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1.
Pharmacol Res ; 176: 106051, 2022 02.
Article in English | MEDLINE | ID: mdl-34973467

ABSTRACT

Aortic dissection (AD) is a disease with high mortality and lacks effective drug treatment. Recent studies have shown that the development of AD is closely related to glucose metabolism. Lactate dehydrogenase A (LDHA) is a key glycolytic enzyme and plays an important role in cardiovascular disease. However, the role of LDHA in the progression of AD remains to be elucidated. Here, we found that the level of LDHA was significantly elevated in AD patients and the mouse model established by BAPN combined with Ang II. In vitro, the knockdown of LDHA reduced the growth of human aortic vascular smooth muscle cells (HAVSMCs), glucose consumption, and lactate production induced by PDGF-BB. The overexpression of LDHA in HAVSMCs promoted the transformation of HAVSMCs from contractile phenotype to synthetic phenotype, and increased the expression of MMP2/9. Mechanistically, LDHA promoted MMP2/9 expression through the LDHA-NDRG3-ERK1/2-MMP2/9 pathway. In vivo, Oxamate, LDH and lactate inhibitor, reduced the degradation of elastic fibers and collagen deposition, inhibited the phenotypic transformation of HAVSMCs from contractile phenotype to synthetic phenotype, reduced the expression of NDRG3, p-ERK1/2, and MMP2/9, and delayed the progression of AD. To sum up, the increase of LDHA promotes the production of MMP2/9, stimulates the degradation of extracellular matrix (ECM), and promoted the transformation of HAVSMCs from contractile phenotype to synthetic phenotype. Oxamate reduced the progression of AD in mice. LDHA may be a therapeutic target for AD.


Subject(s)
Aortic Dissection/drug therapy , Lactate Dehydrogenase 5/antagonists & inhibitors , Oxamic Acid/therapeutic use , Adult , Aged , Aortic Dissection/metabolism , Animals , Aorta, Thoracic/drug effects , Aorta, Thoracic/metabolism , Extracellular Matrix/drug effects , Extracellular Matrix/metabolism , Female , Glucose/metabolism , Humans , Lactate Dehydrogenase 5/genetics , Lactate Dehydrogenase 5/metabolism , Lactic Acid/metabolism , Male , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Mice, Inbred C57BL , Middle Aged , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/metabolism , Oxamic Acid/pharmacology
2.
Cell Signal ; 53: 190-200, 2019 01.
Article in English | MEDLINE | ID: mdl-30304698

ABSTRACT

Although GPR35 is an orphan G protein-coupled receptor, synthetic agonists and antagonists have been developed. Recently, cromolyn, a mast cell stabilizer, was reported as an agonist of GPR35 and was shown to exhibit antifibrotic effects through its actions on hepatocytes and stellate cells. In this study, the role of GPR35 in hepatic steatosis was investigated using an in vitro model of liver X receptor (LXR)-mediated hepatocellular steatosis and an in vivo model of high fat diet-induced liver steatosis. GPR35 was expressed in Hep3B human hepatoma cells and mouse primary hepatocytes. A specific LXR activator, T0901317, induced lipid accumulation in Hep3B cells. Lodoxamide, the most potent agonist of GPR35, inhibited lipid accumulation in a concentration-dependent manner. The protective effect of lodoxamide was inhibited by a specific GPR35 antagonist, CID2745687, and by siRNA-mediated knockdown of GPR35. The expression of SREBP-1c, a key transcription factor for lipid synthesis, was induced by T0901317 and the induction was inhibited by lodoxamide. Through the use of specific inhibitors of cellular signaling components, the lodoxamide-induced inhibition of lipid accumulation was found to be mediated through p38 MAPKs and JNK, but not through Gi/o proteins and ERKs. Furthermore, the protective effect of lodoxamide was confirmed in mouse primary hepatocytes. Lodoxamide suppressed high fat diet-induced fatty liver development, which suggested the protective function of GPR35 in liver steatosis. Therefore, the present data suggest that GPR35 may function to protect against fatty liver development.


Subject(s)
Fatty Liver/drug therapy , Oxamic Acid/analogs & derivatives , Protective Agents/therapeutic use , Receptors, G-Protein-Coupled/metabolism , Animals , Cell Line , Cells, Cultured , Diet, High-Fat/adverse effects , Fatty Liver/metabolism , Humans , Lipid Metabolism/drug effects , Male , Mice , Mice, Inbred C57BL , Oxamic Acid/therapeutic use
3.
Biomed Pharmacother ; 95: 1565-1573, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28950656

ABSTRACT

Several human cancers including the breast display elevated expression of Lactate dehydrogenase-A (LDH-A), the enzyme that converts pyruvate to lactate and oxidizes NADH to NAD+. Indeed, tumor lactate levels correlate with increased metastasis, tumor recurrence, and poor outcome. Lactate also plays roles in promoting tumor inflammation and as a signaling molecule that stimulates tumor angiogenesis. Because of its essential role in cancer metabolism, LDH-A has been considered as a potential target for combination cancer therapy. Therefore, the current study investigated the possible anti-tumor effect of LDH inhibitor (oxamate) in a murine model of breast cancer [Solid Ehrlich Carcinoma (SEC)], alone and in combination with Taxol chemotherapy. The potential underlying mechanisms were also investigated. The results indicated that oxamate induced significant anti-tumor activity against the SEC. Mechanistically, the combination treatment was more efficient than paclitaxel monotherapy in reducing ATP, MDA, TNF-α and Il-17 contents in SEC. Moreover, the apoptotic and anti-angiogenic effects of the combination treatment were triggered more efficiently as compared to paclitaxel monotherapy, Therefore, oxamate may represent a promising agent that enhance the antitumor activity of paclitaxel.


Subject(s)
Carcinoma, Ehrlich Tumor/drug therapy , Oxamic Acid/pharmacology , Oxamic Acid/therapeutic use , Paclitaxel/therapeutic use , Adenosine Triphosphate/metabolism , Animals , Carcinoma, Ehrlich Tumor/enzymology , Carcinoma, Ehrlich Tumor/pathology , Caspase 3/metabolism , Cell Proliferation/drug effects , Female , Interleukin-17/metabolism , L-Lactate Dehydrogenase/metabolism , Malondialdehyde/metabolism , Mice , Paclitaxel/pharmacology , Time Factors , Tumor Necrosis Factor-alpha/metabolism , Vascular Endothelial Growth Factor A/metabolism
4.
PLoS One ; 11(3): e0150303, 2016.
Article in English | MEDLINE | ID: mdl-26938239

ABSTRACT

Oxamate (OXA) is a pyruvate analogue that directly inhibits the lactate dehydrogenase (LDH)-catalyzed conversion process of pyruvate into lactate. Earlier and recent studies have shown elevated blood lactate levels among insulin-resistant and type 2 diabetes subjects and that blood lactate levels independently predicted the development of incident diabetes. To explore the potential of OXA in the treatment of diabetes, db/db mice were treated with OXA in vivo. Treatment of OXA (350-750 mg/kg of body weight) for 12 weeks was shown to decrease body weight gain and blood glucose and HbA1c levels and improve insulin secretion, the morphology of pancreatic islets, and insulin sensitivity in db/db mice. Meanwhile, OXA reduced the lactate production of adipose tissue and skeletal muscle and serum lactate levels and decreased serum levels of TG, FFA, CRP, IL-6, and TNF-α in db/db mice. The PCR array showed that OXA downregulated the expression of Tnf, Il6, leptin, Cxcr3, Map2k1, and Ikbkb, and upregulated the expression of Irs2, Nfkbia, and Pde3b in the skeletal muscle of db/db mice. Interestingly, LDH-A expression increased in the islet cells of db/db mice, and both treatment of OXA and pioglitazone decreased LDH-A expression, which might be related to the improvement of insulin secretion. Taken together, increased lactate production of adipose tissue and skeletal muscle may be at least partially responsible for insulin resistance and diabetes in db/db mice. OXA improved glycemic control and insulin sensitivity in db/db mice primarily via inhibition of tissue lactate production. Oxamic acid derivatives may be a potential drug for the treatment of type 2 diabetes.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/pharmacology , Oxamic Acid/pharmacology , Animals , Blood Glucose , Cytokines/blood , Diabetes Mellitus, Type 2/blood , Drug Evaluation, Preclinical , Eating , Glycated Hemoglobin/metabolism , Hypoglycemic Agents/therapeutic use , Insulin/blood , Insulin/metabolism , Insulin Resistance , Insulin Secretion , Islets of Langerhans/drug effects , Islets of Langerhans/enzymology , Islets of Langerhans/metabolism , Islets of Langerhans/pathology , L-Lactate Dehydrogenase/antagonists & inhibitors , L-Lactate Dehydrogenase/metabolism , Lactic Acid/metabolism , Lipids/blood , Male , Mice, Inbred C57BL , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Oxamic Acid/therapeutic use , Weight Gain/drug effects
5.
Nat Chem Biol ; 12(4): 218-25, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26829472

ABSTRACT

A hallmark of targeted cancer therapies is selective toxicity among cancer cell lines. We evaluated results from a viability screen of over 200,000 small molecules to identify two chemical series, oxalamides and benzothiazoles, that were selectively toxic at low nanomolar concentrations to the same 4 of 12 human lung cancer cell lines. Sensitive cell lines expressed cytochrome P450 (CYP) 4F11, which metabolized the compounds into irreversible inhibitors of stearoyl CoA desaturase (SCD). SCD is recognized as a promising biological target in cancer and metabolic disease. However, SCD is essential to sebocytes, and accordingly SCD inhibitors cause skin toxicity. Mouse sebocytes did not activate the benzothiazoles or oxalamides into SCD inhibitors, providing a therapeutic window for inhibiting SCD in vivo. We thus offer a strategy to target SCD in cancer by taking advantage of high CYP expression in a subset of tumors.


Subject(s)
Antineoplastic Agents/pharmacology , Benzothiazoles/pharmacology , Drug Discovery/methods , Lung Neoplasms/enzymology , Oxamic Acid/analogs & derivatives , Stearoyl-CoA Desaturase/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/toxicity , Benzothiazoles/pharmacokinetics , Benzothiazoles/therapeutic use , Benzothiazoles/toxicity , Cell Line, Tumor , Cytochrome P-450 Enzyme System/metabolism , Cytochrome P450 Family 4 , Female , Humans , Lung Neoplasms/pathology , Male , Mice , Mice, SCID , Molecular Structure , Molecular Targeted Therapy , Oxamic Acid/pharmacokinetics , Oxamic Acid/pharmacology , Oxamic Acid/therapeutic use , Oxamic Acid/toxicity , Protein Binding , Sebaceous Glands/drug effects , Sebaceous Glands/enzymology , Sebaceous Glands/pathology , Xenograft Model Antitumor Assays
6.
BMC Pharmacol Toxicol ; 16: 10, 2015 Apr 22.
Article in English | MEDLINE | ID: mdl-25896924

ABSTRACT

BACKGROUND: Chagas disease, which is caused by Trypanosoma cruzi, is a major health problem in Latin America, and there are currently no drugs for the effective treatment of this disease. The energy metabolism of T. cruzi is an attractive target for drug design, and we previously reported that inhibitors of α-hydroxy acid dehydrogenase (HADH)-isozyme II exhibit trypanocidal activity. N-Propyl oxamate (NPOx) is an inhibitor of HADH-isozyme II, and its non-polar ethyl ester (Et-NPOx) is cytotoxic to T. cruzi. A new derivative of NPOx has been developed in this study with higher trypanocidal activity, which could be used for the treatment of Chagas disease. METHODS: The benzyl ester of NPOx (B-NPOx) was synthesized and its activity evaluated towards epimastigotes and bloodstream trypomastigotes (in vitro), as well as mice infected with T. cruzi (in vivo). The activity of B-NPOx was also compared with those of Et-NPOx, benznidazole (Bz) and nifurtimox (Nx). NINOA, Miguz, Compostela, Nayarit and INC-5 T. cruzi strains were used in this study. RESULTS: Polar NPOx did not penetrate the parasites and exhibited no trypanocidal activity. In contrast, the hydrophobic ester B-NPOx exhibited trypanocidal activity in vitro and in vivo. B-NPOx exhibited higher trypanocidal activity than Et-NPOx, Bz and Nx towards all five of the T. cruzi strains. The increased activity of B-NPOx was attributed to its hydrolysis inside the parasites to give NPOx and benzyl alcohol, which is an antimicrobial compound with trypanocidal effects. B-NPOx was also effective against two strains of T. cruzi that are resistant to Bz and Nx. CONCLUSION: B-NPOx exhibited higher in vitro (2- to 14.8-fold) and in vivo (2.2- to 4.5-fold) trypanocidal activity towards T. cruzi than Et-NPOx. B-NPOx also exhibited higher in vitro (2- to 24-fold) and in vivo (1.9- to 15-fold) trypanocidal activity than Bz and Nx. B-NPOx is more lipophilic than Et-NPOx, allowing for better penetration into T. cruzi parasites, where the enzymatic cleavage of B-NPOx would give NPOx and benzyl alcohol, which are potent trypanocidal agents. Taken together with its low toxicity, these results suggest that B-NPOx could be used as a potent prodrug for the treatment of Chagas disease.


Subject(s)
Chagas Disease/drug therapy , Esters/chemical synthesis , Oxamic Acid/analogs & derivatives , Prodrugs/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Alcohol Oxidoreductases/antagonists & inhibitors , Animals , Cell Line , Cell Survival/drug effects , Disease Models, Animal , Isoenzymes/antagonists & inhibitors , Male , Mice , Nifurtimox/pharmacology , Nitroimidazoles/pharmacology , Oxamic Acid/chemical synthesis , Oxamic Acid/pharmacology , Oxamic Acid/therapeutic use , Prodrugs/chemical synthesis , Prodrugs/therapeutic use , Prodrugs/toxicity , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/therapeutic use , Trypanocidal Agents/toxicity , Trypanosoma cruzi/enzymology
7.
Pediatr Allergy Immunol ; 25(4): 314-22, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24438133

ABSTRACT

Vernal keratoconjunctivitis (VKC) is an unusually severe sight-threatening allergic eye disease, occurring mainly in children. Conventional therapy for allergic conjunctivitis is generally not adequate for VKC. Pediatricians and allergists are often not familiar with the severe clinical symptoms and signs of VKC. As untreated VKC can lead to permanent visual loss, pediatric allergists should be aware of the management and therapeutic options for this disease to allow patients to enter clinical remission with the least side effects and sequelae. Children with VKC present with severe ocular symptoms, that is, severe eye itching and irritation, constant tearing, red eye, eye discharge, and photophobia. On examination, giant papillae are frequently observed on the upper tarsal conjunctiva (cobblestoning appearance), with some developing gelatinous infiltrations around the limbus surrounding the cornea (Horner-Trantas dot). Conjunctival injections are mostly severe with thick mucus ropy discharge. Eosinophils are the predominant cells found in the tears and eye discharge. Common therapies include topical antihistamines and dual-acting agents, such as lodoxamide and olopatadine. These are infrequently sufficient and topical corticosteroids are often required for the treatment of flare ups. Ocular surface remodeling leads to severe suffering and complications, such as corneal ulcers/scars. Other complications include side effects from chronic topical steroids use, such as increased intraocular pressure, glaucoma, cataract and infections. Alternative therapies for VKC include immunomodulators, such as cyclosporine A and tacrolimus. Surgery is reserved for those with complications and should be handled by ophthalmologists with special expertise. Newer research on the pathogenesis of VKC is reviewed in this article. Vernal keratoconjunctivitis is a very important allergic eye disease in children. Complications and remodeling changes are unique and can lead to blindness. Understanding of pathogenesis of VKC may lead to better therapy for these unfortunate patients.


Subject(s)
Blindness/immunology , Conjunctivitis, Allergic/complications , Conjunctivitis, Allergic/pathology , Corneal Ulcer/immunology , Eosinophils/immunology , Adrenal Cortex Hormones/therapeutic use , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Blindness/prevention & control , Child , Conjunctivitis, Allergic/drug therapy , Corneal Ulcer/pathology , Corneal Ulcer/prevention & control , Cyclosporine/therapeutic use , Dibenzoxepins/therapeutic use , Histamine H1 Antagonists, Non-Sedating/therapeutic use , Humans , Immunosuppression Therapy , Olopatadine Hydrochloride , Oxamic Acid/analogs & derivatives , Oxamic Acid/therapeutic use
8.
J Neurosci ; 33(21): 9028-38, 2013 May 22.
Article in English | MEDLINE | ID: mdl-23699514

ABSTRACT

Patients with long-standing diabetes frequently demonstrate gastric hypersensitivity with an unknown mechanism. The present study was designed to investigate roles for nuclear factor-κB (NF-κB) and the endogenous H2S-producing enzyme cystathionine-ß-synthetase (CBS) signaling pathways by examining cbs gene methylation status in adult rats with diabetes. Intraperitoneal injection of streptozotocin (STZ) produced gastric hypersensitivity in female rats in response to gastric balloon distention. Treatment with the CBS inhibitor aminooxyacetic acid significantly attenuated STZ-induced gastric hypersensitivity in a dose-dependent fashion. Aminooxyacetic acid treatment also reversed hyperexcitability of gastric-specific dorsal root ganglion (DRG) neurons labeled by the dye DiI in diabetic rats. Conversely, the H2S donor NaHS enhanced neuronal excitability of gastric DRG neurons. Expression of CBS and p65 were markedly enhanced in gastric DRGs in diabetic rats. Blockade of NF-κB signaling using pyrrolidine dithiocarbamate reversed the upregulation of CBS expression. Interestingly, STZ treatment led to a significant demethylation of CpG islands in the cbs gene promoter region, as determined by methylation-specific PCR and bisulfite sequencing. STZ treatment also remarkably downregulated the expression of DNA methyltransferase 3a and 3b. More importantly, STZ treatment significantly enhanced the ability of cbs to bind DNA at the p65 consensus site, as shown by chromatin immunoprecipitation assays. Our findings suggest that upregulation of cbs expression is attributed to cbs promoter DNA demethylation and p65 activation and that the enhanced interaction of the cbs gene and p65 contributes to gastric hypersensitivity in diabetes. This finding may guide the development and evaluation of new treatment modalities for patients with diabetic gastric hypersensitivity.


Subject(s)
Cystathionine beta-Synthase/metabolism , Diabetes Mellitus, Experimental/complications , Hypersensitivity , NF-kappa B/metabolism , Stomach Diseases/etiology , Amino Acids , Analysis of Variance , Animals , Area Under Curve , Case-Control Studies , Chromatin Immunoprecipitation , CpG Islands/drug effects , CpG Islands/physiology , Cystathionine beta-Synthase/genetics , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methyltransferase 3A , Disease Models, Animal , Dose-Response Relationship, Drug , Electromyography , Enzyme Inhibitors/pharmacology , Female , Ganglia, Spinal/pathology , Hypersensitivity/drug therapy , Hypersensitivity/etiology , Membrane Potentials/drug effects , Methylation/drug effects , Neoplasm Proteins/metabolism , Nucleocytoplasmic Transport Proteins/metabolism , Oxamic Acid/therapeutic use , Patch-Clamp Techniques , Rats , Rats, Sprague-Dawley , Sensory Receptor Cells/drug effects , Sensory Receptor Cells/physiology , Stomach Diseases/drug therapy , Sulfites/pharmacology , Up-Regulation/drug effects , DNA Methyltransferase 3B
9.
Arch Pharm (Weinheim) ; 345(1): 57-64, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21953567

ABSTRACT

A series of novel N(1) -substituted-N(2) ,N(2) -diphenyl oxalamides 3a-l were synthesized in good yield by stirring diphenylcarbamoyl formyl chloride (2) and various substituted aliphatic, alicyclic, aromatic, heterocyclic amines in DMF and K(2) CO(3) . Also 2-substituted amino-N,N-diphenylacetamides 5a-m were designed by pharmacophore generation and synthesized by stirring 2-chloro-N,N-diphenylacetamide (4) and various substituted amines in acetone using triethyl amine as a catalyst. All the synthesized compounds were screened for anticonvulsant activity in Swiss albino mice by MES and ScPTZ induced seizure tests. Neurotoxicity screening and behavioral testing was also carried out. Some of the synthesized test compounds were found to be more potent than the standard drug.


Subject(s)
Acetamides/chemical synthesis , Anticonvulsants/chemical synthesis , Diphenylacetic Acids/chemical synthesis , Drug Design , Oxamic Acid/analogs & derivatives , Acetamides/chemistry , Acetamides/therapeutic use , Acetamides/toxicity , Animals , Anticonvulsants/chemistry , Anticonvulsants/therapeutic use , Anticonvulsants/toxicity , Behavior, Animal/drug effects , Diphenylacetic Acids/chemistry , Diphenylacetic Acids/therapeutic use , Diphenylacetic Acids/toxicity , Dose-Response Relationship, Drug , Female , Male , Mice , Molecular Structure , Motor Activity/drug effects , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/physiopathology , Oxamic Acid/chemical synthesis , Oxamic Acid/chemistry , Oxamic Acid/therapeutic use , Oxamic Acid/toxicity , Seizures/drug therapy , Structure-Activity Relationship
10.
J Pak Med Assoc ; 61(3): 239-41, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21465936

ABSTRACT

OBJECTIVE: To observe the safety and efficacy of topical Lodoxamide eye drops in patients with diagnosed vernal keratoconjunctivitis (VKC). METHODS: This study was conducted at Department of Pharmacology and Therapeutics, BMSI, JPMC, Karachi in collaboration with Department of Ophthalmology, JPMC, Karachi, from April to October, 2009. A total of forty patients with diagnosed vernal keratoconjunctivitis were selected and enrolled consecutively from the out patient department (OPD) of Ophthalmology. Each patient received two drops of Lodoxamide eye drops topically in each eye four times daily. Patients were examined with a torch and slit lamp at baseline and follow-up visits. RESULTS: Out of 40 patients included, 39 completed the study and there was a significant effect of the drug on symptoms and signs of the disease. At the end of the study, 38 (97.4%) were cured, with few side effects. The cure criteria was based on patient's history of becoming symptom-free and resolution of ocular signs. CONCLUSION: Topical lodoxamide eye drops, when used for treatment of VKC, are effective with fewer adverse effects.


Subject(s)
Anti-Allergic Agents/therapeutic use , Conjunctivitis, Allergic/drug therapy , Ophthalmic Solutions/therapeutic use , Oxamic Acid/analogs & derivatives , Administration, Topical , Adult , Anti-Allergic Agents/adverse effects , Conjunctivitis, Allergic/diagnosis , Female , Follow-Up Studies , Humans , Male , Ophthalmic Solutions/adverse effects , Oxamic Acid/adverse effects , Oxamic Acid/therapeutic use , Treatment Outcome
11.
J Enzyme Inhib Med Chem ; 25(1): 111-5, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20030515

ABSTRACT

In this investigation we studied the trypanocidal activity of the ethyl esters of N-propyl (Et-NPOX) and N-isopropyl (Et-NIPOX) oxamates on bloodstream trypomastigotes and on the clinically relevant intracellular amastigotes of Trypanosoma cruzi acute infected mice. In the infected and treated mice, the levels of parasitemia were drastically reduced between days 15 and 20 of treatment and almost to zero between days 35 and 40. We also found that Et-NPOX completely eliminated amastigote nests in the myocardium of mice infected with INC-5 or NINOA T. cruzi strain, and in skeletal muscle the reduction in the number of amastigote nests was between 60 and 80% in both strains. Also, Et-NIPOX reduced by 60-80% the number of amastigote nests in the myocardium and skeletal muscle of mice infected with these T. cruzi strains. In contrast, nifurtimox, used for comparison, produced a reduction of amastigote nests of only 20-40% in the studied tissues in both strains.


Subject(s)
Oxamic Acid/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Trypanosomiasis/drug therapy , Animals , Mice , Oxamic Acid/therapeutic use , Trypanocidal Agents/therapeutic use
12.
Breast Cancer Res ; 10(5): R84, 2008.
Article in English | MEDLINE | ID: mdl-18922152

ABSTRACT

INTRODUCTION: Glycolysis is increased in breast adenocarcinoma cells relative to adjacent normal cells in order to produce the ATP and anabolic precursors required for survival, growth and invasion. Glycolysis also serves as a key source of the reduced form of cytoplasmic nicotinamide adenine dinucleotide (NADH) necessary for the shuttling of electrons into mitochondria for electron transport. Lactate dehydrogenase (LDH) regulates glycolytic flux by converting pyruvate to lactate and has been found to be highly expressed in breast tumours. Aspartate aminotransferase (AAT) functions in tandem with malate dehydrogenase to transfer electrons from NADH across the inner mitochondrial membrane. Oxamate is an inhibitor of both LDH and AAT, and we hypothesised that oxamate may disrupt the metabolism and growth of breast adenocarcinoma cells. METHODS: We examined the effects of oxamate and the AAT inhibitor amino oxyacetate (AOA) on 13C-glucose utilisation, oxygen consumption, NADH and ATP in MDA-MB-231 cells. We then determined the effects of oxamate and AOA on normal human mammary epithelial cells and MDA-MB-231 breast adenocarcinoma cell proliferation, and on the growth of MDA-MB-231 cells as tumours in athymic BALB/c female mice. We ectopically expressed AAT in MDA-MB-231 cells and examined the consequences on the cytostatic effects of oxamate. Finally, we examined the effect of AAT-specific siRNA transfection on MDA-MB-231 cell proliferation. RESULTS: We found that oxamate did not attenuate cellular lactate production as predicted by its LDH inhibitory activity, but did have an anti-metabolic effect that was similar to AAT inhibition with AOA. Specifically, we found that oxamate and AOA decreased the flux of 13C-glucose-derived carbons into glutamate and uridine, both products of the mitochondrial tricarboxylic acid cycle, as well as oxygen consumption, a measure of electron transport chain activity. Oxamate and AOA also selectively suppressed the proliferation of MDA-MB-231 cells relative to normal human mammary epithelial cells and decreased the growth of MDA-MB-231 breast tumours in athymic mice. Importantly, we found that ectopic expression of AAT in MDA-MB-231 cells conferred resistance to the anti-proliferative effects of oxamate and that siRNA silencing of AAT decreased MDA-MB-231 cell proliferation. CONCLUSIONS: We conclude that AAT may be a valid molecular target for the development of anti-neoplastic agents.


Subject(s)
Adenocarcinoma/drug therapy , Aminooxyacetic Acid/therapeutic use , Antineoplastic Agents/therapeutic use , Aspartate Aminotransferases/antagonists & inhibitors , Breast Neoplasms/drug therapy , Neoplasm Proteins/antagonists & inhibitors , Oxamic Acid/therapeutic use , Adenocarcinoma/enzymology , Adenocarcinoma/pathology , Aminooxyacetic Acid/pharmacology , Animals , Antineoplastic Agents/pharmacology , Aspartate Aminotransferases/genetics , Aspartate Aminotransferases/physiology , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Cell Division/drug effects , Cell Line, Tumor/drug effects , Cell Line, Tumor/enzymology , Citric Acid Cycle/drug effects , Cytostatic Agents/pharmacology , Cytostatic Agents/therapeutic use , Drug Delivery Systems , Female , Glycolysis/drug effects , Humans , Isoenzymes/antagonists & inhibitors , Isoenzymes/genetics , L-Lactate Dehydrogenase/antagonists & inhibitors , L-Lactate Dehydrogenase/genetics , Lactate Dehydrogenase 5 , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Proteins/genetics , Neoplasm Proteins/physiology , Oxamic Acid/pharmacology , RNA Interference , RNA, Small Interfering/pharmacology , Recombinant Fusion Proteins/antagonists & inhibitors , Tumor Stem Cell Assay , Xenograft Model Antitumor Assays
13.
Cornea ; 25(8): 974-6, 2006 Sep.
Article in English | MEDLINE | ID: mdl-17102679

ABSTRACT

PURPOSE: To report a patient with vernal keratoconjunctivitis-induced shield ulcer superinfected with Staphylococcus aureus. METHODS: Observational case report. A 12-year-old boy who had been followed for vernal keratoconjunctivitis for 3 years was admitted to our clinic complaining of visual loss, photophobia, and a ropy discharge. On slit-lamp examination, a transversely oval shield ulcer, which was situated in the center of the superior third of the cornea, was seen in the left eye. The vernal corneal plaque area and margins were infiltrated, and hypopyon was also observed. With the diagnosis of shield ulcer with secondary bacterial keratitis and hypopyon, the patient underwent medical treatment consisting of topical fortified cefazolin (50 mg/mL) and tobramycin (14 mg/mL), lodoxamide 0.1%, prednisolone acetate 1%, cyclopentolate, and systemic cetirizine. RESULTS: After treatment, the bacterial keratitis, shield ulcer, and inflammation in the anterior chamber disappeared. CONCLUSION: Bacterial keratitis associated with shield ulcer may be rarely observed in patients with vernal keratoconjunctivitis. Prompt diagnosis and treatment may prevent permanent complications and vision loss.


Subject(s)
Conjunctivitis, Allergic/complications , Corneal Ulcer/etiology , Eye Infections, Bacterial/etiology , Staphylococcal Infections/etiology , Staphylococcus aureus/isolation & purification , Anti-Bacterial Agents/therapeutic use , Cefazolin/therapeutic use , Child , Conjunctivitis, Allergic/diagnosis , Conjunctivitis, Allergic/drug therapy , Corneal Ulcer/diagnosis , Corneal Ulcer/drug therapy , Cyclopentolate/administration & dosage , Drug Therapy, Combination , Eye Infections, Bacterial/diagnosis , Eye Infections, Bacterial/drug therapy , Humans , Male , Oxamic Acid/analogs & derivatives , Oxamic Acid/therapeutic use , Prednisolone/analogs & derivatives , Prednisolone/therapeutic use , Staphylococcal Infections/diagnosis , Staphylococcal Infections/drug therapy , Tobramycin/therapeutic use
14.
Acta Med Croatica ; 56(3): 93-8, 2002.
Article in Croatian | MEDLINE | ID: mdl-12630339

ABSTRACT

PURPOSE: To evaluate the effectiveness of lodoxamide in the therapy and prophylaxis of the ocular allergies. PATIENTS AND METHODS: This prospective study included 64 patients divided in 2 groups. In the first group there were 47 symptomatic patients suffering from seasonal allergic conjunctivitis (n = 27), perennial allergic conjunctivitis (n = 16) and giant papillary conjunctivitis (n = 4). The symptomatic patients were examined upon arrival and every 2 weeks until the symptoms were reduced. During the period, lodoxamide drops were administered 4 times a day. In the second group there were 17 patients who had a history of seasonal ocular allergies during previous years but were still not symptomatic upon arrival. In the group of 17 patients who were very likely to develop ocular allergy but up to inclusion into the study had no ocular symptoms, 12 (70%) presented with allergic rhinitis while 5 (30%) had asthma. The symptoms intensity (itching, discomfort, foreign body sensation, pain, tearing) was graded on a 0-3 scale. The clinical signs (follicles, papillae, hyperemia, conjunctival edema, Trantas dots, stromal infiltrates) were detected on a slit lamp examination and graded on a 0-3 scale. RESULTS: In the group of 47 symptomatic patients 2-4 weeks after lodoxamide administration, 70-80% of symptomatic patients examined clinically had less or no follicles, 60-70% had reduced or no edema, the secretion was stopped or greatly reduced in 50-70% of patients. All of the patients reported reduced or no itching, 60% of patients reported less discomfort, photophobia and reduced tearing. In the asymptomatic group two weeks after the initiation of the prophylaxis 88% of patients were still with no ocular signs of allergy while 12% of patients had a conjunctival hyperemia and follicles. After 4 weeks of the prophylaxis 76% of patients patients were still asympthomatic while only 4 developed a mild form of allergic conjunctivitis (conjunctival hyperemia and papillae), but less severe than during previous episodes. CONCLUSION: Lodoxamide was effective in reduction of symptoms and clinical signs of the ocular allergies. The best results were obtained if the drug was administered as a prophylaxis or very early in the course of the disease.


Subject(s)
Anti-Allergic Agents/therapeutic use , Conjunctivitis, Allergic/drug therapy , Oxamic Acid/analogs & derivatives , Oxamic Acid/therapeutic use , Anti-Allergic Agents/adverse effects , Conjunctivitis, Allergic/prevention & control , Humans , Oxamic Acid/adverse effects , Prospective Studies
15.
Eur J Ophthalmol ; 11(2): 120-5, 2001.
Article in English | MEDLINE | ID: mdl-11456011

ABSTRACT

PURPOSE: To compare the clinical efficacy and safety of lodoxamide 0.1% ophthalmic solution with levocabastine 0.05% ophthalmic suspension, each given four times daily (QID) for three months to patients with vernal keratoconjunctivitis (VKC). METHODS: The study was conducted multinationally according to a triple-masked parallel design in 95 VKC patients, with assessments at baseline then monthly during the three months of treatment. The primary efficacy variables were a Physician's Clinical Judgement Scale and a Patient's Overall Judgement Scale of improvements from baseline. Signs and symptoms of VKC were also assessed. RESULTS: Both primary efficacy variables showed significantly greater overall improvement of VKC from baseline with lodoxamide than levocabastine. The superiority of lodoxamide was demonstrated by the Physician's Clinical Judgement Scale at months 2 and 3, with a trend, at month 1, and by the Patient's Overall Judgement Scale at months 1, 2 and 3. All signs and symptoms of VKC improved significantly from baseline at all time points, regardless of treatment (p<0.001). However, relative to levocabastine, conjunctival discharge, photophobia and lacrimation were significantly reduced by lodoxamide at months 1, 2 and 3, itching at months 2 and 3, and bulbar conjunctiva at month 3. The temporal improvement of superior tarsal papillae did not differ significantly between treatments. Both were well tolerated. CONCLUSIONS: Lodoxamide 0.1% and levocabastine 0.05% eye drops, instilled four times daily for three months, were effective, safe and well tolerated by patients with VKC, but lodoxamide was significantly superior to levocabastine.


Subject(s)
Anti-Allergic Agents/therapeutic use , Conjunctivitis, Allergic/drug therapy , Histamine H1 Antagonists/therapeutic use , Oxamic Acid/analogs & derivatives , Oxamic Acid/therapeutic use , Piperidines/therapeutic use , Adolescent , Adult , Anti-Allergic Agents/administration & dosage , Anti-Allergic Agents/adverse effects , Child , Child, Preschool , Conjunctiva/drug effects , Conjunctivitis, Allergic/physiopathology , Double-Blind Method , Female , Histamine H1 Antagonists/administration & dosage , Histamine H1 Antagonists/adverse effects , Humans , Male , Ophthalmic Solutions , Oxamic Acid/administration & dosage , Oxamic Acid/adverse effects , Piperidines/administration & dosage , Piperidines/adverse effects , Safety , Suspensions , Treatment Outcome
16.
Coll Antropol ; 25 Suppl: 149-52, 2001.
Article in English | MEDLINE | ID: mdl-11817007

ABSTRACT

Dry eye, due to its impaired function of tear film becomes more susceptible to all kinds of airborne allergens. Due to air pollution this is more marked in urban areas, and is compounded by the modern way of life. There are various standard topical medications which alleviate allergic reaction of the eye, but many of them must be administered with caution and only on short term due to their potentially hazardous side effects. The purpose of this work is to assess the efficacy of lodoxamide, a new antiallergic medication for topical use, whose advantage is low or absent risk of adverse side effects, in alleviating local allergic reactions of the eye in patients with dry eye. Research has shown that, compared to treatment with eye lubricants alone (artificial tears), treatment with artificial tears combined with lodoxamide has resulted in more marked decrease in the signs of inflammation, and to the lesser extent to the reduction of the symptoms as well.


Subject(s)
Anti-Allergic Agents/therapeutic use , Dry Eye Syndromes/drug therapy , Oxamic Acid/analogs & derivatives , Oxamic Acid/therapeutic use , Administration, Topical , Anti-Allergic Agents/administration & dosage , Female , Humans , Male , Middle Aged , Ophthalmic Solutions , Oxamic Acid/administration & dosage
17.
Oftalmologia ; 52(2): 81-4, 2001.
Article in Romanian | MEDLINE | ID: mdl-11771108

ABSTRACT

PURPOSE: Evaluating the efficiency and safety of Alomide (lodoxamide 01.%) in the treatment of allergic conjunctivitis. MATERIAL, METHOD: 12 patients have been selected during may-august 1998, in order to be treated with Alomide 4 times daily. The clinical exam of the patient included: general information, history, ocular examination. The ocular status of each patient has been evaluated with a score: the intensity of each symptom and sign has been graded between 1-3. RESULTS: In all cases, the use of Alomide induced the improvement of the typical symptoms and signs of the allergic conjunctivitis. No side effect related to the use of the drug has been noted. CONCLUSION: Due to its dual action (inhibition of both mast cells and eosinophils), Alomide covers most of the allergic response.


Subject(s)
Anti-Allergic Agents/therapeutic use , Conjunctivitis, Allergic/drug therapy , Oxamic Acid/analogs & derivatives , Oxamic Acid/therapeutic use , Administration, Topical , Adolescent , Adult , Anti-Allergic Agents/administration & dosage , Anti-Allergic Agents/adverse effects , Child , Humans , Oxamic Acid/administration & dosage , Oxamic Acid/adverse effects , Treatment Outcome
20.
Oftalmologia ; 50(1): 68-76, 2000.
Article in Romanian | MEDLINE | ID: mdl-11021110

ABSTRACT

Lodoxamid is an antiallergic drug, which stabilizes the mast cells' membrane blocking the release of the type I hypersensitivity reaction chemical mediators. A number of 25 patients with ocular allergic diseases (allergic conjunctivitis, vernal and atopic keratoconjunctivitis, giant papillary conjunctivitis), were included in this study. Lodoxamid, solution 0.1% (Alomide), was given 4 times daily for 6 weeks. The study's aim was to assess the lodoxamid's efficiency, on the ocular signs and symptoms. The study's results showed a significant improvement, or the disappearance of the ocular allergic disease. It is debated upon the lodoxamid's way and place of action, in blocking the type I hypersensitivity reaction. The lodoxamid's efficiency is due to its pharmacological features, by means of which it is effective on many links of the pathogenic chain: mast cells, eosinophils, lymphocytes, neutrophils, antigen presenting cells. Due to its action lodoxamid stabilizes the mast cell's membrane, and inhibits the release of histamine, prostaglandins, leukotrienes, triptase, interleukines -4, -8 and TNF-. During therapy with lodoxamid recruitment and activation of eosinophils is decreased, causing a significant reduction of the basic major protein, cationic eosinophilic protein, eosinophilic derived neurotoxin, eosinophilic peroxidase. Lodoxamid reduces the expression of ICAM-1 on the surface of the antigen presenting cells, and decreases the number of the TH2 cells, from the tears of the allergic patients.


Subject(s)
Anti-Allergic Agents/therapeutic use , Eye Diseases/drug therapy , Hypersensitivity/drug therapy , Oxamic Acid/analogs & derivatives , Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Ophthalmic Solutions , Oxamic Acid/therapeutic use , Prospective Studies , Time Factors
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