Addressing the tuberculosis-depression syndemic to end the tuberculosis epidemic

Tuberculosis (TB) and depression act synergistically via social, behavioral, and biological mechanisms to magnify the burden of disease. Clinical depression is a common, under-recognized, yet treatable condition that, if comorbid with TB, is associated with increased morbidity, mortality, community TB transmission, and drug resistance. Depression may increase risk of TB reactivation, contribute to disease progression, and/or inhibit the physiological response to anti-tuberculosis treatment because of poverty, undernutrition, immunosuppression, and/or negative coping behaviors, including substance abuse. Tuberculous infection and/or disease reactivation may precipitate depression as a result of the inflammatory response and/or dysregulation of the hypothalamic-pituitary-adrenal axis. Clinical depression may also be triggered by TB-related stigma, exacerbating other underlying social vulnerabilities, and/or may be attributed to the side effects of anti-tuberculosis treatment. Depression may negatively impact health behaviors such as diet, health care seeking, medication adherence, and/or treatment completion, posing a significant challenge for global TB elimination. As several of the core symptoms of TB and depression overlap, depression often goes unrecognized in individuals with active TB, or is dismissed as a normative reaction to situational stress. We used evidence to reframe TB and depression comorbidity as the 'TB-depression syndemic', and identified critical research gaps to further elucidate the underlying mechanisms. The World Health Organization's Global End TB Strategy calls for integrated patient-centered care and prevention linked to social protection and innovative research. It will require multidisciplinary approaches that consider conditions such as TB and depression together, rather than as separate problems and diseases, to end the global TB epidemic.

L-Alanyl-Glutamine Attenuates Oxidative Stress in Liver Transplantation Patients

BACKGROUND

Ischemia/reperfusion injury during liver transplantation can cause severe damage to the graft. The objective of this randomized, double-blind study was to evaluate the possible protective effects of L-alanyl-glutamine on the liver graft.

METHODS

The sample included 33 patients from a liver transplantation service in Northeastern Brazil. Before cold ischemia, the patients received 50 g of L-alanyl-glutamine (treatment group) or saline (control group) through the portal vein. The graft was biopsied at the time of recovery, at the beginning of warm ischemia, and at the end of transplantation to determine malondialdehyde (MDA), heat-shock protein (Hsp)70, nuclear factor kappa-beta (NFkB), superoxide dismutase (SOD), and reduced glutathione (GSH) levels.

RESULTS

The blood parameters were similar in the two groups. In the treatment group, MDA did not increase at the beginning of cold ischemia and decreased at the end of transplantation. This phenomenon was not observed in the control group. GSH, SOD, Hsp70, and NFkB levels were similar in the two groups.

CONCLUSIONS

Our findings suggest that preconditioning with L-alanyl-glutamine attenuates the effects of ischemia/reperfusion-related oxidative stress and reduces lipid peroxidation in the grafts of liver transplantation patients.

Rubrolide analogues and their derived lactams as potential anticancer agents

Analogues of rubrolides were synthesized and shown to be cytotoxic to several cancer cell lines and not toxic to L929 normal cells. The cytotoxicity involved the induction of cell death by apoptosis.

Tumor necrosis factor (TNF) and lymphotoxin-alpha (LTA) single nucleotide polymorphisms: importance in ARDS in septic pediatric critically ill patients

Accumulating evidence indicates that genetic background influences the outcome of sepsis, which despite medical advances continues to be a major cause of morbidity and mortality. This study aimed to evaluate the influence of SNPs LTA +252A>G, TNF-863C>A and TNF-308G>A on susceptibility to sepsis, acute respiratory distress syndrome (ARDS), septic shock and sepsis mortality. A prospective case-control study was carried out in a Brazilian pediatric intensive care unit and included 490 septic pediatric patients submitted to mechanical ventilation and 610 healthy children. No SNP association was found with respect to sepsis susceptibility. Nevertheless, a haplotype was identified that was protective against sepsis (+252A/-863A/-308G; OR=0.65; p=0.03). We further observed protection against ARDS in TNF-308 GA genotype carriers (OR=0.29; p=0.0006) and -308A allele carriers (OR=0.40; p=0.003). In addition, increased risk for ARDS was detectable with the TNF-863 CA genotype (OR=1.83; p=0.01) and the -863A carrier status (OR=1.82; p=0.01). After stratification according to age, this outcome remained significantly associated with the -308GA genotype in infants. Finally, protection against sepsis-associated mortality was found for the TNF-308 GA genotype (OR=0.22; p=0.04). Overall, our findings document a protective effect of the TNF-308 GA genotype for the ARDS and sepsis mortality outcomes, further providing evidence for an increased risk of ARDS associated with the TNF-863 CA genotype. Trial registration (www.clinicaltrials.gov): NCT00792883.

Participation of the NO/cGMP/K+ATP pathway in the antinociception induced by Walker tumor bearing in rats

Implantation of Walker 256 tumor decreases acute systemic inflammation in rats. Inflammatory hyperalgesia is one of the most important events of acute inflammation. The L-arginine/NO/cGMP/K⁺ATP pathway has been proposed as the mechanism of peripheral antinociception mediated by several drugs and physical exercise. The objective of this study was to investigate a possible involvement of the NO/cGMP/K⁺ATP pathway in antinociception induced in Walker 256 tumor-bearing male Wistar rats (180-220 g). The groups consisted of 5-6 animals. Mechanical inflammatory hypernociception was evaluated using an electronic version of the von Frey test. Walker tumor (4th and 7th day post-implantation) reduced prostaglandin E₂- (PGE₂, 400 ng/paw; 50 µL; intraplantar injection) and carrageenan-induced hypernociception (500 µg/paw; 100 µL; intraplantar injection). Walker tumor-induced analgesia was reversed (99.3% for carrageenan and 77.2% for PGE₂) by a selective inhibitor of nitric oxide synthase (L-NAME; 90 mg/kg, ip) and L-arginine (200 mg/kg, ip), which prevented (80% for carrageenan and 65% for PGE₂) the effect of L-NAME. Treatment with the soluble guanylyl cyclase inhibitor ODQ (100% for carrageenan and 95% for PGE₂; 8 µg/paw) and the ATP-sensitive K⁺ channel (KATP) blocker glibenclamide (87.5% for carrageenan and 100% for PGE₂; 160 µg/paw) reversed the antinociceptive effect of tumor bearing in a statistically significant manner (P < 0.05). The present study confirmed an intrinsic peripheral antinociceptive effect of Walker tumor bearing in rats. This antinociceptive effect seemed to be mediated by activation of the NO/cGMP pathway followed by the opening of KATP channels.

IFNG +874 T>A single nucleotide polymorphism is associated with leprosy among Brazilians

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, a low virulence mycobacterium, and the outcome of disease is dependent on the host genetics for either susceptibility per se or severity. The IFNG gene codes for interferon-γ (IFN-γ), a cytokine that plays a key role in host defense against intracellular pathogens. Indeed, single nucleotide polymorphisms (SNPs) in IFNG have been evaluated in several genetic epidemiological studies, and the SNP +874T>A, the +874T allele, more specifically, has been associated with protection against infectious diseases, especially tuberculosis. Here, we evaluated the association of the IFNG locus with leprosy enrolling 2,125 Brazilian subjects. First, we conducted a case-control study with subjects recruited from the state of São Paulo, using the +874 T>A (rs2430561), +2109 A>G (rs1861494) and rs2069727 SNPs. Then, a second study including 1,370 individuals from Rio de Janeiro was conducted. Results of the case-control studies have shown a protective effect for +874T carriers (OR(adjusted) = 0.75; p = 0.005 for both studies combined), which was corroborated when these studies were compared with literature data. No association was found between the SNP +874T>A and the quantitative Mitsuda response. Nevertheless, the spontaneous IFN-γ release by peripheral blood mononuclear cells was higher among +874T carriers. The results shown here along with a previously reported meta-analysis of tuberculosis studies indicate that the SNP +874T>A plays a role in resistance to mycobacterial diseases.

Bone marrow-derived mononuclear cell therapy attenuates silica-induced lung fibrosis

This study tests the hypothesis that bone marrow-derived mononuclear cell (BMDMC) therapy may reduce lung inflammation and fibrosis leading to an improvement in respiratory mechanics in a murine model of silicosis. 52 female C57BL/6 mice were randomly assigned into four groups. In the silica group (SIL), silica suspension (20 mg/50 μL in saline) was intratracheally instilled. In the control animals, 50 μL saline was administered intratracheally. At 1 h, the control and SIL groups were further randomised, receiving BMDMC (2×10⁶ i.v. control-cell and SIL-cell) or saline (50 μL i.v. control and SIL). BMDMC were obtained from male donor mice. At day 15, lung mechanics, histology, and the presence of Y chromosome, interleukin (IL)-1β, IL-1α, IL-1 receptor antagonist (IL-1RN), IL-1 receptor type 1, transforming growth factor (TGF)-β and caspase-3 mRNA expressions in lung tissue were analysed. In the SIL-cell group, the fraction area of granuloma, the number of macrophages and the collagen fibre content were reduced, yielding improved lung mechanics. The presence of male donor cells in lung tissue was not confirmed using detection of Y chromosome DNA. Nevertheless, caspase-3, IL-1β, IL-1α, IL-1RN and TGF-β mRNA expression diminished after cell therapy. In conclusion, BMDMC acted on inflammatory and fibrogenic processes improving lung function through paracrine effects.

Structure-mutagenicity relationship of kaurenoic acid from Xylopia sericeae (Annonaceae)

Kaurane diterpenes are considered important compounds in the development of new highly effective anticancer chemotherapeutic agents. Genotoxic effects of anticancer drugs in non-tumour cells are of special significance due to the possibility that they induce secondary tumours in cancer patients. In this context, we evaluated the genotoxic and mutagenic potential of the natural diterpenoid kaurenoic acid (KA), i.e. (-)-kaur-16-en-19-oic acid, isolated from Xylopia sericeae St. Hill, using several standard in vitro and in vivo protocols (comet, chromosomal aberration, micronucleus and Saccharomyces cerevisiae assays). Also, an analysis of structure-activity relationships was performed with two natural diterpenoid compounds, 14-hydroxy-kaurane (1) and xylopic acid (2), isolated from X. sericeae, and three semi-synthetic derivatives of KA (3-5). In addition, considering the importance of the exocyclic double bond (C16) moiety as an active pharmacophore of KA cytotoxicity, we also evaluated the hydrogenated derivative of KA, (-)-kauran-19-oic acid (KAH), to determine the role of the exocyclic bond (C16) in the genotoxic activity of KA. In summary, the present study shows that KA is genotoxic and mutagenic in human peripheral blood leukocytes (PBLs), yeast (S. cerevisiae) and mice (bone marrow, liver and kidney) probably due to the generation of DNA double-strand breaks (DSB) and/or inhibition of topoisomerase I. Unlike KA, compounds 1-5 and KAH are completely devoid of genotoxic and mutagenic effects under the experimental conditions used in this study, suggesting that the exocyclic double bond (C16) moiety may be the active pharmacophore of the genetic toxicity of KA.

Pisosterol induces interphase arrest in HL60 cells with c-MYC amplification

The leukaemia cell line HL60 is widely used in studies of the cell cycle, apoptosis and adhesion mechanisms in cancer cells. One marked characteristic of HL60 cells is the c-MYC proto-oncogene amplification, resulting in the formation of homogeneously staining regions (HSRs) at 8p24. We conducted a fluorescence in situ hybridization study in an HL60 cell line, using a locus-specific probe for c-MYC, before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 microg/mL), a triterpene isolated from the fungus Pisolithus tinctorius. Before treatment, 87.5% of the cells showed HSRs. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 microg/mL). However, at 1.8 microg/mL only 15% of the cells presented HSRs, and 39.5% presented few fluorescent signals (3 or 4 alleles), suggesting that pisosterol probably blocks the cells with HSRs at interphase. This result is particularly interesting because cells that do not show a high degree of c-MYC gene amplification have a less aggressive and invasive behaviour and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.

Tumor bearing decreases systemic acute inflammation in rats--role of mast cell degranulation

OBJECTIVE AND DESIGN

To investigate the effect of experimental tumor bearing on acute inflammation models in rats.

METHODS

Four and 7 days after Walker tumor implantation in the right armpit, carrageenan or dextran- induced edema in the contralateral paw, carrageenan induced neutrophil migration into peritoneal cavities, cutaneous vascular permeability induced by bradykinin, histamine, serotonin, substance P, capsaicin or compound 48/80, and mesenteric mast cell degranulation induced by compound 48/80 were evaluated. The control group did not receive tumor implantation. Statistical analysis was performed using one way analysis of variance (ANOVA) followed by the Bonferroni test.

RESULTS

On the 7(th) day after tumor inoculation, there were significant decreases in both carrageenan and dextran- induced paw edema. Tumor bearing did not change the neutrophil infiltration induced by carrageenan. There were decreases in cutaneous vascular permeability induced by compound 48/80, serotonin or bradykinin, but not that induced by histamine, substance P. A significant inhibition of mesenteric mast cell degranulation induced by compound 48/80 was observed, on the 4(th) and 7(th) days after tumor inoculation.

CONCLUSION

Tumor bearing can limit mast cell function and vascular events in acute systemic inflammation in rats, without changes in neutrophil migration.

Genotoxic effects of tanshinones from Hyptis martiusii in V79 cell line

The genotoxic effect of two tanshinones isolated from roots of Hyptis martiussi Benth (Labiatae) was studied using V79 (Chinese hamster lung) cells by the alkaline comet assay and micronucleus test. Tanshinones were incubated with the cells at concentrations of 1, 3, 6 and 12 microg/mL for 3 h. Tanshinones were shown to be quite strongly genotoxic against V79 cells at all tested concentrations. The data obtained provide support to the view that tanshinones has DNA damaging activity in cultured V79 cells under the conditions of the assays.

Genotoxic and cytotoxic effects of manganese chloride in cultured human lymphocytes treated in different phases of cell cycle

Manganese (Mn) has a natural occurrence and is necessary during the initial periods of the development. However, in high concentrations, Mn can be related to neurodegenerative disorders. The aim of the present study was to evaluate the mutagenic potential of manganese chloride (MnCl2.4H2O). Comet assay and chromosome aberrations analysis were applied to determine the DNA-damaging and clastogenic effects of MnCl2.4H2O. Cultured human lymphocytes were treated with 15, 20 and 25 microM manganese chloride during the G1, G1/S, S (pulses of 1 and 6h), and G2 phases of the cell cycle. All tested concentrations were cytotoxic and reduced significantly the mitotic index in G1, G1/S and S (1 and 6h) treatments, while in G2 treatment only the higher concentrations (20 and 25 microM) showed cytotoxic effects. Clastogenicity and DNA damage were found only in treatments with the highest concentration (25 microM). Chromosome aberrations were found exclusively in the G2 phase of the cell cycle. The absence of polyploidy in mitosis, suggests that manganese does not affect the formation of the mitotic spindle with the concentrations tested. The genotoxicity found in G2 phase and in the comet assay can be related to the short time of treatment in both cases.

Inhibition of sea urchin fertilization by plant lectins

Effects of plant lectins on sea urchin (Lytechinus variegatus) fertilization and a partial characterization of lectin-binding involved in the process were evaluated. IC50 doses for inhibition of fertilization varied from 4.1 to 135.5 microg/ml when the lectins were pre-incubated with sperms and from 0.7 to 33.4 microg/ml when pre-incubated with eggs. Such effects were reversed when the lectins were heat inactivated. FITC-labeled lectins bound egg surfaces while their denatured forms did not. Glucose/mannose specific lectins bound weaker to eggs when pre-incubated with the glycoprotein bovine lactotransferrin. None of the glycoproteins assayed diminished FITC patterns of the Gal/GalNAc binding lectins. Pre-incubation of Glucose/mannose binding lectins with eggs did not alter binding of Gal/GalNAc lectins. Lectins with distinct competencies for binding monosaccharide and glycoconjugates were able to inhibit sea urchin fertilization.

Genotoxic effects of aluminum chloride in cultured human lymphocytes treated in different phases of cell cycle

Aluminum (Al) is the most abundant metal and the third common chemical element on earth. It is known that Al is toxic, especially its trivalent form (Al(3+)), that represents the its most soluble form. Al intoxication is related to some pathogenic disorders, principally neurodegeneratives ones as Parkinson and Alzheimer diseases. The present study aimed to evaluate the mutagenic potential of aluminum chloride (AlCl(3)). Comet assay and chromosome aberrations analysis were applied to evaluate the DNA-damaging and clastogenic effects of AlCl(3), respectively, in different phases of the cell cycle. Cultured human lymphocytes were treated with 5, 10, 15 and 25 microM aluminum chloride during the G1, G1/S, S (pulses of 1 and 6h), and G2 phases of the cell cycle. All tested concentrations were cytotoxic and reduced significantly the mitotic index in all phases of cell cycle. They also induced DNA damage and were clastogenic in all phases of cell cycle, specially in S phase. AlCl(3) also induced endoreduplication and polyploidy in treatments performed during G1 phase. The presence of genotoxicity and polyploidy on interphase and mitosis, respectively, suggests that aluminum chloride is clastogenic and indirectly affects the construction of mitotic fuse in all tested concentrations.

HLA-DRB1*04 and DRB1*10 are associated with resistance and susceptibility, respectively, in Brazilian and Vietnamese leprosy patients

The host genetic background has been considered one of the factors that influence leprosy outcome, a chronic infectious disease caused by Mycobacterium leprae. Genome scans demonstrated that the 6p21 region is associated with leprosy and a substantial number of population-based studies analyzing human leukocyte antigen (HLA) class II loci suggested association of HLA-DR with leprosy. However, some studies lacked robustness as they had limited power. Indeed, experimental designs require increased sample size to achieve adequate power, as well as replication studies with independent samples for confirmation of previous findings. In this work, we analyzed the influence of the HLA-DRB1 locus on leprosy susceptibility per se and disease type using a case-control design carried out in Brazilians (578 cases and 691 controls) and a replication study based on a family design in a Vietnamese population (n=194 families). The results showed that HLA-DRB1*10 is associated with susceptibility to leprosy and HLA-DRB1*04 is associated with resistance, both in the Brazilian and Vietnamese populations suggesting that these alleles play an important role in the activation of cellular immune responses against M. leprae.

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.

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.

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.

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.

Amburoside A, a glucoside from Amburana cearensis, 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.

Phentolamine relaxes human corpus cavernosum by a nonadrenergic mechanism activating ATP-sensitive K+ channel

To investigate the pharmacodynamics of phentolamine in human corpus cavernosum (HCC) with special attention to the role of the K+ channels. Strips of HCC precontracted with nonadrenergic stimuli and kept in isometric organ bath immersed in a modified Krebs-Henseleit solution enriched with guanethidine and indomethacine were used in order to study the mechanism of the phentolamine-induced relaxation. Phentolamine caused relaxation (approximately 50%) in HCC strips precontracted with K+ 40 mM. This effect was not blocked by tetrodotoxin (1 microM) (54.6+/-4.6 vs 48.9+/-6.4%) or (atropine (10 microM) (52.7+/-6.5 vs 58.6+/-5.6%). However, this relaxation was significantly attenuated by L-NAME (100 microM) (59.7+/-5.8 vs 27.8+/-7.1%; P<0.05; n = 8) and ODQ (100 microM) (62.7+/-5.1 vs 26.8+/-3.9%; P<0.05; n = 8). Charybdotoxin and apamin (K(Ca)-channel blockers) did not affect the phentolamine relaxations (54.6+/-4.6 vs 59.3+/-5.2%). Glibenclamide (100 microM), an inhibitor of K(ATP)-channel, caused a significant inhibition (56.7+/-6.3 vs 11.3+/-2.3%; P<0.05; n = 8) of the phentolamine-induced relaxation. In addition, the association of glibenclamide and L-NAME almost abolished the phentolamine-mediated relaxation (54.6+/-5.6 vs 5.7+/-1.4%; P<0.05; n = 8). The results suggest that phentolamine relaxes HCC by a nonadrenergic-noncholinergic mechanism dependent on nitric oxide synthase activity and activation of K(ATP)-channel.

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.

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.

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.

Agarose gel electrophoresis system in the classroom: Detection of DNA strand breaks through the alteration of plasmid topology

Good quality scientific teaching depends on the ability of researchers to translate laboratory experiments into high school and undergraduate classes, bridging the advanced and basic science with common knowledge. A fast-growing field in biomedical sciences is oxidative stress, which has been associated to several diseases, including cancer and neurodegenerative disorders. We suggest herein a simple methodology for exploring DNA damage as an introductory pathway to these themes. The potential of natural or artificial products to induce DNA strand breaks can be easily tested in supercoiled plasmids incubated with selected products followed by agarose gel electrophoresis. This is designed to detect single and double strand breaks caused by reactive oxygen species generated by the products being tested. The altered topology of the damaged plasmid migrates slowly in the gel, creating a new band. We further introduce the quantitation of supercoiled DNA forms using densitometry of the gel with a digital camera; the values can then be used to estimate the number of breaks per genome using Poisson distribution. The system is inexpensive, rapid, and does not need high-cost equipment and supplies and can be performed in high schools and undergraduate classes with a minimal structure.

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.

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.

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.

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.

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.

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.

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.

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.

Shark cartilage as source of antiangiogenic compounds: from basic to clinical research

The discovery that angiogenesis is a key condition for the growth of a tumor beyond a millimeter or two, brings about a new approach in the treatment of tumors using drugs able to inhibit the formation of new blood vessels. Also, it has been realized that antiangiogenic drugs can be useful in the treatment of other pathological processes, now classified as angiogenesis-dependent diseases. Initially, cartilage was considered as a possible natural source of antiangiogenic compounds due to its known avascular nature. To date, a number of in vitro and in vivo studies have suggested the existence of antiangiogenic and antitumor compounds in bovine and shark cartilage. However, the potential usefulness of shark cartilage in the treatment of cancer and other angiogenesis-dependent diseases have not been totally accepted due to (i) unsatisfactory patient outcome in clinical trials that have used shark cartilage in cancer patients, (ii) the lack of data that correlates bioavailability with pharmacological effects using oral shark cartilage. Thus, the objective of this review is to describe the main basic and clinical investigations reported in the literature, in which the antiangiogenic and/or antitumor properties of shark cartilage or of its extracts were evaluated. Possible explanations for conflicting results are discussed as well.

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.

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.

Demonstration of inhibitory effect of oral shark cartilage on basic fibroblast growth factor-induced angiogenesis in the rabbit cornea

Several angiogenic inhibitors have been obtained from shark cartilage, some of these are currently in clinical trials for assessment of safety and therapeutic efficacy in humans. Still, shark cartilage taken orally is commonly used in alternative and complimentary medicine for various ailments including serious diseases such as cancer. However, only few studies of oral shark cartilage have demonstrated pharmacological effects in experimental animals or patients, to indicate safe doses with sufficient bioavailability. In the present study we demonstrated the antiangiogenic properties of oral shark cartilage in the rabbit cornea model. Slow-release, polymethylmetacrylate pellets containing basic fibroblast growth factor (bFGF) were surgically implanted in the rabbit cornea to stimulate neovascularization scored by stereo microscopy. Powdered shark cartilage (PSC; commercial product) was tested orally along with a water-soluble fraction (WSF) of this cartilage product which was tested by local application. Animals were treated with oral dosages of 100 mg/kg PSC or 200 mg/kg thalidomide as positive control. Pellets containing WSF (50, 100 or 200 microg/pellet) or bFGF-inhibitor pentosan polysulfate were implanted adjacent to the bFGF pellet. Oral shark cartilage inhibited bFGF-induced angiogenesis, as did oral thalidomide, in this in vivo model. WSF and pentosan polysulfate was shown to block neovascularization in the cornea when applied locally. This study demonstrates that in the rabbit, oral shark cartilage appears to produce systemic levels of angiogenesis inhibitors that can exert their effect at the cornea.

Sequential erythema nodosum leprosum and reversal reaction with similar lesional cytokine mRNA patterns in a borderline leprosy patient

We compare the clinical and histological data with the immunological status of a borderline leprosy patient who experienced an erythema nodosum leprosum (ENL) reaction followed by a reversal reaction (RR) after 12 weeks of anti-inflammatory treatment (pentoxifylline, PTX, 1200 mg daily). Skin biopsies, serum and blood samples were collected sequentially during the reactional episodes. At the outset of RR, the patient's lymphocytes secreted interferon (IFN) -gamma and there was a positive lymphoproliferative test in response to Mycobacterium leprae, which had been absent during ENL. The lepromin reaction reversed from negative (0 mm) at diagnosis, to positive (3 mm) 3 months after the development of RR. Tumour necrosis factor (TNF) -alpha levels in the serum decreased after 1 week of treatment and increased slightly thereafter. The immunohistochemical data for ENL showed a diffuse dermal and hypodermal infiltrate composed of mononuclear cells and neutrophils, while RR was characterized by an epithelioid granulomatous infiltrate with a marked presence of gammadelta T cells. Reverse transcription-polymerase chain reaction showed a mixed cytokine profile characterized by the expression of TNF-alpha, IFN-gamma, interleukin (IL) -6, IL-10 and IL-12 mRNA in the skin, which persisted throughout the development of ENL and RR lesions. IL-4 mRNA, first detected after 7 days of PTX treatment, was still present during RR. The results suggest the emergence of an initial Th0-like cytokine profile in ENL, typical of a state of immunoactivation, before conditions optimal for the appearance of an antigen-specific cell-mediated immune response and gammadelta T-cell migration are created.

Anti-inflammatory drugs block cytokine mRNA accumulation in the skin and improve the clinical condition of reactional leprosy patients

The aim of this study was to investigate in what ways in vivo anti-inflammatory treatment affects cytokine mRNA expression in situ in both erythema nodosum leprosum and reversal reaction patients. Serial biopsies were collected from the patients undergoing leprosy reactions before and during pentoxifylline (n = 7) or thalidomide (n = 3) treatment for erythema nodosum leprosum and prednisone (n = 3) for reversal reaction. Clinical evolution of the skin lesion was assessed during the study and semiquantitative reverse transcription-polymerase chain reaction was used to investigate cytokine mRNA expression at the lesion site. Results showed expression of interferon-gamma, interleukin-6, interleukin-10, interleukin-12 p40, and tumor necrosis factor-alpha in all patients tested at the onset of reactional episodes, but interleukin-4 mRNA was rarely detected in the lesions (n = 4). Follow-up analysis showed that, irrespective of the drugs used, tumor necrosis factor-alpha mRNA was diminished in 10 of the 13 patients tested. A concomitant decrease of mRNA accumulation was also observed for interferon-gamma (nine of 11 patients), interleukin-6 (nine of 11), and interleukin-12 p40 (six of eight). An inhibitory effect on interleukin-10 mRNA was likewise seen after thalidomide and pentoxifylline, but not subsequent to prednisone treatment. The data also demonstrated that cytokine mRNA inhibition correlates to the resolution of the inflammatory response in situ (n = 10), whereas the persistence/enhancement of cytokine message expression after treatment was associated with worsening of the skin condition, as seen in three erythema nodosum leprosum patients whose maintenance of local inflammation was accompanied by the appearance/persistence of interleukin-4 gene expression in situ subsequent to anti-inflammatory treatment. In summary, the participation of cytokines in leprosy inflammatory episodes seems to be directly associated with the patients' clinical evolution following therapy for reaction.

Bioequivalence evaluation of two roxithromycin formulations in healthy human volunteers by high performance liquid cromatography coupled to tandem mass spectrometry

The bioequivalence of two different formulations containing roxithromycin (SPE-712-1). Oral suspension 300 mg/15 mL as test formulation and Rotram, tablets 300 mg as reference formulation, both by Schering Plough S.A., Brazil) was evaluated in 24 healthy volunteers of both sexes (12 male and 12 female). The study was conducted open with randomized two-period crossover design and a 14-day washout period. Each subject received 300 mg of each roxithromycin formulation. Plasma samples were obtained over a 72-hour interval and roxithromycin concentrations were analyzed by combined LC-MS/MS with positive ion electrospray ionization using selected ion monitoring method. From the plasma roxithromycin concentration vs time curves the following pharmacokinetic parameters were obtained: AUC(0-72 h), AUC(0-infinity), Cmax, t1/2 ratios and tmax individual differences. The 90% for confidence interval (CI) of geometric mean SPE-712-L/Rotram individual percent ratio were 105.0-128.3% for AUC(0-72 h), and 78.4-96.9 for Cmax. Although this 90% CI were marginally outside the interval proposed by the Food and Drug Administration, the probability assessed by the two-one sided West for ratios was included in the 0.8-1.25 interval, as we concluded that SPE-712-L oral suspension formulation was bioequivalent to Rotram tablet formulation for the extent and rate of absorption.

Antiproliferative effects of compounds derived from plants of Northeast Brazil

Ten compounds derived from plants indigenous to Northeast Brazil were examined for antiproliferative effects on human cells in vitro. The effects of these phytochemicals on cell growth were determined by the MTT microtitre assay with 3-day continuous drug exposure. Three human cell lines were used: CEM leukaemia, SW1573 lung tumour and CCD922 normal skin fibroblasts. Four active compounds were found with IC(50) values less than 10 microg/mL in the two cancer cell lines. Oncocalyxones A and C, both 1,4-anthracenediones from Auxemma oncocalyx (Boraginaceae), showed cytotoxicity with mean IC(50) values of 0.8-2, 7-8 and 12-13 microg/mL against CEM, SW1573 and CCD922, respectively. One diterpene and one flavonoid, both from Egletes viscosa (Compositae), were also active. 12-Acetoxy-hawtriwaic acid lactone was cytotoxic with mean IC(50) values of 6, 10 and 10 microg/mL, respectively. 4,5-Dihydroxy-3,3,7, 8-tetramethoxy flavone (ternatin) was only growth-inhibitory with mean IC(50) values of 2, 1 and 10 microg/mL, respectively. These four most active compounds were examined further for their effects on DNA integrity and on DNA synthesis. All but ternatin caused substantial DNA damage and marked inhibition of 5-bromo-2'-deoxyuridine incorporation within 24 h. This study demonstrated the antiproliferative activity of four novel phytochemicals, three of which are DNA-reactive and inhibit DNA synthesis. Further studies are warranted to evaluate these compounds for antitumour potential.

Determination of 21-hydroxydeflazacort in human plasma by high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry. Application to bioequivalence study

A liquid chromatographic atmospheric pressure chemical ionization tandem mass spectrometric method is described for the determination of 21-hydroxydeflazacort in human plasma using dexamethasone 21-acetate as an internal standard. The procedure requires a single diethyl ether extraction. After evaporation of the solvent under a nitrogen flow, the analytes are reconstituted in the mobile phase, chromatographed on a C18 reversed-phase column and analyzed by mass spectrometry via a heated nebulizer interface where they are detected by multiple reaction monitoring. The method has a chromatographic run time of less than 5 min and a linear calibration curve with a range of 1-400 ng ml(-1) (r>0.999). The between-run precision, based on the relative standard deviation for replicate quality controls, was < or =5.5% (10 ng ml(-1)), 1.0% (50 ng ml(-1)) and 2.7% (200 ng ml(-1)). The between-run accuracy was +/-7.1, 3.8 and 4.8% for the above concentrations, respectively. This method was employed in a bioequivalence study of two DFZ tablet formulations (Denacen from Marjan Industria e Comercio, Brazil, as a test formulation, and Calcort from Merrell Lepetit, Brazil, as a reference formulation) in 24 healthy volunteers of both sexes who received a single 30 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 geometric mean ratio for Denacen/Calcort was 89.8-109.5% for area under the curve AUC(0-24 h) and 80.7-98.5% for Cmax. Since both the 90% CI for AUC(0-24 h) and Cmax were included in the 80-125% interval proposed by the US Food and Drug Administration, Denacen was considered bioequivalent to Calcort according to both the rate and extent of absorption.

Oncocalyxones A and C, 1,4-anthracenediones from Auxemma oncocalyx: comparison with anticancer 1,9-anthracenediones

Oncocalyxones A and C are 1,4-anthracenediones isolated from Auxemma oncocalyx (Boraginaceae) that have been shown to be cytotoxic to tumor cells in vitro. The present study compared the cytotoxicity of these compounds with that of two conventional anticancer agents doxorubicin and mitoxantrone, both 1,9-anthracenediones, in a panel of human tumor cell lines. The effect on cell growth was examined using an MTT microtiter assay in two leukemia lines, five solid tumor lines of different histological origin, and two multidrug-resistant sublines of a lung tumor line. The oncocalyxones showed much lower potency than the 1,9-anthracenediones, but were similarly more cytotoxic to leukemia cells compared to solid tumor lines. However, in the multidrug-resistant cells with 10 to 500 times decreased sensitivity to doxorubicin, the cytotoxicity of oncocalyxones A and C was only modestly reduced by about twofold, 1,4-Anthracenediones may be a promising novel class of chemotherapeutic agents effective against multidrug resistant tumors.

Stannous chloride mediates single strand breaks in plasmid DNA through reactive oxygen species formation

Stannous ion (Sn) has been employed in nuclear medicine and in food industry. We described that Stannous Chloride (SnCl2) inactivation effect in Escherichia coli is mediated by a Fenton-like reaction. The effect of SnCl2 was studied through: (i) the alteration of plasmid topology in neutral and acidic pH by gel electrophoresis; and (ii) the transformation efficiency of an wild type E. coli strain. Treatment of plasmid DNA pUC 9.1 with SnCl2, at pH 7.4, results in DNA single-strand breaks (SSB), in a dose-dependent manner. Addition of sodium benzoate partly inhibited the DNA damage, while EDTA completely abolishes DNA-SSB. Furthermore, the ability of the plasmid to transform E. coli was reduced. At pH 1.3, SnCl2 exerts a protective effect on plasmid against HCI depurination. Our results suggest the generation of ROS, such as *OH by a Fenton-like reaction, close to the site of the lesions due to a possible complexation of stannous ion to DNA.

Cytokine mRNA expression in leprosy: a possible role for interferon-gamma and interleukin-12 in reactions (RR and ENL)

Leprosy patients during the natural course of the disease may develop reactional episodes, namely reversal reaction (RR) and erythema nodosum leprosum (ENL). Immunological events described as occurring during RR indicate up-regulation of the immune response, whereas in ENL the events are not fully understood. The aim of this study was to analyse the in vivo pattern of cytokine gene expression in the reactional states of leprosy. Peripheral blood mononuclear cells (PBMC, n = 14) and tissue samples (n = 17) obtained from patients with ENL and RR were obtained and assayed by RT-PCR. PBMC obtained from unreactional patients (n = 15) and normal individuals (n = 5) were also assessed. Expression of interferon (IFN)gamma, granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin (IL)-2Rp55, perforin and IL-1beta mRNA in PBMC were detected mostly in ENL/RR patients, but not in unreactional patients. Likewise, cytokines such as IL-6, IL-8, tumour necrosis factor (TNF)alpha and TNFbeta were also present in reactional and tuberculoid patients as opposed to lepromatous leprosy (BL/LL). Interestingly, the majority of ENL/RR patients showed messages for IL-6, IL-10, IL-12 and TNFalpha in the skin. IFNgamma was detected in 84.6% (ENL) and 100% (RR) of the patients, whereas IL-4 was detected only in few individuals (38.5 and 25%, respectively). Although mRNA expression and protein levels may be different, the data reported in this study suggest a cytokine mRNA profile that seems to be indistinguishable for RR and ENL. In addition, it shows up-regulation of immuno-inflammatory cytokines in the blood and tissue of the same patient examined before and during reaction. Furthermore, it is suggested that this pattern of response results from an immunological reactivation that might lead to an acute inflammatory response in both reactional episodes.

Fluoxetine bioequivalence study: quantification of fluoxetine and norfluoxetine by liquid chromatography coupled to mass spectrometry

In this study, the authors assessed the bioequivalence of two fluoxetine tablet formulations in 24 healthy volunteers of both sexes who received a single 20 mg dose of each fluoxetine formulation, and a new sensitive method for the quantification of fluoxetine and norfluoxetine in human plasma was developed. The study was conducted using an open, randomized, two-period crossover design with a 4-week washout interval. Plasma samples were obtained over a 672-hour period. Plasma fluoxetine and norfluoxetine concentrations were analyzed by combined liquid chromatography coupled to mass spectrometry (LC-MS) with positive ion electrospray ionization using selected ion recording (SIR). Kolmogorov-Smirnov's test, histograms, probit plots, and the correlation between norfluoxetine AUC(0-infinity) and fluoxetine AUC(0-infinity) were used to analyze the population distribution. The limit of quantification was 0.15 ng.ml-1 and 0.50 ng.ml-1 for both fluoxetine and norfluoxetine, respectively. Within- and between-run imprecision was less than 13% and 17%, respectively. The pharmacokinetic parameters obtained for fluoxetine and norfluoxetine after the administration of each formulation included AUC(0-672 h), AUC(0-infinity), Cmax, Cmax/AUC(0-672 h), tmax, t1/2, and Ke. The AUC values for fluoxetine were not consistent with a normal distribution, reflecting the existence of two different populations (poor and extensive metabolizers). The mean pharmacokinetic parameters for extensive fluoxetine metabolizers were 27.0 ng ml-1 for Cmax, 2064.0 ng h ml-1 for AUC(0-infinity), and 85.4 h t1/2. The mean pharmacokinetic parameters for norfluoxetine (in extensive metabolizers only) were 2532.0 ng h ml-1 for AUC(0-infinity) and 8.4 ng ml-1 for Cmax. For fluoxetine bioequivalence, the 90% CI of the individual ratio geometric mean for Psiquial/Prozac (including both extensive and poor metabolizers) was 101.6% to 121.1% for AUC(0-672 h) and 86.1% to 102.6% for Cmax. For norfluoxetine, the 90% CI of the individual ratio geometric mean for Psiquial/Prozac (including both extensive and poor metabolizers) was 90.3% to 108.3% for AUC(0-672 h) and 84.5% to 106.3% for Cmax. The new method developed (LC-MS) presented high sensitivity, specificity, and short chromatographic run for the quantification of both fluoxetine and norfluoxetine in human plasma. Since both 90% CI for AUC and Cmax geometric mean ratios were included in the 80% to 125% interval proposed by the U.S. Food and Drug Administration, Psiquial was considered bioequivalent to Prozac according to both the rate and extent of absorption. The finding that there were no significant differences in the bioequivalence assessed by either fluoxetine or norfluoxetine pharmacokinetic parameters indicates that future bioequivalence trials may be performed by quantifying fluoxetine only.

Fluconazole bioequivalence study: quantification by tandem mass spectrometry

To develop a new method for quantifying fluoconazole in human plasma and to compare the bioavailability of two fluconazole capsule formulations, an open, randomized, two-period crossover study with a one-week washout interval was conducted in 24 healthy volunteers. Plasma samples were obtained up to 168 hours after drug administration and the serum fluconazole concentrations were analyzed using electrospray tandem mass spectrometry coupled to liquid chromatography using multiple reaction monitoring mode. The pharmacokinetic parameters obtained for fluconazole after the administration of each formulation included the Area under the curve (AUC)(0-168h), AUC(0-infinity), Cmax, Cmax/AUC(0-168h), Tmax, elimination rate constant (Ke), and half-life (T1/2). Within- and between-run imprecision was less than 2.3% and 8.2%, respectively. Inaccuracy within and between runs was -1.5% and -9.7%, respectively. The pharmacokinetic parameters for bioequivalence showed a normal distribution, and the variance of AUC(0-168h), AUC(0-infinity), and Cmax were homoscedastic. The geometric mean for the Fluconal/Zoltec (Fluconal; Libbs Farmacêutica Ltda, São Paulo, Brazil; Zoltec; Laboratórios Pfizer Ltda., São Paulo, Brazil) individual percent ratio was 94.9% for AUC(0-168h), 94.7% for AUC(0-infinity), 80.1% for Cmax, 102.6% for Ke, 97.5% for T1/2, and 0.93 for Tmax (arithmetic mean of individual differences). We have developed a method in which liquid chromatography is coupled with electrospray tandem mass spectrometry to improve the pharmacokinetic analysis of fluconazole. Because the 90% CI AUC is within the interval proposed for the Food and Drug Administration, we concluded that Fluconal is bioequivalent to Zoltec in terms of absorption. The CV was 27.5% for the Cmax parameter, indicating that fluconazole's absorption rate is highly variable. The European Union Regulatory Agency accepts an interval of 70-143%, and because the 90% CI for Cmax is within the interval proposed for the European Union agency, we conclude that Fluconal is bioequivalent to Zoltec for the rate of absorption.