In vitro results with minimal blood toxicity of a combretastatin A4 analogue.

Cancer is a disease caused by uncontrolled cell growth that is responsible for several deaths worldwide. Breast cancer is the most common type of cancer among women and is the leading cause of death. Chemotherapy is the most commonly used treatment for cancer; however, it often causes various side effects in patients. In this study, we evaluate the antineoplastic activity of a parent compound based on a combretastatin A4 analogue. We test the compound at 0.01 mg mL- 1, 0.1 mg mL- 1, 1.0 mg mL- 1, 10.0 mg mL- 1, 100.0 mg mL- 1, and 1,000.0 mg mL- 1. To assess molecular antineoplastic activity, we conduct in vitro tests to determine the viability of Ehrlich cells and the blood mononuclear fraction. We also analyze the cytotoxic behavior of the compound in the blood and blood smear. The results show that the molecule has a promising antineoplastic effect and crucial anticarcinogenic action. The toxicity of blood cells does not show statistically significant changes.

Antiproliferative Activity of N-Acylhydrazone Derivative on Hepatocellular Carcinoma Cells Involves Transcriptional Regulation of Genes Required for G2/M Transition.

Liver cancer is the second leading cause of cancer-related death in males. It is estimated that approximately one million deaths will occur by 2030 due to hepatic cancer. Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer subtype and is commonly diagnosed at an advanced stage. The drug arsenal used in systemic therapy for HCC is very limited. Multikinase inhibitors sorafenib (Nexavar®) and lenvatinib (Lenvima®) have been used as first-line drugs with modest therapeutic effects. In this scenario, it is imperative to search for new therapeutic strategies for HCC. Herein, the antiproliferative activity of N-acylhydrazone derivatives was evaluated on HCC cells (HepG2 and Hep3B), which were chemically planned on the ALL-993 scaffold, a potent inhibitor of vascular endothelial growth factor 2 (VEGFR2). The substances efficiently reduced the viability of HCC cells, and the LASSBio-2052 derivative was the most effective. Further, we demonstrated that LASSBio-2052 treatment induced FOXM1 downregulation, which compromises the transcriptional activation of genes required for G2/M transition, such as AURKA and AURKB, PLK1, and CDK1. In addition, LASSBio-2052 significantly reduced CCNB1 and CCND1 expression in HCC cells. Our findings indicate that LASSBio-2052 is a promising prototype for further in vivo studies.

Cytotoxic and Antiproliferative Activity of LASSBio-2208 and the Attempts to Determine Its Drug Metabolism and Pharmacokinetics In Vitro Profile.

Inappropriate expression of histone deacetylase (HDAC-6) and deregulation of the phosphatidylinositol 3-kinase (PI3K) signalling pathway are common aberrations observed in cancers. LASSBio-2208, has been previously described as a dual inhibitor in the nanomolar range of HDAC-6 and PI3Kα and is three times more potent in inhibiting HDAC-6. In this paper we described the cytotoxic and antiproliferative potency of LASSBio-2208 on different tumour cell lines, its possible synergism effect in association with PI3K and HDAC-6 inhibitors, and its drug metabolism and pharmacokinetics (DMPK) in vitro profile. Our studies have demonstrated that LASSBio-2208 has moderate cytotoxic potency on breast cancer cell line MCF-7 (IC50 = 23 µM), human leukaemia cell line CCRF-CEM (IC50 = 8.54 µM) and T lymphoblast cell line MOLT-4 (IC50 = 7.15 µM), with no cytotoxic effect on human peripheral blood mononuclear cells (hPBMC). In addition, it has a good antiproliferative effect on MCF-7 cells (IC50 = 5.44 µM), low absorption by parallel artificial membrane permeability-gastrointestinal tract (PAMPA-GIT) and low permeation by parallel artificial membrane permeability-blood-brain barrier (BBB) (PAMPA-BBB), exhibiting high metabolic stability in rat plasma. Moreover, LASSBio-2208 exhibited synergism when combined with getadolisib and tubastatin A, using the concentrations corresponding to their CC50 values on MOLT-4 and CCRF-CEM cells.

Stereochemical insights into ß-amino-N-acylhydrazones and their impact on DPP-4 inhibition.

Dipeptidyl peptidase IV (DPP-4) is a key enzyme that regulates several important biological processes and it is better known to be targeted by gliptins as a modern validated approach for the management of type 2 diabetes mellitus (T2DM). However, new generations of DPP-4 inhibitors capable of controlling inflammatory processes associated with chronic complications of T2DM are still needed. In this scenario, we report here the design by molecular modelling of new ß-amino-N-acylhydrazones, their racemic synthesis, chiral resolution, determination of physicochemical properties and their DPP4 inhibitory potency. Theoretical and experimental approaches allowed us to propose a preliminary SAR, as well as to identify LASSBio-2124 (6) as a new lead for DPP-4 inhibition, with good physicochemical properties, favourable eudismic ratio, scalable synthesis and anti-diabetes effect in a proof-of-concept model. These findings represent an interesting starting point for the development of a new generation of DPP-4 inhibitors, useful in the treatment of T2DM and comorbidities.

N-acylhydrazone derivative modulates cell cycle regulators promoting mitosis arrest and apoptosis in estrogen positive MCF-7 breast cancer cells.

Breast cancer is the leading cause of cancer death among women worldwide. About 75% of all diagnosed cases are hormone-positive, which are treated with hormone therapy. However, many patients are refractory or become resistant to the drugs used in therapeutic protocols. In this scenario, it is essential to identify new substances with pharmacological potential against breast cancer. VEGFR2 inhibitors are considered promising antitumor agents not only due to their antiangiogenic activity but also by inhibiting the proliferation of tumor cells. Thus, the present study aimed to evaluate the effects of N-acylhydrazone derivative LASSBio-2029 on the proliferative behavior of MCF-7 cells. We observed a promising antitumor potential of this substance due to its ability to modulate critical cell cycle regulators including mitotic kinases (CDK1, AURKA, AURKB, and PLK1) and CDK inhibitor (CDKN1A). Increased frequencies of abnormal mitosis and apoptotic cells were observed in response to treatment. A molecular docking analysis predicts that LASSBio-2029 could bind to the proto-oncoprotein ABL1, which participates in cell cycle control, interacting with other controller proteins and regulating centrosome-associated tubulins. Finally, we created a gene signature with the downregulated genes, whose reduced expression is associated with a higher relapse-free survival probability in breast cancer patients.

Pharmacokinetic Profile Evaluation of Novel Combretastatin Derivative, LASSBio-1920, as a Promising Colorectal Anticancer Agent.

LASSBio-1920 was synthesized due to the poor solubility of its natural precursor, combretastatin A4 (CA4). The cytotoxic potential of the compound against human colorectal cancer cells (HCT-116) and non-small cell lung cancer cells (PC-9) was evaluated, yielding IC50 values of 0.06 and 0.07 µM, respectively. Its mechanism of action was analyzed by microscopy and flow cytometry, where LASSBio-1920 was found to induce apoptosis. Molecular docking simulations and the enzymatic inhibition study with wild-type (wt) EGFR indicated enzyme-substrate interactions similar to other tyrosine kinase inhibitors. We suggest that LASSBio-1920 is metabolized by O-demethylation and NADPH generation. LASSBio-1920 demonstrated excellent absorption in the gastrointestinal tract and high central nervous system (CNS) permeability. The pharmacokinetic parameters obtained by predictions indicated that the compound presents zero-order kinetics and, in a human module simulation, accumulates in the liver, heart, gut, and spleen. The pharmacokinetic parameters obtained will serve as the basis to initiate in vivo studies regarding LASSBio-1920's antitumor potential.

Methyl Effect on the Metabolism, Chemical Stability, and Permeability Profile of Bioactive N-Sulfonylhydrazones.

Sulfonylhydrazones are privileged structures with multifaceted pharmacological activity. Exploring the hypoglycemic properties of these organic compounds, we previously revealed a new series of N-sulfonylhydrazones (NSH) as antidiabetic drug candidates. Here, we evaluated the microsomal metabolism, chemical stability, and permeability profile of these NSH prototypes, focusing on the pharmacokinetic differences in N-methylated and non-N-methylated analogs. Our results demonstrated that the N-methylated analogs (LASSBio-1772 and LASSBio-1774) were metabolized by CYP, forming three and one metabolites, respectively. These prototypes exhibited chemical stability at pH 2.0 and 7.4 and brain penetration ability. On the other hand, non-N-methylated analogs (LASSBio-1771 and LASSBio-1773) were hydrolyzed in acid pH and could not cross the artificial blood-brain barrier. The cyano group in LASSBio-1771 was postulated as a possible site of interaction with the heme group, potentially inhibiting CYP enzymes. Moreover, prototypes with the methyl ester group were metabolized by carboxylesterase, and non-N-methylated analogs did not show oxidative metabolism. The prototypes (except LASSBio-1774) showed excellent gastrointestinal absorption. Altogether, our data support the idea that the methyl effect on NSH strongly alters their pharmacokinetic profile, enhances the recognition by CYP enzymes, promotes brain penetration, and plays a protective effect upon acid hydrolysis.

Discovery of Putative Dual Inhibitor of Tubulin and EGFR by Phenotypic Approach on LASSBio-1586 Homologs.

Combretastatin A-4 (CA-4, 1) is an antimicrotubule agent used as a prototype for the design of several synthetic analogues with anti-tubulin activity, such as LASSBio-1586 (2). A series of branched and unbranched homologs of the lead-compound 2, and vinyl, ethinyl and benzyl analogues, were designed and synthesized. A comparison between the cytotoxic effect of these homologs and 2 on different human tumor cell lines was performed from a cell viability study using MTT with 48 h and 72 h incubations. In general, the compounds were less potent than CA-4, showing CC50 values ranging from 0.030 µM to 7.53 µM (MTT at 72 h) and 0.096 µM to 8.768 µM (MTT at 48 h). The antimitotic effect of the target compounds was demonstrated by cell cycle analysis through flow cytometry, and the cellular mechanism of cytotoxicity was determined by immunofluorescence. While the benzyl homolog 10 (LASSBio-2070) was shown to be a microtubule stabilizer, the lead-compound 2 (LASSBio-1586) and the methylated homolog 3 (LASSBio-1735) had microtubule destabilizing behavior. Molecular docking studies were performed on tubulin protein to investigate their binding mode on colchicine and taxane domain. Surprisingly, the benzyl homolog 10 was able to modulate EGFR phosphorylate activity in a phenotypic model. These data suggest LASSBio-2070 (10) as a putative dual inhibitor of tubulin and EGFR. Its binding mode with EGFR was determined by molecular docking and may be useful in lead-optimization initiatives.

Comparative chemical and biological hydrolytic stability of homologous esters and isosteres.

Esters are one of the major functional groups present in the structures of prodrugs and bioactive compounds. Their presence is often associated with hydrolytic lability. In this paper, we describe a comparative chemical and biological stability of homologous esters and isosteres in base media as well as in rat plasma and rat liver microsomes. Our results provided evidence for the hydrolytic structure lability relationship and demonstrated that the hydrolytic stability in plasma and liver microsome might depend on carboxylesterase activity. Molecular modelling studies were performed in order to understand the experimental data. Taken together, the data could be useful to design bioactive compounds or prodrugs based on the correct choice of the ester subunit, addressing compounds with higher or lower metabolic lability.

Effect of S-Se Bioisosteric Exchange on Affinity and Intrinsic Efficacy of Novel N-acylhydrazone Derivatives at the Adenosine A2A Receptor.

In this work, we evaluated the conformational effect promoted by the isosteric exchange of sulfur by selenium in the heteroaromatic ring of new N-acylhydrazone (NAH) derivatives (3-8, 13, 14), analogues of the cardioactive compounds LASSBio-294 (1) and LASSBio-785 (2). NMR spectra analysis demonstrated a chemical shift variation of the iminic Csp2 of NAH S/Se-isosters, suggesting a stronger intramolecular chalcogen interaction for Se-derivatives. To investigate the pharmacological profile of these compounds at the adenosine A2A receptor (A2AR), we performed a previously validated functional binding assay. As expected for bioisosteres, the isosteric-S/Se replacement affected neither the affinity nor the intrinsic efficacy of our NAH derivatives (1-8). However, the N-methylated compounds (2, 6-8) presented a weak partial agonist profile at A2AR, contrary to the non-methylated counterparts (1, 3-5), which appeared as weak inverse agonists. Additionally, retroisosterism between aromatic rings of NAH on S/Se-isosters mimicked the effect of the N-methylation on intrinsic efficacy at A2AR, while meta-substitution in the phenyl ring of the acyl moiety did not. This study showed that the conformational effect of NAH-N-methylation and aromatic rings retroisosterism changed the intrinsic efficacy on A2AR, indicating the S/Se-chalcogen effect to drive the conformational behavior of this series of NAH.

Design and Synthesis In Silico Drug-like Prediction and Pharmacological Evaluation of Cyclopolymethylenic Homologous of LASSBio-1514.

Acylhydrazones are still an important framework to the design of new bioactive compounds. As treatment of chronic pain represents a clinical challenge, we decided to modify the structure of LASSBio-1514 (1), previously described as anti-inflammatory and analgesic prototype. Applying the homologation as a strategy for molecular modification, we designed a series of cyclopentyl- (2a-e), cyclobutyl- (3a-e), and cyclopropylacylhydrazones (4a-e) that were synthetized and evaluated in murine models of inflammation and pain. A comparison of their in silico physicochemical and drug-like profile was conducted, as well as their anti-inflammatory and analgesic effect. Compounds 4a (LASSBio-1755) and 4e (LASSBio-1757) displayed excellent in silico drug-like profiles and were identified as new analgesic lead-candidates in acute and chronic model of pain, through oral administration.

Identification of LASSBio-1945 as an inhibitor of SARS-CoV-2 main protease (MPRO) through in silico screening supported by molecular docking and a fragment-based pharmacophore model.

In December 2019, an infectious disease was detected in Wuhan, China, caused by a new pathogenic coronavirus, named SARS-CoV-2. It spread very rapidly, and on March 11th of 2020, the outbreak was declared a pandemic by the World Health Organization. Currently, effective treatment options remain limited. SARS-CoV-2 enzyme main protease (MPRO) plays a pivotal role in the viral life cycle, making it a putative drug target. In order to identify suitable hits to develop inhibitors with adequate antiviral properties, we explored the LASSBio Chemical Library employing multiple strategies of virtual screening. A fragment-based pharmacophore model enabled the identification of key interactions involved in the molecular recognition at the catalytic site of MPRO, namely, with amino acid residues His41, His163 and Glu166. Docking-based virtual screening was performed, leading to the identification of LASSBio-1945 (9), a new hit of MPRO, presenting an IC50 = 15.97 µM. This compound, an 1,3-benzodioxolyl sulfonamide, represents an interesting starting point for subsequent hit-to-lead optimization steps and, to the best of our knowledge, a new distinct chemotype for MPRO inhibition.

ß-lactam antibiotics: An overview from a medicinal chemistry perspective.

ß-Lactam antibiotics are one of the most relevant drug classes of antibacterial agents worldwide. The discovery and the market of first ß-lactam antibiotic (Penicillin G) is a symbolic landmark of modern chemotherapy. Since then, several other ß-lactam antibiotics have been introduced in the therapy, revolutionizing the treatment of bacterial infections. Their antibacterial efficacy has been kept in check by the emergence of bacterial resistance. Among the resistance mechanisms, the expression of ß-lactamase enzymes is one of the most studied and prevalent. The combined use of beta-lactamase inhibitors with broad spectrum activity ß-lactam antibiotics has been an effective strategy to circumvent the resistance issue. This review discusses, with a focus on structural aspects, the different classes of beta-lactam antibiotics (penicillins, cephalosporins, carbapenems, monobactams and penems) in light of their stability, sensitivity to ß-lactamases, mechanism of action and spectrum of antimicrobial activity. ß-Lactamase inhibitors (structurally correlated and non-correlated to the ß-lactam system) and their proposed inhibition mechanisms are also discussed.

New Benzofuran N-Acylhydrazone Reduces Cardiovascular Dysfunction in Obese Rats by Blocking TNF-Alpha Synthesis.

INTRODUCTION: Diabetic obese patients are susceptible to the development of cardiovascular disease, including hypertension and cardiac dysfunction culminating in diabetic cardiomyopathy (DC), which represents a life-threatening health problem with increased rates of morbidity and mortality. The aim of the study is to characterize the effects of a new benzofuran N-acylhydrazone compound, LASSBio-2090, on metabolic and cardiovascular alterations in Zucker diabetic fatty (ZDF) rats presenting DC. METHODS: Male non-diabetic lean Zucker rats (ZL) and ZDF rats treated with vehicle (dimethylsulfoxide) or LASSBio-2090 were used in this study. Metabolic parameters, cardiovascular function, left ventricle histology and inflammatory protein expression were analyzed in the experimental groups. RESULTS: LASSBio-2090 administration in ZDF rats reduced glucose levels to 85.0 ± 1.7 mg/dL (p < 0.05). LASSBio-2090 also lowered the cholesterol and triglyceride levels from 177.8 ± 31.2 to 104.8 ± 5.3 mg/dL and from 123.0 ± 11.4 to 90.9 ± 4.8 mg/dL, respectively, in obese diabetic rats (p < 0.05). LASSBio-2090 normalized plasma insulin, insulin sensitivity and endothelial function in aortas from diabetic animals (p < 0.05). It also enhanced systolic and diastolic left-ventricular function and reverted myocardial remodeling by blocking the threefold elevation of TNF-α levels in hearts from ZDF rats. CONCLUSION: LASSBio-2090 alleviates metabolic disturbance and cardiomyopathy in an obese and diabetic rat model, thus representing a novel strategy for the treatment of cardiovascular complications in obesity-associated type 2 diabetes mellitus.

Novel phosphatidylinositol 4-kinases III beta (PI4KIIIß) inhibitors discovered by virtual screening using free energy models.

Herein, the LASSBio Chemical Library is presented as a valuable source of compounds for screening to identify hits suitable for subsequent hit-to-lead optimization stages. A feature of the LASSBio Chemical Library worth highlighting is the fact that it is a smart library designed by medicinal chemists with pharmacological activity as the main priority. The great majority of the compounds part of this library have shown in vivo activity in animal models, which is an indication that they possess overall favorable bioavailability properties and, hence, adequate pharmacokinetic profiles. This, in turn, is supported by the fact that approximately 85% of the compounds are compliant with Lipinski's rule of five and ca. 95% are compliant with Veber's rules, two important guidelines for oral bioavailability. In this work it is presented a virtual screening methodology combining a pharmacophore-based model and an empirical Gibbs free energy-based model for the ligand-protein interaction to explore the LASSBio Chemical Library as a source of new hits for the inhibition of the phosphatidylinositol 4-kinase IIIß (PI4KIIIß) enzyme, which is related to the development of viral infections (including enteroviruses, SARS coronavirus, and hepatitis C virus), cancers and neurological diseases. The approach resulted in the identification of two hits, LASSBio-1799 (7) and LASSBio-1814 (10), which inhibited the target enzyme with IC50 values of 3.66 µM and IC50 and 6.09 µM, respectively. This study also enabled the determination of the structural requirements for interactions with the active site of PI4KIIIß, demonstrating the importance of both acceptor and donor hydrogen bonding groups for forming interactions with binding site residues Val598 and Lys549.

Novel VEGFR-2 inhibitors with an N-acylhydrazone scaffold.

Vascular endothelial growth factor receptor 2 (VEGFR-2) is a tyrosine kinase that mediates a large number of cell responses associated with angiogenesis. The control of the angiogenic pathway in tumorigenesis by the inhibition of VEGFR-2 is considered a promising therapeutic strategy for the prevention and control of solid tumor growth. In this study, the design, synthesis, and biological evaluation of a novel series of VEGFR-2 inhibitors with an N-acylhydrazone (NAH) scaffold (9a-h) are reported. The molecular design is validated by docking studies and by in vitro inhibitory activity assays. Compounds 9b, 9c, 9d, and 9f effectively inhibited neovascularization induced by VEGF in the chorioallantoic membrane assay. Thus, these NAH derivatives are promising antiangiogenic prototypes.

Bioisosteric Replacement of Arylamide-Linked Spine Residues with N-Acylhydrazones and Selenophenes as a Design Strategy to Novel Dibenzosuberone Derivatives as Type I 1/2 p38α MAP Kinase Inhibitors.

The recent disclosure of type I 1/2 inhibitors for p38α MAPK demonstrated how the stabilization of the R-spine can be used as a strategy to greatly increase the target residence time (TRT) of inhibitors. Herein, for the first time, we describe N-acylhydrazone and selenophene residues as spine motifs, yielding metabolically stable inhibitors with high potency on enzymatic, NanoBRET, and whole blood assays, improved metabolic stability, and prolonged TRT.

Carbamoyl-N-aryl-imine-urea: a new framework to obtain a putative leishmanicidal drug-candidate.

Leishmaniasis is a neglected parasitic disease, and current treatment includes limitations of toxicity, variable efficacy, high costs and inconvenient doses and treatment schedules. Therefore, new leishmanicidal drugs are still an unquestionable medical need. In this paper we described the design conception of a new framework, the carbamoyl-N-aryl-imine-urea, to obtain putative leishmanicidal drug-candidates. Compounds 9a-e and 10a-e were designed and synthesized and their leishmanicidal activity was studied in comparison to pentamidine, miltefosine and meglumine antimoniate. The conformational profile of the new carbamoyl-N-aryl-imine-urea framework was investigated by X-ray diffraction studies, using compound 9a as a model. The plasma stability of this putative peptide mimetic subunit was studied for compound 10e (LASSBio-1736). Among the congeneric series, LASSBio-1736 was identified as a new antileishmanial drug-candidate, displaying plasma stability, cytotoxicity against amastigote forms of L. amazonensis and L. braziliensis, and leishmanicidal activity in a cutaneous leishmaniasis murine model, without preliminary evidence of hepatic or renal toxicity.

Reduction of cardiac and renal dysfunction by new inhibitor of DPP4 in diabetic rats.

BACKGROUND: Increased mortality due to type 2 diabetes mellitus (T2DM) has been associated with renal and/or cardiovascular dysfunction. Dipeptidyl dipeptidase-4 inhibitors (iDPP-4s) may exert cardioprotective effects through their pleiotropic actions via glucagon-like peptide 1-dependent mechanisms. In this study, the pharmacological profile of a new iDPP-4 (LASSBio-2124) was investigated in rats with cardiac and renal dysfunction induced by T2DM. METHODS: T2DM was induced in rats by 2 weeks of a high-fat diet followed by intravenous injection of streptozotocin. Metabolic disturbance and cardiac, vascular, and renal dysfunction were analyzed in the experimental groups. RESULTS: Sitagliptin and LASSBio-2124 administration after T2DM induction reduced elevated glucose levels to 319.8 ±â€¯13.2 and 279.7 ±â€¯17.8 mg/dL, respectively (p < 0.05). LASSBio-2124 also lowered the cholesterol and triglyceride levels from 76.8 ±â€¯8.0 to 42.7 ±â€¯3.2 mg/dL and from 229.7 ±â€¯25.4 to 100.7 ±â€¯17.1 mg/dL, in diabetic rats. Sitagliptin and LASSBio-2124 reversed the reduction of the plasma insulin level. LASSBio-2124 recovered the increased urinary flow in diabetic animals and reduced 24-h proteinuria from 23.7 ±â€¯1.5 to 13.3 ±â€¯2.8 mg (p < 0.05). It also reduced systolic and diastolic left-ventricular dysfunction in hearts from diabetic rats. CONCLUSION: The effects of LASSBio-2124 were superior to those of sitagliptin in the cardiovascular systems of T2DM rats. This new prototype showed promise for the avoidance of comorbidities in a T2DM experimental model, and thus may constitute an innovative therapeutic agent for the treatment of these conditions in the clinical field in future.

LASSBio-596 protects gastric mucosa against the development of ethanol-induced gastric lesions in mice.

LASSBio-596 (2-[4-(1,4-thiazinan-4-ylsulfonyl) phenylcarbamoyl] benzoic acid) is a molecular hybrid of anti-tumor necrosis factor α (TNF-α) and phosphodiesterase 5 inhibitors, and its anti-inflammatory effects have been demonstrated in experimental models of inflammation. The aim of this study was to evaluate the gastroprotective effect of LASSBio-596 in an ethanol-induced acute gastritis model. Before induction of gastric damage, mice were pretreated with LASSBio-596 (20 mg per os (p.o.), Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 3 mg/kg, intraperitoneally [i.p.]) or with 1400W (10 mg/kg, i.p.) given alone or in their combinations. Thirty minutes later, gastric damage was induced by intragastric instillation of 50% ethanol (0.5 ml/25 g, by gavage). After 1 h, gastric damage (hemorrhagic or ulcerative lesions) was measured by planimetry. Samples of the stomach were also taken for histopathological assessment and for assays of tissue myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), and inflammatory cytokines. Ethanol administration induced the development of gastric lesions in mice. LASSBio-596 reduced gastric damage, epithelial cell loss and hemorrhage, and restored the antioxidant defense system by decreasing the levels of MDA and the consumption of GSH in gastric mucosa. LASSBio-596 also decreased gastric TNF-α and interleukin-1ß (IL-1ß) protein levels, MPO enzymatic activity, and hemoglobin levels. Treatment with the nitric oxide synthase inhibitors L-NAME and 1400W reversed the effects of LASSBio-596 on ethanol-induced gastric lesions. LASSBio-596 did not alter mucus content and pH of gastric secretions. In summary, LASSBio-596 exerts protective effects against ethanol-induced gastric injury. The gastroprotective effects of LASSBio seem to be NO-dependent.