Biological activity and computational analysis of novel acrylonitrile derived benzazoles as potent antiproliferative agents for pancreatic adenocarcinoma with antioxidative properties

Continuing our research into the anticancer properties of acrylonitriles, we present a study involving the design, synthesis, computational analysis, and biological assessment of novel acrylonitriles derived from methoxy, hydroxy, and N-substituted benzazole. Our aim was to examine how varying the number of methoxy and hydroxy groups, as well as the N-substituents on the benzimidazole core, influences their biological activity. The newly synthesized acrylonitriles exhibited strong and selective antiproliferative effects against the Capan-1 pancreatic adenocarcinoma cell line, with IC50 values ranging from 1.2 to 5.3 μM. Consequently, these compounds were further evaluated in three other pancreatic adenocarcinoma cell lines, while their impact on normal PBMC cells was also investigated to determine selectivity. Among these compounds, the monohydroxy-substituted benzimidazole derivative 27 emerged with the most profound and broad-spectrum anticancer antiproliferative activity being emerged as a promising lead candidate. Moreover, a majority of the acrylonitriles in this series exhibited significant antioxidative activity, surpassing that of the reference molecule BHT, as demonstrated by the FRAP assay (ranging from 3200 to 5235 mmolFe2+/mmolC). Computational analysis highlighted the prevalence of electron ionization in conferring antioxidant properties, with computed ionization energies correlating well with observed activities.

*Inactivation of encysted muscle larvae of Trichinella spiralis in pigs using Mebendazole

We evaluated the effect of 4 anthelmintic treatments on the viability of Trichinella spiralis encysted muscle larvae (ML) 55 days post infection (PI) in experimentally infected pigs. Muscle larvae were isolated from pig muscle by artificial digestion after oral treatment of pigs with Levamisole (8 mg/kg, daily for 5 days) and Mebendazole (50 mg/kg, daily for 5 days); Doramectin (0.3 mg/kg, single IM injection), and Moxidectin (0.5 mg/kg, single pour on). Isolated larvae from treated pigs were orally inoculated into mice to assess viability of ML from each treatment. Only Mebendazole treatment of pigs significantly reduced ML viability in mice. The effect of timing of the effective Mebendazole treatment on ML from a longer term infection was then examined in a second experiment. Analysis revealed that Mebendazole treatment of pigs with 250 mg/kg over 3 days (83 mg/kg/day) or 5 days (50 mg/kg/day) reduced numbers of ML recovered from pig tissues compared to untreated, infected controls, and rendered ML non-infective to mice; Mebendazole treatment of pigs with 250 mg/kg in a single dose was not effective in reducing ML numbers recovered from pigs or in impacting ML infectivity to mice. An examination of the lowest effective dose of Mebendazole on encysted ML was determined in a third experiment. Mebendazole of pigs with 5, 50, or 100 mg/kg over 3 days demonstrated that 5 or 50 mg/kg over 3 days insufficient to reduce infectivity in recovered ML, while 100 mg/kg (and 83 g from experiment 2) over 3 days significantly reduces infectivity of ML. This procedure provides a means to evaluate the efficacy of various anthelmintic treatments on the viability of Trichinella spiralis ML in pig tissues, and identified Mebendazole, at 83-100 mg/kg administered over a 3-5 day period as an anthelmintic which renders encysted Trichinella spiralis ML from pig tissues non-infective. As risk from Trichinella significantly impacts acceptance of pork from pasture-raised pigs, these data provide a method, especially for producers of these high-risk pigs, to eliminate the potential of Trichinella transmission from infected pork.

In Vitro Activity of Benzimidazole (SPR719) Against Clinical Isolates of Nontuberculous Mycobacteria With and Without Clarithromycin or Amikacin Resistance

Limited data are available regarding the in vitro activity of SPR719, a derivative of benzimidazole, against diverse nontuberculous mycobacteria (NTM) species. We investigated the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of SPR719 against clinical NTM isolates, including clarithromycin- and amikacin-resistant strains. NTM isolates were obtained from patients with NTM-pulmonary disease caused by various NTM species, including Mycobacterium avium complex, M. abscessus (subspecies abscessus and massiliense), M. kansasii, and M. fortuitum. Regardless of clarithromycin or amikacin resistance, the MIC and MBC values of SPR719 were comparable among these major pathogenic NTM species. In over 70% of the isolates, the MIC values were ≤2 μg/mL with MBC values of ≤4 μg/mL. The MIC and MBC values of M. kansasii were relatively lower than those of the other species with little difference between them, demonstrating the bactericidal properties of SPR719. The in vitro activity of SPR719 against major clinical NTM species suggests that SPR719 can serve as a novel treatment option for NTM-pulmonary disease.

Visible-Light Photoswitchable Benzimidazole Azo-Arenes as β-Arrestin2-Biased Selective Cannabinoid 2 Receptor Agonists

The cannabinoid 2 receptor (CB2 R) has high therapeutic potential for multiple pathogenic processes, such as neuroinflammation. Pathway-selective ligands are needed to overcome the lack of clinical success and to elucidate correlations between pathways and their respective therapeutic effects. Herein, we report the design and synthesis of a photoswitchable scaffold based on the privileged structure of benzimidazole and its application as a functionally selective CB2 R "efficacy-switch". Benzimidazole azo-arenes offer huge potential for the broad extension of photopharmacology to a wide range of optically addressable biological targets. We used this scaffold to develop compound 10 d, a "trans-on" agonist, which serves as a molecular probe to study the β-arrestin2 (βarr2) pathway at CB2 R. βΑrr2 bias was observed in CB2 R internalization and βarr2 recruitment, while no activation occurred when looking at Gα16 or mini-Gαi . Overall, compound 10 d is the first light-dependent functionally selective agonist to investigate the complex mechanisms of CB2 R-βarr2 dependent endocytosis.

Development of a three-colour digital PCR for early and quantitative detection of benzimidazole resistance-associated single nucleotide polymorphisms in Haemonchus contortus

Haemonchus contortus is the most pathogenic nematode in small ruminants and anthelmintic resistance (AR) hampers its efficient control. Early detection of AR status is required to reduce selection for AR and cannot be achieved using phenotypic tests. For benzimidazoles (BZs), the detection of AR-associated alleles characterised by single nucleotide polymorphisms (SNPs) in the isotype 1 β-tubulin gene allows early AR detection in strongyles. The F200Y, F167Y, E198A and E198L polymorphisms have been described in BZ-resistant populations with a clear variation in frequencies between regions. A novel digital PCR (dPCR) enables the detection of all of the above-described polymorphisms in H. contortus. Assays were validated using synthetic DNA fragments containing these SNPs. Then, larvae obtained and pooled at farm level from 26 Austrian and 10 Italian sheep farms were analysed. For all assays a detection limit of 15 copies/μl of resistance alleles and a high level of accuracy were demonstrated, allowing to detect allele frequencies of 1% in most samples. In Austrian samples, elevated frequencies of F200Y resistance alleles were detected on all farms. Polymorphisms in codon 167 and codon 198 were identified in H. contortus from Austria for the first time. In Italian samples, the frequency of resistance alleles was still comparatively low, but F200Y resistance alleles were traceable. In conclusion we developed for the first time dPCR assays that target all SNPs of relevance associated with BZ-resistance in H. contortus. Future research on AR development could benefit from an early onset of SNP-based surveillance that would include the developed assays for all SNPs of relevance. Improved surveillance in the long term will include other important, though less pathogenic, nematode genera in the analyses.

Evaluation of a refugia-based strategy for gastrointestinal nematodes on weight gain and fecal egg counts in naturally infected stocker calves administered combination anthelmintics

Refugia-based strategies associated with a combination of anthelmintic drugs belonging to different drug classes are becoming more common management practices to mitigate anthelmintic resistance (AR) in gastrointestinal nematodes (GIN) in small ruminants. Though refugia-based strategies have been largely demonstrated in small ruminants, cattle veterinarians and producers are considering such management strategies in grazing cattle production systems. Implementing refugia-based strategies lowers the amount of anthelmintics used in the herd and therefore slows the progression of AR by allowing a proportion of worms to escape drug selection pressure. The objective of this study was to observe the effect of a refugia-based strategy on body weight (BW), average daily gain (ADG) and fecal egg counts (FEC) of trichostongyle-type nematodes in naturally infected beef calves over a 131-day grazing season when compared with a whole herd treatment strategy, using the same combination of drugs. Stocker calves (n = 160) were ranked by body weight within sex then allocated to 16 paddocks, which were randomly assigned to one of two treatment groups. All calves in Group 1 (n = 80) were administered treatment, while in Group 2 (n = 80) the steer with the highest FEC in eggs per gram (EPG) within the paddock was left untreated. Treated calves received an extended release injectable 5 % eprinomectin (LongRange®, Boehringer Ingelheim Animal Health USA Inc.; 1 mL/50 kg of BW) and a 22.5 % oxfendazole oral suspension (Synanthic®, Boehringer Ingelheim Animal Health USA Inc.; 1 mL/50 kg of BW). Fecal egg counts and BW were recorded on days (D) -35, 0, 21, 131, and 148 to calculate the average fecal egg count reduction (FECR) and ADG for both groups. Linear mixed models, with paddock as the experimental unit, were used for analyses. The EPG differed on D21 (p < 0.01) and D131 (p = 0.057) with Group 2 having a higher average FEC (15.2 EPG D21; 57 EPG D131) compared with Group 1 (0.4 EPG D21; 37.25 EPG D131). However, there was no significant difference in average BW or ADG between treatment groups throughout the study. Results suggest refugia-based strategies could be implemented without significant negative impacts on average BW and ADG across other calves in the herd.

Albendazole from ovine excrements in soil and plants under real agricultural conditions: Distribution, persistence, and effects

Albendazole (ABZ), a broad-spectrum anthelmintic drug frequently used in livestock against parasitic worms (helminths), enters the environment mainly via faeces of treated animals left in the pastures or used as dung for field fertilization. To obtain information about the subsequent fate of ABZ, the distribution of ABZ and its metabolites in the soil around faeces along with uptake and effects in plants were monitored under real agricultural conditions. Sheep were treated with a recommended dose of ABZ; faeces were collected and used to fertilize fields with fodder plants. Soil samples (in two depths) and samples of two plants, clover (Trifolium pratense) and alfalfa (Medicago sativa), were collected at distances 0-75 cm from the faeces for 3 months after fertilization. The environmental samples were extracted using QuEChERS and LLE sample preparation procedures. The targeted analysis of ABZ and its metabolites was conducted by using the validated UHPLC-MS method. Two main ABZ metabolites, ABZ-sulfoxide (anthelmintically active) and ABZ-sulfone (inactive), persisted in soil (up to 25 cm from faeces) and in plants for three months when the experiment ended. In plants, ABZ metabolites were detected even 60 cm from the faeces and abiotic stress was observed in the central plants. The considerable distribution and persistence of ABZ metabolites in soil and plants amplify the negative environmental impact of ABZ documented in other studies.

[Treatment concepts for hepatic echinococcosis]

The incidence of both cystic (CE) and alveolar echinococcosis (AE) is increasing in Germany. The CE can often be managed with drug treatment and interventional strategies. In contrast, AE shows characteristics of a malignant disease with a high morbidity and mortality. Benzimidazoles are potent drugs for both entities but with the necessity for a lifelong follow-up and the risk of side effects as well as progression under treatment. Therefore, the indications for surgical resection have to be carefully considered; however, the combination of drug treatment and surgery is the only curative approach. Recently, the use of minimally invasive surgery with reduced morbidity and mortality has justified surgical resection for a broader set of patients; however, minimally invasive surgery requires a high level of expertise and optimal perioperative planning. Therefore, treatment strategies, especially for AE require an individual stratified risk-benefit assessment in an interdisciplinary consensus.

A Review On Modern Approaches To Benzimidazole Synthesis

Cancer is the second most source of cessation of life globally with 9.6 million expirations each stage around the globe. The resistance to the current chemotherapies urges the researchers to develop new drugs to be available in the market. Among the wide range of drugs synthesized, heterocyclic compounds play a major role due to the abundance of heterocyclic rings in biological substances. In medicinal chemistry, benzimidazole is an important pharmacophore and a privileged structure. This bicyclic compound is made up of the fusion of a six-membered benzene ring and a five-membered imidazole ring with two nitrogen atoms at 1,3-positions. The benzimidazole ring has a great deal of stability. Many strong acids and alkalis do not affect benzimidazoles. Only under extreme conditions does benzimidazoles benzene ring cleave. Except in certain circumstances, the benzimidazole ring is also quite resistant to reduction. It is the most popular nucleus to study because of its wide range of biological functions. The recently developed methods for preparing benzimidazoles, such as condensation of o-phenylene diamines (OPDs) with aldehydes and many others using a wide range of nano, metal-based catalysts under solvent-free conditions, are discussed in detail in the current studies.

Synthesis of multifunctional crown ether covalent organic nanospheres as stationary phase for capillary electrochromatography

Crown ethers are macrocyclic polyether compounds containing multiple -oxo-methylene-structural units, which are often used for recognition of metal ions and ammonium ions. Inspired by the molecular design of rotaxanes, a novel covalent organic nanospheres material (CON ADBC-Tp) constructed by 4,4'-diaminodibenzo-18-crown-6 (ADBC) and 2,4,6-triformylphloroglucinol (Tp) was rationally designed as stationary phase for the separation of compounds containing imidazole structure. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were carried out to confirm the morphology and composition of ADBC-Tp and ADBC-Tp modified capillary column. Thanks to the introduction of crown ether building ligands, the prepared capillary column exhibited excellent separation selectivity towards protonated imidazole structure, with benzimidazole and its 2-substituted derivatives as modal analytes. Moreover, separation of fungicides, nucleobases, short peptides and sulfanilamides were achieved on ADBC-Tp@capillary. The multifunctional ADBC-Tp@capillary with satisfactory reproducibility and stability gives great promise for separation science.

Identification of bicyclic compounds that act as dual inhibitors of Bcl-2 and Mcl-1

Elevated expression of anti-apoptotic proteins, such as Bcl-2 and Mcl-1 contributes to poor prognosis and resistance to current treatment modalities in multiple cancers. Here, we report the design, synthesis and characterization of benzimidazole chalcone and flavonoid scaffold-derived bicyclic compounds targeting both Bcl-2 and Mcl-1 by optimizing the structural differences in the binding sites of both these proteins. Initial docking screen of Bcl-2 and Mcl-1 with pro-apoptotic protein Bim revealed possible hits with optimal binding energies. All the optimized bicyclic compounds were screened for their in vitro cytotoxic activity against two oral cancer cell lines (AW8507 and AW13516) which express high levels of Bcl-2 and Mcl-1. Compound 4d from the benzimidazole chalcone series and compound 6d from the flavonoid series exhibited significant cytotoxic activity (IC₅₀ 7.12 μM and 17.18 μM, respectively) against AW13516 cell line. Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) analysis further demonstrated that compound 4d and compound 6d could effectively inhibit the Bcl-2 and Mcl-1 proteins by displacing their BH3 binding partners. Both compounds exhibited potent activation of canonical pathway of apoptosis evident from appearance of cleaved Caspase-3 and PARP. Further, treatment of oral cancer cells with the inhibitors induced dissociation of the BH3 only protein Bim from Mcl-1 and Bak from Bcl-2 but failed to release Bax from Bcl-xL thereby confirming the nature of compounds as BH3-mimetics selectively targeting Bcl-2 and Mcl-1. Our study thus identifies bicyclic compounds as promising candidates for anti-apoptotic Bcl-2/Mcl-1 dual inhibitors with a potential for further development.

Determination of benzimidazoles in fruits by open-tubular capillary electrochromatography based on ionic liquids grafted covalent organic frameworks

A novel capillary electrochromatography method has been developed for the simultaneous quantification of ten benzimidazole fungicides in fruits. Herein, covalent organic frameworks (COFs) and ionic liquids (ILs) were successfully introduced to prepare open-tubular capillary column to improve the loading capacity and separation performance. The parameters effecting the analytical performance including pH and concentration of running buffer, separation voltage and the addition of organic solvent were investigated systematically. Under the optimized conditions, the method allowed the baseline separation of ten benzimidazole fungicides, and showed a good linearity in the range of 3.5-200 μg kg^-1 with the detection limits between 1.0 and 2.8 μg kg^-1. The intraday and interday precisions for recoveries were lower than 7.9% and 12.2%, respectively. Intraday and interday precisions for their retention times were lower than 3.2% and 6.6%, respectively. Satisfactory recoveries for grape, pear and orange samples at two concentrations were obtained ranging from 85.0 to 95.9% with RSDs lower than 7.8%, demonstrating the potential applications of the open-tubular capillary electrochromatography method for trace benzimidazole fungicides analysis in fruits.

Population replacement of benzimidazole-resistant Haemonchus contortus with susceptible strains: evidence of changes in the resistance status

The spread of anthelmintic resistance (AR) in nematode populations threatens the viability of sheep production systems worldwide, and warrants the adoption of sensitive, practical, and standardized tests to detect AR. The aim of this study was to characterize the replacement of an Haemonchus contortus population resistant to benzimidazoles (BZDs) by a susceptible one, by means of both phenotypic and genotypic techniques. Phenotypic methods to assess BZD resistance included in vivo tests, such as the fecal egg count reduction test (FECRT), and in vitro tests, such as the egg hatch assay (EHA). Additionally, genotypification of polymorphisms associated with BZD resistance by sequencing a fragment of the isotype 1 β-tubulin gene was carried out. The initial, BZD-resistant population (initial Balcarce population) exhibited an egg count reduction (ECR) of 59.3%. Following refugium replacement, the final population (final Balcarce population) exhibited an ECR of 95.2%. For the initial Balcarce population, the median effective dose (ED₅₀) for the EHA was 0.607 μg thiabendazole (TBZ)/mL, with a rate of eclosion at a discriminating dose (E_DD) of 0.1 μg TBZ/mL of 76.73%. For the final Balcarce population, ED₅₀ was 0.02 μg TBZ/mL, and E_DD was 1.97%. In the initial population, 93% of the analyzed individuals exhibited genotypic combinations associated with BZD resistance (53% Phe/Phe₁₆₇-Tyr/Tyr₂₀₀, 37% Phe/Tyr₁₆₇-Phe/Tyr₂₀₀, and 3% Phe/Tyr₁₆₇-Glu/Leu₁₉₈). Conversely, no combination associated with resistance was found in individuals from the final population. All of the tests were useful for detecting AR to BZDs. The results from the genetic and phenotypical studies were consistent, and the resulting information greatly aided in interpreting the outcomes of the population replacement and the potential impact of this strategy on management of AR.

PTSA-catalyzed selective synthesis and antibacterial evaluation of 1,2-disubstituted benzimidazoles

Herein, we developed a convenient and efficient method via protonation of p-toluenesulfonic acid promoted cyclocondensation of o-phenylenediamine and aldehydes for selectively synthesizing 1,2-disubstituted benzimidazoles. This method displayed broad substrate adaptability and afforded the desired products in moderate to excellent yield in short reaction time. The effect of different substituents on the yield was investigated by extending optimum reaction conditions, which was further confirmed by theoretical calculations. It suggested that the surface electrostatic potential of oxygen atom and nitrogen atom on the substrates played important role in the synthesis of 1,2-disubstituted benzimidazoles. Besides, the crystal structure of compound 2t in the orthorhombic space group P2(1)/c was presented. Also, the anti-mycolicibacterium smegmatis (MC2155) activity was evaluated using rifampicin as a positive control. The products (2a, 2b, 2c, 2i, 2j, 2k, 2m) showed good antibacterial activities which were comparable to rifampicin.

Moving beyond the state of the art of understanding resistance mechanisms in hookworms: confirming old and suggesting new associated SNPs

Hookworms represent a serious problem for human and animal health in different parts of the world. One of the suggested control strategies for parasitosis caused by members of the Ancylostomatidae family is mass drug aministration with benzimidazole compounds. This strategy has been proven to lead to the establishment of resistant strains in several nematodes related to SNPs at codons 167, 198 and 200 of the beta-tubulin isotype-1 gene. Through bioassay and in vivo analysis, we successfully isolated an albendazole-resistant A. ceylanicum strain by drug selective pressure. We observed a strong correlation between the presence of SNPs at codon 198 and drug resistance. We also described for the first time, in hookworms, the presence of SNP A200L, already described at low frequencies in ruminant nematodes. The results presented here are important for updating the current knowledge about anthelmintic resistance in hookworms. The answers and the new questions raised may provide a basis for the establishment of more effective control strategies.

DNA-Compatible Nitro Reduction and Synthesis of Benzimidazoles

A key factor for productive DNA-encoded libraries is the chemical diversity of the small molecule moiety attached to an encoding DNA oligomer. The library structure diversity is often limited to DNA-compatible chemical reactions in aqueous media. Herein, we describe a facile process for reducing aryl nitro groups to aryl amines by using sodium dithionite (Na₂S₂O₄). The new protocol offers simple operation and circumvents the pyrophoric potential of the conventional method (Raney nickel). The utility of this method is demonstrated by the versatile synthesis of benzimidazoles on DNA.

A magnetic solid phase extraction based on UiO-67@GO@Fe3O4 coupled with UPLC-MS/MS for the determination of nitroimidazoles and benzimidazoles in honey

A novel composite material consisting of zirconiumbiphenyldicarboxylate metal-organic framework, graphite oxide and ferroferric oxide was fabricated by a facile one-step method and served as a magnetic solid phase extraction sorbent for the simultaneous determination of nitroimidazoles and benzimidazoles in honey. The amount of graphite oxide for the synthesis of composite material and analysis parameters were optimized. The optimum parameters were: dipotassium hydrogen phosphate buffer solution (pH 6) as diluent solvent, adsorption time 10 min, desorption time 5 min, methanol/acetonitrile (1:1, V/V) as desorption solvent. The targets were detected by ultra-high performance liquid chromatography tandem mass spectrometry. The recoveries of twelve analytes ranged in 70.5%-103.4% with relative standard deviations lower than 12.9% (n = 3). The quantification limits were 0.2-0.6 μg/kg. Using the composite material as sorbent, a simple, rapid and environmental-friendly method based on magnetic solid phase extraction was successfully developed for determination of seven nitroimidazoles and five benzimidazoles in honey.

Advances in the treatment, diagnosis, control and scientific understanding of taeniid cestode parasite infections over the past 50 years

In the past 50 years, enormous progress has been made in the diagnosis, treatment and control of taeniid cestode infections/diseases and in the scientific understanding thereof. Most interest in this group of parasites stems from the serious diseases that they cause in humans. It is through this lens that we summarize here the most important breakthroughs that have made a difference to the treatment of human diseases caused by these parasites, reduction in transmission of the taeniid species associated with human disease, or understanding of the parasites' biology likely to impact diagnosis or treatment in the foreseeable future. Key topics discussed are the introduction of anti-cestode drugs, including benzimidazoles and praziquantel, and the development of new imaging modalities that have transformed the diagnosis and post-treatment monitoring of human echinococcoses and neurocysticercosis. The availability of new anti-cestode drugs for use in dogs and a detailed understanding of the transmission dynamics of Echinococcus granulosus sensu lato have underpinned successful programs that have eliminated cystic echinococcosis in some areas of the world and greatly reduced the incidence of infection in others. Despite these successes, cystic and alveolar echinococcosis and neurocysticercosis continue to be prevalent in many parts of the world, requiring new or renewed efforts to prevent the associated taeniid infections. Major advances made in the development of practical vaccines against E. granulosus and Taenia solium will hopefully assist in this endeavour, as might the understanding of the parasites' biology that have come from an elucidation of the nuclear genomes of each of the most important taeniid species causing human diseases.

Imidazoles and benzimidazoles as putative inhibitors of SARS-CoV-2 B.1.1.7 (Alpha) and P.1 (Gamma) variant spike glycoproteins: A computational approach

COVID-19 is an unprecedented pandemic threatening global health, and variants were discovered rapidly after the pandemic. The two variants, namely the SARS-CoV-2 B.1.1.7 (Alpha) and P.1 (Gamma), were formed by the mutations in the receptor binding domain of spike glycoprotein (SGP). These two variants are known to possess a high binding affinity with the angiotensin-converting enzyme 2. Amidst the rapid spread of these mutant strains, research and development of novel molecules become tedious and labour-intensive. Imidazole and benzimidazole scaffolds were selected in this study based on their unique structural features and electron-rich environment, resulting in increased affinity against a variety of therapeutic targets. In the current study, imidazole- and benzimidazole-based anti-parasitic drugs are repurposed against SARS-CoV-2 Alpha and Gamma variant spike glycoproteins using computational strategies. Out of the screened 15 molecules, flubendazole and mebendazole have exhibited promising binding features to the two receptors (PDB ID: 7NEH and 7NXC), as evidenced by their glide score and binding free energy. The results are compared with that of the two standard drugs, remdesivir and hydroxychloroquine. Flubendazole and mebendazole have become convenient treatment options against mutant lineages of SARS-CoV-2. The edge of the flubendazole was further established by its stability in MD simulation conducted for 100 ns employing GROMACS software. Further, in vitro and in vivo studies are essential to understand, if flubendazole and mebendazole indeed hold the promise to manage SARS-CoV-2 mutant stains.

Treatment of overdose in the synthetic opioid era

Overdose deaths are often viewed as the leading edge of the opioid epidemic which has gripped the United States over the past two decades (Skolnick, 2018a). This emphasis is perhaps unsurprising because opioid overdose is both the number-one cause of death for individuals between 25 and 64 years old (Dezfulian et al., 2021) and a significant contributor to the decline in average lifespan (Dowell et al., 2017). Exacerbated by the COVID 19 pandemic, it was estimated there were 93,400 drug overdose deaths in the United States during the 12 months ending December 2020, with more than 69,000 (that is, >74%) of these fatalities attributed to opioid overdose (Ahmad et al., 2021). However, the focus on mortality statistics (Ahmad et al., 2021; Shover et al., 2020) tends to obscure the broader medical impact of nonfatal opioid overdose. Analyses of multiple databases indicate that for each opioid-induced fatality, there are between 6.4 and 8.4 non-fatal overdoses, exacting a significant burden on both the individual and society. Over the past 7-8 years, there has been an alarming increase in the misuse of synthetic opioids ("synthetics"), primarily fentanyl and related piperidine-based analogs. Within the past 2-3 years, a structurally unrelated class of high potency synthetics, benzimidazoles exemplified by etonitazene and isotonitazene ("iso"), have also appeared in illicit drug markets (Thompson, 2020; Ujvary et al. 2021). In 2020, it was estimated that over 80% of fatal opioid overdoses in the United States now involve synthetics (Ahmad et al., 2021). The unique physicochemical and pharmacological properties of synthetics described in this review are responsible for both the morbidity and mortality associated with their misuse as well as their widespread availability. This dramatic increase in the misuse of synthetics is often referred to as the "3rd wave" (Pardo et al., 2019; Volkow and Blanco, 2020) of the opioid epidemic. Among the consequences resulting from misuse of these potent opioids is the need for higher doses of the competitive antagonist, naloxone, to reverse an overdose. The development of more effective reversal agents such as those described in this review is an essential component of a tripartite strategy (Volkow and Collins, 2017) to reduce the biopsychosocial impact of opioid misuse in the "synthetic era".

Bioaugmentation of animal feces as a mean to mitigate environmental contamination with anthelmintic benzimidazoles

Anthelmintics are used to control infestations of ruminants by gastrointestinal nematodes. The limited metabolism of anthelmintics in animals result in their excretion in feces. These could be piled up in the floor of livestock farms, constituting a point source of environmental contamination, or used as manures in agricultural soils where they persist or move to water bodies. Hence the removal of anthelmintics from feces could mitigate environmental contamination. We hypothesized that a thiabendazole-degrading bacterial consortium would also degrade other benzimidazole anthelmintics like albendazole, fenbendazole, ricobendazole, mebendazole and flubendazole. In liquid culture tests the consortium was more effective in degrading compounds with smaller benzimidazole substituents (thiabendazole, albendazole, ricobendazole), rather than benzimidazoles with bulky substituents (fenbendazole, flubendazole, mebendazole). We then explored the bioaugmentation capacity of the consortium in sheep feces fortified with 5 and 50 mg kg^-1 of thiabendazole, albendazole and fenbendazole. Bioaugmentation enhanced the degradation of all compounds and its efficiency was accelerated upon fumigation of feces, in the absence of the indigenous fecal microbial community. The latter contributes to anthelmintics degradation as suggested by the significantly lower DT₅₀ values in fumigated vs non-fumigated, non-bioaugmented feces. Overall, bioaugmentation could be an efficient means to reduce environmental exposure to recalcitrant anthelmintic benzimidazoles.

Proof of the environmental circulation of veterinary drug albendazole in real farm conditions

Anthelmintics, drugs against parasitic worms, are frequently used in livestock and might act as danger environmental microcontaminants. The present study was designed to monitor the possible circulation of common anthelmintic drug albendazole (ABZ) and its metabolites in the real agriculture conditions. The sheep were treated with the recommended dose of ABZ. Collected faeces were used for the fertilization of a field with fodder plants (alfalfa and clover) which served as feed for sheep from a different farm. The selective ultrasensitive mass spectrometry revealed surprisingly high concentrations of active ABZ metabolite (ABZ-sulphoxide) in all samples (dung, plants, ovine plasma, rumen content and faeces). Our results prove for the first time an undesirable permeation of ABZ metabolites from sheep excrement into plants (used as fodder) and subsequently to other sheep in real agricultural conditions. This circulation causes the permanent exposition of the ecosystems and food-chain to the drug and can promote the development of drug resistance in helminths.

Improving stool sample processing and pyrosequencing for quantifying benzimidazole resistance alleles in Trichuris trichiura and Necator americanus pooled eggs

BACKGROUND

There is an urgent need for an extensive evaluation of benzimidazole efficacy in humans. In veterinary science, benzimidazole resistance has been mainly associated with three single-nucleotide polymorphisms (SNPs) in the isotype-1 β-tubulin gene. In this study, we optimized the stool sample processing methodology and resistance allele frequency assessment in Trichuris trichiura and Necator americanus anthelmintic-related SNPs by pyrosequencing, and standardized it for large-scale benzimidazole efficacy screening use.

METHODS

Three different protocols for stool sample processing were compared in 19 T. trichiura-positive samples: fresh stool, egg concentration using metallic sieves with decreasing pore size, and egg concentration followed by flotation with saturated salt solution. Yield of each protocol was assessed by estimating the load of parasite DNA by real-time PCR. Then, we sequenced a DNA fragment of the β-tubulin gene containing the putative benzimidazole resistance SNPs in T. trichiura and N. americanus. Afterwards, resistant and susceptible-type plasmids were produced and mixed at different proportions, simulating different resistance levels. These mixtures were used to compare previously described pyrosequencing assays with processes newly designed by our own group. Once the stool sample processing and the pyrosequencing methodology was defined, the utility of the protocols was assessed by measuring the frequencies of putative resistance SNPs in 15 T. trichiura- and 15 N. americanus-positive stool samples.

RESULTS

The highest DNA load was provided by egg concentration using metallic sieves with decreasing pore size. Sequencing information of the β-tubulin gene in Mozambican specimens was highly similar to the sequences previously reported, for T. trichiura and N. americanus, despite the origin of the sample. When we compared pyrosequencing assays using plasmids constructs, primers designed in this study provided the most accurate SNP frequencies. When pooled egg samples were analysed, none of resistant SNPs were observed in T. trichiura, whereas 17% of the resistant SNPs at codon 198 were found in one N. americanus sample.

CONCLUSIONS

We optimized the sample processing methodology and standardized pyrosequencing in soil-transmitted helminth (STH) pooled eggs. These protocols could be used in STH large-scale screenings or anthelmintic efficacy trials.

Design, synthesis, in vitro and in vivo anti-respiratory syncytial virus (RSV) activity of novel oxizine fused benzimidazole derivatives

Respiratory syncytial virus (RSV) causes serious lower respiratory tract infections. Currently, the only clinical anti-RSV drug is ribavirin, but ribavirin has serious toxic side effect and can only be used by critically ill patients. A series of benzimidazole derivatives were synthesized starting from 1,4:3,6-dianhydro-d-fructose and a variety of o-phenylenediamines. Evaluation of their antiviral activity showed that compound a27 had the highest antiviral activity with a half maximal effective concentration (EC₅₀) of 9.49 μM. Investigation of the antiviral mechanism of compound a27 indicated that it can inhibit the replication of RSV by inhibiting apoptosis and autophagy pathways. Retinoic acid-inducible gene (RIG)-I, TNF receptor associated factor (TRAF)-3, TANK binding kinase (TBK)-1, interferon regulatory factor (IRF)-3, nuclear factor Kappa-B (NF-κB), interferon (IFN)-β, Toll-like receptor (TLR)-3, interleukin (IL)-6 were suppressed at the cellular level. Mouse lung tissue was subjected to hematoxylin and eosin (HE) staining and immunohistochemistry, which showed that RSV antigen and M gene expression could be reduced by compound a27. Decreased expression of RIG-I, IRF-3, IFN-β, TLR-3, IL-6, interleukin (IL)-8, interleukin (IL)-10, inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α was also found in vivo.

Synthesis, Characterization and Antimicrobial Evaluation of Some N-Substituted Benzimidazole Derivatives

BACKGROUND

Due to the appearance of communicable microbial diseases and the toxicity related with presently used several antimicrobials such as β-lactam antibiotics, tetracyclines, quinolones, macrolides, glycopeptides (vancomycin) etc, demand for new antimicrobial agents has become a great concern in new technologies to improve efficacy and safety.

METHODS

In search of new antimicrobial agents with higher potency, some N-substituted benzimidazole derivatives (4, 5a-5h & 6) were obtained by chloroacetylation of benzimidazole followed by reaction with different amines, which were characterized by spectroscopic methods. All the target compounds were evaluated for their antibacterial and antifungal activity against microorganisms using two-fold serial dilution method.

RESULTS

Among the compounds evaluated, compounds 4 and 5d exhibited potent activity against Bacillus thuringiensis and Candida albicans while showed moderate activity against Escherischia coli when compared to amoxicillin and fluconazole. Compound 5a showed significant activity against tested microorganisms.

CONCLUSION

From the current study, it may be concluded that synthesized compounds are fulfilling in terms of their structural distinctiveness and marked biological properties. These compounds might be encouraged to initiate a new class of antimicrobial agents.

Multispecific resistance of sheep trichostrongylids in Austria

Anthelmintic overuse and failure to implement methods preventing the development and spread of anthelmintic resistance (AR) have led to an alarming increase of resistant ovine trichostrongylids worldwide. The aim of the present study was to determine whether the routine anthelmintic treatment strategy was effective, to obtain insights into the frequency of AR in trichostrongylids of sheep in Austria, and to determine the presence of different trichostrongylid genera. On 30 sheep farms, the faecal egg count reduction test (FECRT) was performed with the Mini-FLOTAC technique in two consecutive studies. In study 1, only fenbendazole and moxidectin were tested, while different compounds and products were used in study 2. Overall, 33 treatment groups were formed: 11 groups were treated with benzimidazoles (fenbendazole and albendazole), 2 groups with avermectins (ivermectin, doramectin), 18 groups with moxidectin, and two groups with monepantel. Reduced efficacy was detected in 64%, 100%, 28% and 50% of these groups, respectively. The most frequently detected genus in larval cultures was Haemonchus, which had been barely detected in Austria previously, followed by Trichostrongylus. Multispecific resistance of trichostrongylids in Austria seems to be on the rise and H. contortus was detected unexpectedly frequently in comparison to previous studies. There is an urgent need to develop efficient communication strategies aimed at improving the engagement of farmers and veterinarians in sustainable parasite control.

In vitro selection of Giardia duodenalis for Albendazole resistance identifies a β-tubulin mutation at amino acid E198K

Benzimidazole-2-carbamate (BZ) compounds, including Albendazole (Alb), are one of just two drug classes approved to treat the gastrointestinal protist Giardia duodenalis. Benzimidazoles bind to the tubulin dimer interface overlapping the colchicine binding site (CBS) of β-tubulin, thereby inhibiting microtubule polymerisation and disrupting microtubule networks. These BZ compounds are widely used as anthelmintic, anti-fungal and anti-giardial drugs. However, in helminths and fungi, BZ-resistance is widespread and caused by specific point mutations primarily occurring at F167, E198 and F200 in β-tubulin isoform 1. BZ-resistance in Giardia is reported clinically and readily generated in vitro, with significant implications for Giardia control. In Giardia, BZ mode of action (MOA) and resistance mechanisms are presumed but not proven, and no mutations in β-tubulin have been reported in association with Alb resistance (AlbR). Herein, we undertook detailed in vitro drug-susceptibility screens of 13 BZ compounds and 7 Alb structural analogues in isogenic G. duodenalis isolates selected for AlbR and podophyllotoxin, another β-tubulin inhibitor, as well as explored cross-resistance to structurally unrelated, metronidazole (Mtz). AlbR lines exhibited co-resistance to many structural variants in the BZ-pharmacophore, and cross-resistance to podophyllotoxin. AlbR lines were not cross-resistant to Mtz, but MtzR lines had enhanced survival in Alb. Lastly, Alb analogues with longer thioether substituents had decreased potency against our AlbR lines. In silico modelling indicated the Alb-β-tubulin interaction in Giardia partially overlaps the CBS and corresponds to residues associated with BZ-resistance in helminths and fungi (F167, E198, F200). Sequencing of Giardia β-tubulin identified a single nucleotide polymorphism resulting in a mutation from glutamic acid to lysine at amino acid 198 (E198K). To our knowledge, this is the first β-tubulin mutation reported for protistan BZ-resistance. This study provides insight into BZ mode of action and resistance in Giardia, and presents a potential avenue for a genetic test for clinically resistance isolates.

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In vitro albendazole-resistant Giardia were broadly resistant to benzimidazole-2-carbamates.

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Cross-resistance to structurally unrelated microtubule inhibitors was observed.

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The predicted Giardia benzimidazole binding overlaps the colchicine binding site.

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The E198K β-tubulin mutation was identified in the albendazole-resistant line.

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Metronidazole-resistance may enhance acquisition of albendazole-resistance.

Pretreatment and determination methods for benzimidazoles: An update since 2005

Benzimidazoles, commonly used as pesticides and veterinary drugs, have posed a threat to human health and the environment due to unreasonable use and lack of valid regulation. Therefore, an up-to-date and comprehensive summary of the pretreatment and analytical approaches in different substrates is urgently needed. The present review consequently updates and covers various newly developed pretreatment methods (e.g., cationic micellar precipitation, magnetic-solid phase extraction, hollow fiber liquid phase microextraction, disperse liquid-liquid microextraction-solidified floating organic drop, stir cake sorptive extraction, solid phase microextraction method, QuEChERS, and molecular imprinted polymer-based methods) since 2005. The review also elaborates and discusses different determination methods (e.g., newly developed HPLC and related methods, improved spectrofluorimetry methods, capillary electrophoresis, and the electrochemical sensor). Furthermore, some critical points and prospects are highlighted, to describe the trends in this area.

Copper nanoparticles against benzimidazole-resistant Monilinia fructicola field isolates

Nano-fungicides are expected to play an important role in future plant disease management. Their unique properties include a broad antimicrobial action, increased effectiveness in lower doses, slower a.i. release and/or enhanced drug delivery and an ability to control drug-resistant pathogens, which makes them appealing candidates for use as eco-friendly antifungal alternatives to counter fungicides resistance. Copper nanoparticles (Cu-NPs) could suppress mycelial growth in both sensitive (BENS) and resistant (BEN-R) Monilinia fructicola isolates harboring the E198A benzimidazole resistance mutation, more effectively than copper oxide NPs (CuO-NPs) and Cu(OH)₂. A significant synergy of Cu-NPs with thiophanate methyl (TM) was observed against BEN-S isolates both in vitro and when applied on plum fruit suggesting enhanced availability or nanoparticle induced transformation of TM to carbendazim. ATP-dependent metabolism is probably involved in the mode of fungitoxic action of Cu-NPs as indicated by the synergy observed between Cu-NPs and the oxidative phosphorylation-uncoupler fluazinam (FM). Copper ion release contributed in the toxic action of Cu-NPs against M. fructicola, as indicated by synergism experiments with ethylenediaminetetraacetic acid (EDTA), although the lack of correlation between nano and bulk/ionic copper forms indicate an additional nano-property mediated mechanism of fungitoxic action. Results suggested that Cu-NPs can be effectively used in future plant disease management as eco-friendly antifungal alternatives to counter fungicides resistance and reduce the environmental footprint of synthetic fungicides.

Synthesis, Molecular Docking, and Biological Evaluation of Benzimidazole Derivatives as Selective Butyrylcholinesterase Inhibitors

BACKGROUND

Benzimidazole is an interesting pharmacophore which has been extensively studied in medicinal chemistry due to its high affinity towards various enzymes and receptors. Its derivatives have been previously shown to possess a wide range of biological activities including anthelmintic, antihypertensive, antiulcer, as well as anticholinesterase activity.

OBJECTIVE

The objective of this study is to search for more potent benzimidazole-based cholinesterase inhibitors, through the modification of the 1- and 2-positions of the benzimidazole core.

METHODS

Synthesis of compounds were carried out via a 4-step reaction scheme following a previously reported protocol. Structure-activity relationship of the compounds are established through in vitro cholinesterase assays and in silico docking studies. Furthermore, cytotoxicity and blood brain barrier (BBB) permeability of the compounds were also investigated.

RESULTS

Among the synthesised compounds, three of them (5IIa, 5IIb, and 5IIc) exhibited potent selective butyrylcholinesterase inhibition at low micromolar level. The compounds did not show any significant cytotoxicity when tested against a panel of human cell lines. Moreover, the most active compound, 5IIc, was highly permeable across the blood brain barrier.

CONCLUSION

In total 10 benzimidazole derivatives were synthesized and screened for their AChE and BuChE inhibitory activities. Lead compound 5Iic, represents a valuable compound for further development as potential AD therapeutics.

Use of silver nanoparticles to counter fungicide-resistance in Monilinia fructicola

The potential of Ag-NPs to suppress Monilia fructicola isolates and to broaden the effectiveness of fungicides to overcome resistance was tested in vitro and in vivo. Twenty-three M. fructicola isolates were subjected to fungitoxicity screening with a number of fungicides in vitro, which resulted in the detection of 18 isolates resistant to benzimidazoles (BEN-R) thiophanare methyl (TM) and carbendazim (CARB). DNA sequencing revealed the E198A resistance mutation in the β-tubulin gene, target site of the benzimidazole fungicides in all resistant isolates. Ag-NPs effectively suppressed mycelial growth in both sensitive (BENS) and resistant isolates. The combination of Ag-NPs with TM led to a significantly enhanced fungitoxic effect compared to the individual treatments regardless resistant phenotype (BEN-R/S) both in vitro and when applied on apple fruit. The above observed additive/synergistic action is probably associated with an enhanced Ag-NPs activity/availability as indicated by the positive correlation between Ag-NPs and TM + Ag-NPs treatments. No correlation was found between AgNO₃ and Ag-NPs suggesting that difference(s) exist in the fungitoxic mechanism of action between nanoparticles and their ionic counterparts. Synergy observed between Ag-NPs and the oxidative phosphorylation-uncoupler fluazinam (FM) against both resistance phenotypes indicates a possible role of energy (ATP) metabolism in the mode of action of Ag-NPs. Additionally, the role of released silver ions on the fungitoxic action of Ag-NPs against M. fructicola was found to be limited because the combination with NaCl revealed a synergistic rather than the antagonistic effect that would be expected from silver ion binding with chlorine ions. The results of this study suggested that Ag-NPs can be effectively used against M. fructicola and when used in combination with conventional fungicides they could provide the means for countering benzimidazole resistance and at the same time reduce the environmental impact of synthetic fungicides by reducing doses needed for the control of the pathogen.

N-substituted benzimidazole acrylonitriles as in vitro tubulin polymerization inhibitors: Synthesis, biological activity and computational analysis

We present the design, synthesis and biological activity of novel N-substituted benzimidazole based acrylonitriles as potential tubulin polymerization inhibitors. Their synthesis was achieved using classical linear organic and microwave assisted techniques, starting from aromatic aldehydes and N-substituted-2-cyanomethylbenzimidazoles. All newly prepared compounds were tested for their antiproliferative activity in vitro on eight human cancer cell lines and one reference non-cancerous assay. N,N-dimethylamino substituted acrylonitriles 30 and 41, bearing N-isobutyl and cyano substituents placed on the benzimidazole nuclei, showed strong and selective antiproliferative activity in the submicromolar range of inhibitory concentrations (IC₅₀ 0.2-0.6 μM), while being significantly less toxic than reference systems docetaxel and staurosporine, thus promoting them as lead compounds. Mechanism of action studies demonstrated that two most active compounds inhibited tubulin polymerization. Computational analysis confirmed the suitability of the employed benzimidazole-acrylonitrile skeleton for the binding within the colchicine binding site in tubulin, thus rationalizing the observed antitumor activities, and demonstrated that E-isomers are active substances. It also provided structural determinants affecting both the binding position and the matching affinities, identifying the attached NMe₂ group as the most dominant in promoting the binding, which allows ligands to optimize favourable cation∙∙∙π and hydrogen bonding interactions with Lys352.

The use of ITS-2 rDNA nemabiome metabarcoding to enhance anthelmintic resistance diagnosis and surveillance of ovine gastrointestinal nematodes

A lack of quantitative information on the species composition of parasite communities present in fecal samples is a major limiting factor for the sensitivity, accuracy and interpretation of the diagnostic tests commonly used to assess anthelmintic efficacy and resistance. In this paper, we investigate the ability of ITS-2 rDNA nemabiome metabarcoding to enhance fecal egg count reduction testing by providing information on the effect of drug treatments on individual parasite species. Application of ITS-2 rDNA nemabiome metabarcoding to fecal samples from ewes from over 90 flocks across western Canada revealed high gastrointestinal nematode infection intensities in many flocks with Haemonchus contortus being the most abundant species followed by Teladorsagia circumcincta and then Trichostrongylus colubriformis. Integration of ITS-2 rDNA nemabiome metabarcoding with pre- and post-treatment fecal egg counting revealed consistently poor efficacy of producer-applied ivermectin and benzimidazole treatments against H. contortus, but much better efficacy against T. circumcincta and T. colubriformis, except for in a small number of flocks. Integration of nemabiome ITS-2 rDNA metabarcoding with Fecal Egg Count Reduction Tests (FECRT), undertaken on farm visits, confirmed that ivermectin and fenbendazole resistance is widespread in H. contortus but is currently less common in T. circumcincta and T. colubriformis in western Canada. FECRT/nemabiome testing did not detect moxidectin resistance in any GIN species but suggested the early emergence of levamisole resistance specifically in T. circumcincta. It also revealed that although poor efficacy to closantel was relatively common, based on total fecal egg counts, this was due to its narrow spectrum of activity rather than the emergence of anthelmintic resistance. This study illustrates the value of ITS-2 rDNA nemabiome metabarcoding to improve fecal egg count resistance testing, perform large-scale anthelmintic resistance surveillance and direct more targeted rational anthelmintic use.

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Nemabiome metabarcoding in anthelmintic resistance diagnostics and surveillance.

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Producer-applied treatment results were consistent with controlled FECRT.

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Widespread BZ and IVM resistance in H. contortus in western Canada.

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Only sporadic BZ and IVM resistance T. circumcincta and T. colubriformis.

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Early levamisole resistance in T. circumcincta, closantel resistance not prevalent.

Current advances in the clinical development of anti-tubercular agents

Tuberculosis (TB) is a communicable airborne infectious disease caused by the Mycobacterium tuberculosis (MTB) that primarily affects the lungs, and can disseminate to other parts of the body. MTB is one of the most dangerous pathogens, killing about 1.4 million people annually worldwide. Although the standard treatment of TB is comprised of four anti-TB drugs, the emergence of multidrug-resistant (MDR) and extensive drug-resistant (XDR) strains in the recent past and associated side effects have affected the tailor-made regimens. Notably, existing therapies approved by the World Health Organisation (WHO) can only treat less than 50% of drug-resistant TB. Therefore, an expeditious pace in the TB research is highly needed in search of effective, affordable, least toxic novel drugs with shorter regimens to reach the goals viz. 2020 milestones End TB strategy set by the WHO. Currently, twenty-three drug-like molecules are under investigation in different stages of clinical trials. These newer agents are expected to be effective against the resistant strains. This article summarizes the properties, merits, demerits, and the probability of their success as novel potential therapeutic agents.

Quantitative benzimidazole resistance and fitness effects of parasitic nematode beta-tubulin alleles

Infections by parasitic nematodes inflict a huge burden on the health of humans and livestock throughout the world. Anthelmintic drugs are the first line of defense against these infections. Unfortunately, resistance to these drugs is rampant and continues to spread. To improve treatment strategies, we must understand the genetics and molecular mechanisms that underlie resistance. Studies of the fungus Aspergillus nidulans and the free-living nematode Caenorhabditis elegans discovered that a beta-tubulin gene is mutated in benzimidazole (BZ) resistant strains. In parasitic nematode populations, three beta-tubulin alleles, F167Y, E198A, and F200Y, have long been correlated with resistance. Additionally, improvements in sequencing technologies have identified new alleles - E198V, E198L, E198K, E198I, and E198Stop - also correlated with BZ resistance. However, none of these alleles have been proven to cause resistance. To empirically demonstrate this point, we independently introduced the F167Y, E198A, and F200Y alleles as well as two of the newly identified alleles, E198V and E198L, into the BZ susceptible C. elegans N2 genetic background using the CRISPR-Cas9 system. These genome-edited strains were exposed to both albendazole and fenbendazole to quantitatively measure animal responses to BZs. We used a range of concentrations for each BZ compound to define response curves and found that all five of the alleles conferred resistance to BZ compounds equal to a loss of the entire beta-tubulin gene. These results prove that the parasite beta-tubulin alleles cause resistance. The E198V allele is found at low frequencies along with the E198L allele in natural parasite populations, suggesting that it could affect fitness. We performed competitive fitness assays and demonstrated that the E198V allele reduces animal health, supporting the hypothesis that this allele might be less fit in field populations. Overall, we present a powerful platform to quantitatively assess anthelmintic resistance and effects of specific resistance alleles on organismal fitness in the presence or absence of the drug.

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Beta-tubulin alleles from parasitic nematodes were introduced into drug-susceptible C. elegans using CRISPR-Cas9.

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Beta-tubulin variants are strongly selected in albendazole competitive fitness assays.

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The E198V allele confers a fitness cost in control conditions as compared to other alleles.

Antimicrobial evaluation of neutral and cationic iridium(III) and rhodium(III) aminoquinoline-benzimidazole hybrid complexes

A series of neutral and cationic Ir(III) and Rh(III) aminoquinoline-benzimidazole hybrid complexes were synthesised and their inhibitory activities evaluated against Plasmodium falciparum and Mycobacterium tuberculosis. In general, the hybrid complexes display good activity against the chloroquine-sensitive NF54 strain of P. falciparum. The neutral Ir(III)- and Rh(III)-Cp∗ complexes were the most active (IC₅₀ = 0.488 μM for Ir^III), maintaining activity against the multidrug-resistant K1 strain. Low to no cytotoxicity against the Chinese hamster ovarian cell line was observed for the tested complexes. Selected active hybrid complexes demonstrated significant inhibition of β-haematin formation in a cell-free NP-40 assay, suggesting an effect on the host haemoglobin degradation pathway as a potential contributing mechanism of action. When tested against M. tuberculosis H37Rv, most hybrid complexes displayed moderate to good activity. Again, the neutral complexes outperformed the cationic complexes, with the neutral Ir(III)-Cp∗ complexes proving most active (MIC₉₀ = 0.488-1.490 μM).

The first report of multidrug resistance in gastrointestinal nematodes in goat population in Poland

Background

Prophylactic anthelmintic treatment with one of three basic classes of anthelmintics (benzimidazoles, macrocyclic lactones and imidazothiazoles) is still the mainstay of control of gastrointestinal nematode infections in small ruminants worldwide. As a consequence, anthelmintic resistance is a serious threat to small ruminant health and production. While the resistance to one class of anthelmintics has already been reported in most of countries, the newly-emerging problem is the resistance to two or even all of classes referred to as multidrug resistance. This study aimed to evidence the presence of multidrug resistance of gastrointestinal nematodes in goats in Poland.

Results

The combination of one in vivo method (fecal egg count reduction test) and two in vitro methods (egg hatch test and larval development test) performed in two goat herds in the southern Poland showed the presence of gastrointestinal nematodes resistant to fenbendazole and ivermectin in both herds. Moreover, in one herd it revealed the development of resistance to the last effective anthelmintic, levamisole, in response to one-year intensive use. Haemonchus contortus was the most prevalent gastrointestinal nematode in samples in which resistance to benzimidazoles and ivermectin was found, whereas Trichostrongylus colubriformis predominated when resistance to levamisole was observed.

Conclusion

This study shows for the first time that multidrug resistance of gastrointestinal nematodes to three basic classes of anthelmintics is already present in goat population in Poland. Moreover, it may indicate that different species or genera of gastrointestinal nematodes are responsible for the resistance to specific anthelmintics.

Facile synthesis of benzazoles through biocatalytic cyclization and dehydrogenation employing catalase in water

The benzazoles are very important entities having immense biological activities, hence; the synthesis of benzazoles is one of the prime areas for synthetic chemists. In pursuit of sustainable protocol, herein an oxidative enzyme i.e. catalase mediated sustainable synthesis is presented. Catalase is a metalloenzyme which is essential for the breakdown of toxic hydrogen peroxide into water and oxygen inside the cell. Despite the higher activity and turnover number of catalase inside the cell, its activity outside the cell is unexplored. Therefore, to explore the hidden potential of catalase for catalyzing the organic transformations, here we reported a green and efficient method for synthesis of benzazoles by the cyclocondensation of o-aminothiophenol or o-phenylenediammine and various aryl aldehydes with ensuing dehydrogenation. This protocol is greener, sustainable and rapid with excellent yields of the products and in addition to this, the catalase demonstrates good functional group tolerance.

Molecularly imprinted microspheres based multiplexed fluorescence method for simultaneous detection of benzimidazoles and pyrethroids in meat samples

Two molecularly imprinted microspheres and two fluorescent tracers for benzimidazoles and pyrethroids were synthesized respectively. The two types of microspheres were coated in the wells of conventional microplate simultaneously. Then the sample extracts and the two traces were added for differential competition. The fluorescence intensities at two different emission wavelengths were excited and recorded for quantification of the two classes of drugs respectively. The optimized multiplexed fluorescence method could be used to determine 8 benzimidazoles and 10 pyrethroids in mutton and beef samples simultaneously. The limits of detection of the method for the 18 drugs were in the range of 5.2-17 ng/mL, and the recoveries from the standards fortified blank samples were in the range of 67.7%-109%. From the analysis of 60 real mutton and beef samples, this method could be used for multi-screening the residues of benzimidazoles and pyrethroids in meat samples.

Synergy between Cu-NPs and fungicides against Botrytis cinerea

Combating drug-resistance is a daunting task, especially due to the shortage of available drug alternatives with multisite modes of action. In this study, the potential of copper nanoparticles (Cu-NPs) to suppress 15 Botrytis cinerea isolates, which are sensitive or resistant to fungicides, alone or in combination with conventional fungicides, was tested in vitro and in vivo. Sensitivity screening in vitro revealed two fungicide resistance phenotypes, resulting from target site mutations. DNA sequencing revealed three B. cinerea isolates highly resistant to benzimidazoles (BEN-R), thiophanare methyl (TM), and carbendazim, bearing the E198A resistance mutation in the β-tubulin gene, and four isolates highly resistant to the QoI pyraclostrobin (PYR-R) with a G143A mutation in the cytb gene. Cu-NPs were equally effective against sensitive and resistant isolates. An additive/synergistic effect was observed between Cu-NPs and TM in the case of BEN-S isolates both in vitro and when applied in apple fruit. A positive correlation was observed between TM and TM + Cu-NPs treatments, suggesting that an increased TM availability in the target site could be related with the observed additive/synergistic action. No correlation between Cu(OH)₂ and Cu-NPs sensitivity was found, indicating that different mechanisms govern the fungitoxic activity between nano and bulk counterparts. A synergistic profile was observed between Cu-NPs and fluazinam (FM) - an oxidative phosphorylation inhibitor - in all isolates regardless of resistance phenotype, suggesting that ATP metabolism could be involved in the mode of action of Cu-NPs. Furthermore, the observed cross sensitivity and antagonistic action between Cu-NPs and NaCl also provided evidence for copper ions contribution to the fungitoxic action of Cu-NPs. The results suggested that Cu-NPs in combination with conventional fungicides can provide the means for an environmentally safe, sustainable resistance management strategy by reducing fungicide use and combating resistance against B. cinerea.

In-silico molecular design of heterocyclic benzimidazole scaffolds as prospective anticancer agents

Benzimidazole is a valuable pharmacophore in the field of medicinal chemistry and exhibit wide spectrum of biological activity. Molecular docking technique is routinely used in modern drug discovery for understanding the drug-receptor interaction. The selected data set of synthesized benzimidazole compounds was evaluated for its in vitro anticancer activity against cancer cell lines (HCT116 and MCF7) by sulforhodamine B (SRB) assay. Further, molecular docking study of data set was carried out by Schrodinger-Maestro v11.5 using CDK-8 (PDB code: 5FGK) and ER-alpha (PDB code: 3ERT) as possible target for anticancer activity. Molecular docking results demonstrated that compounds 12, 16, N9, W20 and Z24 displayed good docking score with better interaction within crucial amino acids and corelate to their anticancer results. ADME results indicated that compounds 16, N9 and W20 have significant results within the close agreement of the Lipinski's rule of five and Qikprop rule within the range and these compounds may be taken as lead molecules for the discovery of new anticancer agents.

Development and application of anthelminthic drugs in China

China was once a country plagued by parasitic diseases. At the beginning of the founding of the People's Republic of China, nearly 80% of the population suffered from parasitic diseases because of poverty and poor sanitary conditions. After nearly 70 years of development, China has made remarkable achievements in the prevention and control of parasitic diseases, and the prevalence of parasitic diseases has been greatly reduced. In addition to organizational leadership from the government and various preventive measures, drug treatment and drug research & development are important and irreplaceable links in prevention and control work. Since the 1950s, China has begun to introduce, produce and imitate antiparasitic drugs from abroad, such as santonin, benzimidazole, and praziquantel. Chinese scientists have also contributed to the optimization of production techniques, improvements in drug formulation, the application in the clinic and the mechanisms of actions of generic drugs. At the same time, China has independently developed tribendimidine (TrBD, a broad spectrum anthelminthic), and its anthelminthic spectrum has been comprehensively studied. It is active against almost 20 parasites, is especially superior to benzimidazoles against Necator americanus, and surpasses the effectiveness of praziquantel against Clonorchis sinensis. In the treatment of tapeworm disease, the traditional Chinese medicines pumpkin seeds and betel nuts have good curative effects for taeniasis. Chinese scientists have explored the action modes and clinical administration methods of pumpkin seeds and betel nuts, which is still the main clinical regimen for the disease. This paper reviews the history and progress of the study of anthelmintics in intestinal helminth infections since the founding of the People's Republic of China and aiming to support clinicians and drug researchers in China and other countries.

Complexes containing benzimidazolyl-phenol ligands and Ln(III) ions: Synthesis, spectroscopic studies and preliminary cytotoxicity evaluation

Fourteen new complexes were obtained from Ln(III)(NO₃)₃∙n-H₂O and the chromophores 2-(1H-benzo[d]imidazol-2-yl)-phenol (Bzp1) or 2-(5-methyl-1H-benzo[d]imidazol-2-yl)-phenol (Bzp2). The complete characterization allowed us to assign unequivocally the structures of all the complexes. The techniques used for this purpose were Ultraviolet-Visible (UV-Vis) and Fourier-Transform Infrared (FT-IR) spectroscopies, High-Resolution Mass Spectrometry (HRMS), Magnetic Susceptibility (MS), Elemental Analysis (EA) and Molar Conductivity (MC). HRMS allowed us to find the molecular ion and its isotopic pattern. The FT-IR spectral data suggested that benzimidazolyl-phenol ligands coordinate with Ln(III) ions through iminic nitrogen and phenolic oxygen. Thermogravimetric Analysis (TGA) studies of NdBzp1 and GdBzp2 complexes indicate the presence of lattice water along with three nitrates and two benzimidazolyl-phenol ligands; the thermal decomposition was consistent with the minimal formula suggested by EA. The coordination type of the benzimidazolyl-phenol ligands, the geometry and the structural organization of these coordination complexes have been interpreted by Density Functional Theory (DFT) calculations, and they coincided with the physicochemical data suggesting a coordination number eight for the Ln(III) ions. The cytotoxicity of the chromophores and their coordination complexes was tested against a cancer cell line (HeLa), as compared with structure/support cells (NIH-3T3) and defense cells (J774A.1), revealing that three coordination complexes showed moderate cytotoxicity against the cell lines studied.

Similarities and differences in the biotransformation and transcriptomic responses of Caenorhabditis elegans and Haemonchus contortus to five different benzimidazole drugs

We have undertaken a detailed analysis of the biotransformation of five of the most therapeutically important benzimidazole anthelmintics - albendazole (ABZ), mebendazole (MBZ), thiabendazole (TBZ), oxfendazole (OxBZ) and fenbendazole (FBZ) - in Caenorhabditis elegans and the ruminant parasite Haemonchus contortus. Drug metabolites were detected by LC-MS/MS analysis in supernatants of C. elegans cultures with a hexose conjugate, most likely glucose, dominating for all five drugs. This work adds to a growing body of evidence that glucose conjugation is a major pathway of xenobiotic metabolism in nematodes and may be a target for enhancement of anthelmintic potency. Consistent with this, we found that biotransformation of albendazole by C. elegans reduced drug potency. Glucose metabolite production by C. elegans was reduced in the presence of the pharmacological inhibitor chrysin suggesting that UDP-glucuronosyl/glucosyl transferase (UGT) enzymes may catalyze benzimidazole glucosidation. Similar glucoside metabolites were detected following ex vivo culture of adult Haemonchus contortus. As a step towards identifying nematode enzymes potentially responsible for benzimidazole biotransformation, we characterised the transcriptomic response to each of the benzimidazole drugs using the C. elegans resistant strain CB3474 ben-1(e1880)III. In the case of albendazole, mebendazole, thiabendazole, and oxfendazole the shared transcriptomic response was dominated by the up-regulation of classical xenobiotic response genes including a shared group of UGT enzymes (ugt-14/25/33/34/37/41/8/9). In the case of fenbendazole, a much greater number of genes were up-regulated, as well as developmental and brood size effects suggesting the presence of secondary drug targets in addition to BEN-1. The transcriptional xenobiotic response of a multiply resistant H. contortus strain UGA/2004 was essentially undetectable in the adult stage but present in the L3 infective stage, albeit more muted than C. elegans. This suggests that xenobiotic responses may be less efficient in stages of parasitic nematodes that reside in the host compared with the free-living stages.

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C. e. & H. c. display hexose conjugation (likely glucose) and excretion of 5 BZs.

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C. elegans (C.e.) biotransformation of ABZ reduces drug potency.

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UGT inhibitor chrysin reduces ABZ biotransformation by C. elegans.

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Transcriptomic response of C. e. (ben-1) to 5 BZs dominated by xenobiotic response and additional targets for FBZ.

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Minimal transcriptomic response of H. contortus to ABZ exposure.

Therapeutic efficacy of nanocompounds in the treatment of cystic and alveolar echinococcoses: challenges and future prospects

Echinococcus granulosus sensu lato and E. multilocularis are the causative agents of life-threatening cystic and alveolar echinococcoses (CE and AE), respectively, which lead to serious public health concerns across the globe. Benzimidazoles (BMZs) are the drugs of choice for the treatment of human CE and AE. Presently, the chemotherapeutic failures of BMZs against CE and AE are caused by their low aqueous solubility, poor absorption, and consequently their erratic bioavailability. Among the BMZ compounds used for CE/AE treatment, albendazole (ABZ) and mebendazole (MBZ) are the only drugs licensed for human use. Nevertheless, the administration of these BMZs for a long period of time leads to undesirable adverse effects. Therefore, there is an urgent need for designing new formulations of BMZs with increased bioavailability. To bridge these therapeutic gaps, nanoparticle enantiomers of ABZ and drug delivery systems based on nanostructured entities currently provide an interesting new formulation of already existing drugs to improve the pharmacokinetic effects of BMZs. This study provides an overview of the tested nanocompounds against E. granulosus and E. multilocularis, including their effective dose, type of nanoparticles (NPs), assay setting, and therapeutic outcomes. This review suggests that BMZ derivatives loaded in NPs can significantly improve the scolicidal and cysticidal activities compared with single BMZ. Moreover, BMZ-loaded polymeric NPs show a tendency to increase mortality rate against protoscoleces and microcysts compared with metallic formulations, nanoemulsions, lipid nanocapsules, solid lipid NPs, liposomes, and nanocrystals. In the future, the use of the newly structured entities, attained by bridging ligands to the modified surface of NPs, as well as the electromagnetically produced nanodrugs could be helpful for developing fine-tuned formulations as an alternative to the already existing drugs against these neglected parasitic infections.

Diversity in species composition and fungicide resistance profiles in Colletotrichum isolates from apples

Outbreaks of bitter rot were observed in three commercial apple orchards in Illinois despite best management efforts during the 2018 production season. Three isolates from symptomatic fruit from these orchards and two isolates from an orchard in South Carolina were identified to the species level using morphological tools and calmodulin, glyceraldehyde-3-phosphate dehydrogenase, and beta-tubulin gene sequences. The isolates from Illinois were identified as Colletotrichum siamense of the Colletotrichum gloeosporioides species complex and the ones from South Carolina as Colletotrichum fioriniae and Colletotrichum fructicola of the Colletotrichum acutatum and the C. gloeosporioides species complex, respectively. Two of the three C. siamense isolates from Illinois were resistant to azoxystrobin and thiophanate-methyl as determined in mycelial growth tests in vitro. EC₅₀ values were >100 μg/ml for both fungicides. One isolate was only resistant to azoxystrobin. None of the isolates from South Carolina was resistant to either of the two compounds. All five isolates were sensitive to fludioxonil (EC₅₀ values <0.1 μg/ml), propiconazole (EC₅₀ values ranged from 0.15 to 0.36 μg/ml), and benzovindiflupyr (EC₅₀ values ranged from <0.1 to 0.33 μg/ml). Resistance in C. siamense to azoxystrobin and thiophanate-methyl was confirmed in detached fruit studies using apples treated with label rates of registered product. Resistance to thiophanate-methyl in C. siamense was based on E198A mutation in b-tubulin gene, whereas resistance to azoxystrobin was based on G143A in cytochrome b (CYTB). One isolate resistant to azoxystrobin possessed no amino acid variation in CYTB. This study shows that quinone outside inhibitor fungicide resistance in Colletotrichum from apple has emerged and is being selected for in Illinois apple orchards by current spray strategies. Resistance monitoring may alert growers to potential threats, but the employment of molecular tools based on current knowledge of resistance mechanisms will provide incomplete results.

Bioisosteric ferrocenyl aminoquinoline-benzimidazole hybrids: Antimicrobial evaluation and mechanistic insights

Phenyl- and bioisosteric ferrocenyl-derived aminoquinoline-benzimidazole hybrid compounds were synthesised and evaluated for their in vitro antiplasmodial activity against the chloroquine-sensitive NF54 and multi-drug resistant K1 strains of the human malaria parasite, Plasmodium falciparum. All compounds were active against the two strains, generally showing enhanced activity in the K1 strain, with resistance indices less than 1. Cytotoxicity studies using Chinese hamster ovarian cells revealed that the hybrids were relatively non-cytotoxic and demonstrated selective killing of the parasite. Based on favourable in vitro antiplasmodial and cytotoxicity data, the most active phenyl (4c) and ferrocenyl (5b) hybrids were tested in vivo against the rodent Plasmodium berghei mouse model. Both compounds caused a reduction in parasitemia relative to the control, with 5c displaying superior activity (92% reduction in parasitemia at 4 × 50 mg/kg oral doses). The most active phenyl and ferrocenyl derivatives showed inhibition of β-haematin formation in a NP-40 detergent-mediated assay, indicating a possible contributing mechanism of antiplasmodial action. The most active ferrocenyl hybrid did not display appreciable reactive oxygen species (ROS) generation in a ROS-induced DNA cleavage gel electrophoresis study. The compounds were also screened for their in vitro activity against Mycobacterium tuberculosis. The hybrids containing a more hydrophobic substituent had enhanced activity (<32.7 μM) compared to those with a less hydrophobic substituent (>62.5 μM).

Synthesis, characterization and biological evaluation of novel benzimidazole derivatives

In search of achieving less toxic and more potent chemotherapeutics, three novel heterocyclic benzimidazole derivatives: 2-(1H-benzo[d]imidazol-2-yl)-4-chlorophenol (BM1), 4-chloro-2-(6-methyl-1H-benzo[d]imidazol-2-yl)phenol (BM2) and 4-chloro-2-(6-nitro-1H-benzo[d]imidazol-2-yl)phenol (BM3) with DNA-targeting properties, were synthesized and fully characterized by important physicochemical techniques. The DNA binding properties of the compounds were investigated by UV-Visible absorption titrations and thermal denaturation experiments. These molecules exhibited a good binding propensity to fish sperm DNA (FS-DNA), as evident from the high binding constants (K_b) values: 1.9 × 10⁵, 1.39 × 10⁵ and 1.8 × 10⁴ M^‒1 for BM1, BM2 and BM3, respectively. Thermal melting studies of DNA further validated the absorption titration results and best interaction was manifested by BM1 with ΔT_m = 4.96 °C. The experimental DNA binding results were further validated theoretically by molecular docking study. It was confirmed that the molecules (BM1-BM3) bind to DNA via an intercalative and groove binding mode. The investigations showed a correlation between binding constants and energies obtained experimentally and through molecular docking, indicating a binding preference of benzimidazole derivatives with the minor groove of DNA. BM1 was the preferential candidate for DNA binding because of its flat structure, π-π interactions and less steric hindrance. To complement the DNA interaction, antimicrobial assays (antibacterial & antifungal) were performed. It was observed that compound BM2 showed promising activity against all bacterial strains (Micrococcus luteus, Staphylococcus aureus, Enterobacter aerogenes and Escherichia coli) and fungi (Aspergillus flavus, Aspergillus fumigatus and Fusarium solani), while rest of the compounds were active against selective strains. The MIC values of BM2 were found to be in the range of 12.5 ± 2.2-25 ± 1.5 µg/mL. Thus, the compound BM2 was found to be the effective DNA binding antimicrobial agent. Furthermore, the preliminary cytotoxic properties of synthesized compounds were evaluated by brine shrimps lethality assay to check their nontoxic nature towards healthy normal cells.Communicated by Ramaswamy H. Sarma.

Efficacy and Safety of Imarikiren in Patients with Type 2 Diabetes and Microalbuminuria: A Randomized, Controlled Trial

BACKGROUND AND OBJECTIVES

Imarikiren is a novel, potent, and selective direct renin inhibitor that has shown high oral availability during clinical development for the treatment of diabetic nephropathy. We evaluated the efficacy and safety of imarikiren in patients with type 2 diabetes mellitus and microalbuminuria.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a randomized, multicenter, placebo-controlled, double-blind, phase 2, dose-finding trial. A total of 415 patients were randomized to imarikiren 5, 20, 40, or 80 mg; placebo; or candesartan cilexetil 8 mg treatment for 12 weeks. The primary end point was change in log-transformed urine albumin-to-creatinine ratio from baseline to the end of treatment analyzed using analysis of covariance and a fixed sequence testing procedure. Secondary efficacy end points included urine albumin-to-creatinine ratio at each assessment point and remission and progression rates. Exploratory efficacy end points included eGFR and sitting BP before dosing.

RESULTS

Changes in the urine albumin-to-creatinine ratio from baseline to the end of treatment were 16% (placebo), -16% (imarikiren 5 mg), -27% (imarikiren 20 mg), -38% (imarikiren 40 mg), -39% (imarikiren 80 mg), and -31% (candesartan cilexetil 8 mg). Urine albumin-to-creatinine ratio reductions from baseline were statistically significant in all imarikiren groups versus placebo (P<0.001 each) as well as for candesartan cilexetil 8 mg versus placebo (P<0.001). Remission rates (urine albumin-to-creatinine ratio <30 mg/g creatinine and decreased ≥30% from baseline) were higher in all imarikiren groups versus the placebo group. Incidence of adverse events was higher in the imarikiren 80-mg group (52%) versus placebo (42%) and candesartan cilexetil (43%) groups. Incidence of adverse events for the other imarikiren groups ranged from 33% to 42%. Adverse events were mild or moderate in severity. All imarikiren doses were well tolerated.

CONCLUSIONS

Imarikiren resulted in a dose-dependent improvement in albuminuria compared with placebo, and it was well tolerated in patients with type 2 diabetes mellitus and microalbuminuria.

Preparation of a chemiluminescence sensor for multi-detection of benzimidazoles in meat based on molecularly imprinted polymer

In this study, a molecularly imprinted polymer capable of recognizing 8 benzimidazoles was first synthesized. The computation simulation showed that the shape and size of used template were the main factors influencing its recognition ability. Then the polymer was used as recognition reagent to prepare a chemiluminescence sensor on conventional 96-well microplate. The sample solution and a HRP-labeled hapten were added into the microplate wells to perform competitive binding, and the light signal was initiated with 4-(imidazol-1-yl)phenol enhanced luminol-H₂O₂ system. The optimized sensor was used to determine the residues of 8 benzimidazoles in mutton and beef. Result showed that the sensor achieved ultrahigh sensitivity (limits of detection of 1.5-21 pg/mL), rapid assay process (18 min) and satisfactory recovery (65.8%-91.2%). Furthermore, this sensor could be reused for 4 times. Therefore, this sensor could be used as a rapid, simple, sensitive and durable tool for screening the residual benzimidazoles in meat.