RESUMO
The efficacy of ozonation and of photocatalysis processing in the treatment of pulp mill ECF (elementary chlorine free) bleaching and textile effluents was evaluated by determining total organic carbon reduction (TOC) and the toxicity. The chronic toxicity of the effluents was evaluated by the ability to inhibit the growth of algae Selenastrum capricornutum. Cultured hamster V79 fibroblasts were used to assess the cytotoxicity of effluents submitted to different detoxification processes. Two endpoints were measured in V79 cells: 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) reduction and neutral red uptake (NRU). Both treatment processes were able to reduce the TOC, although ozonization was less effective for pulp mill ECF bleaching. The pulp mill ECF bleaching and textile effluents reduced the growth of S. capricornutum by 39% and 27%, respectively. However, at the highest concentration tested, the textile effluents treated by photochemical process for 60 min showed increased cytotoxicity in V79 cells compared to the untreated effluent when assessed by the NRU and MTT reduction assays (increases of 30% and 40%, respectively). Pulp mill ECF bleaching effluent treated by ozonization had a similar cytotoxicity to that of untreated effluent in the NRU assay. In contrast, the MTT reduction assay indicated that effluents treated with ozone were around 20% more cytotoxic than untreated effluents. These results show that cultured fibroblasts may be useful for studying cellular responses to pollutants and may be included in tests to monitor the efficiency of effluent detoxification processes.
Assuntos
Poluentes Ambientais/toxicidade , Eucariotos/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Resíduos Industriais , Têxteis , Gerenciamento de Resíduos/métodos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cricetinae , Cricetulus , Oxidantes FotoquímicosRESUMO
Angiotensin II (AII), a product of rennin-angiotensin system, exerts an important role on the function of immune system cells. In this study, the effect of AII on the phagocytic activity of mouse peritoneal macrophages was assessed. Mice peritoneal macrophages were cultured for 48 h and the influence of different concentrations of AII (10(-14) to 10(-7) M) and/or losartan, 10(-16) to 10(-6) M), an AT1 angiotensin receptor antagonist, on phagocytic activity and superoxide anion production was determined. Dimethylthiazoldiphenyltetrazolium bromide reduction and the nucleic acid content were used to assess the cvtotoxicity of losartan. A stimulatory effect on phagocytic activity (P < 0.05) was observed with 10(-13) M and 10(-12 M) AII concentrations. The addition of losartan (up to10(-14) M) to the cell cultures blocked (P < 0.001) the phagocytosis indicating the involvement of AT1 receptors. In contrast, superoxide anion production was not affected by AII or losartan. The existence of AT1 and AT2 receptors in peritoneal macrophages was demonstrated by immunofluorescence microscopy. These results support the hypothesis that AII receptors can modulate murine macrophage activity and phagocytosis, and suggest that AII may have a therapeutic role as an immunomodulatory agent in modifying the host resistance to infection.
Assuntos
Angiotensina II/farmacologia , Anti-Hipertensivos/farmacologia , Losartan/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Vasoconstritores/farmacologia , Animais , Macrófagos Peritoneais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
The effect of three new derivatives from dehydrocrotonin (DHC-compound I) on gastric damage in different animal models including gastric ulceration induced by a necrotic agent and hypothermic restrained-stress was studied: compound II (produced by reducing the cyclohexenone moiety of DHC with NaBH(4)); compound III (produced by reducing the carbonyls with LiAlH(4)); and compound IV (produced by transforming the lactone moiety into an amide). Their structures were confirmed on the basis of chemical and physicochemical evidence. When previously administered (p.o.) at a dose of 100mg/kg, compound II significantly (P<0.01) reduced gastric injury induced by HCl/ethanol (78%) and indomethacin (88%) better than did reference compound I (48 and 43%, respectively). But the anti-ulcerogenic activity of compound II was completely abolished by the stress-induced ulcer. Reduction of carbonyls with LiAlH(4) (compound III) caused decreased activity, markedly when no protective effect in any of the models was applied (P>0.05). However, compound IV, in which the lactone moiety was changed into an amide, when administered at the same dose (100mg/kg, p.o.), was more effective. The presence of a lactone moiety or Michael acceptor is probably essential for the anti-ulcerogenic effect of these compounds.
Assuntos
Antiulcerosos/uso terapêutico , Croton/química , Diterpenos/uso terapêutico , Lactonas/uso terapêutico , Fitoterapia , Preparações de Plantas/uso terapêutico , Animais , Antiulcerosos/isolamento & purificação , Diterpenos/isolamento & purificação , Diterpenos Clerodânicos/química , Diterpenos Clerodânicos/uso terapêutico , Etanol , Ácido Clorídrico , Hipotermia , Indometacina , Lactonas/isolamento & purificação , Masculino , Camundongos , Casca de Planta/química , Estresse Psicológico/complicações , Relação Estrutura-Atividade , Úlcera/tratamento farmacológico , Úlcera/etiologia , Úlcera/prevenção & controleRESUMO
Two alkaloids were isolated from the leaves of Cissampelos sympodialis; a bisbenzylisoquinoline compound named warifteine and a novel 8,14-dihydromorphinandienone alkaloid named milonine. The cytotoxic effects of these alkaloids were assayed in cultured hepatocytes and V79 fibroblasts. Three independent endpoint assays for cytotoxicity in vitro were used: the nucleic acid content (NAC), tetrazolium reduction (MTT) and neutral red uptake (NRU). Milonine was less toxic than warifteine in both cell cultures. The IC50 values determined in the three different viability assays were around 100 and 400 microM after milonine treatment of V79 cells or hepatocytes. IC50 values ranging from 10 to 35 microM were obtained for warifteine in the viability tests evaluated in V79 cells and hepatocytes. Due to the similar cytotoxic effects detected on V79 cells and hepatocytes, probably warifteine and milonine induced toxic effects independent to the cytochrome P450. This hypothesis was corroborated by the results where Cimetidine (1.0 mM), a traditional cytochrome P450 inhibitor, did not protect the cells from the toxic action of warifteine or milonine. In conclusion, these alkaloids merit further investigations as potential novel pharmacological agents although milonine was less toxic than warifteine in the cells models investigated.
Assuntos
Alcaloides/toxicidade , Cissampelos/química , Fibroblastos/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Alcaloides/isolamento & purificação , Animais , Sobrevivência Celular/efeitos dos fármacos , Cimetidina/farmacologia , Corantes/metabolismo , Cricetinae , Cricetulus , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Inibidores Enzimáticos/farmacologia , Fibroblastos/citologia , Formazans , Hepatócitos/citologia , Masculino , Vermelho Neutro/metabolismo , Raízes de Plantas/química , Ratos , Ratos Wistar , Sais de TetrazólioRESUMO
Dehydrocrotonin (DHC) is a diterpene lactone obtained from Croton cajucara (Sacaca). Dimethylamide-crotonin (DCR), a DHC derivative, has a similar inhibitory effect on leukemic HL60 cells than its parent compound evaluated by different endpoints of cytotoxicity. No cytotoxicity or morphological alterations associated with apoptosis were detected in human peripheral blood mononuclear cells (PBMC) after treatment with up to 400 micro M DCR in presence of phytohemaglutinin (5 micro g/ml). Based on morphological changes and the pattern of DNA fragmentation, DHC and DCR were found to induce apoptosis and terminal differentiation (assessed by nitro blue tetrazolium reduction) in HL60 cells, but these compounds did not show any toxic effect in PBMC. Thus, DCR and DHC inhibit HL60 cell growth in vitro partly by inducing apoptosis and cell differentiation, but does not cause serious damage to immune cells according to our experimental conditions.