanol (C11OEtOH), and 2-(1-dodecyloxy)-1-ethanol (C12OEtOH) showed 100% nematicidal activity, but the others showed weaker activities. C11OEtOH showed similar nematicidal activity to abamectin in terms of LD90 values, which were 13.30 and 12.53 mg/L, respectively. However, C9OEtOH, C10OEtOH, and C12OEtOH (LC90 values: 53.63, 38.18, and 46.68 mg/L, respectively) were less effective than C11OEtOH and abamectin. These results indicate that monochamol could be an effective alternative agent against PWN. The relationship of insecticidal and nematicidal activity to different carbon chain lengths in compounds is discussed.

Design, synthesis and pharmacological evaluation of novel polycyclic heteroarene ethers as PDE10A inhibitors: part II.

We report the design and synthesis of novel pyrrolo[3,2-b]quinoline containing heteroarene ethers as PDE10A inhibitors with good to excellent potency, selectivity and metabolic stability. Further optimization of this primary series resulted in the identification of 1-methyl-3-(4-{[3-(pyridine-4-yl)pyrazin-2-yl]oxy}phenyl)-1H-pyrrolo[3,2-b]pyridine 13a with good hPDE10A potency (IC50: 6.3 nM), excellent selectivity over other related PDEs and desirable physicochemical properties. The compound exhibited high peripheral and adequate brain levels upon oral dosing in rodents. The compound also showed excellent efficacy in multiple preclinical animal models related to psychiatric disorders, particularly schizophrenia.

Structure activity relationship of brevenal hydrazide derivatives.

Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model.

Safety assessment of alkyl PEG ethers as used in cosmetics.

The CIR Expert Panel assessed the safety of Alkyl PEG Ethers as used in cosmetics. These ingredients primarily function in cosmetics as surfactants, and some have additional functions as skin-conditioning agents, fragrance ingredients, and emulsion stabilizers. The Panel reviewed available relevant animal and clinical data, as well as information from previous CIR reports; when data were not available for individual ingredients, the Panel extrapolated from the existing data to support safety. The Panel concluded that the Alkyl PEG ethers are safe as used when formulated to be nonirritating, and the same applies to future alkyl PEG ether cosmetic ingredients that vary from those ingredients recited herein only by the number of ethylene glycol repeat units.

Sofnolime with different water content causes different effects in two sevoflurane inhalational induction techniques with respect to the output of compound-A.

OBJECTIVE: During sevoflurane anesthesia with Sofnolime for CO(2) absorption, the factors affecting the production of compound A (a chemical is nepherotoxic) are still not clear. This study is designed to investigate the effects of different fresh gas flow during induction, the vital capacity induction (VCI) vs. the tidal volume breath induction (TBI) on the compound-A production with a fresh Sofnolime or a dehydrated Sofnolime using a simulated lung model. METHOD: The experiments were randomly divided into four groups: group one, VCIf, vital capacity fresh gas inflow with fresh Sofnolime; group two, TBIf, tidal volume breath fresh gas inflow with fresh Sofnolime; group three, VCId, vital capacity fresh gas inflow with dehydrated Sofnolime, and group four, TBId, tidal volume breath fresh gas inflow with dehydrated Sofnolime. The inspired sevoflurane was maintained at 8%, the concentrations of compound-A were assayed using Gas-spectrum technique, and Sofnolime temperatures were monitored at 1-min intervals throughout the experiment. RESULTS: The mean and maximum concentrations of compound A were significantly higher in the vital capacity group than the tidal volume breath group (P<0.01). At the beginning of anesthesia maintenance, the compound-A concentration in group VCIf was 36.28±6.13 ppm, which was significantly higher than the 27.32±4.21 ppm observed in group TBIf (P<0.01). However, these values decreased to approximately 2 ppm in the dehydrated Sofnolime groups. Sofnolime temperatures increased rapidly in the dehydrated Sofnolime groups but slowly in the fresh Sofnolime groups. CONCLUSION: With fresh Sofnolime, vital capacity induction increased compound-A production in the circuit system compared with tidal volume breath induction. However, with dehydrated Sofnolime, the effects of the two inhalation induction techniques on compound-A output were not significantly different.

Cytoprotective effect of hydroxytyrosyl alkyl ether derivatives after oral administration to rats in a model of glucose-oxygen deprivation in brain slices.

This study was designed to determine whether the oral administration of hydroxytyrosol (HT) alkyl ether derivatives has a neuroprotective effect in rats. The animals were treated for 7 days with HT or ethyl, butyl, hexyl, octyl, and dodecyl HT ether. A method of in vitro hypoxia-reoxygenation in brain slices was used. Hexyl, octyl, and dodecyl HT derivatives reduced brain cell death (LDH efflux). Lipid peroxidation and nitrite concentrations were inhibited most by hexyl, octyl, and dodecyl derivatives. Concentrations of 3-nitrotyrosine were reduced by HT butyl, hexyl, octyl, and dodecyl ether derivatives. Interleukin-1ß was significantly reduced in brain slices from rats treated with all HT ether derivatives. LDH efflux showed a linear correlation with brain concentrations of lipid peroxides, nitrites plus nitrates, and interleukin 1ß. The reduction in oxidative and nitrosative stress and decreased production of pro-inflammatory interleukins may be the basis for the observed neuroprotective effects.

Incorporation and controlled release of silyl ether prodrugs from PRINT nanoparticles.

Asymmetric bifunctional silyl ether (ABS) prodrugs of chemotherapeutics were synthesized and incorporated within 200 nm × 200 nm particles. ABS prodrugs of gemcitabine were selected as model compounds because of the difficulty to encapsulate a water-soluble drug within a hydrogel. The resulting drug delivery systems were degraded under acidic conditions and were found to release only the parent or active drug. Furthermore, changing the steric bulk of the alkyl substituents on the silicon atom could regulate the rate of drug release and, therefore, the intracellular toxicity of the gemcitabine-loaded particles. This yielded a family of novel nanoparticles that could be tuned to release drug over the course of hours, days, or months.

Nanobody-shell functionalized thermosensitive core-crosslinked polymeric micelles for active drug targeting.

The aim of this study was to develop poly(ethylene glycol)-b-poly[N-(2-hydroxypropyl) methacrylamide-lactate] (mPEG-b-p(HPMAm-Lac(n))) core-crosslinked thermosensitive biodegradable polymeric micelles suitable for active tumor targeting, by coupling the anti-EGFR (epidermal growth factor receptor) EGa1 nanobody to their surface. To this end, PEG was functionalized with N-succinimidyl 3-(2-pyridyldithio)-propionate (SPDP) to yield a PDP-PEG-b-p(HPMAm-Lac(n)) block copolymer. Micelles composed of 80% mPEG-b-p(HPMAm-Lac(n)) and 20% PDP-PEG-b-p(HPMAm-Lac(n)) were prepared and lysozyme (as a model protein) was modified with N-succinimidyl-S-acetylthioacetate, deprotected with hydroxylamine hydrochloride and subsequently coupled to the micellar surface. The micellar conjugates were characterized using SDS-PAGE and gel permeation chromatography (GPC). Using the knowledge obtained with lysozyme conjugation, the EGa1 nanobody was coupled to mPEG/PDP-PEG micelles and the conjugation was successful as demonstrated by western blot and dot blot analysis. Rhodamine labeled EGa1-micelles showed substantially higher binding as well as uptake by EGFR over-expressing cancer cells (A431 and UM-SCC-14C) than untargeted rhodamine labeled micelles. Interestingly, no binding of the nanobody micelles was observed to EGFR negative cells (3T3) as well as to14C cells in the presence of an excess of free nanobody. This demonstrates that the binding of the nanobody micelles is indeed by interaction with the EGF receptor. In conclusion, EGa1 decorated (mPEG/PDP-PEG)-b-(pHPMAm-Lac(n)) polymeric micelles are highly promising systems for active drug targeting.

Pharmacokinetics of LJP 993, a tetrameric conjugate of domain 1 of beta2-glycoprotein I for antiphospholipid syndrome.

beta2-glycoprotein I is the best-characterized antigenic target for antiphospholipid autoantibodies. We synthesized a tetrameric conjugate of the domain 1 of beta2-glycoprotein I (LJP 993) aimed at developing the conjugate as a Toleragen to suppress antiphospholipid syndrome. The present studies focused on determining the stability, tissue distribution, plasma concentration-time profile and excretion of the LJP 993 in mice. The stability of LJP 993 in mouse plasma was quantitatively evaluated using strong cation-exchange high performance liquid chromatography. ( 125)I-labeled LJP 993 was intravenously injected to mice, and levels of (125)I-labeled LJP 993 in plasma, tissues, urine and feces were determined at known intervals. Incubation of LJP 993 with mouse serum at 37 degrees C for 8 h resulted in a decrease by 34% of LJP 993 concentration. No degradation fragment was observed during the incubation. After a single intravenous administration of (125)I-LJP 993 (0.5 and 5 mg/kg) to mice, both C(max) and area-under-curve values increased in a dose-proportional manner, and blood radioactivity disappeared in a bi-exponential manner with the distribution half-lives equal to 1.7 min, and the elimination half-lives 188 and 281 min, respectively. The (125)I-LJP 993 was moderately distributed into organs and tissues with the exception that brain level of ( 125)I-LJP 993 was negligible. The major sites of (125)I-LJP 993 uptake were the kidney (at 30 min post dosing), and kidney, lung, liver, heart, spleen, skin, muscle and fat tissues (at 4 h post dosing). Cumulative urinary and fecal radioactivity for 0-48 h post dosing accounted for 44.7% and 4.2% of the administered dose, respectively, with the fast rate of urinal excretion occurring within the first 8 h. In summary, LJP 993 was fairly stable in mouse plasma. After administration to mice, (125)I-LJP 993 was taken up mainly by kidney and then distributed extensively to tissues except brain. Both C(max) and area-under-curve values increased in a dose-proportional manner. It was predominantly excreted in the urine with an elimination half-life longer than 3 h. Kidney is a major route to excrete the tetrameric conjugate.

Anti-osteosarcoma effects and mechanisms of 4-O-amino-phenol-4'-demethylepipodophyllotoxin ether.

The purpose of this study was to investigate the anti-osteosarcoma effects and mechanisms of 4-O-amino-phenol-4'-demethylepipodophyllotoxin ether (ODE), a new derivative of podophyllotoxin. The results showed that ODE inhibited proliferation of K562, OS-9901, CNE, BGC-823 and Tca-8113 cells in a time- and concentration-dependent manner as determined by microculture tetrazolium (MTT) assay. OS-9901 and K562 cells treated with ODE for 24 h showed cell cycle arrest at G(2)/M and a parallel decrease in G(0)/G(1) and S phase as detected by flow cytometry (FCM). Meanwhile, a fraction of cells with hypodiploid DNA content representing apoptosis were detected by FCM. Morphology observation also revealed typical apoptotic features, including shrinkage of cellular and nuclear membranes, condensed heterochromatin around the nuclear periphery and cytoplasmic vacuolation in OS-9901 cells. Under a confocal laser scanning microscope, intracellular Ca2+ and Mg2+ concentrations were greatly increased whereas the pH value, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were markedly reduced in OS-9901 cells after treatment with ODE. Taken together, these results suggest that the anti-osteosarcoma mechanisms of ODE are attributed to apoptosis through increasing intracellular Ca2+ and Mg2+ concentrations, and reducing pH value, MMP and ROS.

Application of in vivo microdialysis for studying the efficacy of protective preparations against sulfur mustard penetrating the skin.

Subcutaneous microdialysis was employed for monitoring thiodiglycol (2,2'-thiodiethanol, TDG) levels with the aim of characterizing the transdermal penetration of topically applied liquid sulfur mustard (2,2'-dichlorodiethyl sulfide, SM) in rats. TDG levels, evaluated in 20 min dialysates collected over a 6 h sampling period, were plotted against time after pooling. Linear correlation was identified between the SM dose and the mean areas under the 0-60 min or the whole curve (AUC(0-60) and AUC, respectively) as well as mean peak concentrations (C(max)) in the range of 1.0-3.0 microl applied volume (7.2-21.7 nmol).A commercially available barrier cream, a perfluoropolyether oil and a vaseline based ointment containing zinc oxide were subsequently tested as topical protectants. Each preparation was layered on the skin surface prior to the application of 2.0 microl SM. The evaluation of the efficacy of the preparations was based on obtained AUC(0-60), AUC and C(max) values. A statistical comparison of these parameters with those obtained when 2.0 microl SM was applied without pretreatment indicated that the barrier cream and the perfluoropolyether oil significantly (P < 0.01) reduced the amount of penetrating SM within the sampling period. In addition, the perfluoropolyether oil almost completely prevented the penetration of SM for 20 min. Pretreatment with the ointment did not prove to be an effective countermeasure as its administration resulted in no significant reduction in AUC(0-60), AUC and C(max) values.