Curcuma longa ingestion protects in vitro hepatocyte membrane peroxidation

O objetivo do presente estudo foi avaliar o efeito da ingestão de cúrcuma sobre a peroxidação lipídica e conteúdo de GSH, por ação tóxica in vitro de paracetamol, utilizando cultura primária de hepatócitos. Quatro grupos de ratos Holtzman foram usados: 1) GNN, normonutrido, alimentado ad libitum com ração de laboratório; 2) GDN, desnutrido, alimentado com 60% da quantidade de ração consumida por GNN; 3) GNN+C, alimentado como GNN, mas contendo 1% de cúrcuma na dieta; 4) GDN+C, alimentado como GDN, mas contendo 1% de cúrcuma na dieta. Os animais foram sacrificados aos 90 dias de vida, e cultura de hepatócitos preparada. Metade das placas de cultura foi tratada com paracetamol. A curva dose-resposta mostrou que 6 mM de paracetamol aumentou em 54% a peroxidação e diminuiu em 63% o conteúdo de GSH. A restrição na ingestão de alimentos (40%) diminuiu o peso corporal (33%) ao sacrifício e o índice de peroxidação cerca de 42%, entretanto, aumentou o conteúdo de GSH cerca de 43%. A ingestão de cúrcuma diminuiu a peroxidação em ambos ratos normonutridos (42%) e desnutridos (33%) e evitou o efeito pro-oxidante de paracetamol em ambos os grupos. A cúrcuma exerceu efeito protetor antioxidante sobre o organismo.The goal of the present study was to evaluate the effect of turmeric ingestion on lipid peroxidation and GSH content, promoted by in vitro acetaminophen, on hepatocytes primary culture from well-nourished and malnourished rats. Four groups of Holtzman male rats were used: 1) WNG, well-nourished, fed lab chow diet ad libitum; 2) MNG, malnourished, fed 60% of the diet consumed by WNG; 3) WNG+T fed the same diet of WNG, but containing 1% of turmeric; 4) MNG+T fed 60% of the diet consumed by WNG+T. The animals were sacrificed at 90 days of age, the livers excised and hepatocytes primary cultures were prepared. Half of the plates of hepatocytes culture were treated with acetaminophen. Dose-response curve showed that 6 mM acetaminophen increased peroxidation around 54% and decreased GSH content around 63%. The model of malnutrition used, by restricting food ingestion (40%), decreased body weight in 33% and peroxidation index around 42% and increased GSH content around 43%. Turmeric ingestion decreased hepatocyte peroxidation in both well-nourished (42%) and malnourished rats (33%) and was able to avoid the acetaminophen pro-oxidant effect in both well-nourished and malnourished animals. Turmeric ingestion played a beneficial role to the organism and, therefore, can be considered a functional food

Curcuma longa ingestion protects in vitro hepatocyte membrane peroxidation Ingestão de Curcuma longa protege contra peroxidação de membrana de hepatócito

The goal of the present study was to evaluate the effect of turmeric ingestion on lipid peroxidation and GSH content, promoted by in vitro acetaminophen, on hepatocytes primary culture from well-nourished and malnourished rats. Four groups of Holtzman male rats were used: 1) WNG, well-nourished, fed lab chow diet ad libitum; 2) MNG, malnourished, fed 60% of the diet consumed by WNG; 3) WNG+T fed the same diet of WNG, but containing 1% of turmeric; 4) MNG+T fed 60% of the diet consumed by WNG+T. The animals were sacrificed at 90 days of age, the livers excised and hepatocytes primary cultures were prepared. Half of the plates of hepatocytes culture were treated with acetaminophen. Dose-response curve showed that 6 mM acetaminophen increased peroxidation around 54% and decreased GSH content around 63%. The model of malnutrition used, by restricting food ingestion (40%), decreased body weight in 33% and peroxidation index around 42% and increased GSH content around 43%. Turmeric ingestion decreased hepatocyte peroxidation in both well-nourished (42%) and malnourished rats (33%) and was able to avoid the acetaminophen pro-oxidant effect in both well-nourished and malnourished animals. Turmeric ingestion played a beneficial role to the organism and, therefore, can be considered a functional food.<br>O objetivo do presente estudo foi avaliar o efeito da ingestão de cúrcuma sobre a peroxidação lipídica e conteúdo de GSH, por ação tóxica in vitro de paracetamol, utilizando cultura primária de hepatócitos. Quatro grupos de ratos Holtzman foram usados: 1) GNN, normonutrido, alimentado ad libitum com ração de laboratório; 2) GDN, desnutrido, alimentado com 60% da quantidade de ração consumida por GNN; 3) GNN+C, alimentado como GNN, mas contendo 1% de cúrcuma na dieta; 4) GDN+C, alimentado como GDN, mas contendo 1% de cúrcuma na dieta. Os animais foram sacrificados aos 90 dias de vida, e cultura de hepatócitos preparada. Metade das placas de cultura foi tratada com paracetamol. A curva dose-resposta mostrou que 6 mM de paracetamol aumentou em 54% a peroxidação e diminuiu em 63% o conteúdo de GSH. A restrição na ingestão de alimentos (40%) diminuiu o peso corporal (33%) ao sacrifício e o índice de peroxidação cerca de 42%, entretanto, aumentou o conteúdo de GSH cerca de 43%. A ingestão de cúrcuma diminuiu a peroxidação em ambos ratos normonutridos (42%) e desnutridos (33%) e evitou o efeito pro-oxidante de paracetamol em ambos os grupos. A cúrcuma exerceu efeito protetor antioxidante sobre o organismo

Arterial Levels of Oxygen Stimulate Intimal Hyperplasia in Human Saphenous Veins via a ROS-Dependent Mechanism

<div><p>Saphenous veins used as arterial grafts are exposed to arterial levels of oxygen partial pressure (pO₂), which are much greater than what they experience in their native environment. The object of this study is to determine the impact of exposing human saphenous veins to arterial pO₂. Saphenous veins and left internal mammary arteries from consenting patients undergoing coronary artery bypass grafting were cultured ex vivo for 2 weeks in the presence of arterial or venous pO₂ using an established organ culture model. Saphenous veins cultured with arterial pO₂ developed intimal hyperplasia as evidenced by 2.8-fold greater intimal area and 5.8-fold increase in cell proliferation compared to those freshly isolated. Saphenous veins cultured at venous pO₂ or internal mammary arteries cultured at arterial pO₂ did not develop intimal hyperplasia. Intimal hyperplasia was accompanied by two markers of elevated reactive oxygen species (ROS): increased dihydroethidium associated fluorescence (4-fold, p<0.05) and increased levels of the lipid peroxidation product, 4-hydroxynonenal (10-fold, p<0.05). A functional role of the increased ROS saphenous veins exposed to arterial pO₂ is suggested by the observation that chronic exposure to tiron, a ROS scavenger, during the two-week culture period, blocked intimal hyperplasia. Electron paramagnetic resonance based oximetry revealed that the pO₂ in the wall of the vessel tracked that of the atmosphere with a ~30 mmHg offset, thus the cells in the vessel wall were directly exposed to variations in pO₂. Monolayer cultures of smooth muscle cells isolated from saphenous veins exhibited increased proliferation when exposed to arterial pO₂ relative to those cultured at venous pO₂. This increased proliferation was blocked by tiron. Taken together, these data suggest that exposure of human SV to arterial pO₂ stimulates IH via a ROS-dependent pathway.</p></div

Oxygen levels within the wall of SV cultured at various levels of pO₂ and the impact of pO₂ on the proliferation of cultured SMC.

<p>(A) Arrow indicates location of the black EPR probe within SV cultured ex vivo for internal pO₂ measurements. Intima and adventitia are labeled to show vessel orientation. Scale bar is 50 μm. (B) Quantification of oxygen levels within intact SV as measured by EPR probe. SV were in ex vivo culture at pO₂ of either 40 (venous), 95 (arterial) or 140 mmHg (typical cell culture atmosphere). Cell number as a function of time during culture for SMC isolated from HSV (C) and 3T3 fibroblasts (D). Isolated SMC were cultured at venous pO₂ or at arterial pO₂, with and without tiron. NIH3T3 fibroblasts were cultured at venous or arterial pO₂. *indicates statistically different compared to other groups at corresponding time point. Standard deviations bars are not visible when their size is small compared to the size of the symbols indicating means.</p

ROS levels in freshly isolated and cultured SV as assessed by DHE staining.

<p>(A) DHE and DAPI staining of freshly isolated SV and SV cultured at arterial or venous pO₂. Scale bar is 100 μm. (B) Average normalized mean of DHE fluorescence intensity (n = 3). * indicates p<0.05 relative to other groups marked with #. There were no intragroup differences among subgroups marked with #.</p