Screening the mutagenic activities of coomonly used antiparasite drugs by the Simultest, a simplified Salmonella/microsome plate incorporation assay

The mutagenic activities of 16 anti-parasite drugs were screened by the Simultest in both qualitative (spot test) and quantitative (plate incorporation) assays with a Salmonella typhimurium pool composed by the indicator strains TA97, TA 98, TA100 and TA102. Four anti Chagas' disease drugs (nifurtimox, benznidazole, CL 64,855, and MK 436) and two anti-amebae drugs (metronidazole and tinidazole) gave positive results in qualitative tests and incorporation of rat liver microsomes did not alter the results. Comparative dose response curves of the mutagenic activities of CL 64,855, metronidazole and benznidazole obtained by the simultest and by individual Salmonella indicator strains demonstrated that both approachs have similar sensitivities. The results corroborate the validity of the Simultest, as a simplified, fast and economic version of the Ames test in preliminary screening of potential mutagenic drugs.

Antibacterial, anti-swarming and anti-biofilm formation activities of Chamaemelum nobile against Pseudomonas aeruginosa

AbstractINTRODUCTION:Chamomile ( Chamaemelum nobile ) is widely used throughout the world, and has anti-inflammatory, deodorant, bacteriostatic, antimicrobial, carminative, sedative, antiseptic, anti-catarrhal, and spasmolytic properties. Because of the increasing incidence of drug-resistant bacteria, the development of natural antibacterial sources such as medical herbs for the treatment of infectious diseases is necessary. Extracts from different plant parts such as the leaves, flowers, fruit, and bark of Combretum albiflorum, Laurus nobilis , and Sonchus oleraceus were found to possess anti-quorum sensing (QS) activities. In this study, we evaluated the effect of C. nobile against Pseudomonas aeruginosa biofilm formationMETHODS:The P. aeruginosa samples were isolated from patients with different types of infection, including wound infection, septicemia, and urinary tract infection. The flowers of C. nobile were dried and the extract was removed using a rotary device and then dissolved in dimethyl sulfoxide at pH 7.4. The microdilution method was used to evaluate the minimum inhibitory concentration (MIC) of this extract on P. aeruginosa , and biofilm inhibition was assayed.RESULTS:Eighty percent of the isolated samples (16/20) could form a biofilm, and most of these were isolated from wound infections. The biofilm inhibitory concentration of the C. nobile extract was 6.25-25mg/ml, whereas the MIC was 12.5-50mg/ml.CONCLUSIONS:The anti-QS property of C. nobile may play an important role in its antibacterial activity, thus offering an additional strategy in the fight against bacterial infections. However, molecular investigation is required to explore the exact mechanisms of the antibacterial action and functions of this phytocompound.

Role of microRNAs 221/222 on Statin Induced Nitric Oxide Release in Human Endothelial Cells

Background: Nitric oxide (NO) has been largely associated with cardiovascular protection through improvement of endothelial function. Recently, new evidence about modulation of NO release by microRNAs (miRs) has been reported, which could be involved with statin-dependent pleiotropic effects, including anti-inflammatory properties related to vascular endothelium function. Objective: To evaluate the effects of cholesterol-lowering drugs including the inhibitors of cholesterol synthesis, atorvastatin and simvastatin, and the inhibitor of cholesterol absorption ezetimibe on NO release, NOS3 mRNA expression and miRs potentially involved in NO bioavailability. Methods: Human umbilical vein endothelial cells (HUVEC) were exposed to atorvastatin, simvastatin or ezetimibe (0 to 5.0 μM). Cells were submitted to total RNA extraction and relative quantification of NOS3 mRNA and miRs -221, -222 and -1303 by qPCR. NO release was measured in supernatants by ozone-chemiluminescence. Results: Both statins increased NO levels and NOS3 mRNA expression but no influence was observed for ezetimibe treatment. Atorvastatin, simvastatin and ezetimibe down-regulated the expression of miR-221, whereas miR-222 was reduced only after the atorvastatin treatment. The magnitude of the reduction of miR-221 and miR-222 after treatment with statins correlated with the increment in NOS3 mRNA levels. No influence was observed on the miR-1303 expression after treatments. Conclusion: NO release in endothelial cells is increased by statins but not by the inhibitor of cholesterol absorption, ezetimibe. Our results provide new evidence about the participation of regulatory miRs 221/222 on NO release induction mediated by statins. Although ezetimibe did not modulate NO levels, the down-regulation of miR-221 could involve potential effects on endothelial function.

Viability of Ascaris lumbricoides eggs eliminated after anti-helminthic therapy

The viability of Ascaris lumbricoides eggs passed in the feces was evaluated after treatment of patients with one of the anti-helminthic drugs (thiabendazole, levamisole, cambendazole, pyrantel pamoate, mebendazole or praziquantel). For each drug, a group of 5 children was selected and their feces collected 24 h before treatment and 24, 48 and 72 h after drug administration, except for mebendazole, with the feces being collected throughout the period of treatment. After sedimentation, the total amount of eggs from each collection was transferred to tissue culture flasks containing 10 ml H2So4 O, 1N, with the addtion of 3 drops of a miconazol solution, and incubated at 28 graus centígrados, individually, for 80 days. The flasks wee maintained open and the culture were oxigenated daily by manual agitation. On the 80th day of culture, 20-days-old albino mice were inoculated with 3,200 embryonated eggs, per os. Larvae were recovered from their lungs and hearts, on the 8th day after infection, according to Baerman's method (Morais, 1948). Thiabendazole showed 100.0% ovicidal capacity as early as 48 after treatment. Inhibition of embrionary development was observed when thiabendazole was used. This drug also had an effect on the eggs infectivity when inoculated into normal mice. No significant effect on embrionary development was observed for the other drugs tested.

Natural bradykinin antagonists

Bradykinin (BK) a nonapeptide generated in plasma during tissue injury, is involved in many physiological and pathological states. Kinin actions are mediated by specific membrane receptors and involve a complex signal transducer and also second messager mechanisms. Due to its inequivocal relevance, an intensive effort has been focused in recent years to develop selective and competitive BK antagonists. Thus, the development of a new series of peptide BK antagonists has made an important contribution to the understanding of the pharmacological, physiological and pathophysiological role of BK, and this is certain to provide a firm basis for developing new drugs to relieve pain and inflammation. However, BK antagonists derived from peptide origin reported to date have limited clinical use due to their poor oral absortion and short duration of effect. Thus, considerable effort has also been made in developing stable nonpeptide BK antagonists. Up to now, most nonpeptide compounds reported to exhibit BK antagonistic activity have been derived from plants, including many flavonoids, terpenes, and also synthetic substances with various molecular structures. Amongst them, the pregnane glycoside compounds isolated from the plant Mandevilla velutina are the most promising. These compounds are effective in antognizing BK responses in a variety of preparations, and they also exhibit potent and long-lasting analgesic and anti-inflammatory activities. The exact mechanism underlying their action however, is not yet completely understood.

Perspective for the reproduction of antimalarial drugs in Brazil

The appears to be no chemical manufacture of antimalarial drugs is Brazil. Technology at laboratory process level has been developed for chloroquine, mefloquine, pyrimethamine and cycloquanil, but not perfected nor scaled-up, largely for economic reasons and market uncertainty. Development of primaquine has been contracted but it will run into the same difficulty. Manufacturing capacity for sulfadoxine was registred in the SDI by Roche. A project to produce artemisinine and its derivates is under way at UNICAMP-CPQBA but is hampered by low content in the plant. Proguanil could be produced easily, but apparently no attempt has been made to do so. Quinine is imported on a large scale mostly for softdrink production. Since malarial treatment falls largely within responsability of the Government health authorities, manufacture of drugs in Brazil will depend on an assured medium-term purchase order made to a potential local manufacturer, since competition in the world market is scarcelyviable at the present moment.

An overview of the effects of annexin 1 on cells involved in the inflammatory process

The concept of anti-inflammation is currently evolving with the definition of several endogenous inhibitory circuits that are important in the control of the host inflammatory response. Here we focus on one of these pathways, the annexin 1 (ANXA1) system. Originally identified as a 37 kDa glucocorticoid-inducible protein, ANXA1 has emerged over the last decade as an important endogenous modulator of inflammation. We review the pharmacological effects of ANXA1 on cell types involved in inflammation, from blood-borne leukocytes to resident cells. This review reveals that there is scope for more research, since most of the studies have so far focused on the effects of the protein and its peptido-mimetics on neutrophil recruitment and activation. However, many other cells central to inflammation, e.g. endothelial cells or mast cells, also express ANXA1: it is foreseen that a better definition of the role(s) of the endogenous protein in these cells will open the way to further pharmacological studies. We propose that a more systematic analysis of ANXA1 physio-pharmacology in cells involved in the host inflammatory reaction could aid in the design of novel anti-inflammatory therapeutics based on this endogenous mediator.

Soluble inflammatory markers as predictors of virological response in patients with chronic hepatitis C virus infection treated with interferon-α plus ribavirin

The host immune response plays an important role in viral clearance in patients who are chronically infected with hepatitis C virus (HCV) and are treated with interferon and ribavirin. Activation of the immune system involves the release of pro and anti-inflammatory molecules that can be measured in plasma samples. The present study aimed to evaluate the association between pretreatment plasma levels of chemokines and soluble tumor necrosis factor receptors (sTNF-R) and the virological response in treated patients with chronic hepatitis C infection. Forty-one chronically-infected HCV patients that were being treated with interferon-α (IFN-α) plus ribavirin were included in the study. Socio-demographic, clinical and laboratory data were collected and pretreatment plasma levels of chemokine CCL2, CCL3, CCL11, CCL24, chemokine CXCL9, CXCL10, sTNF-R1 and sTNF-R2 were measured. The virological response was assessed at treatment week 12, at the end of treatment and 24 weeks after treatment. Pretreatment CXCL10 levels were significantly higher in patients without an early virological response (EVR) or sustained virological response (SVR) compared to responders [512.9 pg/mL vs. 179.1 pg/mL (p = 0.011) and 289.9 pg/mL vs. 142.7 pg/mL (p = 0.045), respectively]. The accuracy of CXCL10 as a predictor of the absence of EVR and SVR was 0.79 [confidence interval (CI) 95%: 0.59-0.99] and 0.69 (CI 95%: 0.51-0.87), respectively. Pretreatment plasma levels of the other soluble inflammatory markers evaluated were not associated with a treatment response. Pretreatment CXCL10 levels were predictive of both EVR and SVR to IFN-α and ribavirin and may be useful in the evaluation of candidates for therapy.

A química medicinal de N-acilidrazonas: novos compostos-protótipos de fármacos analgésicos, antiinflamatórios e anti-trombóticos

In this article are described new bioactive N-acylhydrazone (NAH) derivatives, structurally designed as optimization of aryl hydrazones precursors planned by molecular hybridization of two 5-lipoxigenase inhibitors, e.g. CBS-1108 and BW-755c. The analgesic, antiedematogenic and anti-platelet aggregating profile of several isosteric compounds was investigated by using classic pharmacological assays in vivo and ex-vivo, allowing to identify new potent peripheric analgesic lead, a new anti-inflammatory and an antithrombotic agent. During this study was discovered dozen of active NAH compounds clarifying the structure-activity relationship for this series of NAH derivatives, indicating the pharmacophore character of the N-acylhydrazone functionality.

HIV - recentes avanços na pesquisa de fármacos

The development of new antiretroviral drugs is a dynamic process that is continuously fueled by identification of new molecular targets and new compounds for know targets. The current available drugs can be classified into five categories: nucleoside analogues reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors and entry inhibitors (fusion inhibitors and CCR5 antagonist). In addition, the maturation inhibitors may be considered as potential target for chemotherapeutic intervention. This review presents some anti-HIV agents that have already gone through the advance development process for final approval for the treatment of AIDS.

Constituintes químicos das folhas e avaliação da atividade anti-inflamatória de extratos das raízes e folhas de Guettarda pohliana Müll. Arg. (Rubiaceae)

This phytochemical investigation of Guettarda pohliana leaves led to the isolation of the triterpenes pomolic acid, rotundic acid, 3β,6α,19α,23-tetrahydroxyurs-12-en-28-oic acid, clethric acid, ursolic acid and oleanolic acid, the monoterpenoids loliolide and secoxyloganin, besides daucosterol and steroids. The structures of the isolated compounds were assigned on the basis of NMR data, including two-dimensional NMR methods. The anti-inflammatory activity of the crude methanolic extracts from leaves and roots, as well as of their fractions, was evaluated.

Estudo fitoquímico e avaliação da atividade anti-inflamatória de Aeschynomene fluminensis vell. (Fabaceae)

Phytochemical investigation of Aeschynomene fluminensis leaves and branches led to isolation of the flavonoid glycosides kaempferol 3,7-di-O-α-L-rhamnopyranoside, kaempferol 7-O-α-L-rhamnopyranoside, kaempferol 3-O-apiofuranosil-7-O- rhamnopyranoside, quercitin 3-O-α-L-rhamnopyranoside, quercitin 3-O-arabinofuranoside, 8-β-D-glucopyranosyl 4',5,7-trihydroxyflavanone, the isoflavonoid 4',7-di-hydroxy-isoflavone, the dimer epicatechin-(2β→7, 4β→8)- epicatechin, the polyol 3-O-methyl-chiro-inositol and two steroids in sitosterol and stigmasterol mixture. These compounds were identified by NMR ¹H and 13C and compared with literature data. Anti-inflammatory activity of the crude methanolic extract and its fractions was evaluated.

Constituintes químicos e avaliação das atividades antioxidante e anti-inflamatória das raízes de Sabicea brasiliensis wernh (Rubiaceae)

The phytochemical investigation of Sabicea brasiliensis roots led to the isolation of 5-O-caffeoylquinic acid, 3,5- and 4,5-O-dicaffeoylquinics acids, scopoletin, ursolic acid, a mixture of β-sitosterol, stigmasterol and campesterol, daucosterol and saccharose. The structures of the isolated compounds were assigned on the basis of one- and two-dimensional NMR spectroscopic methods and by comparison with literature data. The anti-inflammatory and antioxidant activities of the crude methanolic extract and its fractions were analyzed.

Mechanisms in anti-inflammation and resolution: the role of lipoxins and aspirin-triggered lipoxins

Multicellular host responses to infection, injury or inflammatory stimuli lead to the formation of a broad range of chemical mediators by the host. The integrated response of the host is essential to health and disease; thus it is important to achieve a more complete understanding of the molecular and cellular events governing the formation and actions of endogenous mediators of resolution that appear to control the duration of inflammation. Lipoxins are trihydroxytetraene-containing lipid mediators that can be formed during cell-cell interactions and are predominantly counterregulators of some well-known mediators of inflammation. Since this circuit of lipoxin formation and action appears to be of physiological relevance for the resolution of inflammation, therapeutic modalities targeted at this system are likely to have fewer unwanted side effects than other candidates and current anti-inflammatory therapies. Here, we present an overview of the recent knowledge about the biosynthesis and bioactions of these anti-inflammatory lipid mediators.

Long-term ethanol intoxication reduces inflammatory responses in rats

The anti-inflammatory effects of long-term ethanol intoxication were determined during ethanol treatment and withdrawal on the basis of neutrophil and eosinophil migration, hind paw edema and mast cell degranulation. Male Wistar rats (180-200 g, around 2 months of age) were exposed to increasing concentrations of ethanol vapor over a 10-day period. One group was evaluated immediately after exposure (treated group - intoxicated), and another was studied 7 h later (withdrawal group). Ethanol inhalation treatment significantly inhibited carrageenan- (62% for the intoxicated group, N = 5, and 35% for the withdrawal group, N = 6) and dextran-induced paw edema (32% for intoxicated rats and 26% for withdrawal rats, N = 5 per group). Ethanol inhalation significantly reduced carrageenan-induced neutrophil migration (95% for intoxicated rats and 41% for withdrawn rats, N = 6 per group) into a subcutaneous 6-day-old air pouch, and Sephadex-induced eosinophil migration to the rat peritoneal cavity (100% for intoxicated rats and 64% for withdrawn rats, N = 6 per group). A significant decrease of mast cell degranulation was also demonstrated (control, 82%; intoxicated, 49%; withdrawn, 51%, N = 6, 6 and 8, respectively). Total leukocyte and neutrophil counts in venous blood increased significantly during the 10 days of ethanol inhalation (leukocytes, 13, 27 and 40%; neutrophils, 42, 238 and 252%, respectively, on days 5, 9 and 10, N = 7, 6 and 6). The cell counts decreased during withdrawal, but were still significantly elevated (leukocytes, 10%; neutrophils, 246%, N = 6). These findings indicate that both the cellular and vascular components of the inflammatory response are compromised by long-term ethanol intoxication and remain reduced during the withdrawal period.