Caffeine and CSC, adenosine A2A antagonists, offer neuroprotection against 6-OHDA-induced neurotoxicity in rat mesencephalic cells.

In this study, the cytoprotective effects of caffeine (CAF) and 8-(3-chlorostyryl)-caffeine (CSC), A(2A) receptor antagonists, were tested against 6-OHDA-induced cytotoxicity, in rat mesencephalic cells. Both drugs significantly increased the number of viable cells, after their exposure to 6-OHDA, as measured by the MTT assay. While nitrite levels in the cells were drastically increased by 6-OHDA, their concentrations were brought toward normality after CAF or CSC, indicating that both drugs block 6-OHDA-induced oxidative stress which leads to free radicals generation. A complete blockade of 6-OHDA-induced lipid peroxidation, considered as a major source of DNA damage, was observed after cells treatment with CAF or CSC. 6-OHDA decreased the number of normal cells while increasing the number of apoptotic cells. In the CAF plus 6-OHDA group, a significant recover in the number of viable cells and a decrease in the number of apoptotic cells were seen, as compared to the group treated with 6-OHDA alone. A similar effect was observed after cells exposure to CSC in the presence of 6-OHDA. Unexpectedly, while a significant lower number of activated microglia was observed after cells exposure to CAF plus 6-OHDA, this was not the case after cells exposure to CSC under the same conditions. While CAF lowered the percentage of reactive astrocytes increased by 6-OHDA, CSC presented no effect. The effects of these drugs were also examined on the releases of myeloperoxidase (MPO), an inflammatory marker, and lactate dehydrogenase (LDH), a marker for cytotoxicity, in human neutrophils, in vitro. CSC and CAF (0.1, 1 and 10 microg/ml) produced inhibitions of the MPO release from PMA-stimulated cells, ranging from 45 to 83%. In addition, CSC and CAF (5, 50 and 100 microg/ml) did not show any cytotoxicity in the range of concentrations used, as determined by the LDH assay. All together, our results showed a strong neuroptrotection afforded by caffeine or CSC, on rat mesencephalic cells exposed to 6-OHDA. Furthermore, CSC and caffeine actions, inhibiting MPO as well as LDH releases, would contribute to their possible benefit in the treatment of neurodegenerative diseases, including DP. These effects are partially due to the ability of these A(2A) antagonists to decrease the cells free radicals production and oxidative stress, that are major components of 6-OHDA-induced cytotoxicity.

Topically applied diterpenoids from Egletes viscosa (Asteraceae) attenuate the dermal inflammation in mouse ear induced by tetradecanoylphorbol 13-acetate- and oxazolone.

The diterpene compounds, centipedic acid (CA) and 12-acetoxyhawtriwaic acid lactone (AHAL, tanabalin) isolated from the flower buds of Egletes viscosa LESS. (Asteraceae) were evaluated on acute and chronic models of mouse ear dermatitis. A single topical application of CA (0.125; 0.25 and 0.5 mg/ear) or AHAL (0.125, 0.25, 0.5 mg/ear) immediately before 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 mug/ear) caused a dose-related significant inhibition of ear inflammatory edema and influx of polymorphonuclear cells, as evidenced by a decrease in ear thickness and reduced myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-alpha) in ear tissue homogenates. The maximal obtained inhibition for both ear edema and neutrophil influx were almost similar to that of topically applied dexamethasone (0.05 mg/ear). The extent of inhibitions for the respective treatments of CA (0.5 mg/ear), AHAL (0.5 mg/ear), or dexamethasone (0.05 mg/ear) were in the order of 63%, 61% and 81% for the ear edema, and 90%, 95% and 95% for the neutrophil influx. Also, at similar doses, both diterpenes and dexamethasone effectively inhibited the delayed-type hypersensitivity reaction induced by repeated topical application of 1% oxazolone (OXA, 20 microl/ear), as evidenced by significant decreases in ear thickness and interferon-gamma (INF-gamma) levels in ear tissue. Histopathological analysis revealed a marked decrease in epidermal hyperplasia and neutrophil infiltration in animals pretreated with CA or AHAL, in a manner similar to dexamethasone. These data provide evidence for the anti-dermatitis effect of Egletes viscosa diterpenes, by mechanisms that involve a reduced neutrophil influx and decreased production of inflammatory cytokines, TNF-alpha and IFN-gamma.

Antinociceptive and anti-inflammatory properties of the hydroalcoholic extract of stems from Equisetum arvense L. in mice.

In this study, antinociceptive and anti-inflammatory effects of hydroalcoholic extract of stem from Equisetum arvense in mice were evaluated. The extract (10, 25, 50 and 100mgkg(-1), i.p.), reduced the writhing induced by acetic acid in 49, 57, 93 and 98%, respectively. In the formalin test, 50 and 100mgkg(-1) (i.p.) extract, reduced in 80 and 95% the licking activity in the first phase, but in the second phase only the latter dose diminished the licking time (35%). In both phases, naloxone failed to revert the analgesic effect of the extract. In the hot-plate test, the extract at 100 and 200mgkg(-1) does not change the latency to licking or jumping. In the carrageenan-induced paw oedema, the extract at 50mgkg(-1), reduced the paw oedema 2h (25%) and 4h (30%) after carrageenan administration. The dose of 100mgkg(-1) caused reduction of the paw oedema (29%) only 4h after carrageenan administration. These results indicate that this extract exhibits an antinociceptive effect in chemical models of nociception which is not related to the opioid system, as well as anti-inflammatory properties.

Estudo dos mecanismos envolvidos na ação da pentoxifilina sobre a lesão hipocampal e deficits de memória induzidos por glutamato em ratos / Study of the mechanisms involved in the action of pentoxifylline on the hippocampal damage and memory deficits induced by glutamate in rats

O presente trabalho mostra os efeitos da pentoxifilina (ptx), no aprendizado e na memória de ratos com lesão hipocampal induzida por glutamato (glu). Os animais (ratos Wistar, machos, 200-250g), foram submetidos à cirurgia estereotáxica e injetados com glutamato nas doses de 24, 48, 96 e 192 μg, na região hipocampal (áreas CA1 e CA3). Após 7 dias, os animais foram submetidos ao teste do campo aberto e aos teste de memória (esquiva passiva, labirinto em T elevado e labirinto aquático de Morris). Após vinte e quatro horas, os animais foram sacrificados para a avaliação histológica da lesão. Não foram observadas lesões significativas nos animais tratados com salina e glu (24 e 48 μg), já os animais que receberam as doses de 96 e 192 μg, apresentaram lesões avaliadas como moderada e grave, respectivamente. Os animais tratados com a dose de 192 μg apresentaram um aumento da atividade locomotora (salina: 14,82 +- 2,59, glu192- 31,10 +- 6,50 quadrantes). No teste de esquiva passiva, os grupos tratados com glu 48, 96 e 192 μg demonstraram um déficit de memória, tanto na memória recente (salina: 200,43 +- 52,09; glu24: 210,20 +- 44,77; glu 48: 27,61 +- 9,89; glu96: 64,46 +- 31,93; glu192: 140,29 +- 40,76s), quanto na memória tardia (salina: 252,57 +- 31,78; glu24: 273,70 +- 22,27; glu48: 44,35 +- 32,21; glu96: 29,39 +- 14,54; glu192: 140,29 +- 40,76s). No teste do labirinto em T elevado, os animais tratados com glu nas maiores doses, demonstraram um aprendizado menos eficiente do que aqueles do grupo tratado com salina...

Aspectos microbiológicos do queijo tipo "coalho" comercializado em Fortaleza - Ceará / Microbiological aspects of \"coalho\" type cheese commercialized in Fortaleza - Ceará

Avaliou-se a qualidade microbiológica de cinquenta e seis amostras de queijo tipo "coalho" provenientes de diferentes pontos comerciais de Fortaleza - Ceará. Foram quantificadas as bactérias mesófilas, Staphylococcus aureus, coliformes totais e fecais, bolores e leveduras. Verificou-se que em relaçäo às contagens de coliformes fecais e Staphylococcus aureus, 67,9 por cento e 62,5 por cento das amostras respectivamente, näo atenderam aos estabelecidos pela legislaçäo brasileira em vigor

Estudo bioquímico, imunológico e farmacológico comparativo do fator de crescimento (NGF) presente no veneno de Crotalus durissus cascavella, Wagler, 1824 e na saliva de camundongo / Study biochemical, immunological and pharmacological comparative growth factor (NGF) present in Crotalus durissus cascavella, Wagler, 1824 and on rat saliva

Os principais objetivos do presente trabalho foram estudar de modo comparativo, as característica bioquímicas e imunológicas do fatos de crescimento do nervo ( NGF ), isolado a partir do veneno de Crotalus durissus cascavella, uma serpente nativa da caatinga nordestina, e da saliva de camundongo. Foram também estudadas as ações farmacológicas do fatos em modelos de inflamação e de dor. Do fracionamento em Sephadex G-100 do veneno, foi obtida uma fração, com um peso molecular ( PM ) de 14,5-33 kD. A eletroforese em gel de poliacrilamida com SDS mostrou a presença de 4 bandas migrando na região de 16,9-36,3 kD. No fracionamento da saliva, foi obtida uma fração com PM de 25-45 kD, que revelou na eletroforese, a presença de 1 banda migrando na região de 18,2-21,4 kD. Os resultados apresentados na imunogeldifusão, demonstraram que um NGF imunologicamente reativo está presente nas frações do veneno e da saliva de camundongo em formas moleculares imunologicamente diferente...