Effects of 5,8-dimethylthieno[2,3-b]quinoline-2-carboxylic acid on the antioxidative defense and lipid membranes in Plasmodium berghei-infected erythrocytes.

Plasmodium parasites degrade hemoglobin producing reactive oxygen species as toxic byproducts which are detoxified by a series of antioxidant mechanisms. Quinoline compounds have demonstrated activity against hemoglobin degradation with 5,8-dimethylthieno[2,3-b]quinoline-2-carboxylic acid (TQCA) representing a recent compound inhibiting this process. Thus, this study was undertaken to determine the ability of TQCA to modify the oxidative status in Plasmodium berghei-infected erythrocytes. After hemolysis, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and dehydrogenase enzymes as well as lipid peroxidation were investigated by spectrophotometry. Saturated and unsaturated fatty acids were determined by gas-liquid chromatography and the in vivo effects of TQCA were confirmed by a malaria murine model (Rane test). The activity of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) in infected cells was diminished by this compound compared to control infection in 75.1 ± 3.5% and 26.5 ± 0.3%, respectively, while that of GPx and GR was also lowered (p <0.05). As an adaptive response we appreciated a 2.3-fold increase of SOD activity compared to control infection. Lipid peroxidation and the saturated/unsaturated fatty acids ratio were also decreased by this quinoline derivate in 49.2 ± 1.32% and 37 ± 0.06%, respectively, protecting the cells from hemolysis caused by the infection. The in vitro results were in concordance with the potential in vivo activity of this compound in an established malaria murine model in which TQCA showed significant decrease in the parasitemia levels and increased the mean survival days of infected mice. In conclusion, the antioxidant defense represents a biochemical target for TQCA actions as a potent antimalarial whose effects were also confirmed in vivo.

Perfil dopaminérgico del compuesto 2-aminoindano N-aralquil sustituido / Profile dopaminergic of the compound 2-aminoindane substituted N-araquil

El sistema dopaminergico central está implicado en las diversas etiologías que involucran a patologías neuropsiquiátricas, tales como la enfermedad de Parkinson, la depresión y la esquizofrenia. Son numerosas las drogas dopaminérgicas utilizadas en el tratamiento de esas dolencias, sin embargo estas terapias causan serios efectos adversos. En este contexto, la génesis de nuevos y más eficientes agentes dopaminergicos, representa un vasto campo de investigación. En el presente trabajo se sintetizó el compuesto 3, concebido como un ligando dopaminérgico, y se evaluó el perfil de su acción dopaminérgica mediante administración central del compuesto y la determinanción de parámetros conductuales como el comportameinto estereotipado (roer) y la medición de la respuesta renal en ratas. Los resultados de la evaluación farmacológica muestran que el compuesto 3 bloquea significativamente la estereotipia inducida por apomorfina, e inhibe la diuresis y natriuresis inducida por la administración central de dopamina. Estos hallazgos sugieren que el compuesto 3 se comporta como un antagonista dopaminérgico, frente a la respuesta tanto conductuales como renales

A new chloroquinolinyl chalcone derivative as inhibitor of inflammatory and immune response in mice and rats.

The synthetic chalcone derivative 1-(2,4-dichlorophenyl)-3-(3-(6,7-dimethoxy-2-chloroquinolinyl))-2-propen-1-one (ClDQ) was evaluated for its anti-inflammatory, analgesic and immunomodulatory efficacy in-vitro and in-vivo. ClDQ concentration-dependently inhibited the production of nitric oxide (NO) (IC50 4.3 microM) and prostaglandin E(2) (PGE(2)) (IC50 1.8 microM) in RAW 264.7 macrophages stimulated with lipopolysaccharide. Human mononuclear cell proliferation was significantly inhibited by 10 microM ClDQ. Oral administration of ClDQ (10-30 mg kg(-1)) in the 24-h zymosan-stimulated mouse air-pouch model produced a dose-dependent reduction of cell migration as well as NO and PGE(2) levels in exudates. ClDQ (20 mg kg(-1), p.o.) inhibited ear swelling and leucocyte infiltration in the delayed-type hypersensitivity response to 2,4-dinitrofluorobenzene in mice. In the rat adjuvant-arthritis model, this compound reduced joint inflammation as well as PGE(2) and cytokine levels. In addition, ClDQ displayed analgesic effects in the phenylbenzoquinone-induced abdominal constriction model in mice and in the late phase of the nociceptive response to formalin. Our findings indicated the potential interest of ClDQ in the modulation of some immune and inflammatory conditions.

1-(2,3,4-trimethoxyphenyl)-3-(3-(2-chloroquinolinyl))-2-propen-1-one, a chalcone derivative with analgesic, anti-inflammatory and immunomodulatory properties.

OBJECTIVE AND DESIGN: The synthetic chalcone derivative 1-(2,3,4-trimethoxyphenyl)-3-(3-(2-chloroquinolinyl))-2-propen-1-one (TQ) was evaluated for its immunomodulatory and anti-inflammatory efficacy in vitro and in vivo. MATERIAL AND SUBJECTS: Human neutrophils and lymphocytes from healthy volunteers and RAW 264.7 murine macrophages. Swiss mice and Lewis rats were randomly divided into groups of six animals. TREATMENT: TQ was orally administered in all in vivo assays (10-30 mg/kg). METHODS: Elastase, superoxide and LTB(4) release were assayed in human neutrophils, NO/PGE(2) production and NF-kappaB activation in RAW 264.7, and (3)H thymidine incorporation in human lymphocytes. Zymosan-stimulated air pouches, DNFB-DTH, PBQ-induced writhings and formalin-induced pain were assayed in mice. Adjuvant-induced arthritis was tested in rats. Dunnett's t-test was employed for statistical analysis. RESULTS: Human T-cell proliferation, neutrophil functions and NO/PGE(2) production in murine macrophages were inhibited by TQ (IC(50) in the microM range), which showed anti-inflammatory, immunomodulatory and analgesic effects. CONCLUSIONS: Our findings indicate the potential interest of TQ in the modulation of some immune and inflammatory responses probably by NF-kappaB inhibition.

Synthesis of quinolinyl chalcones and evaluation of their antimalarial activity.

Quinolinyl chalcones were synthesized and evaluated for their inhibition of the Plasmodium falciparum cystein protease falcipain and their activity against cultured P. falciparum parasites. They were also tested for in vivo efficacy in a rodent P. berghei model. Their activity against falcipain and as antimalarials was moderate, but antimalarial activity was probably not due to the inhibition of falcipain and may follow a different mechanism. 1-(2,4-Dichlorophenyl)-3-[3-(2-chloro-6,7-dimethoxiquinolinyl)]-2-propen-1-one 3j was the most promising compound among those here reported (IC50 19.0 microM).

In vitro antifungal evaluation and structure-activity relationships of a new series of chalcone derivatives and synthetic analogues, with inhibitory properties against polymers of the fungal cell wall.

Here we report the synthesis, in vitro antifungal evaluation and SAR study of 41 chalcones and analogues. In addition, all active structures were tested for their capacity of inhibiting Saccharomyces cerevisiae beta(1,3)-glucan synthase and chitin synthase, enzymes that catalyze the synthesis of the major polymers of the fungal cell wall.

4-dimethylamino-3',4'-dimethoxychalcone downregulates iNOS expression and exerts anti-inflammatory effects.

Reactive oxygen and nitrogen species contribute to the pathophysiology of inflammatory conditions. We have studied the effects of a novel superoxide scavenger, 4-dimethylamino-3', 4'-dimethoxychalcone (CH11) in macrophages and in vivo. CH11 has been shown to inhibit the chemiluminescence induced by zymosan in mouse peritoneal macrophages and the cytotoxic effects of superoxide. In the same cells, the modulation by superoxide of nitric oxide (NO) production in response to zymosan was investigated. CH11 was more effective than the membrane-permeable scavenger Tiron for inhibition of inducible nitric oxide synthase (iNOS) protein expression and nitrite production. We have shown that CH11 inhibited chemiluminescence in vivo, as well as cell migration, and eicosanoid and tumor necrosis factor-alpha (TNF-alpha) levels in the mouse air pouch injected with zymosan. This chalcone derivative also exerted anti-inflammatory effects in the carrageenan paw oedema.

Synthesis of 1-amino-6,7,8,8a-tetrahydroacenaphthene and its effect on the inhibition of the MAO-enzyme at the brain cortex and liver level.

(+/-)-1-Amino-6,7,8,8a-tetrahydroacenaphthene was synthesized and evaluated as a novel drug acting on the dopaminergic system. It was shown that the new compound displays activity as MAO inhibitor.

Synthesis and theoretical study of 2-amino-2,3,3a,4,5,6-hexahydro-1H-phenalene and its biological evaluation on central dopaminergic system.

Compound 2 considered as a rigid non-hydroxylated 2-amino tetralin was synthesized and biologically evaluated. Central administration of compound 2 (50 microg or 100 microg/10 microl) induced a reduction in urinary sodium and potassium excretion at 3 and 6 h of urine collection. We speculate that compound 2 may be acting as a dopamine receptor antagonist.

Novel anti-inflammatory chalcone derivatives inhibit the induction of nitric oxide synthase and cyclooxygenase-2 in mouse peritoneal macrophages.

In a previous work, we tested a series of chalcone derivatives as possible anti-inflammatory compounds. We now investigate the effects of three of those compounds, CHI, CH8 and CH12, on nitric oxide and prostanoid generation in mouse peritoneal macrophages stimulated with lipopolysaccharide and in the mouse air pouch injected with zymosan, where they showed a dose-dependent inhibition with inhibitory concentration 50% values in the microM range. This effect was not the consequence of a direct inhibitory action on enzyme activities. Our results demonstrated that chalcone derivatives inhibited de novo inducible nitric oxide synthase and cyclooxygenase-2 synthesis, being a novel therapeutic approach for inflammatory diseases.

Synthesis and anti-inflammatory activity of chalcone derivatives.

Chalcones and their derivatives were synthesized and evaluated for their anti-inflammatory activity. In vitro, chalcones 2, 4, 8, 10 and 13 inhibited degranulation and 5-lipoxygenase in human neutrophils, whereas 11 behaved as scavenger of superoxide. Only four compounds (4-7) inhibited cyclo-oxygenase-2 activity. The majority of these samples showed anti-inflammatory effects in the mouse air pouch model.

Synthesis and antimalarial effects of phenothiazine inhibitors of a Plasmodium falciparum cysteine protease.

Acridinediones have previously been shown to have potent antimalarial activity. A series of sulfur isosteres of acridinediones have been synthesized and evaluated for their inhibition of the Plasmodium falciparum cysteine protease falcipain and for their antimalarial activity. A number of these phenothiazines inhibited falcipain and demonstrated activity against cultured P. falciparum parasites at low micromolar concentrations. We propose that the compounds exerted their antimalarial effects by two mechanisms, one of which involves the inhibition of falcipain and a consequent block in parasite degradation of hemoglobin. These compounds and related phenothiazines are worthy of further study as potential antimalarial agents.

N-aralkyl substitution of 2-aminoindans. Synthesis and their inotropic and chronotropic activity in isolated guinea pig atria.

Amino substitution of rigid forms of dopamine 4,5-dihydroxy-2-aminoindan and 5,6-dihydroxy-2-aminoindan with aralkyl functionalities were carried out to investigate the role of such structural modifications upon cardiac inotropic-chronotropic activity. Compounds synthesized demonstrated a modest inotropic selectivity, while one of them, described as 5,6-dihydroxy-N-[2-(4-hydroxyphenyl)-1-methylethyl]-2-aminoindan hydrobromide 17, showed a marked inotropic action on isolated heart tissue.

Synthesis of pyridopyrimidone derivatives and their activity against P. falciparum in vitro.

Pyridopyrimidone derivatives 4a-d and 5a- were synthesized as potential antimalarial agents on the basis of the pharmacological properties of existing quinolone analogues such as ciprofloxacine IC50 39.8 microM. Meanwhile among these new compounds, only the 3-amino-7-methyl-1(H)pyrazolo[3,4-b]-pyrido [1,2: 1'2']pyrimido-4-ona 4b, produces significant antimalarial activity IC50 0.42 microM against P. falciparum in vitro. The remaining compounds were effective as antimalarial agents leading from IC50 1.0 microM to IC50 4.47 microM.

Synthesis and activity of some quinolone derivatives against Plasmodium falciparum in vitro.

Quinolones 7a-i and 8a-i were synthesized and tested in vitro as antimalarial against Plasmodium falciparum in chloroquine resistant strain. The above compounds were inactive at concentrations of 1.0 x 10(-4) M except the quinolone 3-amino-9-(2,4-dichlorophenyl)-1H-pyrazolo[3,4-b]-4-quinolone 7h which showed IC50 of 5.06 microM given the most interesting results.

Synthesis of (+/-)-1-amino-6,7,8,8a-tetrahydro acenaphthene with possible central dopaminergic activity.

We describe the non stereoselective synthesis of (+/-)-1-amino-6,7,8,8a-tetrahydroacenaphthene (14), a novel compound that belongs to the acetanaphtene group, that is presented as a rigid non hydroxylated 2-aminoindan which has a structural disposition of a dopaminergic pharmacophore that possess a phenylethylamine fragment. Intracerebroventricular administration of this compound induces an increase in urinary volume and sodium excretion in conscious rats. The renal actions of 14 were blocked by haloperidol pretreatment, suggesting that 14 acts centrally through a dopaminergic mechanism.