Janaína Serra Azul Monteiro Evangelista

Antinociceptive and Anti-Inflammatory Activities of Sulphated Polysaccharides from the Red Seaweed Gracilaria cornea

Seaweeds have attracted special interest as good sources of sulphated polysaccharides (SP) for use in pharmaceutical industries and biotechnology. In this study, we evaluated the effects of SP from the red seaweed Gracilaria cornea (Gc-TSP) in nociceptive and inflammatory models. In mice, Gc-TSP (3, 9 or 27 mg/kg) significantly reduced nociceptive responses, as measured by the number of writhes, at all tested doses. In a formalin test, Gc-TSP significantly reduced licking time in both phases of the test at a dose of 27 mg/kg. In a hot-plate test, the antinociceptive effect was observed only in animals treated with 27 mg/kg of Gc-TSP, suggesting that the analgesic effect occurs through a central action mechanism at the highest dose. Gc-TSP (3, 9 or 27 mg/kg) caused only a slight reduction in neutrophil migration in the rat peritoneal cavity. However, lower doses of Gc-TSP (3 and 9 mg/kg) significantly inhibited paw oedema induced by carrageenan, especially at 3 hr after treatment. Reduction in oedema was confirmed by myeloperoxidase activity in the affected paw tissue. In addition, treatment (s.c.) of animals with different doses of Gc-TSP inhibited paw oedema induced by dextran within the first hour in all doses tested. After 14 consecutive days of intraperitoneal administration of Gc-TSP (9 mg/kg), we measured the wet weight of the liver, kidney, heart, spleen and thymus and performed biochemical, haematological and histopathological evaluations. No systemic damage was found. These results indicate that Gc-TSP possesses analgesic and anti-inflammatory effects and is a potentially important tool worthy of further study.

Purification and characterization of the biological effects of phospholipase A2 from sea anemone Bunodosoma caissarum

Sea anemones contain a variety of biologically active substances. Bunodosoma caissarum is a sea anemone from the Cnidaria phylum, found only in Brazilian coastal waters. The aim of the present work was to study the biological effects of PLA(2) isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens of B. caissarum were collected from the São Vicente Channel on the southern coast of the State of São Paulo, Brazil. Reverse phase HPLC analysis of the crude extract of B. caissarum detected three PLA(2) proteins (named BcPLA(2)1, BcPLA(2)2 and BcPLA(2)3) found to be active in B. caissarum extracts. MALDI-TOF mass spectrometry of BcPLA(2)1 showed one main peak at 14.7 kDa. The N-terminal amino acid sequence of BcPLA(2)1 showed high amino acid sequence identity with PLA(2) group III protein isolated from the Mexican lizard (PA23 HELSU, HELSU, PA22 HELSU) and with the honey bee Apis mellifera (PLA(2) and 1POC_A). In addition, BcPLA(2)1 also showed significant overall homology to bee PLA(2). The enzymatic activity induced by native BcPLA(2)1 (20 microg/well) was reduced by chemical treatment with p-bromophenacyl bromide (p-BPB) and with morin. BcPLA(2)1 strongly induced insulin secretion in presence of high glucose concentration. In isolated kidney, the PLA(2) from B. caissarum increased the perfusion pressure, renal vascular resistance, urinary flow, glomerular filtration rate, and sodium, potassium and chloride levels of excretion. BcPLA(2)1, however, did not increase the perfusion pressure on the mesenteric vascular bed. In conclusion, PLA(2), a group III phospholipase isolated from the sea anemone B. caissarum, exerted effects on renal function and induced insulin secretion in conditions of high glucose concentration.

Peripheral antinociception and anti-edematogenic effect of a sulfated polysaccharide from Acanthophora muscoides

BACKGROUND Sulfated polysaccharides from red marine algae have presented a variety of potentially therapeutic biological effects, however, their antinocicpetive and anti-inflammatory properties are not well understood. METHODS Male Swiss mice were pretreated with a sulfated polysaccharidic fraction obtained from the marine alga Acanthophora muscoides (AmII) (1, 3 or 9 mg/kg, iv) 30 min prior to either receiving an injection of 0.8% acetic acid or 1% formalin or prior to a thermal stimulus. AmII (1, 3 or 9 mg/kg, sc) was evaluated on carrageenan-, dextran- bradykinin-, histamine- and serotonin-induced rat paw edema models. AmII (500 μg, sc) was also injected into the paw. Additionally, mice were treated with the total sulfated polysaccharides from A. muscoides (Am-TSP) (20 mg/kg, ip) for 14 days. RESULTS AmII reduced the number of acetic acid-induced writhes and licking time in the second phase of the formalin test, but it did not alter the response latency in the hot plate test, suggesting that its antinociceptive action occurs through a peripheral mechanism. AmII did not reduce carrageenan-induced paw edema and MPO activity. However, it reduced dextran-, histamine- and serotonin-induced paw edemas, but not bradykinin-induced edema, suggesting that histamine is the major target of AmII anti-edematogenic activity. AmII injected into the paw did not evoke local edema. Furthermore, Am-TSP induced no consistent signs of systemic damage, as revealed by body mass, organs wet weight and by biochemical, hematological and histopathological analyses. CONCLUSION AmII has important antinociceptive and anti-inflammatory properties and represents an important therapeutic agent warranting future studies.

Nephroprotective effects of (−)-α-bisabolol against ischemic-reperfusion acute kidney injury

BACKGROUND Ischemia/reperfusion (I/R) in kidney is commonly related to acute kidney injury (AKI), essentially through oxidative stress. (-)-α-Bisabolol is a sesquiterpene isolated from the essential oil of a variety of plants, including chamomile, which has important antioxidant activity. STUDY DESIGN This study intends to evaluate the nephroprotective activity of (-)-α-bisabolol (Bis) in both in vivo and in vitro models of kidney I/R. METHODS Male Wistar rats were submitted to right nephrectomy, followed by ischemia by clamping of the renal artery in the left kidney for 60min. and 48h of reperfusion. The animals were treated orally with Bis (100mg/kg) or vehicle for 24h after reperfusion, and placed in metabolic cages, to evaluate water consumption, diuresis, urinary osmolality, classic biochemical markers and urinary KIM-1 (kidney injury molecule-1). Additionally, the left kidney was collected for histological evaluation and determination of glutathione (GSH) and Thiobarbituric Acid Reactive Substances (TBARS) levels. Tubular epithelial cells LLC-MK2 were used to assess Bis effect on in vitro I/R, by MTT assay. It was performed the cellular respiration tests by flow cytometry: evaluation of the production of cytoplasmic reactive oxygen species by DCFH-DA assay and mitochondrial transmembrane potential analysis with the dye rhodamine 123. RESULTS I/R caused alterations in diuresis, water intake, urinary osmolality, plasmatic creatinine, urea and uric acid, creatinine clearance, proteinuria and microalbuminuria. Treatment with Bis ameliorated all of these parameters. Also, KIM-1 level enhanced by I/R was also diminished in groups treated with Bis. The histological examination showed that Bis attenuated the morphological changes caused by I/R, markedly vascular congestion and intratubular deposits of proteinaceous material. Additionally, Bis was able to reduce the changes observed in TBARS and GSH levels in kidney tissue. In in vitro assay, Bis was capable to partially protect the cell lineage against cell damage induced by I/R. CONCLUSION (-)-α-Bisabolol has a nephroprotective effect in kidney I/R, with antioxidant effect. Moreover, this result seems to be associated to a direct protective effect on tubular epithelia.

Changes in rat respiratory system produced by exposure to exhaust gases of combustion of glycerol

The combustion of residual glycerol to generate heat in industrial processes has been suggested as a cost-effective solution for disposal of this environmental liability. Thus, we investigated the effects of exposure to the exhaust gases of glycerol combustion in the rat respiratory system. We used 2 rats groups, one exposed to the exhaust gases from glycerol combustion (Glycerol), and the other exposed to ambient air (Control). Exposure occurred 5h a day, 5days a week for 13 weeks. We observed statistically changes in all parameters of respiratory system mechanics in vivo. This results was supported by histological analysis and morphometric data, confirming narrower airways and lung parenchimal changes. Variables related to airway resistance (ΔRN) and elastic properties of the tissue (ΔH), increased after challenge with methacholine. Finally, analysis of lung tissue micromechanics showed statistically increases in all parameters (R, E and hysteresivity). In conclusion, exhaust gases from glycerol combustion were harmful to the respiratory system.

Pulmonary mechanic and lung histology induced by Crotalus durissus cascavella snake venom

ABSTRACT This study have analyzed the pulmonary function in an experimental model of acute lung injury, induced by the Crotalus durissus cascavella venom (C. d. cascavella) (3.0 &mgr;g/kg ‐ i.p), in pulmonary mechanic and histology at 1 h, 3 h, 6 h, 12 h and 24 h after inoculation. The C. d. cascavella venom led to an increase in Newtonian Resistance (Symbol), Tissue Resistance (Symbol) and Tissue Elastance (Symbol) in all groups when compared to the control, particularly at 12 h and 24 h. The Histeresivity (Symbol) increased 6 h, 12 h and 24 h after inoculation. There was a decrease in Static Compliance (Symbol) at 6 h, 12 h and 24 h and inspiratory capacity (Symbol) at 3 h, 6 h, 12 h and 24 h. C. d. cascavella venom showed significant morphological changes such as atelectasis, emphysema, hemorrhage, polymorphonuclear inflammatory infiltrate, edema and congestion. After a challenge with methacholine (MCh), Symbol demonstrated significant changes at 6, 12 and 24 h. This venom caused mechanical and histopathological changes in the lung tissue; however, its mechanisms of action need further studies in order to better elucidate the morphofunctional lesions. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. Symbol. No caption available. HIGHLIGHTSC. d. cascavella venom increased Newtonian resistance, tissue resistance, tissue elastance and histeresivity in rat lungs.C. d. cascavella venom reduced static compliance and inspiratory capacity in rat lungs.C. d. cascavella venom induced morphological changes in the lung tissue.