Modulation of Oxidative Stress and Inflammation in the Aged Lacrimal Gland.

Inflammation and oxidative stress accompany aging. This study investigated the interplay between oxidative stress and inflammation in the lacrimal gland. C57BL/6 mice were used at 2 to 3, 12, and 24 months of age. Nuclear factor erythroid derived-2-related factor 2 (Nrf2)-/- and corresponding wild-type mice were used at 2 to 3 and 12 to 13 months of age. A separate group of 15.5 to 17 months of age C57BL/6 mice received a diet containing an Nrf2 inducer (Oltipraz) for 8 weeks. Aged C57BL/6 lacrimal glands showed significantly greater lymphocytic infiltration, higher levels of MHC II, IFN-γ, IL-1ß, TNF-α, and cathepsin S (Ctss) mRNA transcripts, and greater nitrotyrosine and 4-hydroxynonenal protein. Young Nrf2-/- mice showed an increase in IL-1ß, IFN-γ, MHC II, and Ctss mRNA transcripts compared with young wild-type mice and greater age-related changes at 12 to 13 months of age. Oltipraz diet significantly decreased nitrotyrosine and 4-hydroxynonenal and decreased the expression of IL-1ß and TNF-α mRNA transcripts, while decreasing the frequency of CD45+CD4+ cells in lacrimal glands and significantly increasing conjunctival goblet cell density compared with a standard diet. The findings provide novel insight into the development of chronic, low-grade inflammation and oxidative stress in age-related dry eye. New therapies targeting oxidative stress pathways will be valuable in treating age-related dry eye.

Bactericidal effect of pyridine-2-thiol 1-oxide sodium salt and its complex with iron against resistant clinical isolates of Mycobacterium tuberculosis.

The objective of this study was to determine the activity of pyridine-2-thiol 1-oxide sodium salt (Na mpo) and its complex with iron [Fe(mpo)3] against Mycobacterium tuberculosis. The compounds were tested against a standard strain of M. tuberculosis H37Rv (ATCC 27294), with minimal inhibitory concentrations (MIC90) of 7.20 and 1.07 µM to Na mpo and [Fe(mpo)3], respectively, and against three clinical isolates with different genotypic profiles, with MIC values ranging from 0.74 to 6.52 and 0.30 to 2.25 µM to Na mpo and [Fe(mpo)3], respectively. [Fe(mpo)3] was more effective against susceptible strains but both compounds were effective in inhibiting MDR and XDR-TB clinical strains. The profile activity was determined through the methodology of a time-kill curve against standard and clinical strains of M. tuberculosis. Time-kill studies indicated that Na mpo had an early bactericidal activity against H37Rv and clinical isolates, with sterilizing effects observed in 5 and 7 days, respectively, at its MIC90. The anti MDR and XDR-M. tuberculosis activity and bactericidal effect of Na mpo and [Fe(mpo)3] demonstrate their potential as new compounds for the treatment of tuberculosis.

Synthesis and evaluation of the antileishmanial activity of silver compounds containing imidazolidine-2-thione.

A new series of silver compounds could be of interest on designing new drugs for the treatment of leishmaniasis. The compounds [Ag(phen)(imzt)]NO3(1), [Ag(phen)(imzt)]CF3SO3(2), [Ag(phen)2](BF4)·H2O (3), [Ag2(imzt)6](NO3)2(4), and imzt have been synthesized and evaluated in vitro for antileishmanial activity against Leishmania. (L.) amazonensis (La) and L. (L.) chagasi (Lc), and two of them were selected for in vivo studies. In addition to investigating the action on Leishmania, their effects on the hydrogen peroxide production and cysteine protease inhibition have also been investigated. As for antileishmanial activity, compound (4) was the most potent against promastigote and amastigote forms of La (IC50 = 4.67 and 1.88 µM, respectively) and Lc (IC50 = 9.35 and 8.05 µM, respectively); and comparable to that of amphotericin B, reference drug. Beside showing excellent activity, it also showed a low toxicity. In the in vivo context, compound (4) reduced the number of amastigotes in the liver and spleen when compared to the untreated group. In evaluating the effect of the compounds on Leishmania, the level of hydrogen peroxide production was maintained between the lag and log phases; however, in the treatment with compound (4) it was possible to observe a reduction of 25.44 and 49.13%, respectively, in the hydrogen peroxide rates when compared to the lag and log phases. It was noticed that the presence of a nitrate ion and imzt in compound (4) was important for the modulation of the antileishmanial activity. Thus, this compound can represent a potentially new drug for the treatment of leishmaniasis.

Fatty-monastrol derivatives and its cytotoxic effect against melanoma cell growth.

Melanoma is the most dangerous type of skin cancer due to the occurrence of metastases. This work is aimed at studying the effects of the insertion of palmitic and oleic acid chain into monastrol in the melanoma cell line, B16F10. Cells were treated with monastrol, palmitic-monastrol or oleic-monastrol for periods of 0, 24, 48 and 72 h, and the cytotoxic effect was observed for palmitic-monastrol and oleic-monastrol after 24 h. For monastrol the effects were observed in 48 h on B16F10 cells, and in 24 h for a non-tumour cell line, melan-a. In this cell line, fatty-monastrol derivatives were cytotoxic after 24 h of exposure in the same concentrations as B16F10. However, oleic-monastrol inhibited cell growth at 20µM only after 72 h, in contrast to the B16F10 cell line, in which oleic-monastrol inhibited cell growth at 48 h, showing that at least in this structural modification, melan-a was less sensitive than B16F10. The ability of compounds to induce apoptosis and/or necrosis was measured, and it was observed that monastrol induces apoptosis within 24 h. However, the cells treated with fatty-monastrol derivatives did not remain adhered on the well plate after 3 h of treatment. At this time point, these cells still emitted fluorescence indicating viable cells, suggesting a possible effect of palmitic- and oleic-monastrol in the adhesion proteins found on the cell membrane.

Comparison of the Effects of Monastrol and Oxomonastrol on Human Hepatoma Cell Line HepG2/C3A.

Monastrol and its analog oxomonastrol differ by replacement of the sulfur atom present in monastrol to an oxygen atom in oxomonastrol. Monastrol inhibits the mitotic kinesin family member 11 (EG5), which has been studied for its potential use in cancer therapy. The aim of this study was to investigate the effect of monastrol and oxomonastrol on HepG2/C3A cells. Our results showed that monastrol induced DNA damage, reduced cell proliferation, and up-regulated the cytochrome P450 family 1 subfamily A member 1 (CYP1A1) mRNA levels. However, oxomonastrol was cytotoxic only at the highest concentrations used, without reducing cell proliferation and viability. Moreover, no genotoxic damage or alteration of levels of mRNA were found. Our results suggest that monastrol has greater antiproliferative activity compared to oxomonastrol, and this effect is probably related to the DNA damage induced by monastrol and its possible bioactivation demonstrated by the increase in CYP1A1 mRNA expression. Moreover, these effects appear to be related to the presence of the sulfur atom in its structure.

Antiproliferative activity of monastrol in human adenocarcinoma (MCF-7) and non-tumor (HB4a) breast cells.

Monastrol is an allosteric inhibitor of the mitotic kinesin Eg5 that exhibits an antiproliferative effect against several cell lines. We investigated the antiproliferative effect of monastrol on human breast adenocarcinoma cells (MCF-7) and mammary epithelial cells (HB4a, non-tumoral). Monastrol treatment decreased cell viability only in MCF-7 tumor cells. Real-time cell growth kinetic analysis showed a decrease in the proliferation of MCF-7 cells exposed to monastrol, while in the HB4a cells, only a concentration of 100 µM was able to induce this effect. In a cell cycle analysis, exposure of MCF-7 cells to monastrol led to an increased population of cells in both the G1 and G2/M phases. In HB4a cells, the proportion of cells in the G2/M phase was increased. Monastrol led to an increased mitotic index in both cell lines. Monastrol was not able to induce cell death by apoptosis in any of the cell lines studied. Gene expression analysis was performed to measure the mRNA levels of cell cycle genes, DNA damage indicator gene, and apoptotic related genes. Treatment with monastrol induced in MCF-7 cells a 5-fold increase in the mRNA levels of the CDKN1A gene, an inhibitor of CDKs related with cell cycle arrest in response a stress stimulus, and a 2-fold decrease in CDKN1C mRNA levels in HB4a cells. These results provide evidence that monastrol has a greater antiproliferative effect on MCF-7 tumor cells compared with non-tumor HB4a cells; however, no selective is observed.

Role of sphingomyelinase in mitochondrial ceramide accumulation during reperfusion.

Ceramide accumulation in mitochondria has been associated with reperfusion damage, but the underlying mechanisms are not clearly elucidated. In this work we investigate the role of sphingomyelinases in mitochondrial ceramide accumulation, its effect on reactive oxygen species production, as well as on mitochondrial function by using the sphingomyelinase inhibitor, tricyclodecan-9-yl-xanthogenate (D609). Correlation between neutral sphingomyelinase (nSMase) activity and changes in ceramide content were performed in whole tissue and in isolated mitochondria from reperfused hearts. Overall results demonstrated that D609 treatment attenuates cardiac dysfuncion, mitochondrial injury and oxidative stress. Ceramide was accumulated in mitochondria, but not in the microsomal fraction of the ischemic-reperfused (I/R) group. In close association, the activity of nSMase increased, whereas glutathione (GSH) levels diminished in mitochondria after reperfusion. On the other hand, reduction of ceramide levels in mitochondria from I/R+D609 hearts correlated with diminished nSMase activity, coupling of oxidative phosphorylation and with mitochondrial integrity maintenance. These results suggest that mitochondrial nSMase activity contributes to compartmentation and further accumulation of ceramide in mitochondria, deregulating their function during reperfusion.

Participation of PLA2 and PLC in DhL-induced activation of Rhinella arenarum oocytes.

Rhinella arenarum oocytes can be artificially activated, a process known as parthenogenesis, by a sesquiterpenic lactone of the guaianolide group, dehydroleucodine (DhL). Transient increases in the concentration of cytosolic Ca2+ are essential to trigger egg activation events. In this sense, the 1-4-5 inositol triphosphate receptors (IP3R) seem to be involved in the Ca2+ transient release induced by DhL in this species. We analyzed the involvement of phosphoinositide metabolism, especially the participation of phospholipase A2 (PLA2) and phospholipase C (PLC) in DhL-induced activation. Different doses of quinacrine, aristolochic acid (ATA) (PLA2 inhibitors) or neomycin, an antibiotic that binds to PIP2, thus preventing its hydrolysis, were used in mature Rhinella arenarum oocytes. In order to assay the participation of PI-PLC and PC- PLC we used U73122, a competitive inhibitor of PI-PLC dependent events and D609, an inhibitor of PC-PLC. We found that PLA2 inhibits quinacrine more effectively than ATA. This difference could be explained by the fact that quinacrine is not a specific inhibitor for PLA2 while ATA is specific for this enzyme. With respect to the participation of PLC, a higher decrease in oocyte activation was detected when cells were exposed to neomycin. Inhibition of PC-PLC with D609 and IP-PLC with U73122 indicated that the last PLC has a significant participation in the effect of DhL-induced activation. Results would indicate that DhL induces activation of in vitro matured oocytes of Rhinella arenarum by activation of IP-PLC, which in turn may induce IP3 formation which produces Ca2+ release.

Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil

INTRODUCTION: Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce. METHODS: Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758) were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV) serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus. RESULTS: DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%). Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3). CONCLUSIONS: This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state. .

Activity of LaSOM 65, a monastrol-derived compound, against glioblastoma multiforme cell lines.

BACKGROUND/AIM: Despite recent progress in glioblastoma treatment, prognosis is still poor. Monastrol is a kinesin spindle protein (KSP) inhibitor and anticancer effects for this molecule have been reported. Here we describe the effect of LaSOM 65, a monastrol derivated compound, against glioma cell lines. MATERIALS AND METHODS: Cell counting, viability assay, lactate dehydrogenase (LDH) activity, cell-cycle analysis, immunofluorescence and organotypic hippocampal slice cultures were performed. RESULTS: LaSOM 65 reduced cell number and cell viability of gliomas cells, but did not cause arrest in the cell cycle at the G2/M phase. Measurement of LDH activity showed that LaSOM 65 induces necrosis after 48 h of treatment. CONCLUSION: LaSOM 65 appears to a be promising new molecule to treat glioblastoma since it promotes a decrease of cell growth and cell viability of glioma cells in vitro and does not induces the neurotoxic characteristics of the anti-mitotic drugs currently used.

Anti-inflammatory and immunomodulatory effects of RDV-8 [C18H22N2O2S (ethyl 1-butyl-6-methyl-2-phenyl-4-thioxo-1,4-dihydropyrimidine-5-carboxylate)] in a rat model of induced pleurisy and in vitro lymphoproliferation.

RDV-8 [C(18)H(22)N(2)O(2)S (ethyl 1-butyl-6-methyl-2-phenyl-4-thioxo-1,4-dihydropyrimidine-5-carboxylate)] is derived from the 4-thioxopyrimidine, and presents important clinical effects. The present study explored the RDV-8 effects in the proliferation of human peripheral blood mononuclear cells (PBMCs), as well as in a pleurisy-induced rat model. PBMCs were directly plated in four different RDV-8 concentrations (0.0125, 0.025, 0.05 and 0.1 mg/mL). RDV-8 decreased cell proliferation and monocyte chemotactic protein 1 synthesis. The interleukin 1 levels and the cytotoxic effect were not significantly affected by RDV-8 treatment. In the carrageenan-induced pleurisy model, the RDV-8 (3 mg/kg) treatment induced a significant reduction in the exudate volume, in the polymorphonuclear leukocyte migration and in the pleural exudate NO levels. The results indicate that RDV-8 may have an immunomodulatory effect, as well as anti-inflammatory actions suggesting that it could represent a new strategy in the inflammatory response modulation.

Bax distribution into mitochondrial detergent-resistant microdomains is related to ceramide and cholesterol content in postischemic hearts.

*Diverse changes have been described in mitochondria of apoptotic cells: the phospholipid content is modified, ceramide and GD3 concentrations increase, the cristae structure is modified, and nonresident proteins are recruited into the mitochondrial membranes. In particular, Bax, a Bcl-2 family member protein, moves from the cytosol to the mitochondria, inducing cytochrome c release. Modifications of the content and distribution of specific lipids in the mitochondrial membranes, along with the well-known participation of the mitochondrial permeability transition pore in triggering apoptosis, led us to propose that lipid microdomains in mitochondria could coexist as structural elements with some of the mitochondrial permeability transition pore-forming proteins and with members of the Bcl-2 family. In this work, we demonstrated that Bax was associated preferentially with mitochondrial detergent-resistant membranes (mDRMs) in reperfused rat hearts, a well-known apoptotic model. Bax insertion into mDRMs correlated with cytochrome c release from such mitochondria. Bax location in mDRMs was associated with both the voltage-dependent anion channel and the adenine nucleotide translocator, two mitochondrial permeability transition pore-forming proteins. Interestingly, the voltage-dependent anion channel was more abundant in the mDRM fraction than in the Triton X-100-soluble fraction. Ceramide and cholesterol contents were higher in mDRMs from reperfused hearts. Our results suggest that membrane microenvironments enriched in cholesterol and ceramide in mitochondria favor Bax translocation to this organelle, fostering propagation of the apoptotic cascade.

Synthesis and characterization of a pyridine-2-thiol N-oxide gold(I) complex with potent antiproliferative effect against Trypanosoma cruzi and Leishmania sp. insight into its mechanism of action.

In the search for new therapeutic tools against parasitic diseases caused by the Kinetoplastids Leishmania spp. and Trypanosoma cruzi, a novel gold(I) triphenylphosphine complex with the bioactive coligand pyridine-2-thiol N-oxide (mpo) was synthesized and characterized by using analytical and conductometric measurements, electrospray ionization-mass spectrometry (ESI) and electronic, FTIR and (1)H and (31)P NMR spectroscopies. A dinuclear structure is suggested for the complex. At a 1 microM concentration the complex induced in vitro after 30 min a potent leishmanicidal effect (LD(50)) against promastigotes of Leishmania (L.) mexicana while on Leishmania (V.) braziliensis with the same concentration only a leishmanistatic effect (IC(75)) was observed 48 h after treatment. Similar differential susceptibilities were also found when testing the ligand mpo, but at a higher dose (5 microM). In addition, the compound showed growth inhibitory effect on Dm28c T. cruzi epimastigotes in culture (IC(50) 0.09 microM), being even more active than the anti-trypanosomal reference drug Nifurtimox (IC(50) 6 microM). DNA interaction studies showed that this biomolecule does not constitute a main target for the mpo complex currently tested. Instead, the significant potentiation of the antiproliferative effect against both Leishmania species and T. cruzi could be associated to the inhibition of NADH fumarate reductase, a kinetoplastid parasite-specific enzyme absent in the host. Furthermore, due to its low unspecific cytotoxicity on mammalian cells (J774 macrophages), the new gold complex showed a selective anti-parasite activity. It constitutes a promising new potent chemotherapeutic alternative to be evaluated in vivo in experimental models of leishmaniasis and Chagas disease.

Synthesis and antiprotozoal evaluation of new N4-(benzyl)spermidyl-linked bis(1,3,5-thiadiazinane-2-thiones).

The synthesis and in-vitro antiprotozoal evaluation of novel N(4)-(benzyl)spermidyl-linked bis(1,3,5-thiadiazinane-2-thione) (bis-THTT) derivatives from N(4)-(benzyl)spermidine is disclosed. Several of the new bis-THTT have in-vitro activities against L. donovani and T. cruzi that are comparable or superior to those of currently employed protozoocidal agents.

Participation of Omi Htra2 serine-protease activity in the apoptosis induced by cisplatin on SW480 colon cancer cells.

Apoptosis is triggered by two interconnected pathways, extrinsic and intrinsic. The intrinsic pathway is activated by genomic stress promoting mitochondrial release of apoptotic proteins. One of these proteins is Omi/Htra2, a serine protease which inactivates Inhibitor of Apoptosis Proteins (IAPs). In the present work, we assessed the participation of Omi/Htra2 in the cell death induced by the chemotherapeutic drugs 5-fluorouracil (5-FU) and cisplatin (CDDP) in SW480 colon cancer cells. CDDP and 5-FU induced apoptosis mediated by the intrinsic pathway in colon cancer cells, as demonstrated by morphological analyses, mitochondrial cytochrome c release and cleavage of caspase 3. Omi/Htra2 was also released from mitochondria of cells exposed to these drugs, as demonstrated by immunofluorescence and western blot assays of subcellular fractions. Exposure of cells to the Omi/Htra2 serine protease inhibitor UCF-101 prevented death p<0.0001 and partially suppressed reproductive cell death of cells exposed to cisplatin p<0.05, but not to 5-FU p=0.49. From these experiments we show that Omi/Htra2 serine protease activity participates in the cell death induced by CDDP but not of 5-FU in colon cancer cells.

Potent in vitro anti-Trypanosoma cruzi activity of pyridine-2-thiol N-oxide metal complexes having an inhibitory effect on parasite-specific fumarate reductase.

In the search for new therapeutic tools against Chagas disease (American trypanosomiasis) palladium and platinum complexes of the bioactive ligand pyridine-2-thiol N-oxide were exhaustively characterized and evaluated in vitro. Both complexes showed high in vitro growth inhibition activity (IC(50) values in the nanomolar range) against Trypanosoma cruzi, the causative agent of the disease. They were 39-115 times more active than the antitrypanosomal drug Nifurtimox. The palladium complex showed an approximately threefold enhancement of the activity compared with the parent compound. In addition, owing to their low unspecific cytotoxicity on mammalian cells, the complexes showed a highly selective antiparasite activity. To get an insight into the mechanism of action of these compounds, DNA, redox metabolism (intraparasite free-radical production) and two parasite-specific enzymes absent in the host, namely, trypanothione reductase and NADH-fumarate reductase, were evaluated as potential parasite targets. Additionally, the effect of metal coordination on the free radical scavenger capacity previously reported for the free ligand was studied. All the data strongly suggest that trypanocidal action of the complexes could mainly rely on the inhibition of the parasite-specific enzyme NADH-fumarate reductase.

Synthesis and differential antiproliferative activity of Biginelli compounds against cancer cell lines: Monastrol, oxo-monastrol and oxygenated analogues.

The synthesis and differential antiproliferative activity of monastrol (1a), oxo-monastrol (1b) and eight oxygenated derivatives 3a,b-6a,b on seven human cancer cell lines are described. For all evaluated cell lines, monastrol (1a) was shown to be more active than its oxo-analogue, except for HT-29 cell line, suggesting the importance of the sulfur atom for the antiproliferative activity. Monastrol (1a) and the thio-derivatives 3a, 4a and 6a displayed relevant antiproliferative properties with 3,4-methylenedioxy derivative 6a being approximately more than 30 times more potent than monastrol (1a) against colon cancer (HT-29) cell line.

Study on the decomposition products of thiadiazinthione and their anticancer properties.

Study of the anticancer properties of thirty-four 3,5-disubstituted-tetrahydro-2H-1,3,5-thiadiazin-2-thione derivatives has been carried out by using cytotoxicity assays against HeLa, HT-29 and Hep G2 cells. The decomposition products of thiadiazinthione 1 m have been studied and their anticancer properties evaluated.