Acute copper toxicity in juvenile fat snook Centropomus parallelus (Teleostei: Centropomidae) in sea water

Three experiments were designed to assess the accumulation and acute toxicity of copper (Cu) in juvenile fat snook Centropomus parallelus. The first experiment was performed to determine the 96-h lethal concentration (LC50) of Cu. The second experiment was designed to assess the effects of sublethal concentrations of Cu (0.47 and 0.94 mg/L), while the third one allowed us to test the recovery capacity of fish exposed to the sublethal concentrations Cu and kept in sea water without Cu addition. The LC50 value for Cu was found to be 1.88 mg/L Cu. Fish exposed to the sublethal concentrations of Cu showed a significant accumulation of Cu in gills at 96 h respect to the control ones (0.43 µg/g Cu). No significant difference was observed in the accumulation of Cu in gills between fish exposed to 0.47 mg/L (1.09 µg/g Cu) and 0.94 mg/L (1.26 µg/g Cu). Exposure (24 and 96 h) to the sublethal concentrations of Cu tested induced DNA damage in the erythrocytes. The results show that acute exposure to sublethal concentrations induces Cu accumulation and DNA damage in fish, these effects being recovered after 240 h in sea water without Cu addition.

Três experimentos foram realizados para avaliar o acúmulo e toxicidade aguda do cobre (Cu) em juvenis de robalo-peva Centropomus parallelus. O primeiro experimento foi realizado para determinar a concentração letal (96h-CL50) de Cu. O segundo experimento foi realizado para avaliar os efeitos de concentrações subletais de Cu (0,47 e 0,94 mg/L), enquanto o terceiro permitiu testar a capacidade de recuperação dos peixes expostos a concentrações subletais do Cu e posteriormente mantidos em água do mar sem acréscimo de Cu. O valor de LC50 encontrado para o Cu foi de 1,88 mg/L. Os peixes expostos as concentrações subletais de Cu mostraram um acúmulo significativo nas brânquias em relação ao controle em 96 h de exposição (0,43 µg/g Cu). Nenhuma diferença significativa foi observada entre os peixes expostos a 0,47 mg/L de Cu (1,09 µg/g) e 0,94 mg/L de Cu (1,26 µg/g). A exposição (24 e 96 h) para as concentrações subletais de Cu induziram danos no DNA. Os resultados mostram que a exposição aguda a concentrações subletais induz o acúmulo de Cu e danos ao DNA nas brânquias dos peixes, onde estes efeitos são recuperados após 240 h em água do mar sem adição de Cu.

Efecto antitumoral in vitro del aceite esencial de Piper aduncum L. (matico) y su toxicidad oral en ratones / Piper aduncum L. (matico) essential oil in vitro antitumoral effect and oral toxicity in mice

Introducción: Piper aduncum (matico) es una especie utilizada por sus propiedades medicinales en desórdenes gastrointestinales y genitourinarios. Objetivos: Evaluar el efecto antitumoral del aceite esencial de Piper aduncum (matico) in vitro en siete líneas celulares tumorales humanas y determinar la toxicidad oral en ratones. Diseño: Experimental. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Líneas celulares tumorales humanas H460, DU-145, ME-180, K562, HT-29, MCF 7, M14, K562; fibroblastos normales de ratón 3T3 y ratones albinos machos Balb/C53. Intervenciones: Las líneas celulares fueron expuestas a cuatro concentraciones del aceite esencial de P. aduncum y 5-fluorouracilo (5-FU). Para la toxicidad oral se utilizó ratones albinos machos Balb C/53 de 40 días post destete, a cinco dosis de tratamiento, evaluándose el número de muertes en cada dosis. Principales medidas de los resultados: Porcentaje de inhibición del crecimiento celular (IC50), dosis letal 50 (DL50). Resultados: El aceite esencial mostró IC50 mayor a 250 ug/mL para las líneas celulares M-14 (r = -0,99; p < 0,01), DU-145 (r = 0,99; p < 0,01), ME-180 (r = -0,99; p < 0,01). Para líneas celulares tumorales H460 (r = -0,99; p < 0,01), MCF-7 (r = -0,99; p < 0,01), K562 (r = -0,99; p < 0,01), HT-29 (r = -0,99; p < 0,01), los niveles de IC50 estuvieron entre 20 ug/mL y 250 ug/mL. DL50 > 2 000 mg/kg. Conclusiones: El aceite esencial de P. aduncum no presentó efecto antitumoral in vitro para las siete líneas celulares tumorales humanas y no fue tóxico.

Introduction: Piper aduncum (matìco) is a medicinal plant used for gastrointestinal and genitourinary disorders. Objectives: To determine the in vitro antitumoral effect of Piper aduncum (matico) essential oil on seven human tumoral cell lines and its oral toxicity in mice. Design: Experimental. Setting: Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru. Biologic material: Human tumoral cell lines HT-29, H-460, MCF-7, M-14, ME-180, DU-145, K-562; and 3T3 fibroblasts and male 40 days post weaning Balb C/53 mice. Interventions: The cell lines HT-29, H-460, MCF-7, M-14, ME-180, DU-145, K-562, and 3T3 were exposed to four different concentrations of Piper aduncum essential oil, and to different 5-fluorouracil concentrations used as a positive control. Cell lines growth inhibition (IC50) was determined using linear regression analysis and DL50 by the number of deaths with each dose. Main outcome measures: Antitumor effect. Results: Piper aduncum essential oil showed cytotoxic activity at IC50 levels > 250 ug/mL on cell lines M-14 (r = -0.99; p < 0.01), DU-145 (r = -0.99; p < 0.01), ME-180 (r = -0.99; p < 0.01). IC50 was between 20 ug/mL and 250 ug/mL on cell lines H-460 (r = -0.99; p < 0.01), MCF-7, (r = -0.99; p < 0.01), K562 (r = -0.99; p < 0.01), HT-29 (r = -0.99; p < 0.01). DL50 was > 2 000 mg/kg. Conclusions: P. aduncum essential oil did not show antitumoral effect on seven human tumoral cell lines and it was non toxic.

Hepatic injury and gluconeogenesis after subcutaneous injection of monochloroacetic acid in rats

<p><b>OBJECTIVE</b>Monochloroacetic acid (MCA) is corrosive to skin, and causes not only chemical injury but also fatal systemic poisoning. Little is known about the cause of death. We studied the acute toxicity of MCA before clinical symptoms appeared in fasting rats.</p><p><b>METHODS</b>Blood samples were analyzed 2 h after subcutaneous MCA injection (Ld(90): 162 mg/ml kg body weight). Control rats were injected with saline.</p><p><b>RESULTS</b>Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were about 1.5-fold higher than in the controls, and mitochondrial AST (mAST) was 2-fold higher. Blood urea nitrogen and creatinine were significantly increased, while serum glucose was significantly decreased in the treated group. Lactate was 6-fold higher and pyruvate was 13-fold higher than in the controls.</p><p><b>CONCLUSIONS</b>MCA caused injury to the liver and kidneys but these injuries were slight. However, the larger increase in mAST indicated that hepatocellular mitochondria were selectively targeted. Hepatocellular mitochondrial injury decreased gluconeogenesis and caused hypoglycemia and extremely high levels of lactate and pyruvate. Hypoglycemia and lactic acidosis were insidious before the critical symptoms appeared and this combination accelerated to death, affecting other organs such as the heart and brain. Nosotropic therapy of these abnormalities up to the appearance of symptoms may help to establish an early therapy for skin exposure to MCA.</p>

Hepatic Injury and Gluconeogenesis After Subcutaneous Injection of Monochloroacetic Acid in Rats

Objective: Monochloroacetic acid (MCA) is corrosive to skin, and causes not only chemical injury but also fatal systemic poisoning. Little is known about the cause of death. We studied the acute toxicity of MCA before clinical symptoms appeared in fasting rats. Methods: Blood samples were analyzed 2 h after subcutaneous MCA injection (LD90: 162 mg/ml kg body weight). Control rats were injected with saline. Results: Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were about 1.5-fold higher than in the controls, and mitochondrial AST (mAST) was 2-fold higher. Blood urea nitrogen and creatinine were significantly increased, while serum glucose was significantly decreased in the treated group. Lactate was 6-fold higher and pyruvate was 13-fold higher than in the controls. Conclusions: MCA caused injury to the liver and kidneys but these injuries were slight. However, the larger increase in mAST indicated that hepatocellular mitochondria were selectively targeted. Hepatocellular mitochondrial injury decreased gluconeogenesis and caused hypoglycemia and extremely high levels of lactate and pyruvate. Hypoglycemia and lactic acidosis were insidious before the critical symptoms appeared and this combination accelerated to death, affecting other organs such as the heart and brain. Nosotropic therapy of these abnormalities up to the appearance of symptoms may help to establish an early therapy for skin exposure to MCA.

Combined Lethal Toxicity of TNF and LPS in Tumor-Bearing Mice / 第二军医大学学报

Both TNF and LPS are toxic to host, especially to tumor - bearing host Intravenous administration at a dose of 5?g of TNF or 25?g of LPS could not result in death of mice transplanted with sarcoma 180 (S180) 10 d later, but 80% of S180-bearing mice died after iv injection of 5?g of LPS combined with 0.5?g of TNF. In contrast to TNF, combined toxicity was seriously LPS-dose dependent Combined mortality dropped from 80% to 14% when LPS dose reduced to 1?g, however, 50% of mice died of combined toxicity when only TNF dose dropped to 0.1?g. It suggested that TNF sensitized host response to toxic effect of LPS. Indomethacin could partially block the combined toxicity, demonstrating that combined toxicity of LPS and TNF was partially mediated by prostaglan-dins.