Exploration of ethylene glycol linked nitrofurantoin derivatives against Leishmania: Synthesis and in vitro activity.

Leishmaniasis is a neglected tropical disease that is caused by the Leishmania parasite. It is estimated that there are more than 350 million people at risk of infection annually. Current treatments that are in clinical use are expensive, have toxic side effects, and are facing parasitic resistance. Therefore, new drugs are urgently required. In the quest for new, safe, and cost-effective drugs, a series of novel ethylene glycol derivatives of nitrofurantoin was synthesised and the in vitro antileishmanial efficacy of the compounds tested against Leishmania donovani and Leishmania major strains. Arylated ethylene glycol derivatives were found to be the most potent, with submicromolar activity up to 294-fold greater than the parent compound nitrofurantoin. Analogues 2j and 2k had the best antipromastigote activities with submicromolar IC50 values against L. major IR-173 and antimonial-resistant L. donovani 9515 strains.

Effect of supplementation of cryoprotectant solution with hydroxypropyl cellulose for vitrification of bovine oocytes.

BACKGROUND: Successful cryopreservation of bovine oocytes is very important for research and commercial applications. However, the survival and development rate of vitrified-thawed (VT) oocytes are lower than those of non-vitrified-thawed (non-VT) oocytes. OBJECTIVE: To investigate the effect of adding hydroxypropyl cellulose (HPC) to the vitrification solution for bovine oocytes. MATERIALS AND METHODS: For vitrification, bovine metaphase II oocytes were pretreated with a solution containing 10% ethylene glycol supplemented with 0, 10, 50, or 100 ug/mL HPC for 5 min, exposed to a solution containing 30% ethylene glycol supplemented with 0, 10, 50, or 100 ug/mL HPC for 30 s, and then directly plunged into liquid nitrogen. RESULTS: The survival rate of oocytes was significantly higher in the 50 HPC group than in the 0, 10, and 100 HPC groups. The reactive oxygen species level was lower in the non-VT and 50 HPC groups than in the other groups. The mRNA levels of proapoptotic genes (Bax) were lower in the non-VT, 0, and 50 HPC groups than in the other groups. The mRNA levels of antiapoptotic genes (BCl2) were higher in the non-VT than in the other groups. The development rates of embryos (day 8) obtained via parthenogenetic activation (PA) were determined in the non-VT, 0 HPC, and 50 HPC groups. The cleavage rate was significantly higher in the non-VT group. CONCLUSION: Supplementation of vitrification solution with HPC improves the survival of VT bovine oocytes and the development capacity of embryos derived from these oocytes via PA. doi.org/10.54680/fr23110110212.

Novel imaging techniques using 18 F-florbetapir PET/MRI can guide fascicular nerve biopsy in amyloid multiple mononeuropathy.

BACKGROUND: Multiple mononeuropathy is a rare presentation of primary (AL) amyloidosis and nerve biopsy is usually needed for diagnosis. Conventional imaging is useful to identify proximal nerve involvement but may be inadequate. We report a patient with multiple mononeuropathy whose presentation was suggestive of AL amyloid neuropathy and in whom repeated tissue biopsies were negative for amyloid (including two sensory nerves and one muscle). METHODS: The patient underwent magnetic resonance imaging (MRI) and whole body 18 F-florbetapir positron emission tomography (PET)/MRI. RESULTS: Whole body 18 F-florbetapir PET/MRI revealed abnormal low-level florbetapir uptake in the right proximal tibial and peroneal nerves, which provided a target for a sciatic bifurcation fascicular nerve biopsy that was diagnostic of AL amyloidosis. CONCLUSIONS: 18 F-florbetapir PET/MRI imaging is a promising diagnostic tool for patients with suspected peripheral nerve amyloidosis (including multiple mononeuropathy) in whom conventional imaging and nerve and muscle biopsies miss the pathology.

Tailor-Engineered POSS-Based Hybrid Gels for Bone Regeneration.

Organic-inorganic oligo(ethylene glycol)-polyhedral oligomeric silsesquioxanes (OEGn-POSS) hybrid materials are woven into macroscopically shaped entities by thiol-ene chemistry. The mechanical behavior and interfacial nature of the OEGn-POSS materials are easily tailored by changing the length of OEGn. The nanostructured OEGn-POSS materials exhibited excellent bioactivity to form hydroxyapatite, whose morphology was also dependent on the molecular weight of OEGn. Among them, OEG2-POSS materials enhanced the in vitro differentiation of adipose-derived stem cells to osteoblasts and promoted the in vivo bone formation within a femoral condyle defect site, but they could be limited by the mismatch rates between the degradation and new bone formation. Thus, OEG2-POSS could be practically applied for bone regeneration by optimizing the degradation rate based on its key structural features, which would be of great benefit to bone tissue engineering in the future.

Use of the PET ligand florbetapir for in vivo imaging of pancreatic islet amyloid deposits in hIAPP transgenic mice.

AIMS/HYPOTHESIS: Islet amyloid deposits contribute to beta cell dysfunction and death in most individuals with type 2 diabetes but non-invasive methods to determine the presence of these pathological protein aggregates are currently not available. Therefore, we examined whether florbetapir, a radiopharmaceutical agent used for detection of amyloid-ß deposits in the brain, also allows identification of islet amyloid in the pancreas. METHODS: Saturation binding assays were used to determine the affinity of florbetapir for human islet amyloid polypeptide (hIAPP) aggregates in vitro. Islet amyloid-prone transgenic mice that express hIAPP in their beta cells and amyloid-free non-transgenic control mice were used to examine the ability of florbetapir to detect islet amyloid deposits in vitro, in vivo and ex vivo. Mice or mouse pancreases were subjected to autoradiographic, histochemical and/or positron emission tomography (PET) analyses to assess the utility of florbetapir in identifying islet amyloid. RESULTS: In vitro, florbetapir bound synthetic hIAPP fibrils with a dissociation constant of 7.9 nmol/l. Additionally, florbetapir bound preferentially to amyloid-containing hIAPP transgenic vs amyloid-free non-transgenic mouse pancreas sections in vitro, as determined by autoradiography (16,475 ± 5581 vs 5762 ± 575 density/unit area, p < 0.05). In hIAPP transgenic and non-transgenic mice fed a high-fat diet for 1 year, intravenous administration of florbetapir followed by PET scanning showed that the florbetapir signal was significantly higher in amyloid-laden hIAPP transgenic vs amyloid-free non-transgenic pancreases in vivo during the first 5 min of the scan (36.83 ± 2.22 vs 29.34 ± 2.03 standardised uptake value × min, p < 0.05). Following PET, pancreases were excised and florbetapir uptake was determined ex vivo by γ counting. Pancreatic uptake of florbetapir was significantly correlated with the degree of islet amyloid deposition, the latter assessed by histochemistry (r = 0.74, p < 0.001). CONCLUSIONS/INTERPRETATION: Florbetapir binds to islet amyloid deposits in a specific and quantitative manner. In the future, florbetapir may be useful as a non-invasive tool to identify islet amyloid deposits in humans.

Modulation of rainbow trout (Oncorhynchus mykiss) cutaneous mucosal immune responses following anesthesia: A comparative study on different anesthetic agents.

The present study investigated the possible effects of different anesthetic agents including MS222 (50 ppm), 2-Phenoxyethanol (2-PE) (0.2 mL L-1) and clove oil (25 ppm), on cutaneous mucosal immune parameters in rainbow trout (Oncorhynchus mykiss). The induction and recovery times for each anesthetic agent were assessed. Also, the immune parameters were measured in skin mucus, 1 and 24 h post anesthesia. No significant difference was observed among treatments at 1 h post-anesthesia except for bactericidal and alkaline phosphatase (ALP) activities which was significantly enhanced in fish exposed to 2-PE compared to other anesthetics. At 24 h post-anesthesia, most of the skin mucosal immune parameters were increased upon exposure to clove oil but decreased following exposure to 2-PE. However, no significant change was noticed after MS222 exposure. These results demonstrated that the anesthetics type should be considered to avoid possible immunosuppression in farmed fish. Furthermore, the present results could be useful for better understanding of alterations in cutaneous mucosal immunity in response to chemical stressors such as anesthetic agents.

Upgrading of dissolution and anti-hypertensive effect of Carvedilol via two combined approaches: self-emulsification and liquisolid techniques.

OBJECTIVE: The aim of the study was to design a self-emulsifying drug delivery system (SEDDS) of the anti-hypertensive Carvedilol in liquid and liquisolid forms as a way to enhance its dissolution profile and anti-hypertensive effect. METHODS: Solubility studies of Carvedilol in various oils, surfactants and co-surfactants were conducted, followed by the construction of pseudo-ternary phase diagrams and other in vitro assessments. The selected SEDDS formulation (S1) was adsorbed onto solid powder excipients and compressed into tablets. The resulting liquisolid tablets were evaluated under British Pharmacopoeia (B.P.) specifications. Pre- and post-compression studies were performed to determine the flow properties and evaluate the liquisolid systems, followed by in vivo studies in hypertensive rats. RESULTS: Attempts of self-emulsification, droplet size, and thermodynamic stability studies showed acceptable results for the S1 formulation containing Capryol 90, Tween 20, and Transcutol HP (10:53.3:26.2%), respectively. Pre-compression studies showed adequate flowability and compatibility of liquid and solid excipients with Carvedilol. The selected liquisolid tablet (LS7) demonstrated the best disintegration and water absorption ratio in addition to satisfactory friability and hardness. A significantly (p < .05) fast dissolution rate was observed for both SEDDS and liquisolid formulations when compared to pure drug and marketed Carvepress®. The in vivo study of LS7 formulation revealed a rapid significant (p < .01) decrease in the mean arterial pressure (MAP) of the rats (112.72 mmHg) within the first 30 min followed by a further decline (107.22 mmHg) after 1 h when compared to Carvepress®. CONCLUSION: Self-emulsifying liquisolid tablets expressed rapid onset of action with enhanced anti-hypertensive effect of Carvedilol.

Refolding of SDS-Unfolded Proteins by Nonionic Surfactants.

The strong and usually denaturing interaction between anionic surfactants (AS) and proteins/enzymes has both benefits and drawbacks: for example, it is put to good use in electrophoretic mass determinations but limits enzyme efficiency in detergent formulations. Therefore, studies of the interactions between proteins and AS as well as nonionic surfactants (NIS) are of both basic and applied relevance. The AS sodium dodecyl sulfate (SDS) denatures and unfolds globular proteins under most conditions. In contrast, NIS such as octaethylene glycol monododecyl ether (C12E8) and dodecyl maltoside (DDM) protect bovine serum albumin (BSA) from unfolding in SDS. Membrane proteins denatured in SDS can also be refolded by addition of NIS. Here, we investigate whether globular proteins unfolded by SDS can be refolded upon addition of C12E8 and DDM. Four proteins, BSA, α-lactalbumin (αLA), lysozyme, and ß-lactoglobulin (ßLG), were studied by small-angle x-ray scattering and both near- and far-UV circular dichroism. All proteins and their complexes with SDS were attempted to be refolded by the addition of C12E8, while DDM was additionally added to SDS-denatured αLA and ßLG. Except for αLA, the proteins did not interact with NIS alone. For all proteins, the addition of NIS to the protein-SDS samples resulted in extraction of the SDS from the protein-SDS complexes and refolding of ßLG, BSA, and lysozyme, while αLA changed to its NIS-bound state instead of the native state. We conclude that NIS competes with globular proteins for association with SDS, making it possible to release and refold SDS-denatured proteins by adding sufficient amounts of NIS, unless the protein also interacts with NIS alone.

Design, synthesis and pharmacological evaluation of 4-hydroxyphenylglycine and 4-hydroxyphenylglycinol derivatives as GPR88 agonists.

The orphan receptor GPR88 is an attractive therapeutic target because of its implications in a number of basal ganglia-associated disorders. To date, pharmacological characterization of GPR88 has been limited due to the lack of potent and selective agonists and antagonists appropriate for CNS investigations. We have previously reported that GPR88 couples to Gαi proteins and modulates cAMP levels upon treatment with a small molecule agonist 2-PCCA. Recently, another chemotype of GPR88 agonist, represented by 2-AMPP [(2S)-N-((1R)-2-amino-1-(4-(2-methylpentyloxy)-phenyl)ethyl)-2-phenylpropanamide], has also been discovered. In this report, a new series of 2-AMPP structurally related 4-hydroxyphenylglycine and 4-hydroxyphenylglycinol derivatives have been designed and evaluated for agonist activity at GPR88. The structure-activity relationship (SAR) studies suggest that the amine group in 2-AMPP can be replaced by hydroxyl, ester and amide groups, resulting in analogues with good to moderate potency, whereas the phenyl group on the amide cap is essential for activity and has limited size, shape and electronic tolerance.

Halogenated Compounds from Directed Fermentation of Penicillium concentricum, an Endophytic Fungus of the Liverwort Trichocolea tomentella.

One new chlorinated xanthone, 6-chloro-3,8-dihydroxy-1-methylxanthone (1), a new 2-bromo-gentisyl alcohol (2), and a mixture of 6-epimers of 6-dehydroxy-6-bromogabosine C (3a and 3b), together with 19 previously identified compounds, epoxydon (4), norlichexanthone (5), 2-chlorogentisyl alcohol (6), hydroxychlorogentisyl quinone (7), 6-dehydroxy-6α-chlorogabosine C (8a), 6-dehydroxy-6ß-chlorogabosine C (8b), gentisyl alcohol (9), gentisyl quinone (10), (R,S)-1-phenyl-1,2-ethanediol (11), dehydrodechlorogriseofulvin (12), dechlorogriseofulvin (13), dehydrogriseofulvin (14), griseofulvin (15), ethylene glycol benzoate (16), alternariol (17), griseoxanthone C (18), drimiopsin H (19), griseophenone C (20), and griseophenone B (21), were isolated from cultures of Penicillium concentricum, a fungal endophyte of the liverwort Trichocolea tomentella. The structures of the new compounds (1, 2, 3a, and 3b) were elucidated by interpretation of spectroscopic data including one- and two-dimensional NMR techniques. Among these, compounds 2-4 displayed modest cytotoxicity to the MCF-7 hormone-dependent breast cancer cell line with IC50 values of 8.4, 9.7, and 5.7 µM, respectively, whereas compound 9 exhibited selective cytotoxicity against the HT-29 colon cancer cell line with an IC50 value of 6.4 µM. During this study we confirmed that the brominated gentisyl alcohol (2) was formed by chemical conversion of 4 during bromide salt addition to culture media.

Albumin reduces the antibacterial efficacy of wound antiseptics against Staphylococcus aureus.

OBJECTIVE: The influence of proteins on the efficacy of antiseptic solutions has been rarely investigated even though exudate can contain high levels of protien. The aim of this study was to analyse the antibacterial efficacy of commonly used solutions in the presence of albumin protein. METHOD: Using Staphylococcus aureus in a standardised quantitative suspension assay, the antibacterial effects of poly (1-(2-oxo-1-pyrrolidinyl) ethylene)-iodine (PVP-I) and octenidin-dihydrochloride/phenoxyethanol (OCT/PE) were analysed in the presence of 0-3% bovine serum albumin (BSA). These were compared with previous results obtained with polyhexamethylene biguanide hydrochloride (PHMB). RESULTS: Presence of albumin caused a significant (p<0.001) decrease in antibacterial effect in the analysed solutions. The concentrations of albumin that provoked highly significant decreases in the bacterial reduction factors of the study agents were: 0.01875 % for PVP-I, followed by 0.75 % for OCT/PE. After addition of 3 % albumin, adequate antimicrobial effects were ensured for titrations to 5 % PVP-I and 8 % OCT/PE. As we could show before, it is not possible to titrate PHMB in order to assure adequate potency. CONCLUSION: This study demonstrates that albumin induces a significant decrease of the antibacterial potency of the analysed solutions.

Regulatory effect of hydroquinone-tetraethylene glycol conjugates on zebrafish pigmentation.

We synthesized two hydroquinone-tetraethylene glycol conjugates (HQ-TGs) and investigated their logP, photophysical stability, and redox chemical stability. HQ-TGs are a little more hydrophilic than hydroquinone (HQ) and show an enhanced photophysical and redox chemical stability compared with HQ. In addition we studied the effect of HQ-TGs on cell viability and on zebrafish pigmentation. MTT assay in HF-16 cells showed HQ-TGs are less cytotoxic than HQ. The phenotype-based image analysis of zebrafish larvae suggests that HQ-TGs suppress the pigmentation of zebrafish in a dose-dependent manner. The comparative experiments on stability, cytotoxicity, and zebrafish pigmentation between HQ and HQ-TGs suggest that mono tetraethylene glycol-functionalization of HQ is an alternative solution to overcome the adverse effect of HQ.

Selective cyclooxygenase-1 inhibition by p6 and gastrotoxicity: preliminary investigation.

BACKGROUND/AIMS: Gastrointestinal damage (GD) is commonly associated with the inhibition of cyclooxygenase (COX)-1, one of the two known COXs, by traditional non-steroidal anti-inflammatory drugs. More recent evidences have proven that GD is caused by the simultaneous inhibition of the two COXs. This study was designed to evaluate the effect of the selective COX-1 inhibition on gastric integrity. METHODS: GD was evaluated in male CD1 mice. Drugs were administered by gastric gavage at a dose of 50 mg/kg (injection volume of 100 µl). Control mice received an equal volume of the vehicle (10% ethanol). Each mouse, in groups of at least 6 mice, received one dose/day for 5 days. RESULTS: In Western blot analysis, COX-1 expression levels were found to be significantly reduced in mice treated with 3-(5-chlorofuran-2-yl)-5-methyl-4-phenylisoxazole (P6) in comparison to mice pretreated with aspirin (ASA), which exhibited higher levels of COX-1, thus confirming the high selectivity of P6 towards COX-1 enzyme inhibition. Mucosal sections obtained from ASA-treated mice showed breaks in the epithelial barrier and a marked alteration of foveolae and gastric glands, whereas stomachs isolated from mice sacrificed after 5 days of chronic administration of P6 (at a dose of up to 50 mg/kg/day) showed sporadic transient mucosal hyperemia and did not seem to display any significant gastric damage. CONCLUSIONS: The selective COX-1 inhibition by P6 does not cause gastric damage in mice but preserves mucosal integrity.

Comparison of the effect of four anaesthetics on haematological profiles, oxidative stress and antioxidant enzymes in barbel (Barbus barbus).

OBJECTIVES: Currently, many questions regarding the effect of anaesthetics to fish remain unresolved. Fish species may differ widely in their response to an anaesthetic, the screening of dosages is often necessary. The aim of this study was to compare the effect of tricaine methane sulphonate (MS 222), clove oil, 2-phenoxyethanol and Propiscin on haematological profiles, oxidative stress biomarkers and antioxidant enzymes in barbel (Barbus barbus). DESIGN: The haematological profiles, oxidative stress biomarkers and antioxidant enzymes of barbel were evaluated immediately after a 10 min anaesthesia (MS 222--100 mg.L(-1), clove oil--33 mg.L(-1), 2-phenoxyethanol--0.4 mg.L(-1), Propiscin--1.0 mg.L(-1)), and 24 h after anaesthesia. RESULTS: The 10 min exposure in the recommended concentrations of tested anaesthetics have no significant effect on haematological profiles, levels of thiobarbituric acid reactive substances, and activity of glutathione reductase of barbel. The activity of superoxide dismutase (SOD) was significantly decreased (p<0.01) in the muscle in all experimental groups. The activity of SOD showed a significant decrease (p<0.01) in the liver 24 h after all anaesthetics; however in the gill the activity of SOD was significantly increased (p<0.01) in Propiscin (10 min). The activity of catalase (CAT) was significantly increased (p<0.05) in the muscle 24 h after all anaesthetics. CONCLUSIONS: The observed effects on barbel antioxidant systems may be a defence against oxidative damage. The results of this study suggest that the antioxidant systems of barbel are altered by Propiscin anaesthesia, but are slightly affected by MS 222, clove oil, and 2-phenoxyethanol anaesthesia.

Effect of nasal sprays on an in vitro survival and morphology of nasoseptal cartilage.

Nasal sprays were introduced several years ago to support the treatment of allergic rhinitis. These sprays may come in direct contact with directly exposed nasoseptal cartilage (e.g. is case of nasoseptal perforation). To date, no studies investigated the effects of nasal sprays on cartilage tissues and cells. Therefore, our aim was to analyze the influence of two different nasal spray types (thixotropic and liposomal) on the vitality of nasoseptal chondrocytes. Human chondrocytes were isolated from surgically dissected tissues. Alternatively, nasal septa (porcine and human) tissue explants were used. The cell or explant cultures were treated with nasal sprays for 4-24 h. As a read-out, cell vitality and gene and protein expression profiles of type I and II collagen, SOX 9 and matrix metalloproteinase MMP-1 were compared to the untreated controls by means of real-time RT-PCR and immunostaining. Using the liposomal, but not thixotropic nasal spray in an explant or chondrocyte in vitro culture led to increased cell death, as compared to the untreated controls. A trend towards suppression of type II collagen and SOX 9 on protein level was found in cultures exposed to liposomal nasal spray, as compared to the controls. The thixotropic nasal spray has not affected the nasoseptal chondrocytes. Further studies with the use of viable nasoseptal cartilage explants and particularly using an in vivo animal model of exposed nasoseptal cartilage are necessary to clear the effect of liposomal spray on chondrocytes.

Haematological effects of 2-phenoxyethanol and etomidate in carp (Cyprinus carpio L.).

OBJECTIVE: To evaluate the effects of handling alone versus handling under anaesthesia with 2-phenoxyethanol or etomidate on haematological parameters in carp. STUDY DESIGN: Prospective, randomized, laboratory experiment. ANIMALS: Seventy-two juvenile carp (Cyprinus carpio) weighing 35.9 ± 10.4 g were divided into six groups of 12 fish. METHODS: Either 2-phenoxyethanol or 2% etomidate were administered to induce deep anaesthesia (0.3 mL L(-1) and 0.6 mL L(-1) , respectively) or deep sedation (0.15 mL L(-1) and 0.3 mL L(-1) , respectively). Fish were handled with and without sedation. Blood was sampled at 1 hour and 1 week post-treatment. Phagocyte oxidative activity [nitrotetrazolium blue reduction test (NBT)] and differential erythrocyte [red blood cell (RBC)] and leukocyte (white blood cell) counts were evaluated. RESULTS: At 1 hour after the induction of anaesthesia, haematocrit (Ht) and haemoglobin (Hb) were increased in fish anaesthetized with 2-phenoxyethanol, and mean corpuscular haemoglobin (MCH) was increased in fish anaesthetized with etomidate. At 1 week, an increase in RBC, erythroblastosis, erythrocyte damage, lymphopenia, neutrophilia, monocytosis and thrombocytosis occurred in both groups. Red blood parameters did not change 1 hour after handling alone, but after 1 week Ht, Hb and mean cell volume decreased, whereas MCH concentration (MCHC) and abnormal erythrocytes increased. Lymphopenia, neutrophilia, monocytosis, thrombocytosis and a decrease in NBT occurred. Fish handled under sedation showed an increase in Hb and MCHC followed by a decrease at 1 week in Ht, Hb and MCH, erythroblastosis and increased abnormal erythrocytes. Lymphopenia and neutrophilia were less pronounced than in fish handled without sedation, but a decrease in NBT was noted at 1 week post-treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Deep anaesthesia with 2-phenoxyethanol or etomidate induced significant haematological alterations in juvenile carp. Deep sedation reduced the immediate immunosuppressive effects of handling but did not eliminate longterm effects. These anaesthetics should be avoided during experimental procedures involving haematological measurements. In contexts that require the short-term handling of carp, these drugs should be used with caution in view of their possible side effects.

The effects of exposure duration to optimal concentration of 2-phenoxyethanol on primary and secondary stress responses in kutum (Rutilus frisii kutum).

The goal of this study was to assess the anaesthetic induction and recovery time in kutum (Rutilus frisii kutum) after exposure to various concentrations (0.1, 0.3, 0.5, 0.7 and 0.9 ml/l) of 2-PE as an anaesthetic, as well as the effects of optimal concentration (0.7 ml/l) of 2-PE in relation to different exposure time (3, 10, 15 min) on some haematological and serum biochemical indices in this species. Moreover, the effects of 0.7 ml/l on blood parameters were assessed 24 h after the longest exposure. Significant increase was determined in Hb, MCH and MCHC after 10-min exposure to 2-PE (p < 0.05). Moreover, Hct, Hb and RBC levels increased significantly after 15 min-exposure to 2-PE (p < 0.05). There were no prominent changes in WBC and MCV. The plasma concentrations of glucose, cholesterol and cortisol increased significantly after 10- and 15-min exposure to 2-PE (p < 0.05) compared with the control group and all other exposure times. The activity of ALT and AST were significantly increased after 10- and 15-min exposure respectively (p < 0.05). In this study, it appears that anaesthetizing kutum with 2-PE at 0.7 ml/l for 3 min had no effect on the stress markers.

A tetra(ethylene glycol) derivative of benzothiazole aniline enhances Ras-mediated spinogenesis.

The tetra(ethylene glycol) derivative of benzothiazole aniline, BTA-EG4, is a novel amyloid-binding small molecule that can penetrate the blood-brain barrier and protect cells from Aß-induced toxicity. However, the effects of Aß-targeting molecules on other cellular processes, including those that modulate synaptic plasticity, remain unknown. We report here that BTA-EG4 decreases Aß levels, alters cell surface expression of amyloid precursor protein (APP), and improves memory in wild-type mice. Interestingly, the BTA-EG4-mediated behavioral improvement is not correlated with LTP, but with increased spinogenesis. The higher dendritic spine density reflects an increase in the number of functional synapses as determined by increased miniature EPSC (mEPSC) frequency without changes in presynaptic parameters or postsynaptic mEPSC amplitude. Additionally, BTA-EG4 requires APP to regulate dendritic spine density through a Ras signaling-dependent mechanism. Thus, BTA-EG4 may provide broad therapeutic benefits for improving neuronal and cognitive function, and may have implications in neurodegenerative disease therapy.

Tackling lipophilicity of peptide drugs: replacement of the backbone N-methyl group of cilengitide by N-oligoethylene glycol (N-OEG) chains.

Cilengitide is an RGD-peptide of sequence cyclo[RGDfNMeV] that was was developed as a highly active and selective ligand for the αvß3 and αvß5 integrin receptors. We describe the synthesis of three analogues of this peptide in which the N-Me group has been replaced by N-oligoethylene glycol (N-OEG) chains of increasing size: namely N-OEG2, N-OEG11, and N-OEG23, which are respectively composed of 2, 11, and 23 ethylene oxide monomer units. The different N-OEG cyclopeptides and the original peptide were compared with respect to lipophilicity and biological activity. The N-OEG2 analogue was straightforward to synthesize in solid phase using an Fmoc-N-OEG2 building block. The syntheses of the N-OEG11 and N-OEG23 cyclopeptides are hampered by the increased steric hindrance of the N-substituent, and could only be achieved by segment coupling, which takes place with epimerization and thus requires extensive product purification. All the N-OEG analogues were found to be more hydrophobic than the parent peptide, and their hydrophobicity was systematically enhanced upon increasing the length of the OEG chain. The N-OEG2 cyclopeptide displayed the same capacity as Cilengitide to inhibit the integrin-mediated adhesion of HUVEC endothelial, DAOY gliobastoma, and HT-29 colon cancer cells to their ligands vitronectin and fibrinogen. The N-OEG11 and N-OEG23 analogues also inhibited cell adhesion to these immobilized ligands, but their IC50 values dropped by 1 order of magnitude with respect to the parent peptide. These results indicate that replacement of the backbone N-Me group of Cilengitide by a short N-OEG chain provides a more lipophilic analogue with a similar biological activity. Upon increasing the size of the N-OEG chain, liophilicity is enhanced, but synthetic yields drop and the longer polymer chains may impede targeted binding.

Separation of preferential interaction and excluded volume effects on DNA duplex and hairpin stability.

Small solutes affect protein and nucleic acid processes because of favorable or unfavorable chemical interactions of the solute with the biopolymer surface exposed or buried in the process. Large solutes also exclude volume and affect processes where biopolymer molecularity and/or shape changes. Here, we develop an analysis to separate and interpret or predict excluded volume and chemical effects of a flexible coil polymer on a process. We report a study of the concentration-dependent effects of the full series from monomeric to polymeric PEG on intramolecular hairpin and intermolecular duplex formation by 12-nucleotide DNA strands. We find that chemical effects of PEG on these processes increase in proportion to the product of the amount of DNA surface exposed on melting and the amount of PEG surface that is accessible to this DNA, and these effects are completely described by two interaction terms that quantify the interactions between this DNA surface and PEG end and interior groups. We find that excluded volume effects, once separated from these chemical effects, are quantitatively described by the analytical theory of Hermans, which predicts the excluded volume between a flexible polymer and a rigid molecule. From this analysis, we show that at constant concentration of PEG monomer, increasing PEG size increases the excluded volume effect but decreases the chemical interaction effect, because in a large PEG coil a smaller fraction of the monomers are accessible to the DNA. Volume exclusion by PEG has a much larger effect on intermolecular duplex formation than on intramolecular hairpin formation.