Liver fibrosis, a common condition occurring during the evolution of almost all chronic liver diseases, is the consequence of hepatocyte injury that leads to the activation of Kupffer cells and hepatic stellate cells (HSC). Silymarin (Si) is a herbal product widely used for its hepatoprotective potential. Our study aims to investigate the effects of two different doses of Silymarin on a CCl4-induced model of liver fibrosis with a focus on the early stages of liver injury. Fifty Wistar rats were randomly divided into five groups (n=10): control group (sunflower oil twice a week); CMC group (carboxymethyl cellulose five times a week, sunflower oil twice a week); CCl4 group (CCl4 in sunflower oil, by gavage, twice a week); CCl4+Si 50 group (CCl4 twice a week, Silymarin 50 mg/b.w. in CMC five times a week); and CCl4+Si 200 group (similar to the previous group, with Si 200 mg/b.w.). One month after the experiment began we explored hepato-cytolysis (aminotransferases and lactate dehydrogenase), oxidative stress, fibrosis (histological score, hyaluronic acid), markers of HSC activation (transforming growth factor β1 [TGF-β1], and α-smooth muscle actin [α-SMA] expression by western blot) and activation of Kupffer cells by immunohistochemistry. Our data showed that Si 50 mg/b.w. had the capacity of reducing oxidative stress, hepato-cytolysis, fibrosis, activation of Kupffer cells, and the expression of α-SMA and TGF-β1 with better results than Si 200 mg/b.w. Thus, the usual therapeutic dose of Silymarin, administered in the early stages of fibrotic changes is capable of inhibiting the fibrogenetic mechanism and the progression of initial liver fibrosis.

Background: Diabetes mellitus (DM) is a chronic endocrine-metabolic disorder associated with endothelial dysfunction. Hyperglycemia, dyslipidemia and abnormal nitric oxide-mediated vasodilatation are the major causal factors in the development of endothelial dysfunction in DM. The prevention of endothelial dysfunction may be a first target against the appearance of atherosclerosis and cardiovascular diseases. We have investigated the synergistic protective effects of quercetin administration and moderate exercise training on thoracic aorta injuries induced by diabetes. Methods: Diabetic rats that performed exercise training were subjected to a swimming training program (1 h/day, 5 days/week, 4 weeks). The diabetic rats received quercetin (30 mg/kg body weight/day) for 4 weeks. At the end of the study, the thoracic aorta was isolated and divided into two parts; one part was immersed in 10% formalin for histopathological evaluations and the other was frozen for the assessment of oxidative stress markers (malondialdehyde, MDA and protein carbonyls groups, PC), the activity of antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT), nitrite plus nitrate (NOx) production and inducible nitric oxide synthase (iNOS) protein expression. Results: Diabetic rats showed significantly increased MDA and PC levels, NOx production and iNOS expression and a reduction of SOD and CAT activity in aortic tissues. A decrease in the levels of oxidative stress markers, NOx production and iNOS expression associated with elevated activity of antioxidant enzymes in the aortic tissue were observed in quercetin-treated diabetic trained rats. Conclusions: These findings suggest that quercetin administration in association with moderate exercise training reduces vascular complications and tissue injuries induced by diabetes in rat aorta by decreasing oxidative stress and restoring NO bioavailability.

Background: To investigate the protective effects of Quercetin administration associated with chronic moderate exercise (training) on oxidative stress in the liver in streptozotocin-induced diabetic rats. Methods: Diabetic rats that performed exercise training were subjected to a swimming training program (1 hour/day, 5 days/week, 4 weeks). The diabetic rats received natural antioxidant, Quercetin (20 mg/kg body weight/day) for 4 weeks. At the end of the study, all animals were sacrificed and liver samples were collected for estimation: some oxidative stress markers (malondialdehyde, MDA and protein carbonyls groups, PC), the activity of antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT), reduced glutathione (GSH) level and reduced (GSH) and oxidized (GSSG) glutathione ratio. Results: Diabetic rats submitted to exercise training showed significantly increased the oxidative stress markers (MDA and PC) and a reduction of antioxidant enzyme (SOD and CAT) activity, GSH level and GSH/ GSSG ratio in hepatic tissues. A decrease in the levels of oxidative stress markers associated with elevated activity of antioxidant enzymes, the GSH level and GSH/GSSG ratio in the hepatic tissue were observed in Quercetin-treated diabetic trained rats. Conclusions: These findings suggest that Quercetin administration in association with chronic moderate exercise exerts a protective effect in diabetes by attenuating hyperglycemia-mediated oxidative stress in hepatic tissue.

Silymarin (Si) is a herbal product with hepatoprotective potential, well-known for its antioxidant, anti-inflammatory, and immunomodulatory properties. We have recently demonstrated that the usual therapeutic doses of Si are capable of inhibiting the progression of incipient liver fibrosis. We aimed at further investigating the benefits of Si administration upon liver alterations after the hepatotoxin discontinuation, using CCl4 to induce liver injuries on rats. CCl4 administration induces first of all oxidative stress, but other mechanisms, such as inflammation and liver fibrosis are also triggered. Fifty Wistar rats were randomly divided into five groups (n = 10). The control group received sunflower oil twice a week for 8 weeks. Carboxymethyl cellulose group received sunflower oil twice a week, for 8 weeks and CMC daily, for the next 2 weeks. CCl4 group received CCl4 in sunflower oil, by gavage, twice a week, for 8 weeks. CCl4 + Si 50 group received CCl4 twice a week, for 8 weeks, and then 50 mg/body weight (b.w.) Silymarin for the next 2 weeks. CCl4 + Si 200 group was similar to the previous group, but with Si 200 mg/b.w. Ten weeks after the experiment had begun, we assessed inflammation (IL-6, MAPK, NF-κB, pNF-κB), fibrosis (hyaluronic acid), TGF-β1, MMP-9, markers of hepatic stellate cell activation (α-SMA expression), and proliferative capacity (proliferating cell nuclear antigen). Our data showed that Silymarin administered after the toxic liver injury is capable of reducing inflammation and liver fibrosis. The benefits were more important for the higher dose than for the usual therapeutic dose.

BackgroundMetallic phosphides are extremely toxic pesticides that are regulated in their usage. Information concerning the impact of metallic phosphides on human health is abundant. Data regarding the clinical pathology of phosphide poisoning in humans or domestic and wild animals is largely incomplete with only a few cases of metallic phosphide poisoning being reported every year, especially in humans. For the majority of cases reported in dogs the data are vague or incomplete. Here we report a complete and detailed description of pathological changes in a case of intentional metallic phosphide poisoning in a dog including an exhaustive examination of the brain.Case presentationA 1 year old, male, Belgian Shepherd crossbreed dog with a clean medical history and no observed clinical signs prior to death, was submitted for post mortem examination. The dog was found dead by the owner. Near the body a suspect mix of bread, fat and a blackish powder was found. The owner announced the authorities and submitted the animal and the possible bait for forensic examination. At necropsy, multisystemic necrotic and degenerative lesions were observed. Histological exam confirmed the presence of necrotic and degenerative lesions of variable severity in all of the examined organs. The toxicological forensic examination revealed the presence of the phosphine gas in the gastric content and the bait.ConclusionMetallic phosphide poisoning is a rarely reported entity, since the diagnosis of intentional poisoning with these compounds is a great challenge for forensic pathologists and toxicologists. To our knowledge, this is the first study describing the lesions completely in veterinary forensic toxicology. We assume that the toxic shows systemic endotheliotropism and damage of the endothelial cells responsible for the hemorrhagic lesions and for the secondary ischemic necrosis in various organs. This report will contribute to a better understanding of the pathogenesis in cases of acute metallic phosphide exposure in animals.