HDAC specificity and kinase off-targeting by purine-benzohydroxamate anti-hematological tumor agents.

A series of hybrid inhibitors, combining pharmacophores of known kinase inhibitors bearing anilino-purines (ruxolitinib, ibrutinib) and benzohydroxamate HDAC inhibitors (nexturastat A), were generated in the present study. The compounds have been synthesized and tested against solid and hematological tumor cell lines. Compounds 4d-f were the most promising in cytotoxicity assays (IC50 ≤ 50 nM) vs. hematological cells and displayed moderate activity in solid tumor models (EC50 = 9.3-21.7 µM). Compound 4d potently inhibited multiple kinase targets of interest for anticancer effects, including JAK2, JAK3, HDAC1, and HDAC6. Molecular dynamics simulations showed that 4d has stable interactions with HDAC and members of the JAK family, with differences in the hinge binding energy conferring selectivity for JAK3 and JAK2 over JAK1. The kinase inhibition profile of compounds 4d-f allows selective cytotoxicity, with minimal effects on non-tumorigenic cells. Moreover, these compounds have favorable pharmacokinetic profiles, with high stability in human liver microsomes (e.g., see t1/2: >120 min for 4f), low intrinsic clearance, and lack of significant inhibition of four major CYP450 isoforms.

Drug repositioning in the COVID-19 pandemic: fundamentals, synthetic routes, and overview of clinical studies.

INTRODUCTION: Drug repositioning is a strategy to identify a new therapeutic indication for molecules that have been approved for other conditions, aiming to speed up the traditional drug development process and reduce its costs. The high prevalence and incidence of coronavirus disease 2019 (COVID-19) underline the importance of searching for a safe and effective treatment for the disease, and drug repositioning is the most rational strategy to achieve this goal in a short period of time. Another advantage of repositioning is the fact that these compounds already have established synthetic routes, which facilitates their production at the industrial level. However, the hope for treatment cannot allow the indiscriminate use of medicines without a scientific basis. RESULTS: The main small molecules in clinical trials being studied to be potentially repositioned to treat COVID-19 are chloroquine, hydroxychloroquine, ivermectin, favipiravir, colchicine, remdesivir, dexamethasone, nitazoxanide, azithromycin, camostat, methylprednisolone, and baricitinib. In the context of clinical tests, in general, they were carried out under the supervision of large consortiums with a methodology based on and recognized in the scientific community, factors that ensure the reliability of the data collected. From the synthetic perspective, compounds with less structural complexity have more simplified synthetic routes. Stereochemical complexity still represents the major challenge in the preparation of dexamethasone, ivermectin, and azithromycin, for instance. CONCLUSION: Remdesivir and baricitinib were approved for the treatment of hospitalized patients with severe COVID-19. Dexamethasone and methylprednisolone should be used with caution. Hydroxychloroquine, chloroquine, ivermectin, and azithromycin are ineffective for the treatment of the disease, and the other compounds presented uncertain results. Preclinical and clinical studies should not be analyzed alone, and their methodology's accuracy should also be considered. Regulatory agencies are responsible for analyzing the efficacy and safety of a treatment and must be respected as the competent authorities for this decision, avoiding the indiscriminate use of medicines.

Folate Pathway Inhibitors, An Underestimated and Underexplored Molecular Target for New Anti-tuberculosis Agents.

The folate metabolic cycle is an important biochemical process for the maintenance of cellular homeostasis, and is a widely studied pathway of cellular replication control in all organisms. In microorganisms such as M. tuberculosis (Mtb), for instance, dihydrofolate reductase (MtDHFR) is the enzyme commonly explored as a molecular target for the development of new antibiotics. In the same way, dihydropteroate synthase (MtDHPS) was studied extensively until the first multidrug-resistant strains of mycobacteria that could not be killed by sulfonamides were found. However, the other enzymes belonging to the metabolic cycle, until recently less explored, have drawn attention as potential molecular targets for obtaining new antituberculosis agents. Recent structural determinations and mechanism of action studies of Mtb flavin-dependent thymidylate synthase (MtFDTS) and MtRv2671, enzymes that acts on alternative metabolic pathways within the folate cycle, have greatly expanded the scope of potential targets that can be screened in drug design process. Despite the crystallographic elucidation of most cycle proteins, some enzymes, such as dihydrofolate synthase (MtDHFS) and serine hydroxylmethyltransferase (MtSHMT), remain underexplored. In this review, we highlight recent efforts towards the inhibitor design to achieve innovative antituberculosis agents and a brief history of all enzymes present in the folate metabolic cycle. In the final section of this work, we have presented the main synthetic strategies used to obtain the most promising inhibitors.

New kinase and HDAC hybrid inhibitors: recent advances and perspectives.

Cancer is the second most common cause of death worldwide. It can easily acquire resistance to treatments, demanding new therapeutic strategies, such as simultaneous inhibition of kinase and HDAC enzymes with hybrid inhibitors. Different approaches to this have varied according to their targets, with a few common trends, such as the usage of heterocycle scaffolds for kinase interaction, especially pyrimidine and quinazolines, and hydroxamic acids and benzamides for HDAC inhibition. Besides the hybrid compounds developed focusing on the inhibition tyrosine kinase and receptor tyrosine kinase, many advances have occurred in the development of serine-threonine kinase/HDAC and lipid kinase/HDAC novel compounds. Here, the latest strategies employed in this research area will be reviewed, alongside trends in inhibitor design, and observed gaps will be punctuated.

Peppers: A "Hot" Natural Source for Antitumor Compounds.

Piper, Capsicum, and Pimenta are the main genera of peppers consumed worldwide. The traditional use of peppers by either ancient civilizations or modern societies has raised interest in their biological applications, including cytotoxic and antiproliferative effects. Cellular responses upon treatment with isolated pepper-derived compounds involve mechanisms of cell death, especially through proapoptotic stimuli in tumorigenic cells. In this review, we highlight naturally occurring secondary metabolites of peppers with cytotoxic effects on cancer cell lines. Available mechanisms of cell death, as well as the development of analogues, are also discussed.

Structure-activity relationship and mechanistic studies for a series of cinnamyl hydroxamate histone deacetylase inhibitors.

Histone deacetylases (HDACs) are a family of enzymes that modulate the acetylation status histones and non-histone proteins. Histone deacetylase inhibitors (HDACis) have emerged as an alternative therapeutic approach for the treatment of several malignancies. Herein, a series of urea-based cinnamyl hydroxamate derivatives is presented as potential anticancer HDACis. In addition, structure-activity relationship (SAR) studies have been performed in order to verify the influence of the linker on the biological profile of the compounds. All tested compounds demonstrated significant antiproliferative effects against solid and hematological human tumor cell lines. Among them, 11b exhibited nanomolar potency against hematological tumor cells including Jurkat and Namalwa, with IC50 values of 40 and 200 nM, respectively. Cellular and molecular proliferation studies, in presence of compounds 11a-d, showed significant cell growth arrest, apoptosis induction, and up to 43-fold selective cytotoxicity for leukemia cells versus non-tumorigenic cells. Moreover, compounds 11a-d increased acetylated α-tubulin expression levels, which is phenotypically consistent with HDAC inhibition, and indirectly induced DNA damage. In vitro enzymatic assays performed for 11b revealed a potent HDAC6 inhibitory activity (IC50: 8.1 nM) and 402-fold selectivity over HDAC1. Regarding SAR analysis, the distance between the hydroxamate moiety and the aromatic ring as well as the presence of the double bond in the cinnamyl linker were the most relevant chemical feature for the antiproliferative activity of the series. Molecular modeling studies suggest that cinnamyl hydroxamate is the best moiety of the series for binding HDAC6 catalytic pocket whereas exploration of Ser568 by the urea connecting unity (CU) might be related with the selectivity observed for the cinnamyl derivatives. In summary, cinnamyl hydroxamate derived compounds with HDAC6 inhibitory activity exhibited cell growth arrest and increased apoptosis, as well as selectivity to acute lymphoblastic leukemia cells. This study explores interesting compounds to fight against neoplastic hematological cells.

Design of Arylsulfonylhydrazones as Potential FabH Inhibitors: Synthesis, Antimicrobial Evaluation and Molecular Docking.

BACKGROUND: Antimicrobial resistance is a persistent problem regarding infection treatment and calls for developing new antimicrobial agents. Inhibition of bacterial ß-ketoacyl acyl carrier protein synthase III (FabH), which catalyzes the condensation reaction between a CoAattached acetyl group and an ACP-attached malonyl group in bacteria is an interesting strategy to find new antibacterial agents. OBJECTIVE: The aim of this work was to design and synthesize arylsulfonylhydrazones potentially FabH inhibitors and evaluate their antimicrobial activity. METHODS: MIC50 values of sulfonylhydrazones against E. coli and S. aureus were determined. Antioxidant activity was evaluated by DPPH (1-1'-diphenyl-2-picrylhydrazyl) assay and cytotoxicity against LL24 lung fibroblast cells was verified by MTT method. Principal component analysis (PCA) was performed in order to suggest a structure-activity relationship. Molecular docking allowed to propose sulfonylhydrazones interactions with FabH. RESULTS: The most active compound showed activity against S. aureus and E. coli, with MIC50 = 0.21 and 0.44 µM, respectively. PCA studies correlated better activity to lipophilicity and molecular docking indicated that sulfonylhydrazone moiety is important to hydrogen-bond with FabH while methylcatechol ring performs π-π stacking interaction. The DPPH assay revealed that some sulfonylhydrazones derived from the methylcatechol series had antioxidant activity. None of the evaluated compounds was cytotoxic to human lung fibroblast cells, suggesting that the compounds might be considered safe at the tested concentration. CONCLUSION: Arylsufonylhydrazones is a promising scaffold to be explored for the design of new antimicrobial agents.

Using a Fragment-Based Approach to Identify Alternative Chemical Scaffolds Targeting Dihydrofolate Reductase from Mycobacterium tuberculosis.

Dihydrofolate reductase (DHFR), a key enzyme involved in folate metabolism, is a widely explored target in the treatment of cancer, immune diseases, bacteria, and protozoa infections. Although several antifolates have proved successful in the treatment of infectious diseases, they have been underexplored to combat tuberculosis, despite the essentiality of M. tuberculosis DHFR (MtDHFR). Herein, we describe an integrated fragment-based drug discovery approach to target MtDHFR that has identified hits with scaffolds not yet explored in any previous drug design campaign for this enzyme. The application of a SAR by catalog strategy of an in house library for one of the identified fragments has led to a series of molecules that bind to MtDHFR with low micromolar affinities. Crystal structures of MtDHFR in complex with compounds of this series demonstrated a novel binding mode that considerably differs from other DHFR antifolates, thus opening perspectives for the development of relevant MtDHFR inhibitors.

Dendrimers in the context of nanomedicine.

Dendrimers are globular structures, presenting an initiator core, repetitive layers starting radially from the core and terminal groups on the surface, resembling tree architecture. These structures have been studied in many biological applications, as drug, DNA, RNA and proteins delivery, as well as imaging and radiocontrast agents. With reference to that, this review focused in providing examples of dendrimers used in nanomedicine. Although most studies emphasize cancer, there are others which reveal action in the neurosystem, reducing either neuroinflammation or protein aggregation. Dendrimers can carry bioactive compounds by covalent bond (dendrimer prodrug), or by ionic interaction or adsortion in the internal space of the nanostructure. Additionally, dendrimers can be associated with other polymers, as PEG (polyethylene glycol), and with targeting structures as aptamers, antibodies, folic acid and carbohydrates. Their products in preclinical/clinical trial and those in the market are also discussed, with a total of six derivatives in clinical trials and seven products available in the market.

Capsaicin-like analogue induced selective apoptosis in A2058 melanoma cells: Design, synthesis and molecular modeling.

The use of molecules inspired by natural scaffolds has proven to be a very promising and efficient method of drug discovery. In this work, capsaicin, a natural product from Capsicum peppers with antitumor properties, was used as a prototype to obtain urea and thiourea analogues. Among the most promising compounds, the thiourea compound 6g exhibited significant cytotoxic activity against human melanoma A2058 cells that was twice as high as that of capsaicin. Compound 6g induced significant and dose-dependent G0/G1 cell cycle arrest in A2058 cells triggering cell death by apoptosis. Our results suggest that 6g modulates the RAF/MEK/ERK pathway, inducing important morphological changes, such as formation of apoptotic bodies and increased levels of cleaved caspase-3. Compared to capsaicin, 6g had no significant TRPV1/6 agonist effect or irritant effects on mice. Molecular modeling studies corroborate the biological findings and suggest that 6g, besides being a more reactive molecule towards its target, may also present a better pharmacokinetic profile than capsaicin. Inverse virtual screening strategy found MEK1 as a possible biological target for 6g. Consistent with these findings, our observations suggested that 6g could be developed as a potential anticancer agent.

Crystal Structure of GenD2, an NAD-Dependent Oxidoreductase Involved in the Biosynthesis of Gentamicin.

Gentamicins are clinically relevant aminoglycoside antibiotics produced by several Micromonospora species. Gentamicins are highly methylated and functionalized molecules, and their biosynthesis include glycosyltransferases, dehydratase/oxidoreductases, aminotransferases, and methyltransferases. The biosynthesis of gentamicin A from gentamicin A2 involves three enzymatic steps that modify the hydroxyl group at position 3″ of the unusual garosamine sugar to provide its substitution for an amino group, followed by an N-methylation. The first of these reactions is catalyzed by GenD2, an oxidoreductase from the Gfo/Idh/MocA protein family, which reduces the hydroxyl at the C3″ of gentamicin A to produce 3''-dehydro-3''-oxo-gentamicin A2 (DOA2). In this work, we solved the structure of GenD2 in complex with NAD+. Although the structure of GenD2 has a similar fold to other members of the Gfo/Idh/MocA family, this enzyme has several new features, including a 3D-domain swapping of two ß-strands that are involved in a novel oligomerization interface for this protein family. In addition, the active site of this enzyme also has several specialties which are possibly involved in the substrate specificity, including a number of aromatic residues and a negatively charged region, which is complementary to the polycationic aminoglycoside-substrate. Therefore, docking simulations provided insights into the recognition of gentamicin A2 and into the catalytic mechanism of GenD2. This is the first report describing the structure of an oxidoreductase involved in aminoglycoside biosynthesis and could open perspectives into producing new aminoglycoside derivatives by protein engineering.

Capsaicin-like analogue induced selective apoptosis in A2058 melanoma cells: design, synthesis and molecular modeling

The use of molecules inspired by natural scaffolds has proven to be a very promising and efficient method of drug discovery. In this work, capsaicin, a natural product from Capsicum peppers with antitumor properties, was used as a prototype to obtain urea and thiourea analogues. Among the most promising compounds, the thiourea compound 6g exhibited significant cytotoxic activity against human melanoma A2058 cells that was twice as high as that of capsaicin. Compound 6g induced significant and dose-dependent G0/G1 cell cycle arrest in A2058 cells triggering cell death by apoptosis. Our results suggest that 6g modulates the RAF/MEK/ERK pathway, inducing important morphological changes, such as formation of apoptotic bodies and increased levels of cleaved caspase-3. Compared to capsaicin, 6g had no significant TRPV1/6 agonist effect or irritant effects on mice. Molecular modeling studies corroborate the biological findings and suggest that 6g, besides being a more reactive molecule towards its target, may also present a better pharmacokinetic profile than capsaicin. Inverse virtual screening strategy found MEK1 as a possible biological target for 6g. Consistent with these findings, our observations suggested that 6g could be developed as a potential anticancer agent.

Multi-Spectroscopic and Theoretical Analysis on the Interaction between Human Serum Albumin and a Capsaicin Derivative-RPF101.

The interaction between the main carrier of endogenous and exogenous compounds in the human bloodstream (human serum albumin, HSA) and a potential anticancer compound (the capsaicin analogue RPF101) was investigated by spectroscopic techniques (circular dichroism, steady-state, time-resolved, and synchronous fluorescence), zeta potential, and computational method (molecular docking). Steady-state and time-resolved fluorescence experiments indicated an association in the ground state between HSA:RPF101. The interaction is moderate, spontaneous (ΔG° < 0), and entropically driven (ΔS° = 0.573 ± 0.069 kJ/molK). This association does not perturb significantly the potential surface of the protein, as well as the secondary structure of the albumin and the microenvironment around tyrosine and tryptophan residues. Competitive binding studies indicated Sudlow's site I as the main protein pocket and molecular docking results suggested hydrogen bonding and hydrophobic interactions as the main binding forces.

Synthesis, Molecular Modeling, and Evaluation of Novel Sulfonylhydrazones as Acetylcholinesterase Inhibitors for Alzheimer's Disease.

Alzheimer's disease (AD) is the most common type of dementia and related to the degeneration of hippocampal cholinergic neurons, which dramatically affects cognitive ability. Acetylcholinesterase (AChE) inhibitors are employed as drugs for AD therapy. Three series of sulfonylhydrazone compounds were designed, and their ability to inhibit AChE was evaluated. Fifteen compounds were synthesized and twelve of them had IC50 values of 0.64-51.09 µM. The preliminary structure-activity relationships indicated that the methylcatechol moiety and arylsulfonyl substituents generated better compounds than both the benzodioxole and alkylsulfonyl chains. Molecular dynamics studies of compound 6d showed that the interaction with the peripheral binding site of AChE was similar to donepezil, which may explain its low IC50 (0.64 µM). Furthermore, the drug-likeness of 6d suggests that the compound may have appropriate oral absorption and brain penetration. Compound 6d also presented antiradical activity and was not cytotoxic to LL24 cells, suggesting that this compound might be considered safe. Our findings indicate that arylsulfonylhydrazones may be a promising scaffold for the design of new drug candidates for the treatment of AD.

Toward chelerythrine optimization: Analogues designed by molecular simplification exhibit selective growth inhibition in non-small-cell lung cancer cells.

A series of novel chelerythrine analogues was designed and synthesized. Antitumor activity was evaluated against A549, NCI-H1299, NCI-H292, and NCI-H460 non-small-cell lung cancer (NSCLC) cell lines in vitro. The selectivity of the most active analogues and chelerythrine was also evaluated, and we compared their cytotoxicity in NSCLC cells and non-tumorigenic cell lines, including human umbilical vein endothelial cells (HUVECs) and LL24 human lung fibroblasts. In silico studies were performed to establish structure-activity relationships between chelerythrine and the analogues. The results showed that analogue compound 3f induced significant dose-dependent G0/G1 cell cycle arrest in A549 and NCI-H1299 cells. Theoretical studies indicated that the molecular arrangement and electron characteristics of compound 3f were closely related to the profile of chelerythrine, supporting its activity. The present study presents a new and simplified chelerythrinoid scaffold with enhanced selectivity against NSCLC tumor cells for further optimization.

Oleanolic acid (OA) as an antileishmanial agent: Biological evaluation and in silico mechanistic insights.

Although a worldwide health problem, leishmaniasis is considered a highly neglected disease, lacking efficient and low toxic treatment. The efforts for new drug development are based on alternatives such as new uses for well-known drugs, in silico and synthetic studies and naturally derived compounds. Oleanolic acid (OA) is a pentacyclic triterpenoid widely distributed throughout the Plantae kingdom that displays several pharmacological activities. OA showed potent leishmancidal effects in different Leishmania species, both against promastigotes (IC(50 L. braziliensis) 30.47 ± 6.35 µM; IC(50 L. amazonensis) 40.46 ± 14.21 µM; IC(50 L. infantum) 65.93 ± 15.12 µM) and amastigotes (IC(50 L. braziliensis) 68.75 ± 16.55 µM; IC(50 L. amazonensis) 38.45 ± 12.05 µM; IC(50 L. infantum) 64.08 ± 23.52 µM), with low cytotoxicity against mouse peritoneal macrophages (CC(50) 235.80 ± 36.95 µM). Moreover, in silico studies performed to evaluate OA molecular properties and to elucidate the possible mechanism of action over the Leishmania enzyme sterol 14α-demethylase (CYP51) suggested that OA interacts efficiently with CYP51 and could inhibit the ergosterol synthesis pathway. Collectively, these data indicate that OA is a good candidate as leading compound for the development of a new leishmaniasis treatment.

RPF151, a novel capsaicin-like analogue: in vitro studies and in vivo preclinical antitumor evaluation in a breast cancer model.

Capsaicin, the primary pungent component of the chili pepper, has antitumor activity. Herein, we describe the activity of RPF151, an alkyl sulfonamide analogue of capsaicin, against MDA-MB-231 breast cancer cells. RPF151 was synthetized, and molecular modeling was used to compare capsaicin and RPF151. Cytotoxicity of RPF151 on MDA-MB-231 was also evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5diphenyltetrazolium bromide (MTT) assay. Cell cycle analysis, by flow cytometry, and Western blot analysis of cycle-related proteins were used to evaluate the antiproliferative mechanisms. Apoptosis was evaluated by phosphatidyl-serine externalization, cleavage of Ac-YVAD-AMC, and Bcl-2 expression. The production of reactive oxygen species was evaluated by flow cytometry. RPF151 in vivo antitumor effects were investigated in murine MDA-MB-231 model. This study shows that RPF151 downregulated p21 and cyclins A, D1, and D3, leading to S-phase arrest and apoptosis. Although RPF151 has induced the activation of TRPV-1 and TRAIL-R1/DR4 and TRAIL-2/DR5 on the surface of MDA-MB-231 cells, its in vivo antitumor activity was TRPV-1-independent, thus suggesting that RPF151 should not have the same pungency-based limitation of capsaicin. In silico analysis corroborated the biological findings, showing that RPF151 has physicochemical improvements over capsaicin. Overall, the activity of RPF151 against MDA-MB-231 and its lower pungency suggest that it may have a relevant role in cancer therapy.

Novel capsaicin analogues as potential anticancer agents: synthesis, biological evaluation, and in silico approach.

A novel class of benzo[d][1,3]dioxol-5-ylmethyl alkyl/aryl amide and ester analogues of capsaicin were designed, synthesized, and evaluated for their cytotoxic activity against human and murine cancer cell lines (B16F10, SK-MEL-28, NCI-H1299, NCI-H460, SK-BR-3, and MDA-MB-231) and human lung fibroblasts (MRC-5). Three compounds (5f, 6c, and 6e) selectively inhibited the growth of aggressive cancer cells in the micromolar (µM) range. Furthermore, an exploratory data analysis pointed at the topological and electronic molecular properties as responsible for the discrimination process regarding the set of investigated compounds. The findings suggest that the applied designing strategy, besides providing more potent analogues, indicates the aryl amides and esters as well as the alkyl esters as interesting scaffolds to design and develop novel anticancer agents.

To be drug or prodrug: structure-property exploratory approach regarding oral bioavailability.

PURPOSE: Prodrug design is a strategy that can be used to adjust physicochemical properties of drugs in order to overcome pharmacokinetic problems, such as poor oral bioavailability. However, Lipinski´s and Veber´s rules predict whether compounds will have absorption problems even before the design of prodrugs. In this context, our goal was to evaluate the molecular properties which most influenced the absorption process of prodrugs compared to its precursor through exploratory data analysis approach. METHODS: A variety of prodrugs and respective precursors were randomly selected and classified by its percentage of human intestinal absorption. Subsequently, different molecular properties were calculated and hierarchical cluster analysis (HCA) and principal components analysis (PCA) were carried out. RESULTS: According to the findings, antiviral, anti-hypertensive, and antibiotic prodrugs exhibited higher absorption levels than their respective precursors. Also, some relevant descriptors (molecular weight, MW, routable bonds, rot_bonds, hydrogen bond acceptors, HBA_count and polar surface area, PSA), which are included in Lipinski´s and Veber´s rules, influenced the separation process between prodrugs and drugs. Furthermore, other molecular properties, such as polarizability (α) and molar refractivity (MR), were pointed out. CONCLUSION: Lipinski´s and Veber´s rules proved to be important to design an orally administered drug but other descriptors should be considered by medicinal chemists in the prodrug designing process.

Cytotoxic effects of dillapiole on MDA-MB-231 cells involve the induction of apoptosis through the mitochondrial pathway by inducing an oxidative stress while altering the cytoskeleton network.

Breast cancer is the world's leading cause of death among women. This situation imposes an urgent development of more selective and less toxic agents. The use of natural molecular fingerprints as sources for new bioactive chemical entities has proven to be a quite promising and efficient method. Here, we have demonstrated for the first time that dillapiole has broad cytotoxic effects against a variety tumor cells. For instance, we found that it can act as a pro-oxidant compound through the induction of reactive oxygen species (ROS) release in MDA-MB-231 cells. We also demonstrated that dillapiole exhibits anti-proliferative properties, arresting cells at the G0/G1 phase and its antimigration effects can be associated with the disruption of actin filaments, which in turn can prevent tumor cell proliferation. Molecular modeling studies corroborated the biological findings and suggested that dillapiole may present a good pharmacokinetic profile, mainly because its hydrophobic character, which can facilitate its diffusion through tumor cell membranes. All these findings support the fact that dillapiole is a promising anticancer agent.