A Combined Computer-Aided Approach to Drive the Identification of Potential Epitopes in Protein Therapeutics.

BACKGROUND: The identification of fragment sequences, or motifs, within a therapeutic protein that may elicit an immune response when processed by T-cells can be provided by computer-aided approaches. Immunogenicity is a significant problem associated with protein therapeutics and should be investigated in the early stage of protein-based drug development to avoid treatment resistance and potentially life-threatening immune responses. PURPOSE: To provide a combined computer-aided protocol for investigating the immunogenic profile of a recombinant Kunitz-type inhibitor, which has been reported as promising antitumor agent by our research group. METHODS: The combination of databases searching (IEDB and SYFPEITHI) and molecular docking simulations was exploited, herein. This combined protocol has allowed the identification of potential epitopes before in vitro/in vivo evaluation. Predictors of human proteasome cleavage transport and major histocompatibility complex (MHC) binding were considered as overall score assigning the corresponding intrinsic potential of being a T cell epitope to each fragment sequence. The peptides or motifs better classified in the two databases were docked into the three-dimensional (3D) structure of MHC (class I and II) complex to verify the calculated binding affinity.  The binding interactions regarding the molecular recognition process by T-cells were also exploited through the MHC:ligand:T-cell complexes. RESULTS: Regarding the Kunitz-type sequence, four motifs were identified as potentially epitopes for MHC-I and three motifs were found for MHC-II. But, those motifs were classified as moderately immunogenic. Final remarks: The combined computer-aided protocol has significantly reduced the number of potential epitopes to be considered for further analysis and could be useful to identify immunogenic fragments (high, moderate and low) in protein pharmaceutics before in vitro/in vivo experimentation.

BFD-22 a new potential inhibitor of BRAF inhibits the metastasis of B16F10 melanoma cells and simultaneously increased the tumor immunogenicity.

Benzofuroxan is an interesting ring system, which has shown a wide spectrum of biological responses against tumor cell lines. We investigated, herein, the antitumor effects of benzofuroxan derivatives (BFDs) in vitro and in a melanoma mouse model. Cytotoxic effects of twenty-two BFDs were determined by MTT assay. Effects of BFD-22 in apoptosis and cell proliferation were evaluated using Annexin V-FITC/PI and CFSE staining. In addition, the effects in the cell cycle were assessed. Flow cytometry, western blot, and fluorescence microscopy analysis were employed to investigate the apoptosis-related proteins and the BRAF signaling. Cell motility was also exploited through cell invasion and migration assays. Molecular docking approach was performed in order to verify the BFD-22 binding mode into the ATP catalytic site of BRAF kinase. Moreover, the BFD-22 antitumor effects were evaluated in a melanoma murine model using B16F10. BFD-22 was identified as a potential hit against melanoma cells. BFD-22 induced apoptosis and inhibited cell proliferation of B16F10 cells. BFD-22 has suppressed, indeed, the migratory and invasive behavior of B16F10 cells. Cyclin D1 and CDK4 expression were reduced leading to cell cycle arrest at G0/G1 phase. Of note, phosphorylation of BRAF at Ser338 was strongly down-regulated by BFD-22 in B16F10 cells. The accommodation/orientation into the binding site of BRAF was similar of BAY43-9006 (co-crystallized inhibitor of BRAF, sorafenib). Importantly, BFD-22 presented in vivo antimetastatic effects and showed better therapeutic efficacy than sorafenib and taxol. BFD-22 can be considered as a new lead compound and, then, can be helpful for the designing of novel drug candidates to treat melanoma.

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.

Exploring 5-nitrofuran derivatives against nosocomial pathogens: synthesis, antimicrobial activity and chemometric analysis.

The burden of nosocomial or health care-associated infection (HCAI) is increasing worldwide. According to the World Health Organization (WHO), it is several fold higher in low- and middle-income countries. Considering the multidrug-resistant infections, the development of new and more effective drugs is crucial. Herein, two series (I and II) of 5-nitrofuran derivatives were designed, synthesized and assayed against microorganisms, including Gram-positive and -negative bacteria, and fungi. The pathogens screened was directly related to either the most currently relevant HCAI, or to multidrug-resistant infection caused by MRSA/VRSA strains, for instance. The sets I and II were composed by substituted-[N'-(5-nitrofuran-2-yl)methylene]benzhydrazide and 3-acetyl-5-(substituted-phenyl)-2-(5-nitro-furan-2-yl)-2,3-dihydro-1,3,4-oxadiazole compounds, respectively. The selection of the substituent groups was based upon physicochemical properties, such as hydrophobicity and electronic effect. The compounds have showed better activity against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis. The findings from S. aureus strain, which was more susceptible, were used to investigate the intersamples and intervariables relationships by applying chemometric methods. It is noteworthy that the compound 4-butyl-[N'-(5-nitrofuran-2-yl)methylene]benzhydrazide has showed similar MIC value to vancomycin, which is the reference drug for multidrug-resistant S. aureus infections. Taken the findings together, the 5-nitrofuran derivatives might be indeed considered as promising hits to develop novel antimicrobial drugs to fight against nosocomial infection.

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.

RPF101, a new capsaicin-like analogue, disrupts the microtubule network accompanied by arrest in the G2/M phase, inducing apoptosis and mitotic catastrophe in the MCF-7 breast cancer cells.

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. Capsaicin, which is the primary pungent compound in red peppers, was reported to selectively inhibit the growth of a variety tumor cell lines. Here, we report for the first time a novel synthetic capsaicin-like analogue, RPF101, which presents a high antitumor activity on MCF-7 cell line, inducing arrest of the cell cycle at the G2/M phase through a disruption of the microtubule network. Furthermore, it causes cellular morphologic changes characteristic of apoptosis and a decrease of Δψm. Molecular modeling studies corroborated the biological findings and suggested that RPF101, besides being a more reactive molecule towards its target, may also present a better pharmacokinetic profile than capsaicin. All these findings support the fact that RPF101 is a promising anticancer agent.

5-Nitro-2-furfuriliden derivatives as potential anti-Trypanosoma cruzi agents: design, synthesis, bioactivity evaluation, cytotoxicity and exploratory data analysis.

The anti-Trypanosoma cruzi activity of 5-nitro-2-furfuriliden derivatives as well as the cytotoxicity of these compounds on J774 macrophages cell line and FN1 human fibroblast cells were investigated in this study. The most active compounds of series I and II were 4-butyl-[N'-(5-nitrofuran-2-yl) methylene] benzidrazide (3g; IC50=1.05µM±0.07) and 3-acetyl-5-(4-butylphenyl)-2-(5-nitrofuran-2-yl)-2,3-dihydro,1,3,4-oxadiazole (4g; IC50=8.27µM±0.42), respectively. Also, compound 3g was more active than the standard drugs, benznidazole (IC50=22.69µM±1.96) and nifurtimox (IC50=3.78µM±0.10). Regarding the cytotoxicity assay, the 3g compound presented IC50 value of 28.05µM (SI=26.71) against J774 cells. For the FN1 fibroblast assay, 3g showed IC50 value of 98µM (SI=93.33). On the other hand, compound 4g presented a cytotoxicity value on J774 cells higher than 400µM (SI >48), and for the FN1 cells its IC50 value was 186µM (SI=22.49). Moreover, an exploratory data analysis, which comprises hierarchical cluster (HCA) and principal component analysis (PCA), was carried out and the findings were complementary. The molecular properties that most influenced the compounds' grouping were ClogP and total dipole moment, pointing out the need of a lipophilic/hydrophilic balance in the designing of novel potential anti-T. cruzi molecules.

Design and exploratory data analysis of a second generation of dendrimer prodrugs potentially antichagasic and leishmanicide.

Chagas disease and leishmaniasis are neglected tropical diseases, considered as a serious public health. Also, the drugs available for their treatment are toxic and exhibit questionable efficacy. Consequently, the discovery and development of new drug candidates are currently necessary. Dendrimers are highly branched molecules with extremely controlled structure. Those molecular systems display several biological applications (i.e., drug carriers), especially when the focus is prodrug design. Herein, a second generation of dendrimer prodrugs was planned to obtain potentially antichagasic and leishmanicide delivery systems. These dendrimers were composed by myo-inositol (core), L-malic acid (spacer), and three bioactive agents [hydroxymethylnitrofurazone (NFOH), quercetin, 3-hydroxyflavone]. The major aim of this study was to investigate the molecular properties (thermodynamics, steric, steric/electronic, electronic, and hydrophobic) to further describe intersamples relationships through either similarity indices or linear combinations of the original variables. Then, an exploratory data analysis, which comprises hierarchical cluster analysis (HCA) and principal components analysis (PCA), was carried out. Complementary findings were observed for PCA and HCA. Steric, intrinsic/steric, steric/electronic, steric/hydrophobic, hydrophobic, and electronic properties influenced the discrimination process. In addition, these molecular properties can also contribute to enzymatic hydrolysis mechanism elucidation, which depends upon the approximation and a subsequent nucleophilic attack to release the drug from the dendrimer prodrugs.

Dillapiole as antileishmanial agent: discovery, cytotoxic activity and preliminary SAR studies of dillapiole analogues.

In this paper, the isolation of dillapiole (1) from Piper aduncum was reported as well as the semi-synthesis of two phenylpropanoid derivatives [di-hydrodillapiole (2), isodillapiole (3)], via reduction and isomerization reactions. Also, the compounds' molecular properties (structural, electronic, hydrophobic, and steric) were calculated and investigated to establish some preliminary structure-activity relationships (SAR). Compounds were evaluated for in vitro antileishmanial activity and cytotoxic effects on fibroblast cells. Compound 1 presented inhibitory activity against Leishmania amazonensis (IC(50) = 69.3 µM) and Leishmania brasiliensis (IC(50) = 59.4 µM) and induced cytotoxic effects on fibroblast cells mainly in high concentrations. Compounds 2 (IC(50) = 99.9 µM for L. amazonensis and IC(50) = 90.5 µM for L. braziliensis) and 3 (IC(50) = 122.9 µM for L. amazonensis and IC(50) = 109.8 µM for L. brasiliensis) were less active than dillapiole (1). Regarding the molecular properties, the conformational arrangement of the side chain, electronic features, and the hydrophilic/hydrophobic balance seem to be relevant for explaining the antileishmanial activity of dillapiole and its analogues.

Pycard and BC017158 Candidate Genes of Irm1 Locus Modulate Inflammasome Activation for IL-1ß Production.

We identified Pycard and BC017158 genes as putative effectors of the Quantitative Trait locus (QTL) that we mapped at distal chromosome 7 named Irm1 for Inflammatory response modulator 1, controlling acute inflammatory response (AIR) and the production of IL-1ß, dependent on the activation of the NLRP3 inflammasome. We obtained the mapping through genome-wide linkage analysis of Single Nucleotide Polymorphisms (SNPs) in a cross between High (AIRmax) and Low (AIRmin) responder mouse lines that we produced by several generations of bidirectional selection for Acute Inflammatory Response. A highly significant linkage signal (LOD score peak of 72) for ex vivo IL-1ß production limited a 4 Mbp interval to chromosome 7. Sequencing of the locus region revealed 14 SNPs between "High" and "Low" responders that narrowed the locus to a 420 Kb interval. Variants were detected in non-coding regions of Itgam, Rgs10 and BC017158 genes and at the first exon of Pycard gene, resulting in an E19K substitution in the protein ASC (apoptosis associated speck-like protein containing a CARD) an adaptor molecule in the inflammasome complex. Silencing of BC017158 inhibited IL1-ß production by stimulated macrophages and the E19K ASC mutation carried by AIRmin mice impaired the ex vivo IL-1ß response and the formation of ASC specks in stimulated cells. IL-1ß and ASC specks play major roles in inflammatory reactions and in inflammation-related diseases. Our results delineate a novel genetic factor and a molecular mechanism affecting the acute inflammatory response.

Novel benzofuroxan derivatives against multidrug-resistant Staphylococcus aureus strains: design using Topliss' decision tree, synthesis and biological assay.

The aim of this study was the design of a set of benzofuroxan derivatives as antimicrobial agents exploring the physicochemical properties of the related substituents. Topliss' decision tree approach was applied to select the substituent groups. Hierarchical cluster analysis was also performed to emphasize natural clusters and patterns. The compounds were obtained using two synthetic approaches for reducing the synthetic steps as well as improving the yield. The minimal inhibitory concentration method was employed to evaluate the activity against multidrug-resistant Staphylococcus aureus strains. The most active compound was 4-nitro-3-(trifluoromethyl)[N'-(benzofuroxan-5-yl)methylene]benzhydrazide (MIC range 12.7-11.4 µg/mL), pointing out that the antimicrobial activity was indeed influenced by the hydrophobic and electron-withdrawing property of the substituent groups 3-CF(3) and 4-NO(2), respectively.

Synthesis, molecular modeling and preliminary biological evaluation of a set of 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole as potential antibacterial, anti-Trypanosoma cruzi and antifungal agents.

A series of 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole derivatives was synthesized and their activity screened in vitro against Staphylococcus aureus, Trypanosoma cruzi, and Candida albicans. The bioactivity was expressed as minimum inhibitory concentration (MIC) for S. aureus strains, and as fifty-percent inhibitory concentration (IC(50)) of parasite population growth for T. cruzi. A molecular modeling approach was performed to establish qualitative relationships regarding the biological data and the compounds' physicochemical properties. The 5-(4-OC(4)H(9)Ph, 5l), and 5-(4-CO(2)CH(3)Ph, 5o) derivatives were the most active compounds for S. aureus ATCC 25923 (MIC=1.95-1.25 µg/mL) and T. cruzi (IC(50)=7.91 µM), respectively. Also, a preliminary evaluation against C. albicans involving some compounds was performed and the 5-(4-CH(3)Ph, 5e) derivative was the most active compound (MIC=3.28-2.95 µg/mL). In this preliminary study, all synthesized 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole derivatives were active against all microorganisms tested.

Antimicrobial Activity of Snake ß-Defensins and Derived Peptides.

ß-defensins are antimicrobial peptides presenting in vertebrate animals. They participate in innate immunity, but little is known about them in reptiles, including snakes. Although several ß-defensin genes were described in Brazilian snakes, their function is still unknown. The peptide sequence from these genes was deduced, and synthetic peptides (with approximately 40 amino acids and derived peptides) were tested against pathogenic bacteria and fungi using microbroth dilution assays. The linear peptides, derived from ß-defensins, were designed applying the bioisosterism strategy. The linear ß-defensins were more active against Escherichia coli, Micrococcus luteus, Citrobacter freundii, and Staphylococcus aureus. The derived peptides (7-14 mer) showed antibacterial activity against those bacteria and on Klebsiella pneumoniae. Nonetheless, they did not present activity against Candida albicans, Cryptococcus neoformans, Trychophyton rubrum, and Aspergillus fumigatus showing that the cysteine substitution to serine is deleterious to antifungal properties. Tryptophan residue showed to be necessary to improve antibacterial activity. Even though the studied snake ß-defensins do not have high antimicrobial activity, they proved to be attractive as template molecules for the development of antibiotics.

Correlating biological activity to thermo-structural analysis of the interaction of CTX with synthetic models of macrophage membranes.

The important pharmacological actions of Crotoxin (CTX) on macrophages, the main toxin in the venom of Crotalus durissus terrificus, and its important participation in the control of different pathophysiological processes, have been demonstrated. The biological activities performed by macrophages are related to signaling mediated by receptors expressed on the membrane surface of these cells or opening and closing of ion channels, generation of membrane curvature and pore formation. In the present work, the interaction of the CTX complex with the cell membrane of macrophages is studied, both using biological cells and synthetic lipid membranes to monitor structural alterations induced by the protein. Here we show that CTX can penetrate THP-1 cells and induce pores only in anionic lipid model membranes, suggesting that a possible access pathway for CTX to the cell is via lipids with anionic polar heads. Considering that the selectivity of the lipid composition varies in different tissues and organs of the human body, the thermostructural studies presented here are extremely important to open new investigations on the biological activities of CTX in different biological systems.

Molecular modeling studies and in vitro bioactivity evaluation of a set of novel 5-nitro-heterocyclic derivatives as anti-T. cruzi agents.

In this study, in vitro anti-T. cruzi activity assays of nifuroxazide (NX) analogues, such as 5-nitro-2-furfuryliden and 5-nitro-2-theniliden derivatives, were performed. A molecular modeling approach was also carried out to relate the lipophilicity potential (LP) property and biological activity data. The majority of the NX derivatives showed increased anti-T. cruzi activity in comparison to the reference drug, benznidazole (BZN). Additionally, the 5-nitro-2-furfuryliden derivatives presented better pharmacological profile than the 5-nitro-2-theniliden analogues. The LP maps and corresponding ClogP values indicate that there is an optimum lipophilicity value, which must be observed in the design of new potential anti-T. cruzi agents.

Design, synthesis, antimicrobial activity and molecular modeling studies of novel benzofuroxan derivatives against Staphylococcus aureus.

Molecular modification is a quite promising strategy in the design and development of drug analogs with better bioavailability, higher intrinsic activity and less toxicity. In the search of new leads with potential antimicrobial activity, a new series of 14 4-substituted [N'-(benzofuroxan-5-yl)methylene]benzohydrazides, nifuroxazide derivatives, were synthesized and tested against standard and multidrug-resistant Staphylococcus aureus strains. The selection of the substituent groups was based on physicochemical properties, such as hydrophobicity and electronic effect. These properties were also evaluated through the lipophilic and electrostatic potential maps, respectively, considering the compounds with better biological profile. Twelve compounds exhibited similar bacteriostatic activity against standard and multidrug-resistant strains. The most active compound was the 4-CF(3) substituted derivative, which presented a minimum inhibitory concentration (MIC) value of 14.6-13.1 microg/mL, and a ClogP value of 1.87. The results highlight the benzofuroxan derivatives as potential leads for designing new future antimicrobial drug candidates.

Investigating the structure-activity relationships of N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides against Trypanosoma cruzi to design novel active compounds.

Chagas disease, caused by the protozoan Trypanosoma cruzi, is a neglected chronic tropical infection endemic in Latin America. New and effective treatments are urgently needed because the two available drugs - benznidazole (BZD) and nifurtimox (NFX) - have limited curative power in the chronic phase of the disease. We have previously reported the design and synthesis of N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides that showed high trypanocidal activity against axenic epimastigote forms of three T. cruzi strains. Here we show that these compounds are also active against a BZD- and NFX-resistant strain. Herein, multivariate approaches (hierarchical cluster analysis and principal component analysis) were applied to a set of thirty-six formerly characterized compounds. Based on the findings from exploratory data analysis, novel compounds were designed and synthesized. These compounds showed two-to three-fold higher trypanocidal activity against epimastigote forms than the previous set and were 25-30-fold more active than BZD. Their activity was also evaluated against intracellular amastigotes by high content screening (HCS). The most active compounds (BSF-38 to BSF-40) showed a selective index (SI') greater than 200, in contrast to the SI' values of reference drugs (NFX, 16.45; BZD, > 3), and a 70-fold greater activity than BZD. These findings indicate that nitrofuran compounds designed based on the activity against epimastigote forms show promising trypanocidal activity against intracellular amastigotes, which correspond to the predominant parasite stage in the chronic phase of Chagas disease.

Tick salivary gland as potential natural source for the discovery of promising antitumor drug candidates.

Nowadays, the relationship between cancer blood coagulation is well established. Regarding biodiversity and bioprospection, the tick biology has become quite attractive natural source for coagulation inhibitors, since its saliva has a very rich variety of bioactive molecules. For instance, a Kunitz-type FXa inhibitor, named Amblyomin-X, was found through transcriptome of the salivary gland of the Amblyomma cajennense. tick. This TFPI-like inhibitor, after obtained as recombinant protein, has presented anticoagulant, antigionenic, and antitumor properties. Although its effects on blood coagulation could be relevant for antitumor effect, Amblyomin-X acts by non-hemostatic mechanisms, such as proteasome inhibition and autophagy inhibition. Notably, cytotoxicity was not observed on non-tumor cells treated with this protein, suggesting some selectivity for tumor cells. Considering the current efforts in order to develop effective anticancer therapies, the findings presented in this review strongly suggest Amblyomin-X as a promising novel antitumor drug candidate.

Exploring the in vivo wound healing effects of a recombinant hemolin from the caterpillar Lonomia obliqua.

BACKGROUND: Hemolin proteins are cell adhesion molecules from lepidopterans involved in a wide range of cell interactions concerning their adhesion properties. However, hemolin's roles in cell proliferation and wound healing are not fully elucidated. It has been recently reported that rLosac, a recombinant hemolin from the caterpillar Lonomia obliqua, presents antiapoptotic activity and is capable of improving in vitro wound healing. Therefore, this study aimed to explore rLosac's in vivo effects using a skin wound healing model in rats. METHODS: Circular full-thickness wounds in the rat dorsum skin were treated either with rLosac, or with saline (control), allowing healing by keeping the wounds occluded and moist. During the wound healing, the following tissue regeneration parameters were evaluated: wound closure and collagen content. Furthermore, tissue sections were subjected to histological and immunohistochemical analyses. RESULTS: The rLosac treatment has demonstrated its capacity to improve wound healing, as reflected in findings of a larger number of activated fibroblasts, proliferation of epithelial cells, increase of collagen type 1, and decrease of inflammatory infiltrate. CONCLUSION: The findings have indicated the rLosac protein as a very promising molecule for the development of new wound-healing formulations.

Apoptotic effect of eugenol envolves G2/M phase abrogation accompanied by mitochondrial damage and clastogenic effect on cancer cell in vitro.

BACKGROUND: Eugenol (EUG) is a major phenolic compound present in clove whose anti-cancer properties have been demonstrated previously. These anti-cancer properties may involves the modulation of different mechanisms, including α-estrogen receptor (αER) in luminal breast cancer cells, COX-2 inhibition in melanoma cells or p53 and caspase-3 activation in colon cancer cells. HYPOTHESIS: EUG promotes a burst in ROS production causing cell-cycle perturbations, mitochondria toxicity and clastogenesis triggering apoptosis in melanoma breast- and cervix-cancer cells in vitro. METHODS: Morphological changes were evaluated through the light- and electronic- microscopy. Cell-cycle, ROS, PCNA and Apoptosis was detected by flow cytometry and clastogenicity was evaluated by Comet-assay. RESULTS: The results obtained herein pointed out that EUG promotes, increasing ROS production leading to abrogation of G2/M of phase of cell-cycle, and consecutively, clastogenesis in vitro. In addition, EUG induces Proliferation Cell Nuclear Antigen (PCNA) downregulation and decreasing in mitochondria potential (ΔΨm). Of note, a Bax up-regulation was also observed on cells treated with EUG. All of these findings cooperate in order to induce apoptosis in cancer cells. CONCLUSION: These promising results presented herein shed new light on the mechanisms of action of EUG suggesting a possible applicability of this phenylpropanoid as adjuvant in anti-cancer therapy.