Effects of silymarin on angiogenesis and oxidative stress in streptozotocin-induced diabetes in mice.

The present study evaluated the effects of acute treatment with silymarin, an extract that is obtained from Silybum marianum, on angiogenesis, oxidative stress, and inflammation in normoglycemic and diabetic mice. Diabetes was induced by streptozotocin (80 mg/kg, intraperitoneal) in male Swiss mice, 6 weeks of age. A polyether-polyurethane sponge was surgically implanted in the back of the mice as a model of healing in both diabetic and normoglycemic animals that were treated with oral silymarin or water for 10 days. The pancreas, liver, kidneys, blood, and sponges were collected and analyzed. Diabetes led to impairments of antioxidant defenses, reflected by a reduction of pancreatic superoxide dismutase and hepatic and renal catalase and an increase in pancreatic lipoperoxidation. An inflammatory process was observed in diabetic mice, reflected by an increase in pancreatic tumor necrosis factor α (TNF-α) and the infiltration of inflammatory cells in islets. The number of vessels was lower in the implanted sponges in diabetic mice. Silymarin treatment attenuated this damage, restoring antioxidant enzymes and reducing pancreatic TNF-α and inflammatory infiltration. However, silymarin treatment did not restore angiogenesis or glycemia. In conclusion, treatment with silymarin red uced oxidative stress and inflammation that were induced in the model of streptozotocin-induced diabetes in several organs, without apparent toxicity. Silymarin may be a promising drug for controlling diabetic complications.

Polyphenol-Rich Foods Alleviate Pain and Ameliorate Quality of Life in Fibromyalgic Women.

Objectives: The present study aimed to describe the antioxidant dietary intake of patients with fibromyalgia and explore the association of the results with glutathione status, pain, quality of life, and socioeconomic status. METHODS: 38 fibromyalgic female patients and 35 female controls (mean age = 48.6 ± 8.1 and 47.6 ± 10.0 years, respectively) were evaluated. The number of tender points, pain threshold, quality of life, physical activity, socioeconomic status, nutritional status, intake of antioxidant micronutrients and foods with high total antioxidant capacity, and total salivary glutathione were evaluated. RESULTS: The number of tender points, pain threshold, and quality of life were worse in the fibromyalgia group. The consumption of vegetable juices was more common among women with fibromyalgia and consumption of red wine and beer were more common among healthy women. The adjusted mean intakes of antioxidant vitamins as well as selenium were higher for the control group (p ≤ 0.01). There was no difference for salivary levels of glutathione between the groups and no correlation for intake of antioxidant micronutrients and pain or quality of life among fibromyalgic women. However, intake of foods rich in polyphenols was associated with lower numbers of tender points (coffee, r = - 0.346; pear, r = - 0.331) and better quality of life (red fruits, r = - 0.342; dark chocolate, r = - 0.404) in the fibromyalgic group. In these women, associations between glutathione levels and food intake, pain or quality of life were not found. CONCLUSION: This study indicated that antioxidant protection from bioactive compounds present in fruit and vegetables could have an adjuvant role in fibromyalgia treatment.

Metabolic switches during the first steps of adipogenic stem cells differentiation.

The understanding of metabolism during cell proliferation and commitment provides a greater insight into the basic biology of cells, allowing future applications. Here we evaluated the energy and oxidative changes during the early adipogenic differentiation of human adipose tissue-derived stromal cells (hASCs). hASCs were maintained under differentiation conditions during 3 and 7days. Oxygen consumption, mitochondrial mass and membrane potential, reactive oxygen species (ROS) generation, superoxide dismutase (SOD) and catalase activities, non-protein thiols (NPT) concentration and lipid peroxidation were analyzed. We observed that 7days of adipogenic induction are required to stimulate cells to consume more oxygen and increase mitochondrial activity, indicating organelle maturation and a transition from glycolytic to oxidative energy metabolism. ROS production was only increased after 3days and may be involved in the differentiation commitment. ROS source was not only the mitochondria and we suggest that NOX proteins are related to ROS generation and therefore adipogenic commitment. ROS production did not change after 7days, but an increased activity of catalase and NPT concentration as well as a decreased lipid peroxidation were observed. Thus, a short period of differentiation induction is able to change the energetic and oxidative metabolic profile of hASCs and stimulate cytoprotection processes.

Impairment of oxidative phosphorylation increases the toxicity of SYD-1 on hepatocarcinoma cells (HepG2).

Toxicity of the SYD-1 mesoionic compound (3-[4-chloro-3-nitrophenyl]-1,2,3-oxadiazolium-5-olate) was evaluated on human liver cancer cells (HepG2) grown in either high glucose (HG) or galactose (GAL) medium, and also on suspended cells kept in HG medium. SYD-1 was able to decrease the viability of cultured HepG2 cells in a dose-dependent manner, as assessed by MTT, LDH release and dye with crystal violet assays, but no effect was observed on suspended cells after 1-40 min of treatment. Respiration analysis was performed after 2 min (suspended cells) or 24 h (cultured cells) of treatment: no change was observed in suspended cells, whereas SYD-1 inhibited as well basal, leak and uncoupled states of the respiration in cultured cells with HG medium. These inhibitions were consistent with the decrease in pyruvate level and increase in lactate level. Even more extended results were obtained with HepG2 cells grown in GAL medium where, additionally, the ATP amount was reduced. Furthermore, SYD-1 appears not to be transported by the main ABC multidrug transporters. These results show that SYD-1 is able to change the metabolism of HepG2 cells, and suggest that its cytotoxicity is related to impairment of mitochondrial metabolism. Therefore, we may propose that SYD-1 is a potential candidate for hepatocarcinoma treatment.

The lectin BJcuL induces apoptosis through TRAIL expression, caspase cascade activation and mitochondrial membrane permeability in a human colon adenocarcinoma cell line.

It has been demonstrated that the cytotoxic effect of BJcuL, the lectin isolated from Bothrops jararacussu venom, on human gastric carcinoma is accompanied by the inhibition of extracellular matrix adhesion, cytoskeleton disassembly and apoptosis induction. The present study aimed to evaluate the apoptosis mechanisms triggered by the BJcuL interaction with specific glycans on the surface of HT29 human colon adenocarcinoma cells. The results demonstrated that BJcuL interacts with glycoligands targets on the cell, which were inhibited in the presence of d-galactose. It shows a dose-dependently cytotoxic effect that is inhibited in the presence of d-galactose. A dose-dependent cell aggregation decrease was also observed for the HT29 cells. Analysis of cell proliferation inhibition was assessed by anti-PCNA and demonstrated that lectin diminishes PCNA expression when compared with untreated cells. Differences in apoptotic marker expression estimated by immunohistochemistry revealed that the lectin promotes an increase in TRAIL expression, leading to an increase in the expression of FADD, caspase-8 and Bax. Besides the increased expression of apoptosis-related proteins, our results revealed that the lectin promotes a mitochondrial respiration decrease and a 75% increase in the amount of cytochrome c released. Together these results suggest that the cytotoxicity of BJcuL can sensitize pro-apoptotic proteins in the cytoplasm and mitochondria, leading to the apoptotic cascade.

Sydnone SYD-1 affects the metabolic functions of isolated rat hepatocytes.

Previously, we demonstrated that sydnone SYD-1 (3-[4-chloro-3-nitrophenyl]-1,2,3-oxadiazolium-5-olate) impairs the mitochondrial functions linked to energy provision and suggested that this effect could be associated with its antitumor activity. Herein, we evaluated the effects of SYD-1 (25 and 50 µM) on rat hepatocytes to determine its cytotoxicity on non-tumor cells. SYD-1 (25 and 50 µM) did not affect the viability of hepatocytes in suspension after 1-40 min of incubation. However, the viability of the cultured hepatocytes was decreased by ∼66% as a consequence of treatment with SYD-1 (50 µM) for 18 h. Under the same conditions, SYD-1 promoted an increase in the release of LDH by ∼19%. The morphological changes in the cultured cells treated with SYD-1 (50 µM) were suggestive of cell distress, which was demonstrated by the presence of rounded hepatocytes, cell fragments and monolayer impairment. Furthermore, fluorescence microscopy showed an increase in the annexin label after treatment with SYD-1 (50 µM), suggesting that apoptosis had been induced in these cells. SYD-1 did not affect the states of respiration in the suspended hepatocytes, but the pyruvate levels were decreased by ∼36%, whereas the lactate levels were increased by ∼22% (for the 50 µM treatment). The basal and uncoupled states of respiration of the cultured hepatocytes were inhibited by ∼79% and ∼51%, respectively, by SYD-1 (50 µM). In these cells, SYD-1 (50 µM) increased the pyruvate and lactate levels by ∼84% and ∼16%, respectively. These results show that SYD-1 affects important metabolic functions related to energy provision in hepatocytes and that this effect was more pronounced on cells in culture than those in suspension.

Effects of statins on liver cell function and inflammation in septic rats.

BACKGROUND: Several studies suggest that the presence of statins may be beneficial during sepsis, but this idea is controversial. The aim of this study was to investigate the effects of long-term statin treatment in the livers of septic animals, focusing on its antioxidant, antiinflammatory, and metabolic properties. MATERIALS AND METHODS: Male Wistar rats were treated orally with simvastatin, atorvastatin, or vehicle once a d. After 30 d, sepsis was induced by cecal ligation and puncture (CLP) in Control, Simvastatin-treated, and Atorvastatin-treated groups, while the Sham group underwent only laparotomy. The Basal Simvastatin and Basal Atorvastatin groups received only their respective drugs without surgery. Twenty-four h after CLP or laparotomy, samples were collected from anesthetized rats for evaluation of hepatic oxidative stress, liver histology, hepatic mitochondria enzyme activity, leukocyte counts in blood and peritoneal cavity, gene expression of hepatic superoxide dismutase and TNF-2, and plasma biochemistry. RESULTS: Most parameters that we tested exhibited expected changes upon sepsis induction. However, statin treatment only improved liver mitochondrial enzymatic activity. In other parameters, simvastatin and atorvastatin failed to protect the liver against injuries incurred upon the CLP-induced polymicrobial sepsis model. CONCLUSIONS: Pretreatment with simvastatin or atorvastatin alone before sepsis induction improved mitochondrial activity in the liver; however, this result was not reproduced in other biomarkers of liver function and leukocyte migration during sepsis. Future studies should be performed to evaluate whether statins can be combined with other drugs to increase the efficacy of sepsis therapy.

Avaliação in vivo do efeito hipocolesterolêmico e toxicológico preliminar do extrato bruto hidroalcoólico e decocção da Vitex megapotamica (Spreng) Moldenke (V. montevidensis Cham) / Evaluation of prospective hypocholesterolemic effect and preliminary toxicology of crude extract and decoction from Vitex megapotamica (Spreng) Moldenke (V. montevidensis Cham) in vivo

As doenças cardiovasculares (DC) estão, de modo geral, associadas a elevados níveis séricos de lipídeos, atingindo homens e mulheres, sem distinção de idade. Entre as propriedades atribuídas pela medicina popular à Vitex megapotamica (Spreng) Moldenke (V. montevidensis Cham) -Tarumã estão a de reduzir os níveis séricos de colesterol e triglicerídeo. O principal objetivo do presente estudo foi avaliar o potencial hipocolesterolêmico e hipolipidêmico da V. megapotamica, bem como fazer um estudo toxicológico preliminar. Para tanto, foi realizada indução hiperlipidêmica usando um modelo que preconiza o emprego de propiltiuracil 1,25 mg/300 g de peso e colesterol 200 mg/kg de peso, aplicados via oral em ratos machos pesando 300 ± 10 g. Foi administrado, por via oral, aos animais hiperlipidêmicos previamente induzidos 300 mg/kg de extrato hidroalcoólico das folhas de V. megapotamica ou 300 mL da decocção da casca da planta. Após o final de cada tratamento, o perfil lipídico foi ensaiado, bem como os níveis de glicose, quando relevante. Nossos resultados confirmaram o efeito hipolipidêmico do extrato hidroalcoólico e da decocção pela redução dos níveis séricos de colesterol e triacilglicerol nas concentrações, via e forma utilizadas. Além disso, foi possível verificar que não houve lesão cardíaca, hepática ou renal pelo extrato e decocção utilizados nas avaliações toxicológicas preliminares ensaiadas.

The cardiovascular diseases are, in general, associated with high levels of serum lipids which have high incidence in middle-age men and women. Among other properties characterized by popular medicine, the Vitex megapotamica (Spreng) Moldenke (V. montevidensis Cham) - Tarumã, decreases the serum cholesterol and triacylglycerol levels. The main proposition of the present study was to evaluate the hypocholesterolemic and hipolipidaemic potential of V. megapotamica and to analyze the preliminary toxicity. It was an induction hyperlipidaemic model using propiltiuracil 1.25 mg/kg weight and cholesterol 200 mg/ kg weight per oros in male rats, weigthing 300 ± 10 g. It was administred to the animals 300 mg/ kg of hydroalcoholic leaves extract of V. megapotamica or 300 mL of hull decoction per oros. After the end of each treatment, the lipid profile was essayed as well as glucose, when relevant. Our results confirmed the V. megapotamica extract and decoction hypolipidaemic effect by the decrease of cholesterol and triacylglycerides serum levels in concentration, via and preparation performed. Furthermore, the toxicological preliminary assays showed there was not extract and decoction damage induction in cardiac and hepatic tissues, as well as in kidney physiology by assays performed.