(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties ...with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC50 varying from 40 to 60 μM after 48 h and between 13 and 20 μM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity.
1H-benzimidazol-2-yl hydrazones with varying hydroxy and methoxy phenyl moieties were designed. Their effect on tubulin polymerization was evaluated in vitro on porcine tubulin. The compounds ...elongated the nucleation phase and slowed down the tubulin polymerization comparably to nocodazole. The possible binding modes of the hydrazones with tubulin were explored by molecular docking at the colchicine binding site. The anticancer activity was evaluated against human malignant cell lines MCF-7 and AR-230, as well as against normal fibroblast cells 3T3 and CCL-1. The compounds demonstrated a marked antineoplastic activity in low micromolar concentrations in both screened in vitro tumor models. The most active were the trimethoxy substituted derivative
and the positional isomers
and
, containing hydroxy and methoxy substituents: they showed IC
similar to the reference podophyllotoxin in both tumor cell lines, accompanied with high selectivity towards the malignantly transformed cells. The compounds exerted moderate to high ability to scavenge peroxyl radicals and certain derivatives-
containing
-hydroxy and
-methoxy group, and
with di/trihydroxy phenyl moiety, revealed HORAC values high or comparable to those of well-known phenolic antioxidants. Thus the 1H-benisimidazol-2-yl hydrazones with hydroxy/methoxy phenyl fragments were recognized as new agents exhibiting promising combined antioxidant and antineoplastic action.
Parasitic infections, caused mainly by the species Trichinella spiralis (T. spiralis), are widespread around the world and lead to morbidity and mortality in the population. Meanwhile, some studies ...have showed that these parasites induce oxidative stress in the infected host. With the aim of developing a class of compounds combining anthelmintic with antioxidant properties, a series of new benzimidazolyl-2-hydrazones 5a-l, bearing hydroxyl- and methoxy-groups, were synthesized. The anthelmintic activity on encapsulated T. spiralis was studied in vitro thus indicating that all hydrazones were more active than the clinically used anthelmintic drugs albendazole and ivermectin. 5b and 5d killed the total parasitic larvae (100% effectiveness) after 24 hours incubation period at 37 °C in both concentrations (50 and 100 μg ml−1). The antioxidant activity of the target compounds was elucidated in vitro against stable free radicals DPPH and ABTS as well as iron induced oxidative damage in model systems containing biologically relevant molecules lecithin and deoxyribose. The two 2,3- and 3,4-dihydroxy hydrazones 5b and 5d were the most effective radical scavengers in all studied systems. DFT calculations were applied to calculate the reaction enthalpies in polar and nonpolar medium and estimate the preferred mechanism of antioxidant activity. The relative radical scavenging ability of compounds 5a-l showed a good correlation to the experimentally observed trends. It was found that the studied compounds are capable to react with various free radicals – ·OCH3, ·OOH and ·OOCH3, through several possible reaction pathways – HAT in nonpolar medium, SPLET in polar medium and RAF in both media.
In the present work we studied the interactions of a newly synthesized drug candidate, 2-(2-hydroxy-4-methoxybenzylidene)-1-(1H-benzimidazol-2-yl)hydrazine (
2H4MBBH
), with human serum albumin (HSA) ...by fluorescence spectroscopy.
2H4MBBH
-HSA binding parameters were assessed by fluorescence quenching strategy. As made clear by the concentration data,
2H4MBBH
unequivocally quenched the instrinsic HSA fluorescence. The calculated Stern-Volmer quenching constant Ksv, the Ka of
2H4MBBH
-HSA complexes, as well as the thermodynamic parameters ∆H°, ∆S° and ∆G°, showed that the H-bonding forces play major part in the interaction of
2H4MBBH
with HSA. These calculations point to a quenching component based on
2H4MBBH
-HSA static complex formation rather than energetic collisions.
Fluorescent micellar carriers with controlled release of a novel anticancer drug were developed to enable intracellular imaging and cancer treatment simultaneously. The nanosized fluorescent micellar ...systems were embedded with a novel anticancer drug via the self-assembling behavior of well-defined block copolymers based on amphiphilic poly(acrylic acid)-block-poly(n-butyl acrylate) (PAA-b-PnBA) copolymer obtained by Atom Transfer Radical Polymerization (ATRP) and hydrophobic anticancer benzimidazole-hydrazone drug (BzH). Through this method, well-defined nanosized fluorescent micelles were obtained consisting of a hydrophilic PAA shell and a hydrophobic PnBA core embedded with the BzH drug due to the hydrophobic interactions, thus reaching very high encapsulation efficiency. The size, morphology, and fluorescent properties of blank and drug-loaded micelles were investigated using dynamic light scattering (DLS), transmission electron microscopy (TEM), and fluorescent spectroscopy, respectively. Additionally, after 72 h of incubation, drug-loaded micelles released 3.25 μM of BzH, which was spectrophotometrically determined. The BzH drug-loaded micelles were found to exhibit enhanced antiproliferative and cytotoxic effects on MDA-MB-231 cells, with long-lasting effects on microtubule organization, with apoptotic alterations and preferential localization in the perinuclear space of cancer cells. In contrast, the antitumor effect of BzH alone or incorporated in micelles on non-cancerous cells MCF-10A was relatively weak.
Parasitic infections, caused mainly by the species
(
), are widespread around the world and lead to morbidity and mortality in the population. Meanwhile, some studies have showed that these parasites ...induce oxidative stress in the infected host. With the aim of developing a class of compounds combining anthelmintic with antioxidant properties, a series of new benzimidazolyl-2-hydrazones 5a-l, bearing hydroxyl- and methoxy-groups, were synthesized. The anthelmintic activity on encapsulated
was studied
thus indicating that all hydrazones were more active than the clinically used anthelmintic drugs albendazole and ivermectin. 5b and 5d killed the total parasitic larvae (100% effectiveness) after 24 hours incubation period at 37 °C in both concentrations (50 and 100 μg ml
). The antioxidant activity of the target compounds was elucidated
against stable free radicals DPPH and ABTS as well as iron induced oxidative damage in model systems containing biologically relevant molecules lecithin and deoxyribose. The two 2,3- and 3,4-dihydroxy hydrazones 5b and 5d were the most effective radical scavengers in all studied systems. DFT calculations were applied to calculate the reaction enthalpies in polar and nonpolar medium and estimate the preferred mechanism of antioxidant activity. The relative radical scavenging ability of compounds 5a-l showed a good correlation to the experimentally observed trends. It was found that the studied compounds are capable to react with various free radicals - ˙OCH
, ˙OOH and ˙OOCH
, through several possible reaction pathways - HAT in nonpolar medium, SPLET in polar medium and RAF in both media.
Neuroprotective drugs and selective monoamine oxidase inhibitors can slow down the progression and improve symptoms of Parkinson's disease (PD). Since there is an implication of oxidative stress in ...the pathophysiological mechanisms of the disease, the compounds possessing an ability to reduce the oxidative stress are prime candidates for neuroprotection. Thereby our current study is focused on the development of new multi-target PD drugs capable of inhibiting the activity of monoamine oxidase-B while exerting neuroprotective and antioxidant properties. A small series of benzimidazole derivatives containing hydroxy and methoxy arylhydrazone fragments has been synthesized and the neurotoxicity of the compounds has been evaluated in vitro on neuroblastoma SH-SY5Y cells and on isolated rat brain synaptosomes by measuring the cell viability and the levels of reduced glutathione and a good safety profile has been shown. The 2-hydroxy-4-methoxy substituted arylhydrazone 7 was the least toxic on neuronal SH-SY5Y cells and showed the lowest neurotoxicity in rat brain synaptosomes. The neuroprotective properties of the test compounds were further assessed using two models: H2O2-induced oxidative stress on SH-SY5Y cells and 6-hydroxydopamine-induced neurotoxicity in rat brain synaptosomes. Compound 7 showed more pronounced neuroprotective activity on SH-SY5Y cells, compared to the referent melatonin and rasagiline. It also preserved the synaptosomal viability and the reduced glutathione levels; the effects were stronger than those of rasagiline and comparable to melatonin. All the tested compounds were capable to inhibit human monoamine oxidase-B enzyme to a significant extent, however, compound 7 exerted the most prominent inhibitory activity, similar to selegiline and rasagiline. The carried out molecular docking studies revealed that the activity is related to the appropriate molecular structure enabling the ligand to enter deeper in the narrow and highly lipophylic active site pocket of the human monoamine oxidase-B and has a favoring interaction with the key amino acid residues Tyr326 and Cys172. Since much scientific evidence points out the implication of iron dyshomeostasis in PD, the compounds were tested to reduce the ferrous iron induced oxidative molecular damage on biologically important molecules in an in vitro lecithin containing model system. All the investigated compounds denoted protection effect, stronger than the one of the referent melatonin. In order to support the assignments of the significant neuroprotective and antioxidant pharmacological activities, the radical-scavenging mechanisms of the most promising compound 7 were evaluated using DFT methods. It was found that the most probable free radicals scavenging mechanism in nonpolar phase is the hydrogen atom transfer from the amide group of compound 7, while in polar medium the process is expected to occur by a proton transfer. The current study outlines a perspective leading structure, bearing the potential for a new anti-PD drug. All performed procedures were approved by the Institutional Animal Care Committee of the Medical University of Sofia (Bulgarian Agency for Food Safety with Permission № 190, approved on February 6, 2020).
(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties ...with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with ICsub.50 varying from 40 to 60 μM after 48 h and between 13 and 20 μM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity.
In the present study, fifteen benzimidazolyl-2-hydrazones 7a-7o of fluoro-, hydroxy- and methoxy-substituted benzaldehydes and 1,3-benzodioxole-5-carbaldehyde were synthesized and their structure was ...identified by IR, NMR, and elemental analysis. The compounds 7j 2-(3-hydroxybenzylidene)-1-(5(6)-methyl-1H-benzimidazol-2-yl)hydrazone and 7i 2-(3-hydroxybenzylidene)-1-(1H-benzimidazol-2-yl)hydrazone have exerted the strongest anthelmintic activity (100% after 24 h incubation period at 37 °C) against isolated muscle larvae of Trichinella spiralis in an in vitro experiment. The in vitro cytotoxicity assay towards MCF-7 breast cancer cells and mouse embryo fibroblasts 3T3 showed that the studied benzimidazolyl-2-hydrazones exhibit low to moderate cytotoxic effects. The ability of the studied benzimidazolyl-2-hydrazones to modulate microtubule polymerization was confirmed and suggested that their anthelmintic action is mediated through inhibition of the tubulin polymerization likewise the other known benzimidazole anthelmitics. It was also shown that the four most promising benzimidazolyl-2-hydrazones do not affect significantly the AChE activity even at high tested concentration, thus indicating that they do not have the potential for neurotoxic effects. The binding mode of compounds 7j and 7n in the colchicine-binding site of tubulin were clarified by molecular docking simulations. Taken together, these results demonstrate that for the synthesized benzimidazole derivatives the anthelmintic activity against T. spiralis and the inhibition of tubulin polymerization are closely related.
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•A small library of benzimidazolyl-2-hydrazones were synthesized.•Compounds 7j and 7i 2 exerted 100 % efficacy against isolated Trichinella spiralis muscle larvae after 24 h of incubation.•The studied benzimidazolyl-2-hydrazones exhibit low to moderate cytotoxic effects towards MCF-7 and 3T3 cells.•The studied benzimidazolyl-2-hydrazones modulate microtubule polymerization.•The binding mode of compounds 7j and 7n in the colchicine-binding site of tubulin were clarified by molecular docking.
(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties ...with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC
varying from 40 to 60 μM after 48 h and between 13 and 20 μM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound
prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative
containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity.
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