Search Results (101)

Background: Benzimidazole (BZ) resistance in the gastrointestinal nematode Haemonchus contortus is a major constraint to sheep production worldwide. However, data on the prevalence and molecular mechanisms of resistance in Yili Prefecture, Xinjiang—a key livestock region in Northwestern China—remain limited. This study aimed to determine the frequency of BZ resistance-associated single nucleotide polymorphisms (SNPs) in H. contortus populations from Zhaosu and Tekesi counties. Methods: Adult male worms (n = 150) were collected from naturally infected sheep at local abattoirs. Species identity was confirmed morphologically by sequencing the internal transcribed spacer 2 (ITS-2) region. A 385 bp fragment of the isotype-1 β-tubulin gene was amplified and sequenced to detect SNPs at codons 167 (F167Y), 198 (E198A), and 200 (F200Y). Results: The F167Y mutation was absent in all individuals. In contrast, the E198A mutation occurred at exceptionally high frequencies, with resistant allele frequencies (RAF) of 64.7% in Zhaosu and 52.7% in Tekesi. The F200Y mutation showed clear geographical variation: it remained low in Zhaosu (RAF = 9.3%) but was substantially higher in Tekesi (RAF = 33.3%). Haplotype analysis revealed that resistance in Zhaosu was driven primarily by the E198A mutation, whereas the Tekesi population exhibited complex patterns of co-selection of both E198A and F200Y, with a high proportion of double-heterozygous individuals (29.3%). Conclusions: This study provides comprehensive molecular evidence of severe BZ resistance in H. contortus populations from Zhaosu and Tekesi counties, Yili Prefecture. The marked predominance of the E198A mutation, together with the emergence of multi-locus resistance in Tekesi, indicates a rapid escalation of resistance beyond historical levels. These findings suggest that benzimidazoles are likely ineffective in this region and highlight the urgent need to revise local parasite control strategies. Full article

The aim of this study was to evaluate the effect of short-term dietary restriction on the in vivo efficacy of albendazole (ALB) on a goat farm with suspected reduced efficacy of benzidazoles (BZs). Initially, pooled faecal samples were analysed using the in vitro egg hatch test (EHT) to assess the level of BZ resistance. Subsequently, 58 goats were allocated into six experimental groups: three groups received a single dose of ALB (5 mg/kg body weight, BW) and three groups received a double dose (10 mg/kg BW). Each group was subdivided into animals fasted for 24 h before treatment, 24 h after treatment, and non-fasted controls. Morphological identification of third-stage larvae before and after treatment confirmed the predominance of Haemonchus contortus (91% and 100%, respectively). The in vitro EHT demonstrated reduced susceptibility to BZs, with the concentration of thiabendazole (TBZ) required to inhibit 50% of egg hatching exceeding the resistance threshold of 0.05 μg/mL, ranging from 0.166 to 0.247 μg/mL TBZ. Despite the presence of BZ resistance, fasting significantly increased the in vivo efficacy of ALB by up to 18%. These findings demonstrate that short-term dietary manipulation represents an effective strategy to enhance anthelmintic efficacy and partially overcome reduced drug performance. Full article

Background/Objectives: Four novel thymol–benzimidazolium–chalcone hybrids were designed based on a molecular hybridization strategy that integrates bioactive scaffolds known for their antimicrobial and antioxidant properties. This approach aims to enhance biological activity through synergistic effects and multi-target interactions, as supported by previous studies on phenolic and benzimidazole derivatives. The inclusion of both antioxidant and antibacterial evaluations was motivated by the well-established role of oxidative stress in bacterial pathogenicity and resistance mechanisms. Methods: Their antibacterial potential was initially screened using the disk diffusion method and subsequently evaluated by determining MIC and MBC values against eight clinical Staphylococcus aureus isolates. Results: Among the tested compounds, compound 3a emerged as the most potent derivative, exhibiting MIC values ranging from 0.25 to 1 µg/mL. Morphological analysis confirmed significant disruption of bacterial cell integrity, and further investigation demonstrated strong antibiofilm activity accompanied by downregulation of key biofilm- and resistance-associated genes (icaA, dltB, and mepA). Molecular docking studies were performed against selected target proteins, including 1MWT, 3VSL, 3ZG5 (sortase A), and 2ZCS, which are associated with bacterial cell wall biosynthesis, DNA replication, virulence, and metabolic pathways. Compound 3a exhibited the highest binding affinity, with a docking score of −11.953 kcal/mol against 2ZCS. Conclusions: Overall, these findings highlight the potential of thymol-based benzimidazolium–chalcone hybrids as promising multifunctional agents with combined antibacterial, antibiofilm, and antioxidant properties. Full article

Background/Objectives: Protein kinases play a crucial role in cancer initiation, progression, and therapeutic resistance by regulating signalling pathways involved in tumour growth and survival. Consequently, they represent major targets in anticancer drug discovery. Among heterocyclic scaffolds explored in kinase inhibitor design, benzimidazole has emerged as a privileged structure due to its strong hydrogen-bonding capability and structural resemblance to purine moieties. Triazole motifs are also widely incorporated into bioactive molecules because of their metabolic stability, favourable electronic properties, and ability to establish key interactions within kinase active sites. This review aims to summarise and critically discuss benzimidazole- and triazole-based kinase inhibitors, both as individual scaffolds and as hybrid systems, with emphasis on their kinase targets and multitarget potential. Methods: The relevant literature was surveyed from major scientific databases focusing on studies describing the synthesis, biological evaluation, and molecular modelling of benzimidazole- and triazole-containing kinase inhibitors. Results: Numerous studies demonstrate that both benzimidazole and triazole scaffolds exhibit significant kinase inhibitory activity against oncogenic targets, including EGFR, cyclin-dependent kinases (CDKs), and components of the PI3K/Akt/mTOR signalling pathway. Hybrid molecules combining these pharmacophores frequently enhance binding interactions and facilitate the development of multitarget kinase inhibitors. Structure–activity relationship trends indicate that pharmacophore accessibility, substitution patterns, and linker architecture influence inhibitory potency and selectivity. Conclusions: Overall, benzimidazole- and triazole-based scaffolds represent promising platforms for developing next-generation multitarget anticancer agents and provide valuable insights for the rational design of improved kinase inhibitors. Full article

Fasciola infection, which is widely distributed and has a major impact on livestock production, is emerging as a significant zoonotic parasitic disease affecting both human and animal health worldwide. The main control strategy currently relies on a limited number of anthelmintic drugs, especially benzimidazoles such as albendazole and triclabendazole. The aim of this study was to evaluate the efficacy of albendazole and triclabendazole in a sheep flock in northwestern Spain naturally infected with F. hepatica and to test fenbendazole and oxfendazole as alternative formulations. For this purpose, a faecal egg count reduction test (FECRT) was conducted applying various statistical methods based on the guidelines used for gastrointestinal nematodes. This study represents the first application of the new classification framework for F. hepatica, emphasizing the urgent need for standardized resistance detection protocols for this parasite and underlining the growing challenge of anthelmintic resistance in the treatment of fasciolosis. Full article

This study investigated the cyathostomin species composition, anthelmintic efficacy, and potential resistance-associated mutations in Chinese grazing horses. Fecal samples were collected from 90 adult horses. Fecal egg counts (FECs) were determined using a modified McMaster method. Third stage larvae (L3) cultured from the eggs were identified to species level by PCR amplification and sequencing of the internal transcribed spacer-2 (ITS-2). The main species included Cylicocyclus nassatus and Cylicostephanus spp. However, differences in the relative abundance of less common species, including Cyathostomum pateratum and Cylicocyclus ashworthi, suggests regional variation. Anthelmintic efficacy was assessed by a fecal egg count reduction test (FECRT) following albendazole administration. Mutations at six codons of the β-tubulin iso-type-1 (tbb-iso-1) gene were screened by gene sequencing. The results showed that, despite harboring an abundant and diverse cyathostomin community, this herd remained susceptible to albendazole. Overall, this study provides baseline data on cyathostomin species composition and anthelmintic susceptibility in horses from China, contributing to global surveillance of equine cyathostomin resistance. Full article

Gastrointestinal nematodes, particularly Haemonchus contortus, represent a major threat to ruminant health and productivity worldwide, largely due to the widespread emergence of anthelmintic resistance. In Bosnia and Herzegovina, benzimidazole resistance has previously been confirmed in domestic ruminants; however, data on wildlife remain lacking. Given the frequent spatial and temporal overlap between domestic and wild ruminants on shared pastures, this study aimed to investigate the occurrence of benzimidazole-resistant H. contortus genotypes within a multi-host system. During the 2024/2025 season, a total of 111 abomasal samples were collected from sheep (n = 20), lambs (n = 12), goats (n = 17), roe deer (n = 40) and chamois (n = 22) across four localities in Bosnia and Herzegovina (Laktaši, Banja Luka, Modriča and Višegrad). Adult H. contortus specimens were morphologically identified and confirmed using real-time quantitative PCR (rt-qPCR). Benzimidazole resistance was assessed by allele-specific rt-qPCR targeting the F200Y mutation in the β-tubulin isotype 1 gene. Statistically significant interspecies differences in β-tubulin genotype distribution were observed (p < 0.05), primarily driven by variation in the homozygous resistant (RR) genotype. High RR prevalence was detected in sheep (60%), lambs (50%) and roe deer (52.5%), whereas lower proportions were observed in chamois (27.3%) and goats (23.5%). Overall, 44.1% of all analyzed H. contortus isolates carried homozygous resistant alleles, indicating an advanced stage of benzimidazole resistance within this multi-host system. These findings demonstrate that benzimidazole resistance in H. contortus is not confined to domestic livestock but is also present in wild ruminants sharing the same grazing areas, consistent with circulation of resistant parasites within shared grazing systems. Full article

Background: Haemonchus contortus is a gastrointestinal nematode that affects small ruminants and exhibits widespread resistance to commercial anthelmintics. This has driven interest in natural compounds such as fatty acids and sterols; however, their biological relevance against resistant parasite strains remains insufficiently understood. Methods: The nematicidal potential of four fatty acids (palmitic, linoleic, pentadecanoic, and stearic acids) and two sterols (β-sitosterol and ergosterol), all of them commercially available in Mexico, was evaluated against infective L3 larvae of a benzimidazole-resistant H. contortus strain. In vitro larval mortality and migration inhibition assays were performed, and molecular docking analyses were conducted to explore interactions with the glutamate-gated chloride channel (GluCl) using AutoDock4. Statistical analyses were performed using ANOVA followed by Tukey’s post hoc test (p < 0.05). Results: Molecular docking indicated strong binding affinities of ergosterol and β-sitosterol to GluCl, comparable to that of ivermectin. In vitro assays showed that fatty acids, particularly linoleic acid, produced more pronounced effects on larval motility, suggesting predominantly nematostatic activity. No clear dose–response relationship was observed in migration assays, and in vitro mortality remained limited across treatments. Conclusions: The results highlight a disconnect between in silico binding affinity and in vitro biological activity, particularly in a drug-resistant H. contortus strain. Integrating in vitro bioassays with computational approaches provides valuable mechanistic insight but also underscores the limitations of affinity-based predictions for assessing anthelmintic efficacy. Full article

Although best known as a major parasite of sheep and goats, the blood-feeding abomasal nematode Haemonchus contortus can also infect cattle and buffaloes under the mixed-grazing Mediterranean conditions prevalent in Greece. The objectives of this study were as follows: (i) to determine the prevalence of H. contortus infections in dairy and beef cattle and buffaloes in Greece through an abattoir survey, (ii) to evaluate potential host- and farm-related risk factors including age, sex, management system, cattle productive orientation, and the co-existence of cattle and buffaloes on the occurrence of haemonchosis, and (iii) to assess the likelihood of detecting homozygous benzimidazole (BZ)-resistant H. contortus in large ruminant populations in relation to these determinants. A total of 213 abomasa (115, 55, and 43 from dairy, beef cattle, and buffaloes, respectively) were examined. A structured questionnaire provided additional animal- and farm-level information. Haemonchus-like helminths were collected and molecularly identified at the species level by amplifying a 321 bp fragment of the internal transcribed spacer 2 region of nuclear DNA. An allele-specific multiplex PCR, targeting codon 200 of the β-tubulin gene, was applied to detect BZ-resistant alleles. The prevalence of H. contortus infection was 21.2% in cattle and 69.8% in buffaloes. In cattle, multivariable analysis revealed that mixed-species farming (i.e., farms where cattle were the primary species and buffaloes were kept in smaller numbers), productive orientation, and slaughter age were significant predictors of increased H. contortus infection. Controversially, none of these factors were significantly associated with infection in buffaloes. Finally, multivariable modelling suggested that resistance patterns varied by host species, being more prevalent in intensively managed, older cattle, yet less common among older buffaloes and in herds where both species coexisted. Full article

Background/Objectives: Giardia lamblia is an intestinal protozoan responsible for giardiasis, a globally prevalent parasitic disease. Current therapeutic options, including nitroimidazoles and benzimidazoles, have increasing treatment failures due to resistance, adverse reactions, and patient non-compliance. Drug repositioning offers a cost-effective strategy for identifying new antigiardial agents. This study aimed to evaluate the in vitro antiparasitic effects and possible mechanisms of action of the tricyclic antidepressant imipramine against G. lamblia trophozoites. Methods: Trophozoites were exposed to increasing concentrations of imipramine (25–125 µM). Growth inhibition and adhesion capacity were quantified using cell counts. Apoptosis- or necrosis-like death was evaluated through Annexin V/PI staining. The expression and distribution of α-tubulin and lipid rafts were analyzed by immunofluorescence microscopy. Finally, the effect of the drug on encystment efficiency was assessed in vitro. Results: Imipramine inhibited G. lamblia trophozoite growth in a concentration-dependent manner, with an IC₅₀ of 42.31 µM at 48 h. The drug significantly reduced adhesion capacity (>90% at 125 µM) and induced apoptosis-like cell death, as evidenced by Annexin V positivity. Immunofluorescence revealed disruption of α-tubulin distribution and lipid raft organization, accompanied by morphological rounding. Moreover, encystment efficiency decreased in a concentration-dependent mode, suggesting interference in the differentiation process. Conclusions: This investigation describes, for the first time, the antigiardial potential of imipramine, which alters cytoskeletal organization, membrane microdomains, and differentiation pathways, ultimately leading to apoptosis-like cell death. These findings position this compound as a promising lead structure and support further exploration of tricyclic antidepressants as scaffolds for the development and optimization of new antiparasitic agents, as well as future studies on their molecular targets and in vivo efficacy. Full article

Coumarin derivatives constitute a versatile small-molecule chemotype with broad anticancer potential. This narrative review synthesizes recent in vitro and in vivo evidence on coumarin-based scaffolds, emphasizing breast cancer and covering lung, prostate, and colorectal models. We summarize major mechanisms of action—including induction of apoptosis (caspase activation and BAX/BCL-2 balance), modulation of PI3K/Akt/mTOR signaling, inhibition of angiogenesis (VEGFR-2), interference with estrogen biosynthesis (aromatase/ER axis), chaperone targeting (Hsp90), and attenuation of multidrug resistance (efflux pumps/autophagy)—and highlight representative chemotypes (e.g., benzimidazole, triazole, furocoumarins, topoisomerase- and CDK-oriented hybrids). Where available, we contrast potency and selectivity across models (e.g., MCF-7 vs. MDA-MB-231; A549; PC-3; colon lines) and discuss structure–activity trends linking substituent patterns (heteroaryl linkers, judicious halogenation, polar handles) to pathway engagement. We also delineate translational gaps limiting clinical progress—selectivity versus non-malignant cells, incomplete pharmacokinetic and safety characterization, and limited validation beyond xenografts. Finally, we outline priorities for preclinical optimization: biology-aligned target selection with biomarkers, resistance-aware combinations (e.g., PI3K/mTOR ± autophagy modulation; MDR mitigation), and early integration of ADME/tox and PK/PD to confirm on-target exposure. Collectively, the evidence supports coumarins as adaptable, multi-target anticancer leads, particularly promising in hormone-dependent breast cancer while remaining relevant to other tumor types. Full article

Cancer is a highly significant medical concern, as it is the second most prevalent cause of mortality after cardiovascular diseases. It arises due to dysregulated cell cycle control, leading to a gradual decline in cellular differentiation and unrestricted cellular proliferation. Therefore, the primary objective for researchers is to develop a cancer treatment that addresses drug resistance while providing effective therapeutic benefits and minimizing side effects. Benzimidazole has garnered significant attention because it serves as an auxiliary isostere of nucleotides, which are found in several natural and biologically active molecules. Benzimidazole compounds possess a privileged pharmacophore that exhibits various pharmacological actions. Several benzimidazole derivatives exhibit dual or multiple anticancer properties through diverse mechanisms, focusing on specific compounds or employing strategies that are not gene specific. Furthermore, many drugs based on benzimidazole have previously been approved to treat cancer. This comprehensive review encompasses the most important reports on various benzimidazole hybrids, highlighting their anticancer significance, mechanism of action, and structure-activity relationships from 2005 up to 2025. These provide valuable knowledge for designing effective anticancer drugs. Full article

Hypoxia and activation of the pentose phosphate pathway (PPP), as well as overexpression of glucose-6-phosphate dehydrogenase (G6PD), are hallmark features of glioblastomas (GBM), contributing significantly to tumor progression metabolic adaptation and drug resistance. This study aimed to evaluate the cytotoxic effects of nine synthetic compounds incorporating annulated benzimidazole and nitrothiazole scaffolds in two glioblastoma cell lines (A172 and U87-MG) under both normoxic and hypoxic conditions. Three compounds (BZM-7, BZM-9, and CNZ-3) demonstrated potent anticancer activity, with CNZ-3 exhibiting the highest efficacy, particularly in hypoxia. The study further investigated the effects of these compounds on the expression of the G6PD gene, as well as post-translational regulatory genes SIRT2 and KAT9, and the angiogenesis-related VEGF gene. Transcriptional analyses showed that the nitrothiazole-derived compound CNZ-3 significantly downregulated G6PD, SIRT2, KAT9 and VEGF expression under hypoxic conditions, suggesting selective interference with hypoxia-adaptative pathways. In contrast, BZM-7 and BZM-9 showed distinct expression patterns, indicating diverse mechanisms of action despite structural similarity. In addition, BZM-7, BZM-9, and CNZ-3 were identified as potent inhibitors of recombinant G6PD, demonstrating both enzymatic inhibition and structural alterations, suggesting that G6PD could be a relevant therapeutic target for these compounds. Furthermore, molecular docking analysis revealed favorable binding interactions between the compounds and key amino acids of the G6PD, reinforcing their potential as a direct enzyme inhibitors. These findings highlight the pivotal role of G6PD in gliomas under hypoxic conditions and support its inhibition as a promising therapeutic strategy. Full article

Resistance to anthelmintics in gastrointestinal nematodes (GINs) is highly prevalent, as these parasites have been treated with anthelmintics for decades in ruminants and horses. Anthelmintics belong to different classes, each with a different mode of action. The most used are benzimidazoles and macrocyclic lactones and, to a lesser extent, levamisole and pyrantel in herbivores, as estimated from the literature. Combining these classes should be effective in controlling GIN. However, several farmers’ practices tend to promote GIN resistance. Therefore, it is unclear whether the use of anthelmintic associations is a sustainable solution for controlling resistance in natural conditions. It is not easy to establish the association of anthelmintic resistances on farms since rarely several anthelmintics and their combinations are used on a single farm. Composed probability calculations were employed when literature data indicated the presence of resistance (to benzimidazoles, levamisole, or macrocyclic lactones) in several ruminant GIN cases. The efficacy of different anthelmintics (benzimidazoles, pyrantel, or macrocyclic lactones) was evaluated in terms of the correlation between faecal nematode egg counts in horses in the available literature. No associations of anthelmintic resistance were found between the different classes of anthelmintics in either ruminants or horses. However, the association between anthelmintic resistance in GIN may appear in the long term. It is presumed that combining drugs may reduce the development of resistance and allow better control of infection on farms where resistance is already established to a low level. Full article

A series of new 3′-deoxyribosides of substituted benzimidazoles was obtained by the chemo-enzymatic method using genetically engineered E. coli purine nucleoside phosphorylase (PNP). In the case of asymmetrically substituted benzimidazole derivatives, a mixture of N1- and N3-regioisomers was formed (confirmed by NMR). The antiviral activity of the obtained compounds against herpes simplex virus 1 of reference strain L2 and a strain deeply resistant to acyclovir in Vero E6 cell culture was studied. 4,6-Difluoro-1-(β-D-3′-deoxyribofuranosyl)benzimidazole (IC₅₀ = 250.92 µM, SI = 12.00) and 4,5,6-trifluoro-1-(β-D-3′-deoxyribofuranosyl)benzimidazole (IC₅₀ = 249.96 µM, SI = 16.00) showed significant selective activity against both viral models in comparison to ribavirin (IC₅₀ = 511.88 µM, SI > 8.00). Full article