Lack of genotoxicity potential and safety assessment of 4-(2-hydroxyethyl) morpholine present as an impurity in pharmaceuticals and nutritional supplements

4-(2-Hydroxyethyl) morpholine (HEM) is widely used as a building block of macromolecules in the manufacture of pharmaceuticals and dietary supplements and could remain as an impurity in the finished products. An evaluation of HEM was conducted to identify endpoints that could be used to determine the point-of-departure (POD) for use in assessing the potential risk from exposure to HEM. No oral repeated dose toxicological studies of appropriate duration were found for HEM. Therefore, suitable analogue(s) were identified. Although oral repeated dose studies were available for the analogues, the studies were not of sufficient duration for use in the assignment of a POD for risk evaluation. Accordingly, the Threshold of Toxicological Concern (TTC) approach, which proposes that a de minimis value can be derived to qualitatively assess risk, was considered for HEM. To determine the appropriate TTC approach (genotoxic or non-genotoxic), the genotoxicity of HEM and its analogues were evaluated. The weight of the evidence indicated that HEM, and the appropriate analogues, are not genotoxic. Considering the chemical structure of HEM, the non-genotoxic Cramer class III TTC value of 1.5 μg/kg bw/day was determined to be appropriate for use in safety assessment of HEM as an impurity in products intended for human consumption.

Combined Developmental Toxicity of the Pesticides Difenoconazole and Dimethomorph on Embryonic Zebrafish

Difenoconazole (DIF) and dimethomorph (DIM) are widely used pesticides frequently detected together in environmental samples, so the deleterious effects of combined exposure warrant detailed examination. In this study, the individual and combined effects of DIM and DIF on conventional developmental parameters (hatching rate, deformity rate, lethality) and gene expression were measured in embryonic zebrafish. Both DIF and DIM interfered with normal zebrafish embryo development, and the most sensitive toxicity index for both was 96 h post-fertilization (hpf) deformity rate (BMDL₁₀ values of 0.30 and 1.10 mg/L, respectively). The combination of DIF and DIM had mainly synergistic deleterious effects on 96 hpf deformity and mortality rates. Transcriptome analysis showed that these compounds markedly downregulated expression of mcm family genes, cdk1, and cdc20, thereby potentially disrupting DNA replication and cell cycle progression. Enhanced surveillance for this pesticide combination is recommended as simultaneous environmental exposure may be substantially more harmful than exposure to either compound alone.

Identification of GSK3186899/DDD853651 as a Preclinical Development Candidate for the Treatment of Visceral Leishmaniasis

The leishmaniases are diseases that affect millions of people across the world, in particular visceral leishmaniasis (VL) which is fatal unless treated. Current standard of care for VL suffers from multiple issues and there is a limited pipeline of new candidate drugs. As such, there is a clear unmet medical need to identify new treatments. This paper describes the optimization of a phenotypic hit against Leishmania donovani, the major causative organism of VL. The key challenges were to balance solubility and metabolic stability while maintaining potency. Herein, strategies to address these shortcomings and enhance efficacy are discussed, culminating in the discovery of preclinical development candidate GSK3186899/DDD853651 (1) for VL.

Otilonium and pinaverium trigger mitochondrial-mediated apoptosis in rat embryo cortical neurons in vitro

In the frame of a repositioning programme with cholinergic medicines in clinical use searching for neuroprotective properties, we surprisingly found that spasmolytic antimuscarinics otilonium and pinaverium exhibited neurotoxic effects in neuronal cultures. We decided to characterize such unexpected action in primary cultures of rat embryo cortical neurons. Neurotoxicity was time- and concentration-dependent, exhibiting approximate EC₅₀ values of 5 μM for both drugs. Seven antimuscarinic drugs endowed with a quaternary ammonium, and another 10 drugs with different cholinergic activities, carrying in their molecule a ternary ammonium did not exhibit neurotoxicity. Both drugs caused a concentration-dependent blockade of whole-cell inward currents through voltage-activated calcium channels (VACCs). Consistent with this, they also blocked the K⁺-elicited [Ca²⁺]_c transients. Neither antioxidant catalase, glutathione, n-acetylcysteine, nor melatonin protected against neurotoxicity of otilonium or pinaverium. However cyclosporine A, a blocker of the mitochondrial permeability transition pore, prevented the neurotoxic effects of otilonium and pinaverium monitored as the fraction of cells undergoing apoptosis. Furthermore, the caspase-9 and caspase-3 inhibitor Ac-LEHD-CHO mitigated the apoptotic neuronal death of both drugs by around 50%. Data are compatible with the hypothesis that otilonium and pinaverium elicit neuronal death by activating the intrinsic mitochondrial-mediated signaling pathway of apoptosis. This may have its origin in the mitigation of Ca²⁺ entry and the uncoupling of the Ca²⁺-dependent generation of mitochondrial bioenergetics, thus causing the opening of the mitochondrial mPTP to elicit apoptotic neuronal death.

Chronic, intermittent treatment with a cannabinoid receptor agonist impairs recognition memory and brain network functional connectivity

Elucidating how cannabinoids affect brain function is instrumental for the development of therapeutic tools aiming to mitigate 'on target' side effects of cannabinoid-based therapies. A single treatment with the cannabinoid receptor agonist, WIN 55,212-2, disrupts recognition memory in mice. Here, we evaluate how prolonged, intermittent (30 days) exposure to WIN 55,212-2 (1 mg/kg) alters recognition memory and impacts on brain metabolism and functional connectivity. We show that chronic, intermittent treatment with WIN 55,212-2 disrupts recognition memory (Novel Object Recognition Test) without affecting locomotion and anxiety-like behaviour (Open Field and Elevated Plus Maze). Through 14 C-2-deoxyglucose functional brain imaging we show that chronic, intermittent WIN 55,212-2 exposure induces hypometabolism in the hippocampal dorsal subiculum and in the mediodorsal nucleus of the thalamus, two brain regions directly involved in recognition memory. In addition, WIN 55,212-2 exposure induces hypometabolism in the habenula with a contrasting hypermetabolism in the globus pallidus. Through the application of the Partial Least Squares Regression (PLSR) algorithm to the brain imaging data, we observed that prolonged WIN 55,212-2 administration alters functional connectivity in brain networks that underlie recognition memory, including that between the hippocampus and prefrontal cortex, the thalamus and prefrontal cortex, and between the hippocampus and the perirhinal cortex. In addition, our results support disturbed lateral habenula and serotonin system functional connectivity following WIN 55,212-2 exposure. Overall, this study provides new insight into the functional mechanisms underlying the impact of chronic cannabinoid exposure on memory and highlights the serotonin system as a particularly vulnerable target.

Impacts of temperature, morpholine, and chronic radiation on the embryonic development of round whitefish (Prosopium cylindraceum)

During incubation, round whitefish embryos may experience fluctuating or elevated temperatures from natural (e.g., seasonal temperature changes) and/or anthropogenic sources. Anthropogenic sources like once-through cooling discharges from nuclear power plants can also expose embryos to chemicals (e.g., morpholine) and/or radiation. To examine the effects of these potential stressors on embryogenesis, round whitefish were incubated under fluctuating or constant temperatures, with morpholine or ¹³⁷ Cs gamma rays. We report the percentage of prehatch and posthatch mortality, developmental rate, hatch dynamics, and morphometrics at 4 development stages. Embryos reared at constant temperatures had delayed developmental stage onset and median hatch, higher mortality at constant 8 °C, and lower mortality at ≤5 °C, compared with embryos reared under seasonal temperature regimes. Embryos incubated with ≥500 mg L^-1 morpholine (>200× regulatory limits) had advanced hatch, reduced body size, and increased prehatch (100% at 1000 mg L^-1 ) and posthatch (≈95% at 500 mg L^-1 ) mortality compared with controls. Relative to controls, embryos irradiated with ≥0.16 mGy/d had larger body mass early in development, and all irradiated embryos had decreased posthatch mortality; the lowest dose was >300× discharge limits. Our study suggests that fluctuating or elevated temperatures and high-dose morpholine can alter development rate, hatch dynamics, and growth, and/or increase mortality compared with embryos reared at constant temperatures of ≤5 °C; conversely, low-dose irradiation had transient developmental effects but may benefit early posthatch survival. Environ Toxicol Chem 2018;37:2593-2608. © 2018 SETAC.

UV-irradiated 2-methyl-4'-(methylthio)-2-morpholinopropiophenone-containing injection solution produced frameshift mutations in the Ames mutagenicity assay

In previous studies, we detected the photoinitiators 1-hydroxycyclohexyl phenyl ketone (1-HCHPK), methyl 2-benzoylbenzoate (MBB), and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMP) in intravenous injection solutions. In addition, we reported that 1-HCHPK, MBB, and MTMP exhibited cytotoxicity towards normal human peripheral blood mononuclear cells. A previous in vitro study reported that a free-radical photoinitiator introduced covalently bound purine residues into DNA. However, little is known about the in vitro mutagenicity of 1-HCHPK, MBB, and MTMP. In the present in vitro study, we evaluated the mutagenicity of 1-HCHPK, MBB, and MTMP using the Ames test. We found that untreated 1-HCHPK, MBB, and MTMP were not mutagenic in S. typhimurium strain TA97, TA98, TA100, TA102, or TA1535, regardless of the presence/absence of S9 activation. However, ultraviolet (UV) light-irradiated MTMP exhibited mutagenicity in S. typhimurium strain TA97 in the absence of S9 activation. In conclusion, we suggest that exposure to UV-irradiated MTMP, including in intravenous injection solutions, can result in frameshift mutations.

A Phase I Trial of the PI3K Inhibitor Buparlisib Combined With Capecitabine in Patients With Metastatic Breast Cancer

BACKGROUND

Buparlisib is an oral pan-class I phosphotidyinositol-3-kinase (PI3K) inhibitor. The present phase I study evaluated the safety, pharmacokinetics, and efficacy of buparlisib with capecitabine in patients with metastatic breast cancer.

PATIENTS AND METHODS

Patients received buparlisib once daily (range, 50 to 100 mg) for 3 weeks with capecitabine twice daily (range, 1000 to 1250 mg/m²) for 2 weeks with a 1-week break. Dose escalation used a traditional "3 + 3" design with standard definitions of dose-limiting toxicity (DLT) and maximum tolerated dose.

RESULTS

Of the 25 patients enrolled, 23 were evaluable for DLT and 17 were evaluable for response. The maximum tolerated dose of the combination was buparlisib 100 mg daily and capecitabine 1000 mg/m² twice daily. DLTs included grade 3 hyperglycemia and grade 3 confusion. The most common grade 3 toxicities were diarrhea and elevation of aspartate aminotransferase and alanine transaminase. One patient exhibited a complete response to treatment and four had a confirmed partial response. In cohorts 3 and 4, in which the buparlisib dose remained constant but the capecitabine dose was increased, significant increases in the buparlisib plasma concentration were noted.

CONCLUSION

The combination of buparlisib with capecitabine in patients with metastatic breast cancer was generally well-tolerated, with several patients demonstrating prolonged responses. Unexpectedly low rates of PIK3CA mutations (3 of 17) were seen, and only 2 of 7 tumors with subtyping were luminal, making exploration of these putative predictive markers impossible. Further study of the combination is not unreasonable, with expanded pharmacokinetics and sequencing analysis to better elucidate potential drug-drug interactions and more accurate predictive biomarkers of response.

Pharmacological and Toxicological Screening of Novel Benzimidazole-Morpholine Derivatives as Dual-Acting Inhibitors

The aim of this study was to investigate acetylcholinesterase (AChE), monoamine oxidase A (MAO-A), monoamine oxidase B (MAO-B), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzyme inhibitory, and antimicrobial activities of a new series of 2-(4-substituted phenyl)-1-[2-(morpholin-4-yl)ethyl]-1H-benzimidazole derivatives, for their possible use as multi-action therapeutic agents. Target compounds (n = 15) were synthesized under microwave irradiation conditions in two steps, and their structures were elucidated by FT-IR, ¹H-NMR, ¹³C-NMR and high resolution mass spectroscopic analyses. Pharmacological screening studies revealed that two of the compounds (2b and 2j) have inhibitory potential on both COX-1 and COX-2 enzymes. In addition, cytotoxic and genotoxic properties of the compounds 2b, 2j and 2m were investigated via the well-known MTT and Ames tests, which revealed that the mentioned compounds are non-cytotoxic and non-genotoxic. As a concise conclusion, two novel compounds were characterized as potential candidates for treatment of frequently encountered inflammatory diseases.

Developmental effects of the industrial cooling water additives morpholine and sodium hypochlorite on lake whitefish (Coregonus clupeaformis)

Chemicals used in the prevention of corrosion and biofouling may be released into the environment via industrial cooling water discharges. The authors assessed the impacts of 2 commonly used chemicals, morpholine and sodium hypochlorite, on development in lake whitefish (Coregonus clupeaformis). Embryos were exposed chronically, beginning at fertilization or at the eyed stage. Acute 96-h exposures were also examined at 4 development stages. Chronic morpholine resulted in median lethal concentrations (LC50s) of 219 ± 54 mg/L when exposure began at fertilization and 674 ± 12 mg/L when exposure began at the eyed stage, suggesting that embryos are more sensitive earlier in development. Chronic morpholine exposure advanced hatching by up to 30%, and the early hatching embryos were up to 10% smaller in body length. A decrease in yolk conversion efficiency was also observed in embryos exposed to chronic morpholine concentrations of 1000 mg/L. The majority of effects from morpholine exposure manifested near hatch, possibly reflecting changes in chorion permeability at the end of embryonic development. Sodium hypochlorite only impacted survival with chronic exposure from fertilization, where the total residual chlorine LC50 was 0.52 ± 0.11 mg/L. Acute exposures to both chemicals had minimal effects up to the highest tested concentrations. Overall, the results suggest that the risk during development from exposure to morpholine and sodium hypochlorite is low under normal operating conditions. Environ Toxicol Chem 2017;36:1955-1965. © 2016 SETAC.

Toxicological effects of dimethomorph on soil enzymatic activity and soil earthworm (Eisenia fetida)

The objective of this study was to evaluate the toxicity of the fungicide dimethomorph to soil microbial activity and the earthworm Eisenia fetida. Multiple biomarkers, namely, four soil enzymes (urease, dehydrogenase, invertase, and acid phosphatase), four earthworm biochemical indices (dismutase, catalase, cellulase, and malondialdehyde), and the transcriptional levels of both target genes (dismutase and catalase) were measured at 1, 10, and 100 mg kg^-1 after 1, 7, 21, and 28 days. The degradation rate of dimethomorph in soil was also determined, and the results indicated that most parameters did not differ from the controls at 1 and 10 mg kg^-1 dimethomorph by the last exposure time (28 d). However, high concentrations (100 mg kg^-1) of dimethomorph had varying effects on soil enzymatic activity and earthworms. These effects gradually decreased with prolonged exposure times. Positive correlations (R² > 0.57) between the target gene expression levels and antioxidant enzyme activities were observed in this study. We also found that earthworms have improved soil microbial activity and accelerated the degradation of dimethomorph. Overall, higher concentrations of dimethomorph might pose an ecological hazard to soil environments in the short term.

Evaluation of cytotoxic and genotoxic activity of fungicide formulation Tango® Super in bovine lymphocytes

Tango^® Super is a two-compound fungicide formulation widely employed in grain protection. However, details of Tango^® Super effects on cell cultures have not been fully investigated. In this study, bovine lymphocytes were exposed to a concentration range 0.5; 1.5; 3; 6; and 15 μg mL^-1 for 4 h to assess the cytotoxicity and genotoxicity of the fungicide. Our experiments revealed that this fungicide treatment reduced cell viability, decreased cell proliferation and provoked apoptotic cell death. Cell cycle analysis showed predominant accumulation of cells in the G₀/G₁ phase of the cell cycle. The fungicide was able to induce mitochondrial superoxide production accompanied by elevated levels of carbonylated proteins and changes in the lipid membrane composition. The fungicide did not induce micronuclei production, but stimulated both DNA double-strand breaks and the formation of p53 binding protein, which is accumulated during the DNA repair process at the site of double-strand breaks. Based on the obtained data we suppose that the fungicide-induced DNA damage is the result of oxidative stress, which may contribute to higher occurrence of apoptotic cell death. Because ergosterol biosynthesis-inhibiting fungicides are widely used in agriculture to ensure higher crop yields and may cause health impairment of animals and humans, there is a need for further testing to elucidate their potential genotoxic effects using in vivo and/or in vitro systems.

Evaluation of potential genotoxic/cytotoxic effects induced by epoxiconazole and fenpropimorph-based fungicide in bovine lymphocytes in vitro

Potential genotoxic/cytotoxic effects of the epoxiconazole/fenpropimorph-based fungicide were investigated using single cell gel electrophoresis and cytogenetic assays: chromosomal aberrations, sister chromatid exchanges, micronuclei and fluorescence in situ hybridization in cultured bovine lymphocytes. No statistically significant elevations of DNA damage and increases in cytogenetic endpoints were seen. However, evident cytotoxic effect presented as a decrease in mitotic and proliferation indices were recorded after exposure of bovine lymphocytes to the fungicide for 24 and 48 h at concentrations ranging from 3 to 15 µg mL(-1) (P < 0.05, P < 0.01, P < 0.001). Similarly, for 24 h an inhibition in the cytokinesis block proliferation index (CBPI) was obtained after exposure to the fungicide at concentrations ranging from 1.5 to 15 µg mL(-1) (P < 0.01, P < 0.001) in each donor.

NU7441 Enhances the Radiosensitivity of Liver Cancer Cells

OBJECTIVE

Radiation therapy, one of the major treatments for liver cancer, causes DNA damage and cell death. Since the liver cancer cells have a strong capacity to repair irradiative injury, new medicines to enhance this treatment are urgently required. In this study, we investigated the effect of NU7441, a synthetic small-molecule compound, as a specific inhibitor of DNA-dependent protein kinase (DNA-PK) in radiosensitization of hepatocellular carcinoma HepG2 cells.

METHODS

Cell Counting Kit-8 (CCK-8) was first used to evaluate the proliferation of HepG2 cells under NU7441 treatment. SDS-PAGE and Western blot were then performed to study the protein expression leading to the DNA damage repair. Further, neutral single cell gel electrophoresis and immunofluorescence assay were carried out to assess DNA repair. Finally, flow cytometry was implemented to examine the changes in cell cycle.

RESULTS

NU7441 reduced the CCK-8 counts in the HepG2 culture, further enhanced 60Cox03B3; radiation injury to HepG2 cells, which was manifested by decreasing the DNA-PKcs (S2056) protein expression, increasing x03B3;H2AX foci number, prolonging the tail moment of the comet cells, and inducing cell cycle arrest at G2/M phase.

CONCLUSION

NU7441 inhibited the growth of liver cancer cells, enhanced the radiosensitization of these cancer cells by interfering with the DNA repair and cell cycle checkpoint. These data implicate NU7441 as a potential radiotherapy sensitizer for the treatment of liver cancer.

The Use of Styrene Maleic Acid Nanomicelles Encapsulating the Synthetic Cannabinoid Analog WIN55,212-2 for the Treatment of Cancer

Synthetic cannabinoid WIN55,212-2 (WIN) has shown a promise as an anticancer agent but causes psychoactive side-effects. In the present study, nano-micelles of styrene maleic acid (SMA)-conjugated WIN were synthesized to reduce side-effects and increase drug efficacy. SMA-WIN micelles were characterised and their in vitro cytotoxic effect was compared to that of free WIN against triple-negative breast cancer (MDA-MB-231), hormone receptor-positive breast cancer (MCF-7) and castration-resistant prostate cancer (PC3) cell lines. SMA-WIN micelles were synthesised with a ~15% loading, 132.7 nm average diameter, -0.0388 mV charge, and pH-dependent release rate. A dose-dependent inhibition of cell growth was observed in all three cell lines treated with both free and micellar WIN, with both formulations demonstrating equal cytotoxicity.

CONCLUSION

SMA-WIN demonstrated characteristics theorized to improve in vivo drug biodistribution. Potent cytotoxicity was found against breast and prostate cancer cells in vitro, showing promise as a novel treatment against breast and prostate cancer.

Effects on MC3T3-E1 Cells and In silico Toxicological Study of Two 6-(Propan-2-yl)-4-methyl-morpholine-2,5-diones

Recently, we found that two cyclodidepsipeptides, 3,6-di-(propan-2-yl)-4-methyl-morpholine-2,5-dione (1) and 3-(2-methylpropyl)-6-(propan-2-yl)-4-methyl- morpholine-2,5-dione (2), are excellent inhibitors of xanthine oxidase. In order to obtain more information about the toxicological potential of compounds 1 and 2 on bone cells, the current study was designed to evaluate the effect of these compounds on viability and proliferation of MC3T3-E1 cells. Compound 1 showed neither cytotoxic nor stimulatory effect on cell viability, while compound 2 showed a slight stimulatory effect on cell viability. Both studied compounds showed slight stimulatory effects on proliferation of MC3T3-E1 cells, in a dose dependent manner. Additionally, an in silico toxicological study of compounds 1 and 2 was performed, and the results indicate that they have a good probability of safe biological intake.

Monitoring the anticoagulant effect after a massive rivaroxaban overdose

Rivaroxaban is a direct factor Xa inhibitor approved for prevention of stroke, prevention and treatment of venous thromboembolism and secondary prevention of acute coronary syndrome in many countries. As the use of this agent increases, so does the potential for overdose, both intentional and unintentional. Clinical data on overdoses of rivaroxaban in humans are limited. We report the case of a 42-year-old man who took an overdose of 1400 mg of rivaroxaban and describe how resolution of the anticoagulant effect was monitored using readily available coagulation assays.

DNA and aptamer stabilized gold nanoparticles for targeted delivery of anticancer therapeutics

Gold nanoparticles (GNPs) can be used as carriers of a variety of therapeutics. Ideally, drugs are released in the target cells in response to cell specific intracellular triggers. In this study, GNPs are loaded with doxorubicin or AZD8055, using a self-immolative linker which facilitates the release of anticancer therapeutics in malignant cells without modifications of the active compound. An additional modification with the aptamer AS1411 further increases the selectivity of GNPs towards cancer cells. Both modifications increase targeted delivery of therapeutics with GNPs. Whereas GNPs without anticancer drugs do not affect cell viability in all cells tested, AS1411 modified GNPs loaded with doxorubicin or AZD8055 show significant and increased reduction of cell viability in breast cancer and uveal melanoma cell lines. These results highlight that modified GNPs can be functionalized to increase the efficacy of cancer therapeutics and may further reduce toxicity by increasing targeted delivery towards malignant cells.

Adolescent cannabinoid exposure permanently suppresses cortical oscillations in adult mice

Regular marijuana use during adolescence, but not adulthood, may permanently impair cognition and increase the risk for psychiatric diseases, such as schizophrenia. Cortical oscillations are integral for cognitive processes and are abnormal in patients with schizophrenia. We test the hypothesis that adolescence is a sensitive period because of the active development of cortical oscillations and neuromodulatory systems that underlie them. The endocannabinoid system upon which marijuana acts is one such system. Here we test the prediction that adolescent cannabinoid exposure alters cortical oscillations in adults. Using in vitro local field potential, in vivo electrocorticogram recordings and cognitive behavioral testing in adult mice, we demonstrate that chronic adolescent, but not adult, cannabinoid exposure suppresses pharmacologically evoked cortical oscillations and impairs working memory performance in adults. The later-maturing prefrontal cortex is more sensitive to adolescent exposure than the earlier-maturing, primary somatosensory cortex. These data establish a link between chronic adolescent cannabinoid exposure and alterations in adult cortical network activity that underlie cognitive processes.

Simultaneous effects of two fungicides (copper and dimethomorph) on their phytoremediation using Lemna minor

Effects of two fungicides, copper and dimethomorph ((E,Z)4-[3-(4-chlorophenyl)-3-(3-4dimethoxyphenyl) acryloyl] morpholine) on Lemna minor growth and phytoremediation were evaluated. The toxicity of copper and dimethomorph alone and in combination, was assessed by growth inhibition of L. minor cultures after 96 and 168 h. Copper had a severe impact on growth (max. inhibition: 90 % at 1,000 μg L(-1)) while dimethomorph (as pure ingredient or formulated as Forum) did not (inhibition <45 % at 1,000 μg L(-1)) after 168 h of treatment. When both chemicals were combined, synergism was observed after 96 h of exposure to copper and Forum. However, this interaction was a simple additivity after 168 h. Additivity was also observed when the pure active ingredient (dimethomorph) replaced Forum in the mixture of copper and dimethomorph at 96 and 168 h. L. minor showed an excellent performance in removing copper from the medium since after 96 h, 36, 60, and 76 % removal were reached for 10, 20, and 30 μg L(-1) of Cu respectively. Copper accumulated in the plants. The removal of copper increased with Forum concentration. After 96 h copper (10 μg L(-1) initial concentration) elimination increased from 36.39 ± 5.86-60.70 ± 6.06 % when Forum concentration increased from 0 to 500 μg L(-1). Accumulation of copper in plants was also increased by Forum but not by the active ingredient alone. Depuration of Forum by L. minor varied between 10 and 40 % after 96 h and it was generally more efficient than that of the pure ingredient. This depuration decreased in the presence of copper possibly due to the metal toxicity.

Tumor selective cytotoxic action of a thiomorpholin hydroxamate inhibitor (TMI-1) in breast cancer

Background

Targeted therapies, associated with standard chemotherapies, have improved breast cancer care. However, primary and acquired resistances are frequently observed and the development of new concepts is needed. High-throughput approaches to identify new active and safe molecules with or without an “a priori” are currently developed. Also, repositioning already-approved drugs in cancer therapy is of growing interest. The thiomorpholine hydroxamate compound TMI-1 has been previously designed to inhibit metalloproteinase activity for the treatment of rheumatoid arthritis. We present here the repositioning of TMI-1 drug in breast cancer.

Methodology/Principal Findings

We tested the effect of TMI-1 on luminal, basal and ERBB2-overexpressing breast tumor cell lines and on MMTV-ERBB2/neu tumor evolution. We measured the effects on i) cell survival, ii) cell cycle, iii) extrinsic and intrinsic apoptotic pathways, iv) association with doxorubicin, docetaxel and lapatinib, v) cancer stem cells compartment. In contrast with conventional cytotoxic drugs, TMI-1 was highly selective for tumor cells and cancer stem cells at submicromolar range. All non-malignant cells tested were resistant even at high concentration. TMI-1 was active on triple negative (TN) and ERBB2-overexpressing breast tumor cell lines, and was also highly efficient on human and murine “primary” ERBB2-overexpressing cells. Treatment of transgenic MMTV-ERBB2/neu mice with 100 mg/kg/day TMI-1 alone induced tumor apoptosis, inhibiting mammary gland tumor occurrence and development. No adverse effects were noticed during the treatment. This compound had a strong synergistic effect in association with docetaxel, doxorubicin and lapatinib. We showed that TMI-1 mediates its selective effects by caspase-dependent apoptosis. TMI-1 was efficient in 34/40 tumor cell lines of various origins (ED50: 0.6 µM to 12.5 µM).

Conclusions/Significance

This is the first demonstration of the tumor selective cytotoxic action of a thiomorpholin hydroxamate compound. TMI-1 is a novel repositionable drug not only for the treatment of adverse prognosis breast cancers but also for other neoplasms.

Toxicity of metalaxyl, azoxystrobin, dimethomorph, cymoxanil, zoxamide and mancozeb to Phytophthora infestans isolates from Serbia

A study of the in vitro sensitivity of 12 isolates of Phytophthora infestans to metalaxyl, azoxystrobin, dimethomorph, cymoxanil, zoxamide and mancozeb, was conducted. The isolates derived from infected potato leaves collected at eight different localities in Serbia during 2005-2007. The widest range of EC(50) values for mycelial growth of the isolates was recorded for metalaxyl. They varied from 0.3 to 3.9 μg mL(-1) and were higher than those expected in a susceptible population of P. infestans. The EC(50) values of the isolates were 0.16-0.30 μg mL(-1) for dimethomorph, 0.27-0.57 μg mL(-1) for cymoxanil, 0.0026-0.0049 μg mL(-1) for zoxamide and 2.9-5.0 μg mL(-1) for mancozeb. The results indicated that according to effective concentration (EC(50)) the 12 isolates of P. infestans were sensitive to azoxystrobin (0.019-0.074 μg mL(-1)), and intermediate resistant to metalaxyl, dimethomorph and cymoxanil. According to resistance factor, all P. infestans isolates were sensitive to dimethomorph, cymoxanil, mancozeb and zoxamide, 58.3% of isolates were sensitive to azoxystrobin and 50% to metalaxyl. Gout's scale indicated that 41.7% isolates were moderately sensitive to azoxystrobin and 50% to metalaxyl.

Acute toxicity and bioconcentration of pyrimorph in zebrafish, Brachydanio rerio

BACKGROUND

Pyrimorph is a novel fungicide being developed in China that shows high antifungal activity against diseases caused by Phytophthora infestans, Phytophthora capsici, Rhizoctonia solani, Peronophythora litchi and Pseudoperonospora cubensis. Until now, no information on the toxicity of pyrimorph to untargeted organisms has been reported. To assess the potential environmental impacts of pyrimorph in fish, the acute toxicity and bioconcentration of pyrimorph in zebrafish were studied in this paper.

RESULTS

When tested by the semi-static method, the 48, 72 and 96 h median lethal concentration (LC50 ) values of pyrimorph to zebrafish were 24.33, 22.61 and 19.79 mg L(-1) respectively. To study the bioconcentration of pyrimorph in zebrafish, the fish were exposed to sublethal concentrations of pyrimorph (2.00 and 0.25 mg L(-1) ) for 192 h, a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method was applied to extract pyrimorph from samples and the residues of pyrimorph in the water and fish were determined by high-performance liquid chromatography (HPLC). The highest bioconcentration factor (BCF) of pyrimorph in the fish was 1.07 × 10(2) (144 h) and 23.1 (96 h) after exposure to 2.00 and 0.25 mg L(-1) of pyrimorph respectively.

CONCLUSIONS

The novel fungicide pyrimorph has low toxicity to zebrafish; however, it showed medium BCF to zebrafish. Therefore, more attention should be paid to the residue of pyrimorph in fish, as well as to its long-term ecological effects.

Acute toxicity and biodegradability of N-alkyl-N-methylmorpholinium and N-alkyl-DABCO based ionic liquids

N-alkyl-N-methylmorpholinium and N-alkyl substituted 1,4-diazabicyclo[2.2.2]octane (DABCO) based ionic liquids (ILs), N-alkyl-DABCO, bearing short alkyl chains are characterised by a low toxicity to Vibrio fischeri, although toxicity significantly increases on increasing the alkyl chain length. Alkyl chain length affects also biodegradability in the 28 days tests; the higher level of biodegradation was found in both the series in the case of the ethyl (C2) derivatives. In the case of N-ethyl DABCO based IL, although biodegradability is still around 40%, and consequently this IL cannot be classified as "readily biodegradable", this value is similar to the more biodegradable functionalized imidazolium based ILs.

Synthetic cannabinoid WIN 55,212-2 mesylate enhances the protective action of four classical antiepileptic drugs against maximal electroshock-induced seizures in mice

The aim of this study was to determine the effect of WIN 55,212-2 mesylate (WIN--a non-selective cannabinoid CB1 and CB2 receptor agonist) on the protective action of four classical antiepileptic drugs (carbamazepine, phenytoin, phenobarbital, and valproate) in the mouse maximal electroshock seizure (MES) model. The results indicate that WIN (10 mg/kg, i.p.) significantly enhanced the anticonvulsant action of carbamazepine, phenytoin, phenobarbital and valproate in the MES test in mice. WIN (5 mg/kg) potentiated the anticonvulsant action of carbamazepine and valproate, but not that of phenytoin or phenobarbital in the MES test in mice. However, WIN administered alone and in combination with carbamazepine, phenytoin, phenobarbital and valproate significantly reduced muscular strength in mice in the grip-strength test. In the passive avoidance task, WIN in combination with phenobarbital, phenytoin and valproate significantly impaired long-term memory in mice. In the chimney test, only the combinations of WIN with phenobarbital and valproate significantly impaired motor coordination in mice. In conclusion, WIN enhanced the anticonvulsant action of carbamazepine, phenytoin, phenobarbital and valproate in the MES test. However, the utmost caution is advised when combining WIN with classical antiepileptic drugs due to impairment of motor coordination and long-term memory and/or reduction of skeletal muscular strength that might appear during combined treatment.

Contribution of limbic norepinephrine to cannabinoid-induced aversion

RATIONALE

The cannabinoid system has risen to the forefront in the development of novel treatments for a number of pathophysiological processes. However, significant side effects have been observed in clinical trials raising concerns regarding the potential clinical utility of cannabinoid-based agents. Understanding the neural circuits and neurochemical substrates impacted by cannabinoids will provide a better means of gaging their actions within the central nervous system that may contribute to the expression of unwanted side effects.

OBJECTIVES

In the present study, we investigated whether norepinephrine (NE) in the limbic forebrain is a critical determinant of cannabinoid receptor agonist-induced aversion and anxiety in rats.

METHODS

An immunotoxin lesion approach was combined with behavioral analysis using a place conditioning paradigm and the elevated zero maze.

RESULTS

Our results show that the non-selective CB1/CB2 receptor agonist, WIN 55,212-2, produced a significant place aversion in rats. Further, NE in the nucleus accumbens was critical for WIN 55,212-2-induced aversion but did not affect anxiety-like behaviors. Depletion of NE from the bed nucleus of the stria terminalis was ineffective in altering WIN 55,212-2-induced aversion and anxiety.

CONCLUSIONS

These results indicate that limbic, specifically accumbal, NE is required for cannabinoid-induced aversion but is not essential to cannabinoid-induced anxiety.

Synthesis and characterization of N,N-dialkyl and N-alkyl-N-aralkyl fenpropimorph-derived compounds as high affinity ligands for sigma receptors

The sigma-1 receptor is a unique non-opioid, non-PCP binding site that has been implicated in many different pathophysiological conditions including psychosis, drug addiction, retinal degeneration and cancer. Based on the structure of fenpropimorph, a high affinity (K(i)=0.005 nM)(1) sigma-1 receptor ligand and strong inhibitor of the yeast sterol isomerase (ERG2), we previously deduced a basic sigma-1 receptor pharmacophore or chemical backbone composed of a phenyl ring attached to a di-substituted nitrogen atom via an alkyl chain.(2) Here, we report the design and synthesis of various N,N-dialkyl or N-alkyl-N-aralkyl derivatives based on this pharmacophore as well as their binding affinities to the sigma-1 receptor. We introduce three high affinity sigma-1 receptor compounds, N,N-dibutyl-3-(4-fluorophenyl)propylamine (9), N,N-dibutyl-3-(4-nitrophenyl)propylamine (3), and N-propyl-N'-4-aminophenylethyl-3-(4-nitrophenyl)propylamine (20) with K(i) values of 17.7 nM, 0.36 nM, and 6 nM, respectively. In addition to sigma receptor affinity, we show through cytotoxicity assays that growth inhibition of various tumor cell lines occurs with our high affinity N,N-dialkyl or N-alkyl-N-aralkyl derivatives.

Pesticide cocktails can interact synergistically on aquatic crustaceans

BACKGROUND, AIM AND SCOPE

The ergosterol biosynthesis-inhibiting (EBI) fungicide prochloraz can enhance the effect of other pesticides in a range of animal species. Approximately 50% of the fungicides used in Denmark are EBI fungicides. Hence, if they all have synergising potential, a risk assessment of pesticide mixtures based on additivity might not suffice. This study investigates the synergising potential of six different EBI fungicides representing the imidazoles (prochloraz), the triazoles (epoxiconazole, propiconazole and tebuconazole), the piperidines (fenpropidin) and the morpholines (fenpropimorph) together with the pyrethroid insecticide alpha-cypermethrin.

MATERIALS AND METHODS

Tests were made on the aquatic crustacean Daphnia magna. Mixtures of each of the fungicides were tested together with the insecticide both at a 50:50% effect mixture ratio and, subsequently, in a ray design including five mixture ratios. The results were tested against the concentration addition reference model using dose-response surface analyses.

RESULTS

The results of the binary dose-response surface studies showed that mixtures with prochloraz increased toxicity up to 12-fold compared with what was expected using the reference model concentration addition (CA). Epoxiconazole and propiconazole enhanced toxicity up to six and sevenfold, respectively. Fenpropimorph showed antagonism, whilst mixtures with tebuconazole and fenpropidin did not deviate statistically from CA.

CONCLUSIONS

Hence, it can be concluded that both imidazoles and some, but not all, triazoles can enhance the effect of a pyrethroid insecticide towards D. magna substantially. Epoxiconazole and propiconazole are often sprayed out together with pyrethroids in tank mixtures. The extent to which this might create unforeseen ecological problems is discussed.

Influence of initial pesticide concentrations and plant population density on dimethomorph toxicity and removal by two duckweed species

Aquatic plants take up, transform and sequester organic contaminants and may therefore be used in phytoremediation for the removal of pollutants from wastewaters. A better understanding of factors affecting the rate of contaminant uptake by aquatic plants is needed to improve engineered systems for removal of pollutants from wastewaters. This work focused on the influence of initial concentrations of pesticide and population density of plants on toxicity and uptake of the fungicide dimethomorph by two duckweed species. An increased sensitivity to dimethomorph was observed with increasing duckweed population density. Less light, due to crowding, may explain this higher sensitivity and reduced removal rate. A positive relationship was also found between toxicity or contaminant uptake and initial pesticide concentration with a maximal removal of 41 and 26 microg g(-1) fresh weight of dimethomorph (at 600 microg L(-1) of dimethomorph and an initial density of 0.10g E-flask(-1)) by Lemna minor and Spirodela polyrhiza, respectively. This research also indicated that these aquatic plants can efficiently eliminate organic contaminants and may ultimately serve as phytoremediation agents in the natural environment.

Arbuscular mycorrhiza partially protect chicory roots against oxidative stress induced by two fungicides, fenpropimorph and fenhexamid

The present work examined the oxidative stress induced by different concentrations (0.02 and 0.2 mg l-1) of two sterol biosynthesis inhibitor fungicides (fenpropimorph and fenhexamid) in non-target chicory root colonised or not by Glomus intraradices in a monoxenic system. The fungicides were found to cause oxidative damage by increasing lipid peroxidation measured by malondialdehyde production in non-colonised roots. Detoxification of the H(2)O(2) product was measured at 0.2 mg l-1 of fenpropimorph by an increase in peroxidase activities suggesting an antioxidant capacity in these roots. Moreover, this study pointed out the ability of arbuscular mycorrhiza to alleviate partially the oxidative stress in chicory roots, probably by lowering reactive oxygen species concentrations, resulting from increases in antioxidant defences. Our results suggest that the enhanced fungicide tolerance in the AM symbiosis could be related to less cell membrane damage.

Fungicides and herbicide removal in Scenedesmus cell suspensions

Remediation capacities of two freshwater microalgae, Scenedesmus obliquus and Scenedesmus quadricauda, were assessed for the removal of two fungicides (dimethomorph and pyrimethanil) and one herbicide (isoproturon) from their medium. To ensure these studies were performed with healthy algae, pesticide effects where first apprehended on chlorophyll a fluorescence emission and growth rate. After a 4d-exposure to 600 microg L(-1) of dimethomorph or pyrimethanil, or to 10 microg L(-1) of isoproturon, algal growth rate and some of their photosynthetic processes were weakly affected (< 30% variation). The pesticide removal percentage of Scenedesmus cells reached a maximum of 10%, 24% and 58% for pyrimethanil, dimethomorph and isoproturon, respectively. In parallel, the maximum removal rate was 36 and 40 microg x 10(-9) cells for dimethomorph, 17 and 26 microg x 10(-9) cells for pyrimethanil, 2 and 2 microg x 10(-9) cells for isoproturon, in the presence of Sc. obliquus and Sc. quadricauda, respectively. Results showed that Sc. quadricauda was more effective in the removal of dimethomorph and pyrimethanil compared to Sc. obliquus.

Targeted inhibition of the serotonin 5HT2A receptor improves coronary patency in an in vivo model of recurrent thrombosis

BACKGROUND

Release of serotonin and activation of serotonin 5HT2A receptors on platelet surfaces is a potent augmentative stimulus for platelet aggregation. However, earlier-generation serotonin receptor antagonists were not successfully exploited as antiplatelet agents, possibly owing to their lack of specificity for the 5HT2A receptor subtype.

OBJECTIVE

To assess whether targeted inhibition of the serotonin 5HT2A receptor attenuates recurrent thrombosis and improves coronary patency in an in vivo canine model mimicking unstable angina.

METHODS

In protocol 1, anesthetized dogs were pretreated with a novel, selective inverse agonist of the 5HT2A receptor (APD791) or saline. Recurrent coronary thrombosis was then initiated by coronary artery injury+stenosis, and coronary patency was monitored for 3 h. Protocol 2 was similar, except that: (i) treatment with APD791 or saline was begun 1 h after the onset of recurrent thrombosis; (ii) template bleeding time was measured; and (iii) blood samples were obtained for in vitro flow cytometric assessment of platelet responsiveness to serotonin.

RESULTS

APD791 attenuated recurrent thrombosis, irrespective of the time of treatment: in both protocols, flow-time area (index of coronary patency; normalized to baseline coronary flow) averaged 58-59% (P<0.01) following administration of APD791 vs. 21-28% in saline controls. Moreover, the in vivo antithrombotic effect of APD791 was not accompanied by increased bleeding, but was associated with significant and selective inhibition of serotonin-mediated platelet activation.

CONCLUSION

5HT2A receptor inhibition with APD791, even when initiated after the onset of recurrent thrombosis, improves coronary patency in the in vivo canine model.

Phytoremediation of fungicides by aquatic macrophytes: toxicity and removal rate

The rate of removal of two fungicides (dimethomorph and pyrimethanil) from water by five macrophyte species (L. minor, S. polyrhiza, C. aquatica, C. palustris and E. canadensis) was assessed in laboratory tests. In order to assure that these studies were performed with healthy plants the effects of the fungicides on chlorophyll fluorescence were studied as well. At exposure concentrations of 600microgL(-1) the effects of the fungicides on chlorophyll fluorescence were minor, so that this initial concentration level was selected for the fungicide removal rate tests. The removal yields during the 4-d test periods varied from 10% to 18% and 7% to 12% for dimethomorph and pyrimethanil, respectively. The maximum removal rate during the 4-d test period was 48microgg(-1) fresh weight (FW) for dimethomorph and 33microgg(-1) FW for pyrimethanil. L. minor and S. polyrhiza showed the highest removal efficiency for the two fungicides.

Toxicity of copper/dimethomorph combination for Lemna minor and depuration of the fungicides by aquatic plant

Runoff-water of Champagne vineyards is often collected in decantation ponds where pesticides may be eliminated before the water is transferred to rivers. In order to accelerate this process, Lemna minor was tested for its phytoremediation capacity. In the ponds several pesticides coexist. Therefore, the cross-influence of copper and dimethomorph, two pesticides frequently used on grape to control fungal diseases, was studied on toxicity and their removal by L. minor. The toxicity of copper and dimethomorph alone and in combination, was assessed by growth inhibition of L. minor cultures after 96 h and 168 h. Copper had a severe impact on growth (maximum inhibition: 90% at 1000 microg/L) while dimethomorph (as pure ingredient DMM(P) or formulated as Forum DMM(F)) did not (inhibition < 45% at 1000 microg/L) after 168 h of treatment. When both chemicals were combined, a synergistic effect was detected after 96 h of exposure to copper and DMM(F). However, this interaction tended towards additivity after 168 h. Additivity was also observed when DMM(P) replaced DMM(F) in the mixture of copper and dimethomorph at 96h00 and 168h00. The removal of copper depended on DMM(F) concentration. For example, with 250 microg/L of dimethomorph as Forum, removal of copper increased from 36 to 41%. Depuration of DMM(F) by L. minor varied between 10 and 40% after 96 h. This depuration decreased in the presence of copper possibly due to the metal toxicity.

Assessing the risk of resistance in Pseudoperonospora cubensis to the fungicide flumorph in vitro

BACKGROUND

The oomycete fungicide flumorph is a recently introduced carboxylic acid amide (CAA) fungicide. In order to evaluate the risk of developing field resistance to flumorph, the authors compared it with dimethomorph and azoxystrobin with respect to the ease of obtaining resistant isolates to these fungicides, the level of resistance and their fitness in the laboratory.

RESULTS

Mutants with a high level of resistance to azoxystrobin were isolated readily by adaptation and UV irradiation, and their fitness was as good as that of the parent isolates. Attempts to generate mutants of Pseudoperonospora cubensis (Burk. & MA Curtis) Rostovsev resistant to flumorph and dimethomorph by sporangia adaptation on fungicide-treated leaves were unsuccessful. However, moderately resistant mutants were isolated using UV mutagenesis, but their resistance level [maximum resistance factor (MRF) < 100] was much lower than that of the azoxystrobin-resistant mutant (MRF = 733). With the exception of stability of resistance, all mutants showed low pathogenicity and sporulation compared with wild-type isolates and azoxystrobin-resistant mutants. There is cross-resistance between flumorph and dimethomorph, suggesting that they have the same resistance mechanism.

CONCLUSION

The above results suggest that the resistance risk of flumorph may be similar to that of dimethomorph but lower than that of azoxystrobin and can be classified as moderate. Thus, it can be managed by appropriate product use strategies.

Survival in the presence of antifungals: genome-wide expression profiling of Aspergillus niger in response to sublethal concentrations of caspofungin and fenpropimorph

How yeast cells respond to cell wall stress is relatively well understood; however, how filamentous fungi cope with cell wall damage is largely unexplored. Here we report the first transcriptome analysis of Aspergillus niger exposed to the antifungal compounds caspofungin, an inhibitor of beta-1,3-glucan synthesis, and fenpropimorph, which inhibits ergosterol synthesis. The presence of sublethal drug concentrations allowed A. niger to adapt to the stress conditions and to continue growth by the establishment of new polarity axes and formation of new germ tubes. By comparing the expression profile between caspofungin-exposed and nonexposed A. niger germlings, we identified a total of 172 responsive genes out of 14,509 open reading frames present on the Affymetrix microarray chips. Among 165 up-regulated genes, mainly genes predicted to function in (i) cell wall assembly and remodeling, (ii) cytoskeletal organization, (iii) signaling, and (iv) oxidative stress response were affected. Fenpropimorph modulated expression of 43 genes, of which 41 showed enhanced expression. Here, genes predicted to function in (i) membrane reconstruction, (ii) lipid signaling, (iii) cell wall remodeling, and (iv) oxidative stress response were identified. Northern analyses of selected genes were used to confirm the microarray analyses. The results further show that expression of the agsA gene encoding an alpha-1,3-glucan synthase is up-regulated by both compounds. Using two PagsA-GFP reporter strains of A. niger and subjecting them to 16 different antifungal compounds, including caspofungin and fenpropimorph, we could show that agsA is specifically activated by compounds interfering directly or indirectly with cell wall biosynthesis.

Treatment of Proximal Deep-Vein Thrombosis With the Oral Direct Factor Xa Inhibitor Rivaroxaban (BAY 59-7939)

Background— An effective and safe oral anticoagulant that needs no monitoring for dose adjustment is urgently needed for the treatment of diseases that require long-term anticoagulation. Rivaroxaban (BAY 59-7939) is an oral direct factor Xa inhibitor currently under clinical development.

Methods and Results— This randomized, parallel-group phase II trial in patients with proximal deep-vein thrombosis explored the efficacy and safety of rivaroxaban 10, 20, or 30 mg BID or 40 mg once daily compared with enoxaparin 1 mg/kg BID followed by vitamin K antagonist. Each treatment was administered for 12 weeks. The primary efficacy end point was an improvement in thrombotic burden at day 21 (assessed by quantitative compression ultrasonography; ≥4-point improvement in thrombus score) without recurrent symptomatic venous thromboembolism or venous thromboembolism-related death. The primary safety end point was major bleeding during 12 weeks of treatment. Outcomes were adjudicated centrally without knowledge of treatment allocation. The primary efficacy end point was achieved in 53 (53.0%) of 100, 58 (59.2%) of 98, 62 (56.9%) of 109, and 49 (43.8%) of 112 patients receiving rivaroxaban 10, 20, or 30 mg BID or 40 mg once daily, respectively, compared with 50 (45.9%) of 109 patients treated with enoxaparin/vitamin K antagonist. There was no significant trend in the dose-response relationship between rivaroxaban BID and the primary efficacy end point ( P =0.67). Major bleeding was observed in 1.7%, 1.7%, 3.3%, and 1.7% of patients receiving rivaroxaban 10, 20, or 30 mg BID or 40 mg once daily, respectively. There were no major bleeding events with enoxaparin/vitamin K antagonist.

Conclusions— Results of this proof-of-concept and dose-finding study support phase III evaluation of the orally active direct factor Xa inhibitor rivaroxaban, because efficacy and safety were apparent in the treatment of proximal deep-vein thrombosis across a 3-fold range of fixed daily dosing.

Pharmacokinetics, biodistribution, stability and toxicity of a cell-penetrating peptide-morpholino oligomer conjugate

OBJECTIVE

Conjugation of arginine-rich cell-penetrating peptide (CPP) to phosphorodiamidate morpholino oligomers (PMO) has been shown to enhance cytosolic and nuclear delivery of PMO. However, the in vivo disposition of CPP-PMO is largely unknown. In this study, we investigated the pharmacokinetics, tissue distribution, stability, and safety profile of an anti-c-myc PMO conjugated to the CPP, (RXR)4 (X = 6-aminohexanoic acid) in rats.

METHODS

The PMO and CPP-PMO were administrated intravenously into rats. The concentrations of the PMO and the CPP-PMO in plasma and tissues were monitored by HPLC. The stability of the CPP portion of the CPP-PMO conjugate in rat plasma and tissue lysates was determined by mass spectrometry. The safety profile of the CPP-PMO was assessed by body weight changes, serum chemistry, and animal behavior.

RESULTS

CPP conjugation improved the kinetic behavior of PMO with a 2-fold increase in the estimated elimination half-life, a 4-fold increase in volume of distribution, and increased area under the plasma concentration vs time curve. Consistent with the improved pharmacokinetic profile, conjugation to CPP increased the uptake of PMO in all tissues except brain, varied between organ type with greater uptake enhancement occurring in liver, spleen, and lungs. The CPP-PMO conjugate had greater tissue retention than the corresponding PMO. Mass spectrometry data indicated no observable degradation of the PMO portion, while there was identifiable degradation of the CPP portion. Time-dependent CPP degradation was observed in plasma and tissue lysates, with the degradation in plasma being more rapid. The pattern of degraded products differed between the plasma and lysates. Safety evaluation data showed that the CPP-PMO was well-tolerated at the dose of 15 mg/kg with no apparent signs of toxicity. In contrast, at the dose of 150 mg/kg, adverse events such as lethargy, weight loss, and elevated BUN (p < 0.01) and serum creatinine (p < 0.001) levels were recorded. Supplementation with free L-arginine ad libitum showed improved clearance of serum creatinine (p < 0.05) and BUN (p < 0.01) at the toxicological dose, suggesting that the CPP caused toxicity in kidney.

CONCLUSION

This study demonstrates that conjugation of CPP to PMO enhances the PMO pharmacokinetic profile, tissue uptake, and subsequent retention. Therefore, when dosed at < or = 15 mg/kg, CPP is a promising transporter for enhancing PMO delivery in therapeutic settings.

Pharmacological and toxicological testing of the enantiomers of two chiral fomocaine alkylmorpholine derivatives in comparison to their in vitro interactions on drug metabolism in rats

Between the stereoisomers of amide-type local anaesthetics differences have been noticed with respect to pharmacokinetics and side effects, but not regarding local anaesthetic capacity. Therefore, only S-(-)-ropivacaine has been introduced into clinical practice and with bupivacaine both the racemate and the S-(-)-enantiomer (levobupivacaine) are available by now. Based on this background, the aim of the present study was to evaluate if there are also dissimilarities to be found both in the toxicity and in the effectiveness of the enantiomers of two newly synthesized chiral fomocaine alkylmorpholine derivatives, OW3 and OW13, with an additional C2-chain in 2- or an additional C3-chain in 3-position at the morpholine ring, respectively. For this purpose, in vitro the interaction capacity with cytochrome P450 (CYP)-mediated monooxygenase and oxidase functions was investigated using rat liver 9000 g supernatants or microsomes. In vivo LD50, paresis of the N. ischiadicus and surface and conduction anaesthesia (cornea, N. ischiadicus) were tested in rats. The enantiomers of both OW3 and OW13 caused a concentration dependent inhibition of all CYP-mediated model reactions investigated. With all model reactions the (-)-enantiomer of OW3 was less effective than the (+)-form, whereas the opposite was the case with OW13. Also toxicity was lower with the (-)-enantiomer of OW3 and with the (+)-form of OW13 than with the respective counterparts. With both derivatives no clear-cut dissimilarities were noticed in the local anaesthetic capacity of the enantiomers. None of the four compounds caused paresis. Thus, similar to amide-type local anaesthetics, also with the enantiomers of chiral fomocaine alkylmorpholine derivatives differences in pharmacokinetic properties and toxicity could be demonstrated.

Antimycobacterial Agents. Novel Diarylpyrrole Derivatives of BM212 Endowed with High Activity toward Mycobacterium tuberculosis and Low Cytotoxicity

On the basis of suggestions derived either from a pharmacophoric model for antitubercular agents or from a structure-activity relationship analysis of many pyrroles previously described by us, we report here the design and synthesis of new analogues of 1,5-(4-chlorophenyl)-2-methyl-3-(4-methylpiperazin-1-yl)methyl-1H-pyrrole (BM212). Various substituents with different substitution patterns were added to both positions 1 and 5 of the pyrrole nucleus to evaluate their influence on the activity toward Mycobacterium tuberculosis (MTB) and atypical mycobacteria. Biological data showed that, although some nontuberculosis mycobacterial strains were found to be sensitive, MIC values were higher than those found toward MTB. The best compound (1-(4-fluorophenyl)-2-methyl-3-(thiomorpholin-4-yl)methyl-5-(4-methylphenyl)-1H-pyrrole, 5) possessed a MIC of 0.4 microg/mL (better than BM212 and streptomycin) and a very high protection index (160), better than BM212, isoniazid, and streptomycin (6, 128, and 128, respectively). Finally, molecular modeling studies were performed to rationalize the activity of the new compounds in terms of both superposition onto a pharmacophoric model for antitubercular compounds and their hydrophobic character.

Use of the multispecies freshwater biomonitor to assess behavioral changes of Corophium volutator (Pallas, 1766) (Crustacea, Amphipoda) in response to toxicant exposure in sediment

Automated sediment toxicity testing and biomonitoring has grown rapidly. This study tested the suitability of the marine amphipod Corophium volutator (Pallas, 1766) for sediment biomonitoring using the Multispecies Freshwater Biomonitor (MFB). Two experiments were undertaken to (1) characterize individual behaviors of C. volutator using the MFB and (2) examine behavioral changes in response to sediment spiked with the pesticide Bioban. Four behaviors were visually identified (walking, swimming, grooming and falling) and characterized in the MFB as different patterns of locomotor activity (0-2 Hz range). Ventilation was not visually observed but was detected by the MFB (2-8 Hz). No clear diel activity patterns were detected. The MFB detected an overall increase in C. volutator locomotor activity after Bioban addition to the sediments (56, 100, 121 mg kg(-1)). C. volutator was more active (both locomotion and ventilation) in the water column than the spiked sediment. C. volutator appears a sensitive and appropriate species for behavioral sediment toxicity assessment and biomonitoring.

A nitric oxide synthase inhibitor (L-NAME) attenuates abstinence-induced withdrawal from both cocaine and a cannabinoid agonist (WIN 55212-2) in Planaria

We previously reported that planarians (Dugesia dorotocephala) that have been exposed to cocaine for 1 h undergo abstinence-induced withdrawal when placed into cocaine-free, but not cocaine-containing, water. We now report that planarians also display dose-related abstinence-induced withdrawal following exposure to the synthetic cannabinoid agonist WIN 55212-2, but not its inactive enantiomer (WIN 55212-3). The withdrawal from WIN 55212-2 was manifested as a significant (P < 0.05) decrease in the rate of planarian spontaneous locomotor activity over a 5-min observation period, using a recently designed metric (pLMV). We also report that withdrawal from cocaine (80 microM) or WIN 55212-2 (10 microM) was attenuated by the selective inhibitor of nitric oxide synthesis L-NAME (L-nitro-arginine methyl ester), which had no effect of its own on pLMV. These results suggest a common NO-dependent pathway of withdrawal from cocaine and WIN 55212-2 in Planaria.

In vitro interactions with the Cytochrome P450 system, toxicity, and local anaesthetic effects of Fomocaine Alkylmorpholine derivatives in rats

Fomocaine (CAS 56583-43-8) is a basic ether-type local anaesthetic used in dermatological practice for surface anaesthesia. For many years, modifications of the fomocaine molecule have been pursued, e.g. to improve its affinity to the sodium channel and also in view of possible new (systemic) applications. In the present study fomocaine and eight fomocaine derivatives with an additional alkyl chain in 2- or 3-position of different length (C1 up to C4), or with a branched C3 chain in 3-position, respectively, at the morpholine ring were evaluated in vitro for possible structure-activity relationships with respect to the interactions with cytochrome P450 (CYP) mediated monooxygenase and oxidase functions using rat liver 9000 g supernatants or microsomes. Results were compared to in vivo data from rats on toxicity (LD50), paresis of the N. ischiadicus and surface and conduction anaesthesia (cornea, N. ischiadicus). In general, the influence of the derivatives on the CYP system was less than that of fomocaine, showing a further decline with enlarging chain length. Toxicity of the derivatives was comparable to that of fomocaine and lower only with the compound with a C4 alkyl chain in 2-position. The derivatives caused a stronger surface anaesthesia than fomocaine, exhibiting an additional increase with enlarging chain length. No clear-cut structure-activity relationships were observed with respect to paresis of the N. ischiadicus and to conduction anaesthesia. Especially the derivatives having a C2 or C4 chain in 2- or a C3 chain in 3-position, respectively, may be of interest for further investigations. In comparison to fomocaine they caused a stronger surface anaesthesia combined with a lower interaction capacity with the CYP system.

A COMBINED APPROACH TO DRUG METABOLISM AND TOXICITY ASSESSMENT

The challenge of predicting the metabolism or toxicity of a drug in humans has been approached using in vivo animal models, in vitro systems, high throughput genomics and proteomics methods, and, more recently, computational approaches. Understanding the complexity of biological systems requires a broader perspective rather than focusing on just one method in isolation for prediction. Multiple methods may therefore be necessary and combined for a more accurate prediction. In the field of drug metabolism and toxicology, we have seen the growth, in recent years, of computational quantitative structure-activity relationships (QSARs), as well as empirical data from microarrays. In the current study we have further developed a novel computational approach, MetaDrug, that 1) predicts metabolites for molecules based on their chemical structure, 2) predicts the activity of the original compound and its metabolites with various absorption, distribution, metabolism, excretion, and toxicity models, 3) incorporates the predictions with human cell signaling and metabolic pathways and networks, and 4) integrates networks and metabolites, with relevant toxicogenomic or other high throughput data. We have demonstrated the utility of such an approach using recently published data from in vitro metabolism and microarray studies for aprepitant, 2(S)-((3,5-bis(trifluoromethyl)benzyl)-oxy)-3(S)phenyl-4-((3-oxo-1,2,4-triazol-5-yl)methyl)morpholine (L-742694), trovofloxacin, 4-hydroxytamoxifen, and artemisinin and other artemisinin analogs to show the predicted interactions with cytochromes P450, pregnane X receptor, and P-glycoprotein, and the metabolites and the networks of genes that are affected. As a comparison, we used a second computational approach, MetaCore, to generate statistically significant gene networks with the available expression data. These case studies demonstrate the combination of QSARs and systems biology methods.

Effects of anthracycline derivatives on human leukemia K562 cell growth and differentiation

New derivatives of daunorubicin (DRB), doxorubicin (DOX), and epidoxorubicin (EDOX) with an amidine group bonded to C-3' of daunosamine moiety with either morpholine or hexamethyleneimine ring attached to the amidine group are studied in this paper. We have shown that all of these newly synthesized anthracycline derivatives inhibit human leukemia K562 cell line proliferation but only some of them induce erythroid differentiation when used at subtoxic concentrations. Morpholine derivative of DOX has the greatest potential to inhibit proliferation and to induce differentiation in vitro. The correlation between these two cellular processes was also significant for other tested compounds. In cell cycle analysis, we have demonstrated that those anthracycline derivatives that exert the greatest cytostatic potential caused G(2)/M arrest, which in turn, might contribute to the development of a differentiating phenotype. The concentrations of the compounds used in the study are pharmacologically relevant. These new potent inducers of differentiation might be exploited as anticancer drugs for treatment of leukemia by differentiation therapy.

Effect of Some Biologically Interesting Substituted Tetrahydro-1,4- Oxazines on Drug Metabolising Enzymes and on Inflammation

The effect on hepatic drug metabolising enzymes was evaluated for three representative structures and that were selected from a series of substituted oxazine derivatives designed to possess particular pharmacological properties such as analgesic, antioxidant and hypolipidemic activity. In addition, since xenobiotic metabolism, reactive oxygen and nitrogen species, atherosclerosis and inflammation are interrelated and mutually affected, the effects of and on acute inflammation in vivo and lipoxygenase activity in vitro were also investigated. It was found that treatment of rats with caused induction of cytochrome P450, enhancement of the metabolism of aminopyrine in vitro and of zoxazolamine and hexobarbital in vivo. Compound appeared to induce particularly erythromycin N-demethylation, while, a nitric ester, reduced the catalytically active cytochrome P450, although it increased the metabolism of specific cytochrome P450 substrates, i.e. 4-nitrophenol and erythromycin. Compounds and with strong hypolipidemic and antioxidant properties, reduced acute inflammatory response in two inflammation models and inhibited lipoxygenase activity in vitro. These results are helpful in optimising the biological profile as well as the potential applications of substituted oxazines.

Tsc2 Expression Increases the Susceptibility of Renal Tumor Cells to Apoptosis

Although the precise role for the tuberous sclerosis complex-2 tumor suppressor gene (Tsc2) in tumor suppression is not clear, many studies have implicated Tsc2 in the regulation of cell differentiation, cell cycle control, GTPase activity, transcription, polycystin-1 localization, and translation initiation. We propose that Tsc2 also increases susceptibility to apoptosis, and that this functional role may contribute to the tumor suppressor activity of Tsc2. We previously characterized the apoptotic response of a Tsc2-null renal tumor cell line (ERC-18) to the tumor promoter okadaic acid (OKA). In the present study, we expressed Tsc2 in ERC-18 cells and compared the effect of Tsc2 expression on apoptotic induction. Tsc2 expression increased the susceptibility of ERC-18 cells to apoptosis induced by OKA and the phosphatidylinositol-3' kinase inhibitor, LY294002. In addition, Tsc2 expression abrogated OKA-induced cell detachment of ERC-18 cells. These results indicate that the OKA-induced, caspase-independent detachment previously observed in ERC-18 cells is Tsc2-dependent, and may support an additional role for the Tsc2 in regulating cell adhesion.

Common pesticide increases costs of antipredator defenses in Rana temporaria tadpoles

Pesticides represent an important threat for natural populations. While their effects are assessed on short terms acute exposure, some of their harmful consequences may only become apparent when combined with other stressors, notably natural ones, such as predation. Here, we investigated in a laboratory experiment how exposure to a common fungicide (fenpropimorph) would affect the responses to predation in the common frog Rana temporaria. The concentrations of fungicide we used were comparable to those found in nature (0, 2, or 11 microg/L). The higher concentration of fungicide reduced tadpole activity late in the experiment, and only 7% of the tadpoles reached metamorphosis. In the lower concentration, the ability to respond adaptively to predator presence was not affected, but the costs (delayed metamorphosis, smaller relative body size) of this response were increased. Our results highlightthe need to investigate sublethal effects of pesticides on organismal performance if assessment of pesticides real impact is to be obtained.

The small heart mutation reveals novel roles of Na+/K+-ATPase in maintaining ventricular cardiomyocyte morphology and viability in zebrafish

Forward genetic screens in zebrafish have been used to identify mutations in genes with important roles in organogenesis. One of these mutants, small heart, develops a diminutive and severely malformed heart and multiple developmental defects of the brain, ears, eyes, and kidneys. Using a positional cloning approach, we identify that the mutant gene encodes the zebrafish Na+/K+-ATPase alpha1B1 protein. Disruption of Na+/K+-ATPase alpha1B1 function via morpholino "knockdown" or pharmacological inhibition with ouabain phenocopies the mutant phenotype, in a dose-dependent manner. Heterozygosity for the mutation sensitizes embryos to ouabain treatment. Our findings present novel genetic and morphological details on the function of the Na+/K+-ATPase alpha1B1 in early cardiac morphogenesis and the pathogenesis of the small heart malformation. We demonstrate that the reduced size of the mutant heart is caused by dysmorphic ventricular cardiomyocytes and an increase in ventricular cardiomyocyte apoptosis. This study provides a new insight that Na+/K+-ATPase alpha1B1 is required for maintaining ventricular cardiomyocyte morphology and viability.

Canertinib pfizer

Canertinib, a water-soluble, orally available analog of PD-169414 (Pfizer Inc), is an EGFR tyrosine kinase inhibitor under development by Pfizer Inc as a potential treatment for cancer.