A systematic evaluation of the cucurbit[7]uril pharmacokinetics and toxicity after a single dose and short-term repeated administration in mice.

Cucurbit[n]urils are macrocyclic compounds capable of forming host-guest complexes with different molecules. In this study, we focused on cucurbit[7]uril (CB[7]) safety and pharmacokinetics. We investigated CB[7] cytotocixity in human renal cells ACHN using the xCELLigence system. We also determined maximum tolerated doses (MTD) and no observed adverse effect levels (NOAEL) after intramuscular (i.m.), intraperitoneal (i.p.), and intragastric (i.g.) administration in mice using clinical observation, blood biochemistry, and histopathology. At NOAELs, we studied its pharmacokinetics in plasma and kidneys. Finally, we performed a 7 day repeated-dose toxicity study at 50% of NOAEL after i.p. administration, assaying CB[7] concentration in plasma, brain, kidney, and liver; we also assessed the liver and kidney histopathology. In vitro, CB[7] did not show toxicity up to 0.94 mg/mL. MTDs in vivo were set at 300, 350, and 600 mg/kg, and NOAEL were established at 150, 100, and 300 mg/kg after i.m., i.p., and i.g. administration, respectively. Parenteral administration produced tissue damage mainly to the kidney, while i.g. administration caused only minor liver damage. Parenteral CB[7] administration led to fast elimination from blood, accompanied with kidney accumulation; absorption from the gastrointestinal tract was minimal. Short repeated i.p. administration was well tolerated. After initial CB[7] accumulation in blood and kidney, the concentrations stabilised and decreased during the experiment. Approximately 3.6% of animals showed signs of nephrotoxicity. Although CB[7] appears to be a promising molecule, nephrotoxicity may be the most critical drawback of its parenteral use, because the kidney represents the main organ of its elimination.

Identification and characterization of in vitro and in vivo fidarestat metabolites: Toxicity and efficacy evaluation of metabolites.

The progression of diabetic complications can be prevented by inhibition of aldose reductase and fidarestat considered to be highly potent. To date, metabolites of the fidarestat, toxicity, and efficacy are unknown. Therefore, the present study on characterization of hitherto unknown in vitro and in vivo metabolites of fidarestat using liquid chromatography-electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS) is undertaken. In vitro and in vivo metabolites of fidarestat have been identified and characterized by using LC/ESI/MS/MS and accurate mass measurements. To identify in vivo metabolites, plasma, urine, and feces samples were collected after oral administration of fidarestat to Sprague-Dawley rats, whereas for in vitro metabolites, fidarestat was incubated in human S9 fraction, human liver microsomes, and rat liver microsomes. Furthermore, in silico toxicity and efficacy of the identified metabolites were evaluated. Eighteen metabolites have been identified. The main in vitro phase I metabolites of fidarestat are oxidative deamination, oxidative deamination and hydroxylation, reductive defluroniation, and trihydroxylation. Phase II metabolites are methylation, acetylation, glycosylation, cysteamination, and glucuronidation. Docking studies suggest that oxidative deaminated metabolite has better docking energy and conformation that keeps consensus with fidarestat whereas the rest of the metabolites do not give satisfactory results. Aldose reductase activity has been determined for oxidative deaminated metabolite (F-1), and it shows an IC50 value of 0.44 µM. The major metabolite, oxidative deaminated, did not show any cytotoxicity in H9C2, HEK, HEPG2, and Panc1 cell lines. However, in silico toxicity, the predication result showed toxicity in skin irritation and ocular irritancy SEV/MOD versus MLD/NON (v5.1) model for fidarestat and its all metabolites. In drug discovery and development research, it is distinctly the case that the potential for pharmacologically active metabolites must be considered. Thus, the active metabolites of fidarestat may have an advantage as drug candidates as many drugs were initially observed as metabolites.

Synthesis and evaluation of the antileishmanial activity of silver compounds containing imidazolidine-2-thione.

A new series of silver compounds could be of interest on designing new drugs for the treatment of leishmaniasis. The compounds [Ag(phen)(imzt)]NO3(1), [Ag(phen)(imzt)]CF3SO3(2), [Ag(phen)2](BF4)·H2O (3), [Ag2(imzt)6](NO3)2(4), and imzt have been synthesized and evaluated in vitro for antileishmanial activity against Leishmania. (L.) amazonensis (La) and L. (L.) chagasi (Lc), and two of them were selected for in vivo studies. In addition to investigating the action on Leishmania, their effects on the hydrogen peroxide production and cysteine protease inhibition have also been investigated. As for antileishmanial activity, compound (4) was the most potent against promastigote and amastigote forms of La (IC50 = 4.67 and 1.88 µM, respectively) and Lc (IC50 = 9.35 and 8.05 µM, respectively); and comparable to that of amphotericin B, reference drug. Beside showing excellent activity, it also showed a low toxicity. In the in vivo context, compound (4) reduced the number of amastigotes in the liver and spleen when compared to the untreated group. In evaluating the effect of the compounds on Leishmania, the level of hydrogen peroxide production was maintained between the lag and log phases; however, in the treatment with compound (4) it was possible to observe a reduction of 25.44 and 49.13%, respectively, in the hydrogen peroxide rates when compared to the lag and log phases. It was noticed that the presence of a nitrate ion and imzt in compound (4) was important for the modulation of the antileishmanial activity. Thus, this compound can represent a potentially new drug for the treatment of leishmaniasis.

Synthesis and biological evaluation of novel imidazolidine derivatives as candidates to schistosomicidal agents.

INTRODUCTION:: Schistosomiasis is an infectious parasitic disease caused by trematodes of the genus Schistosoma, which threatens at least 258 million people worldwide and its control is dependent on a single drug, praziquantel. The aim of this study was to evaluate the anti-Schistosoma mansoni activity in vitro of novel imidazolidine derivatives. MATERIAL AND METHODS:: We synthesized two novel imidazolidine derivatives: (LPSF/PTS10) (Z)-1-(2-chloro-6-fluorobenzyl)-4-(4-dimethylaminobenzylidene)-5-thioxoimidazolidin-2-one and (LPSF/PTS23) (Z)-1-(2-chloro-6-fluoro-benzyl)-5-thioxo-4-(2,4,6-trimethoxy-benzylidene)-imidazolidin-2-one. The structures of two compounds were determined by spectroscopic methods. During the biological assays, parameters such as motility, oviposition, mortality and analysis by Scanning Electron Microscopy were performed. RESULTS:: LPSF/PTS10 and LPSF/PTS23 were considered to be active in the separation of coupled pairs, mortality and to decrease the motor activity. In addition, LPSF/PTS23 induced ultrastructural alterations in worms, after 24 h of contact, causing extensive erosion over the entire body of the worms. CONCLUSION:: The imidazolidine derivatives containing the trimetoxy and benzylidene halogens showed promising in vitro schistosomicidal activity.

The effect of different anesthetics on tumor cytotoxicity by natural killer cells.

A number of retrospective studies have suggested that choice of anesthetic drugs during surgical tumor resection might affect tumor recurrence/metastasis, or outcome of patients. The recent study showed that volatile anesthetics-based general anesthesia was associated with the worse outcomes than intravenous anesthetics-based general anesthesia. However, the underlying mechanism is yet to be determined. Because natural killer (NK) cells are implicated as important immune cells for tumor recurrence/metastasis in the perioperative period, we examined the effect of different anesthetics on NK cell-mediated tumor cytotoxicity. Because adhesion molecule leukocyte function-associated antigen-1 (LFA-1) is functionally important in NK cells and is inhibited by commonly used volatile anesthetics isoflurane and sevoflurane, we hypothesized that these anesthetics would attenuate NK cell-mediated cytotoxicity. Using human NK cell line NK92-MI cells and tumor cell line K562 cells as a model system, we performed cytotoxicity, proliferation, conjugation and degranulation assays. Lytic granule polarization was also assessed. We showed that isoflurane, sevoflurane and LFA-1 inhibitor BIRT377 attenuated cytotoxicity, and reduced conjugation and polarization, but not degranulation of NK cells. Our data suggest that isoflurane and sevoflurane attenuated NK cell-mediated cytotoxicity at least partly by their LFA-1 inhibition in vitro. Whether or not isoflurane and sevoflurane attenuate NK cell-mediated tumor cytotoxicity in patients needs to be determined in the future.

Synthesis and biological evaluation of novel imidazolidine derivatives as candidates to schistosomicidal agents

ABSTRACT Introduction: Schistosomiasis is an infectious parasitic disease caused by trematodes of the genus Schistosoma, which threatens at least 258 million people worldwide and its control is dependent on a single drug, praziquantel. The aim of this study was to evaluate the anti-Schistosoma mansoni activity in vitro of novel imidazolidine derivatives. Material and methods: We synthesized two novel imidazolidine derivatives: (LPSF/PTS10) (Z)-1-(2-chloro-6-fluorobenzyl)-4-(4-dimethylaminobenzylidene)-5-thioxoimidazolidin-2-one and (LPSF/PTS23) (Z)-1-(2-chloro-6-fluoro-benzyl)-5-thioxo-4-(2,4,6-trimethoxy-benzylidene)-imidazolidin-2-one. The structures of two compounds were determined by spectroscopic methods. During the biological assays, parameters such as motility, oviposition, mortality and analysis by Scanning Electron Microscopy were performed. Results: LPSF/PTS10 and LPSF/PTS23 were considered to be active in the separation of coupled pairs, mortality and to decrease the motor activity. In addition, LPSF/PTS23 induced ultrastructural alterations in worms, after 24 h of contact, causing extensive erosion over the entire body of the worms. Conclusion: The imidazolidine derivatives containing the trimetoxy and benzylidene halogens showed promising in vitro schistosomicidal activity.

[PREDICTING OF RISK OF SOIL CONTAMINATION BY DIFFERENT CLASSES OF FUNGICIDES IN SOIL AND CLIMATIC CONDITIONS OF UKRAINE].

Application of pesticides in modern agriculture is a powerful permanent risk factor for public health and the natural environment. The aim of the study was a comparative hygienic assessment of soil pollution hazards by the most widely used herbicides of different chemical classes (sulfonylureas, imidazolinones, pyrimidinyl (thio) benzoates, semicarbazones). Hygienic field experiment for studying of the dynamics of residual amounts of the test substances in the soil under different climatic zones of Ukraine was conducted. Half life periods (DT50) or herbicides in soil were calculated using the method of mathematical modeling. Ecotoxicological risk of herbicides on ecosystems and ecological communities was determined. It was established that bispyribac-sodium (pyrimidinyl (thio) benzoates) and imidazolinones are persist the longest time in soil and most rapidly degradable is diflufenzopyr (semicarbazone); ecotoxicological risk of the studied herbicides for terrestrial biocenoses of Ukraine by 4-6 orders of magnitude lower than dihlordifeniltrihlormetilmetan (DDT).

Systematic Evaluation of the Metabolism and Toxicity of Thiazolidinone and Imidazolidinone Heterocycles.

The thiazolidine and imidazolidine heterocyclic scaffolds, i.e., the rhodanines, 2,4-thiazolidinediones, 2-thiohydantoins, and hydantoins have been the subject of debate on their suitability as starting points in drug discovery. This attention arose from the wide variety of biological activities exhibited by these scaffolds and their frequent occurrence as hits in screening campaigns. Studies have been conducted to evaluate their value in drug discovery in terms of their biological activity, chemical reactivity, aggregation-based promiscuity, and electronic properties. However, the metabolic profiles and toxicities have not been systematically assessed. In this study, a series of five-membered multiheterocyclic (FMMH) compounds were selected for a systematic evaluation of their metabolic profiles and toxicities on TAMH cells, a metabolically competent rodent liver cell line and HepG2 cells, a model of human hepatocytes. Our studies showed that generally the rhodanines are the most toxic, followed by the thiazolidinediones, thiohydantoins, and hydantoins. However, not all compounds within the family of heterocycles were toxic. In terms of metabolic stability, 5-substituted rhodanines and 5-benzylidene thiohydantoins were found to have short half-lives in the presence of human liver microsomes (t1/2 < 30 min) suggesting that the presence of the endocyclic sulfur and thiocarbonyl group or a combination of C5 benzylidene substituent and thiocarbonyl group in these heterocycles could be recognition motifs for P450 metabolism. However, the stability of these compounds could be improved by installing hydrophilic functional groups. Therefore, the toxicities and metabolic profiles of FMMH derivatives will ultimately depend on the overall chemical entity, and a blanket statement on the effect of the FMMH scaffold on toxicity or metabolic stability cannot and should not be made.

Discovery of a highly selective PLD2 inhibitor (ML395): a new probe with improved physiochemical properties and broad-spectrum antiviral activity against influenza strains.

Further chemical optimization of the halopemide-derived family of dual phospholipase D1/2 (PLD1/2) inhibitors afforded ML395 (VU0468809), a potent, >80-fold PLD2 selective allosteric inhibitor (cellular PLD1, IC50 >30,000 nM; cellular PLD2, IC50 =360 nM). Moreover, ML395 possesses an attractive in vitro DMPK profile, improved physiochemical properties, ancillary pharmacology (Eurofins Panel) cleaner than any other reported PLD inhibitor, and has been found to possess interesting activity as an antiviral agent in cellular assays against a range of influenza strains (H1, H3, H5 and H7).

Synthesis and pharmacological evaluation of novel 1'-[2-(difluoromethoxy)benzyl]-2'H,5'H-spiro[8-azabicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-diones and their derivatives.

A series of novel 1'-[2-(difluoromethoxy)benzyl]-2'H,5'H-spiro[8-azabicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-dione substituted hydantoins (5-32) were synthesized using an appropriate synthetic route and characterized by elemental analysis and spectral data. The novel molecules were screened for anticonvulsant activity in mice by maximal electroshock (MES) and subcutaneous pentylenetetrazol (ScPTZ)-induced seizure tests. The neurotoxicity was assessed using the rotarod method. Compounds 9, 10, 18, 30, and 31 exhibited anticonvulsant potency against MES seizure and in the ScPTZ model, with lesser neurotoxicity. Some title compounds showed lesser central nervous system depression compared to phenytoin.

Novel diphenylamine 2,4'-dicarboxamide based azoles as potential epidermal growth factor receptor inhibitors: synthesis and biological activity.

Several hybrid molecules of diphenylamine-2,4'-dicarboxamide with various azolidinones and related heterocyclic rings have been synthesized and explored as epidermal growth factor receptor (EGFR) kinase inhibitors. Most of them displayed promising in vitro tyrosine kinase inhibition as well as potent cellular antiproliferative activity in the EGFR over-expressing breast cancer cell line (MCF-7). Compounds 12b and 13b that exhibited the highest inhibition in the kinase assay (89, 81% inhibition at 10 µM, respectively), showed potent antiproliferative effect against MCF-7 tumor cell line (IC(50) 1.04, 0.91 µM respectively). Molecular docking studies revealed that these compounds can bind to ATP binding site of the EGFR kinase domain and were involved in H-bonding with Met 793, in analogy to the known EGFR tyrosine kinase inhibitors. Moreover, compounds 15a-c possessed profound antitumor activity (IC(50) 0.59-0.73 µM) and significant EGFR-TK inhibition, making them of particular interest. In summary, the newly synthesized compounds provide promising new lead for the future design and development of anticancer agents of potential EGFR-TK inhibitory activity.

Antischistosomal action of thioxo-imidazolidine compounds: an ultrastructural and cytotoxicity study.

Schistosomiasis is a disease caused by helminthes of the genus Schistosoma, which threatens approximately 207 million people worldwide. Recently, strains of Schistosoma mansoni appear to be developing tolerance and resistance against Praziquantel, the most commonly available drug on the market used in the treatment of disease. This worrisome development justifies studies that seek alternatives for the prevention, treatment and cure of this disease. This study aimed to evaluate the in vitro activity of new imidazolidine compounds 1-benzyl-4-[(4-chloro-phenyl)-hydrazono]-5-thioxo-imidazolidin-2-one (LPSF/PT-5) and 1-(4-chloro-benzyl)-4-[(4-fluoro-phenyl)-hydrazono]-5-thioxo-imidazolidin-2-one (LPSF/PT-11) against adult worms of S. mansoni. LPSF/PT-5 and LPSF/PT-11 imidazolidine derivatives showed relevant schistosomicidal activity in vitro and induced significant ultrastructural alterations in worms and cell death: results similar to praziquantel. Thus, it is possible that these imidazolidine derivatives can be future candidates as schistosomotic drugs, but further studies are needed to elucidate the induced mechanisms behind this response.

The safety, tolerability, pharmacokinetics, and pharmacodynamics of single oral doses of RO5068760, an MEK inhibitor, in healthy volunteers: assessment of target suppression.

RO5068760, a substituted hydantoin, represents a new class of potent, highly selective, non-adenosine triphosphate (ATP)-competitive MEK1/2 inhibitors. The study aimed to determine the safety/tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of RO5068760 in human healthy volunteers. All participants received a single dose followed by 48 hours of pharmacokinetics, pharmacodynamics, and safety/tolerability assessments. The pharmacodynamics were measured by changes in ERK phosphorylation (pERK) in peripheral blood mononuclear cells, ex vivo stimulated by phorbol 12-myristate 13-acetate (PMA). Forty-eight participants received 6 doses (50, 100, 200, 400, 600, 800 mg). RO5068760 was well tolerated up to 800 mg. There were no clinically significant safety findings, including laboratory, electrocardiogram, ophthalmological assessment, and fecal occult blood tests. Of the total 13 adverse events (n = 12), 11 were mild, 2 were moderate, and none were severe, and only 5 were considered by the investigator as possibly related to treatment. RO5068760 was absorbed with a t(max), of 2 hours. Disposition appeared to be biphasic with a terminal elimination t(1/2) of 5 to 9 hours. The variability was moderate to high, ranging from 38% to 62% for C(max) and 41% to 69% AUC. Within the dose range tested, pERK inhibition was relatively modest with a mean maximal pERK suppression of 55%.

Synthesis and cytotoxic activity of 1-(1-benzoylindoline-5-sulfonyl)-4-phenylimidazolidinones.

The novel 1-(1-benzoylindoline-5-sulfonyl)-4-phenyl-4,5-dihydroimidazolones 2 shows highly potent and broad cytotoxicities. Their cytotoxicities against human lung carcinoma A549, human chronic myelogenous leukemia K562, and human ovarian adenocarcinoma SK-OV-3 are compatible with doxorubicin. Compound 2p (1-[(4-aminobenzoyl)indoline-5-sulfonyl])-4-phenyl-4,5-dihydroimidazolone) exhibits a cytotoxicity that is far more potent than doxorubicin and also exhibits highly effective antitumour activities against murine (3LL, Colon 26) and human xenograft (NCI-H23, SW620) tumor models.