Biomedical subjects

M O Moraes

Publications and source records attributed to M O Moraes.

At least 19 recordsLinked to original sources

PubMed2006

In vivo growth-inhibition of Sarcoma 180 by piplartine and piperine, two alkaloid amides from Piper.

Piplartine {5,6-dihydro-1-[1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)pyridinone} and piperine {1-5-(1,3)-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine} are alkaloid amides isolated from Piper. Both have been reported to show cytotoxic activity towards several tumor cell lines. In the present study, the in vivo antitumor activity of these compounds was evaluated in 60 female Swiss mice (N = 10 per group) transplanted with Sarcoma 180. Histopathological and morphological analyses of the tumor and the organs, including liver, spleen, and kidney, were performed in order to evaluate the toxicological aspects of the treatment with these amides. Administration of piplartine or piperine (50 or 100 mg kg(-1) day(-1) intraperitoneally for 7 days starting 1 day after inoculation) inhibited solid tumor development in mice transplanted with Sarcoma 180 cells. The inhibition rates were 28.7 and 52.3% for piplartine and 55.1 and 56.8% for piperine, after 7 days of treatment, at the lower and higher doses, respectively. The antitumor activity of piplartine was related to inhibition of the tumor proliferation rate, as observed by reduction of Ki67 staining, a nuclear antigen associated with G1, S, G2, and M cell cycle phases, in tumors from treated animals. However, piperine did not inhibit cell proliferation as observed in Ki67 immunohistochemical analysis. Histopathological analysis of liver and kidney showed that both organs were reversibly affected by piplartine and piperine treatment, but in a different way. Piperine was more toxic to the liver, leading to ballooning degeneration of hepatocytes, accompanied by microvesicular steatosis in some areas, than piplartine which, in turn, was more toxic to the kidney, leading to discrete hydropic changes of the proximal tubular and glomerular epithelium and tubular hemorrhage in treated animals.

Alkaloids↗

PubMed2006

Quebrachitol (2-O-methyl-L-inositol) attenuates 6-hydroxydopamine-induced cytotoxicity in rat fetal mesencephalic cell cultures.

Naturally occurring plant substances have the potential to prevent oxidative damage in various pathophysiological conditions including neurodegenerative disorders. Recent findings indicate that impaired energy metabolism plays a prominent role in neurodegeneration. The present study investigated whether quebrachitol (2-O-methyl-L-inositol) (QCT), a sugar like natural compound that was suggested to have both antioxidant and membrane stabilization activity prevents the cytotoxic effect of 6-hydroxydopamine (6-OHDA, 200 microM) on cultured rat fetal mesencephalic cells. While QCT (0.1-100 microg/ml) produced no effect per se on cell viability as measured in the 3[4,5-dimethylthiazole-2il]-2,5-diphenyltetrazolium bromide (MTT) test, it offered concentration-related protection against cell death induced by 6-OHDA. In addition, QCT demonstrated an antioxidant activity against 6-OHDA-induced oxidative stress as evidenced by reduced formation of nitrite-nitrate and thiobarbituric acid-related substances. Fluorescence microscopy using acridine orange/ethidium bromide double staining further affirmed the absence of 6-OHDA (200 microM)-induced morphological changes characteristic of apoptosis/necrosis in cultures pretreated with QCT (100 microg/ml). Also, results of tyrosine hydroxylase immunoreactivity indicated that 6-OHDA induces cell death in mesencephalic cultures affecting both TH+ positive and TH- negative (TH+ and TH-, respectively) and QCT pretreatment protects them from cell death, in a non-specific manner. Our data indicate that QCT has a cytoprotective role due, at least in part, to an antioxidant and free radical scavenging mechanism. Furthermore, the study suggests that inositol compounds might serve as leads in developing drugs for the treatment of various neurodegenerative disorders.

Animals↗

PubMed2006

Efficacy and safety of combined piroxicam, dexamethasone, orphenadrine, and cyanocobalamin treatment in mandibular molar surgery.

Third molar extraction is a common procedure frequently accompanied by moderate or severe pain, and involves sufficient numbers of patients to make studies relatively easy to perform. The aim of the present study was to determine the efficacy and safety of the therapeutic combination of 10 mg piroxicam, 1 mg dexamethasone, 35 mg orphenadrine citrate, and 2.5 mg cyanocobalamin (Rheumazin) when compared with 20 mg piroxicam alone (Feldene) in mandibular third molar surgery. Eighty patients scheduled for removal of the third molar were included in this randomized and double-blind study. They received (vo) Rheumazin or Feldene 30 min after tooth extraction and once daily for 4 consecutive days. Pain was determined by a visual analogue scale and by the need for escape analgesia (paracetamol). Facial swelling was evaluated with a measuring tape and adverse effects and patient satisfaction were recorded. There was no statistically significant difference in facial swelling between Rheumazin and Feldene (control group). Both drugs were equally effective in the control of pain, with Rheumazin displaying less adverse effects than Feldene. Therefore, Rheumazin appears to provide a better risk/benefit ratio in the mandibular molar surgery. Since the side effects resulting from nonsteroidal anti-inflammatory drug administration are a severe limitation to the routine use of these drugs in clinical practice, our results suggest that Rheumazin can be a good choice for third molar removal treatment.

Adolescent↗

PubMed2005

Amburoside A, a glucoside from Amburanacearensis, protects mesencephalic cells against 6-hydroxydopamine-induced neurotoxicity.

This study evaluates the potential neuroprotective properties of amburoside A, a glucoside isolated from Amburana cearensis, on rat mesencephalic cell cultures exposure to the neurotoxin 6-hydroxydopamine (6-OHDA). The parameters determined were cell viability by the 3[4,5-dimethylthiazole-2-il]-2,5-diphenyltetrazolium bromide (MTT) method, nitric oxide (NO) and free radical formation by the measurement of nitrite concentration and thiobarbituric acid reacting substance (TBARS) formation as an indication of cellular lipid peroxidation. The results showed that AMB was less effective as a curative agent in the MTT assay, since its addition after 6-OHDA did not reverse the neurotoxin's effect, except at the highest concentration (AMB, 100 microg/ml). Similarly, the higher nitrite levels observed after exposure of the cells to 6-OHDA were only partially reversed by AMB, at this highest concentration. However, when AMB (0.5, 1, 10 and 100 microg/ml) was added before the toxin, it appeared to protect neuronal cells against 6-OHDA toxicity in a concentration-dependent manner, as shown by MTT assay. AMB also prevented free radical formation indicated by the increased nitrite concentration induced by 6-OHDA. Cells exposed to 6-OHDA showed a 3.4 times increase in TBARS concentration as compared to controls, and this effect was inhibited from 24% up to 64% by AMB (0.1-100 microg/ml), indicative of a neuroprotective effect. In conclusion, we show that AMB, acting as an antioxidant compound, presents a significant neuroprotective effect, suggesting that this compound could provide benefits as a therapeutic agent in neurodegenerative disease such as Parkinson's.

Animals↗

PubMed2005

Genotoxicity evaluation of kaurenoic acid, a bioactive diterpenoid present in Copaiba oil.

Copaiba oil extracted from the Amazon traditional medicinal plant Copaifera langsdorffii is rich in kaurenoic acid (ent-kaur-16-en-19-oic acid), a diterpene that has been shown to exert anti-inflammatory, hypotensive, and diuretic effects in vivo and antimicrobial, smooth muscle relaxant and cytotoxic actions in vitro. This study evaluated its potential genotoxicity against Chinese hamster lung fibroblast (V79) cells in vitro, using the Comet and the micronucleus assays. Kaurenoic acid was tested at concentrations of 2.5, 5,10, 30 and 60 microg/mL. The positive control was the methylmethanesulfonate (MMS). The duration of the treatment of V79 cells with these agents was 3h. The results showed that unlike MMS, kaurenoic acid (2.5, 5, and 10 microg/mL) failed to induce significantly elevated cell DNA damage or the micronucleus frequencies in the studied tests. However, exposure of V79 cells to higher concentrations of kaurenoic acid (30 and 60 microg/mL) caused significant increases in cell damage index and frequency. The data obtained provide support to the view that the diterpene kaurenoic acid induces genotoxicity.

Animals↗

PubMed2004

Mycophenolate mofetil attenuates Walker's tumor growth when used alone, but the effect is lost when associated with cyclosporine.

PURPOSE: To investigate the effect of mycophenolate mofetil on Walker's carcinosarcoma, without versus with the growth and regression of cyclosporine. METHODS AND RESULTS: Wistar rats received water (control), MMF, and/or CsA-N 1 day before tumor inoculation. On day 10, tumor volume (TV) was lower among MMF (10.3 +/- 2.8 cm(3)) than control rats (14.9 +/- 4.2 cm(3), P <.05), and similar to that in CsA-N (13.9 +/- 3.0 cm(3)). However, tumor weight (TW) was significantly lower in MMF (5.2 +/- 2.0 g) than CsA-N (8.8 +/- 2.1g) or control hosts (7.3 +/- 2.0 g, P < or =.01). Growth was inhibited by MMF (-28.2%). In experiment II, CsA-N, MMF + CsA-N, or water were introduced 1 day before tumor inoculation. On day 10, TV and TW were similar for MMF + CsA-N as compared to CsA-N and control animals. In experiment III, water or MMF was introduced on the day 4 after tumor inoculation. On day 10, tumor growth are TW in the MMF group was similar to, that in the controls. CONCLUSIONS: MMF produces an anti-tumoral effect against Walker's carcinosarcoma. However, this inhibitory effect was lost when MMF was used in combination with CsA-N or administered in the presence of a well- established tumor.

Animals↗

PubMed2004

Tumor necrosis factor and interleukin-10 gene promoter polymorphisms in Brazilian population and in Terena Indians.

The Terena Amerindians are located in the midwestern region of Brazil. We have previously reported a restricted polymorphism for HLA class I and class II in 99 unrelated Terena using PCR-SSO and more recently for MICA. There are single nucleotide polymorphisms (SNPs) that determine high or low production of certain cytokines. We have now studied the frequencies of mutant allele (A) at position -308 in the promoter of the gene tumor necrosis factor (TNF)-alpha (pro-inflammatory cytokine) and the alleles A and T, at position -1082 and -819, respectively, in the promoter of the interleukin (IL)-10 gene, in 51 of these subjects from the Terena tribe using PCR SSP and in 195 normal unrelated healthy Brazilians using PCR-RLFP. All 51 Terena Indians tested (100%) had the G/G genotype at position TNF-alpha -308, with no mutation found thus far. In contrast, among the Brazilian general population, the allelic frequency of A was 18.9%. When anti-inflammatory cytokine IL-10 was studied at two different positions, -1082 and -819, a high mutation rate was found when Terena were compared with the general Brazilian population (P <.05). The genetic cytokine profile may be required to balance the restricted HLA repertoire for peptide presentation in this native population.

Brazil↗

PubMed2004

Rapamycin even when combined with cyclosporine attenuates tumor growth but does not induce regression of established walker sarcomas.

PURPOSE: To investigate the effect of rapamycin (Rapa) on growth or regression of Walker tumor used alone or in combination with CsA and MMF. METHODS AND RESULTS: Wistar rats received water (control) or Rapa or CsA 1 day before and daily after tumor inoculation. On day 10, tumor volume (TV) was smaller among Rapa (6.8 +/- 2.7 cm(3)) versus control (14.9 +/- 4.2 cm(3), P <.001) or CsA (13.9 +/- 3.0 cm(3), P <.0001) treatment groups. Tumor growth was greatly inhibited (TI) by Rapa (-49.3%). Tumor weight (TW) was significantly (P < or =.001) lower in Rapa (3.7 +/- 1.2 g) versus CsA (8.8 +/- 2.1 g) or control (7.3 +/- 2.0 g) animals. An additional set of rats received water or Rapa or CsA + Rapa, or MMF + Rapa 1 day before tumor inoculation. On day 10, TV and TW were lower among Rapa (3.8 +/- 1.5 cm(3)) and Rapa + CsA (3.1 +/- 1.2 cm(3)) and Rapa + MMF (4.6 +/- 2.7 cm(3)) groups compared with controls (10.9 +/- 3.8 cm(3), P <.0001). TI was -52.1% in Rapa, -68.5% in Rapa + CsA, and -63% in Rapa + MMF. A further set of rats received either water or Rapa on the day 4 after tumor inoculation. On day 10, tumor growth and TW among the Rapa and control groups were similar. CONCLUSION: Rapamycin greatly inhibited tumor growth when used alone or with CsA or MMF, but did not produce an effect on a well-established Walker sarcoma.

Animals↗

PubMed2004

Interleukin-10 promoter single-nucleotide polymorphisms as markers for disease susceptibility and disease severity in leprosy.

We have determined IL-10 promoter genotypes of five single-nucleotide polymorphisms (SNPs): T-3575A, A-2849G, C-2763A, -A-1082G and C-819T. The haplotype frequencies were defined in healthy subjects compared to leprosy patients, and analyzed for their occurrence in multi- (MB) vs paucibacillary (PB) as severe and mild forms of leprosy, respectively. Haplotypes defined by three SNP positions (-3575, -2849 and -2763) captured significant differences between controls and patients (P=0.04). The haplotype carrying -3575A, -2849G and -2763C was associated with resistance to leprosy and to the development of severe forms of the disease using either a binomial (controls vs cases, P=0.005, OR=0.35, CI=0.13-0.91) or ordinal (controls vs PB vs MB, P=0.006, OR=0.32, CI=0.12-0.83) model. By contrast, the IL-10 haplotype -3575T/-2849A/-2763C was found to be associated with susceptibility to leprosy per se (P=0.027, OR=2.37, CI=1.04-5.39), but not leprosy type. The data suggest that the IL-10 locus contributes to the outcome of leprosy.

Confidence Intervals↗

PubMed2004

Phentolamine bioequivalence study.

OBJECTIVE: To assess the bioequivalence of 2 tablet formulations of phentolamine (Regitine phentolamine 40 mg tablet formulation by Novartis, Brazil, as test formulation, and Vasomax, phentolamine 40 mg tablet formulation by Schering Plough S.A., Brazil, as reference formulation). METHODS: A single 40 mg oral dose of each formulation was administered to 36 male healthy volunteers. The study was conducted after screening, using an open, randomized, 2-period crossover design, a 7-day interval between doses, and wash-out period of at least 4 weeks. Plasma samples for determination of phentolamine were obtained predose and at intervals over 720 min postdose. Plasma concentrations were quantified by reversed-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using multiple reactions monitoring (MRM) method. Precision of the method was evaluated using calibration curves and plasma quality control samples. The subjects were monitored throughout the study. Systolic and diastolic blood pressure and pulse rate measurement were taken predose and at intervals up to 720 min. Tolerance of both products was good. No serious adverse reactions were reported. The pharmacokinetic parameters calculated for both compounds included: AUC(0-720 min), AUC(0-infinity), C(max), Ca and k(e). RESULTS: The maximum concentrations reached (C(max)) were compared. Regitine 40 mg formulation C(max) geometric mean ratio was 108.29% (90% CI = 98.58-118.96) of Vasomax 40 mg formulation. The areas under the curve (AUC(0-720 min)) were compared. Regitine 40 formulation (AUC(0-720 min)) geometric mean ratio was 102.33% (90% CI = 97.21-107.72) of Vasomax 40 mg formulation. CONCLUSION: Since the 90% CI for both C(max) and AUC ratio where inside the 80 to 125% interval proposed by the Food and Drug Administration, it is concluded that Regitine 40 mg tablet is bioequivalent to Vasomax for the rate and extent of absorption.

Administration, Oral↗

PubMed2004

Antiproliferative effects of abietane diterpenoids isolated from Hyptis martiusii Benth (Labiatae).

Two abietane diterpenes were isolated from a hexane extract of Hyptis martiusii roots and identified as carnasol 11,14-dihidroxy-8,11,13-abietatrien-7-one. These compounds were tested for their antiproliferative effects on tumor cell lines using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and on the sea urchin egg development. Both compounds displayed cytotoxic activity against tumor cell lines, but only carnasol was able to inhibit the sea urchin egg cleavages.

Abietanes↗

PubMed2003

Oncocalyxone A from Auxemma oncocalyx lacks genotoxic activity in phytohemagglutinin-stimulated lymphocytes.

Inadequate doses or prolonged chemotherapy can be cytotoxic or genotoxic to cancer patients, increasing the risk for the development of a second cancer, particularly acute leukemia. The association between therapeutic and genotoxic properties of oncocalyxone A (Onco A), make cytotoxic tests (mitotic index and chromosomal aberrations) fundamental in the accompaniment of the effects of this active compound. Therefore, the aim of the present study was to determine the genotoxic action of Onco A in vitro, during different phases of the cell cycle, utilizing primary cultures of lymphocytes of healthy individuals. The results showed that Onco A is cytotoxic during the cell cycle phases G1, G1/S, and S, however, not in G2. Onco A did not demonstrate a genotoxic effect in any of the cell cycle phases at the concentration studied. It is concluded that during the period of exposure, this active substance inhibits DNA synthesis and consequently cell division. Therefore, the absence of such genotoxicity for Onco A in the tests performed in this study provides important information in regard to the therapeutic use of this agent. Further studies are necessary to better understand the molecular mechanism of action of Onco A.

Adolescent↗

PubMed2003

Catechin attenuates 6-hydroxydopamine (6-OHDA)-induced cell death in primary cultures of mesencephalic cells.

Past studies have shown the protective effects of tea catechins on oxidative cell damage induced by 6-OHDA in PC12 cells. In this study we verified whether or not catechin prevents 6-OHDA-induced oxidative cell damage in primary cultures of rat mesencephalic cells. On exposure to 6-OHDA (200 microM), the cultures showed a marked decrease in cell viability, disturbances in lipid peroxidation, and an increased generation of NO, as assayed by MTT, TBARS and nitrite assays, respectively. Introduction of catechin significantly attenuated the cell death caused by 6-OHDA at concentrations of 3.4, 34 and 340 microM in a dose-related manner. Catechin produced no marked changes on 6-OHDA-induced increases in NO, but caused a significant inhibition of lipid peroxidation. These results suggest that catechins offer similar cytoprotection against 6-OHDA-induced oxidative cell damage in mesencephalic cell cultures, as previously described in PC12 cells. The cytoprotective function of catechin results from its antioxidant property and is not due to the inhibition of nitric oxide synthase. These findings further support and substantiate traditional consumption of catechin rich green/black tea as protection against neurodegenerative diseases like Parkinsonism.

Animals↗

PubMed2002

The cytotoxic and embryotoxic effects of kaurenoic acid, a diterpene isolated from Copaifera langsdorffii oleo-resin.

In this work, we studied the effects of kaurenoic acid, a diterpene isolated from the oleo-resin of Copaifera langsdorffii in developing sea urchin (Lytechinus variegatus) embryos, on tumor cell growth in microculture tetrazolium (MTT) test and on mouse and human erythrocytes in hemolysis assay. Continuous exposure of embryos to kaurenoic acid starting immediately after fertilization inhibited the first cleavage (IC(50): 84.2 microM) and progressively induced embryo destruction (IC(50): 44.7 microM and < 10 microM for blastulae and larvae stages, respectively). In MTT assay, kaurenoic acid at a concentration of 78 microM produced growth inhibition of CEM leukemic cells by 95%, MCF-7 breast and HCT-8 colon cancer cells by 45% each. Further, kaurenoic acid induced a dose-dependent hemolysis of mouse and human erythrocytes with an EC(50) of 74.0 and 56.4 microM, respectively. The destruction of sea urchin embryos, the inhibition of tumor cell growth and the hemolysis of mouse and human erythrocytes indicate the potential cytotoxicity of kaurenoic acid.

Animals↗

PubMed2002

Genotoxic effects of stannous chloride (SnCl2) in K562 cell line.

The toxic effects of SnCl2 in K562 cells were analyzed in this study. This cell line is resistant to reactive oxygen species (ROS) making it suitable to evaluate the impact of SnCl2 in culture either through ROS or by direct toxicity using Trypan blue dye exclusion, comet and flow cytometry assays. An important loss of viability induced by SnCl2 in a dose-response manner was observed in cells treated in Tris-buffered saline (TBS). This necrotic cell death was further confirmed by flow cytometry. On the other hand, there was no loss of viability when cells were treated in rich medium (RPMI). DNA damage was visualized in SnCl2-treated K562 cells in both tested conditions. The data indicate that SnCl2 induces DNA damage and reduces K562 viability. Both actions seem to be correlated with ROS formation and direct linkage to DNA.

Cell Survival↗

PubMed2002

Dna damage in peripheral blood nuclear cells assessed by comet assay from individuals submitted to scintigraphic examinations.

Stannous chloride (SnCl2) is employed as a reducing agent to obtain Technetium-99m-labelled radiophamaceuticals in nuclear medicine kits, being injected endovenously in humans. Toxic effects of these kits were not studied, thus making it important to evaluate their impact in humans. In this study, the toxic effects were evaluated from peripheral blood nuclear cells (PBNC) from patients who received radiopharmaceuticals obtained using such kits. The analyses included results performed by comet assay. DNA damage was visualized in PBNC samples collected within a time up to 2 hr, and 24 hr after radiopharmaceutical injection in the patients. Initially we observed an increase of comet signals, which subsequently were reduced to zero after 24 hr. The diminishing of comet amounts probably is associated with DNA repair of damaged cells or with the elimination by apoptosis of cells whose DNA are not repaired.

Apoptosis↗

PubMed2001

Determination of minocycline in human plasma by high-performance liquid chromatography coupled to tandem mass spectrometry: application to bioequivalence study.

Minocycline was determined in human plasma by HPLC-MS-MS using clarithromycin as an internal standard. The method is fast (single liquid extraction and run time of <3 min) and sensitive (5 ng/ml) and it was employed in a bioequivalence study of two 100 mg tablet formulations in 24 healthy volunteers. The 90% confidence interval of the individual ratio geometric mean for both AUC(0-96 h) and Cmax were 99.2-111.1% and 95.6-117.5%, respectively. Thus, Minoderm was considered bioequivalent to Minomax according to both the rate and extent of absorption. No food interaction was observed with either formulation.

Administration, Oral↗

PubMed2001

Gabapentin quantification in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry. Application to bioequivalence study.

A rapid, sensitive and specific analytical method was developed and validated to quantify gabapentin in human plasma using acetaminophen as an internal standard. The method employs a single plasma protein precipitation. The analytes are chromatographed on a C4 reversed-phase chromatographic column and analyzed by mass spectrometry in the multiple reaction monitoring (MRM) mode. The method has a chromatographic run time of 4 min and a linear calibration curve over the range 50-10 000 ng x ml(-1) (r > 0.999). The between-run precision, based on the relative standard deviation for replicate quality controls, was < or = 4.8 % (200 ng x ml(-1)), 6.0% (1000 ng x ml(-1)) and 4.4% (5000 ng x ml(-1)). The between-run accuracy was +/-2.6, 4.4 and 0.5% for the above-mentioned concentrations, respectively. This method was employed in a bioequivalence study of two gabentin capsule formulations (Progresse from Biosintética, Brazil, as a test formulation, and Neurotin from Parke-Davis, as a reference formulation) in 24 healthy volunteers of both sexes who received a single 300 mg dose of each formulation. The study was conducted using an open, randomized, two-period crossover design with a 7-day washout interval. The 90% confidence interval (CI) of the individual ratio geometric mean for Progresse/Neurotin was 87.9-115.6% for AUC(0-36 h) and 88.6-111.7% for Cmax. Since both 90% CI for AUC(0-36 h) and Cmax were included in the 80-125% interval proposed by the US Food and Drug Administration, Progresse was considered bioequivalent to Neurotin according to both the rate and extent of absorption.

Acetates↗