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Almeida F.,Laboratorio Of Toxicologia Experimental | Schiavo L.V.,Laboratorio Of Toxicologia Experimental | Vieira A.D.,Laboratorio Of Toxicologia Experimental | Araujo G.L.,Laboratorio Of Toxicologia Experimental | And 4 more authors.
Food and Chemical Toxicology | Year: 2012

Lithothamnion calcareum is a red alga of the Corallinacea family whose main feature is the formation of calcium carbonate precipitate in its cell walls. L. calcareum is marketed as a nutritional supplement for calcium and other minerals in Brazil and other countries under the pharmaceutical name of Vitality 50+® In this study, gastroprotective and pre-clinical toxicity assays were performed on this product. Doses of 30, 120 and 480. mg/kg were used in the gastroprotective study on Wistar rats. A dose of 2000. mg/kg was used in the preclinical acute toxicity study and oral doses of 1000 and 2000. mg/kg were used in the subchronic toxicity evaluation. L. calcareum played no significant role in the protection of the rats' gastric mucosa, nor did it cause increase in gastric irritation. No impact on the acute toxicity test was identified. In the subchronic toxicity test, serum levels of albumin, total protein and calcium decreased, and creatinine levels increased, suggesting hypercalcemia and possible kidney damage associated with liver damage, given that the majority of these parameters were irreversible. Thus, this work aims to discuss the relationship of the high concentration of calcium in the product with the observed effects. © 2012 Elsevier Ltd. Source

De Avelar C.B.,Laboratorio Of Toxicologia Experimental | Mauricio H.D.,Laboratorio Of Toxicologia Experimental | Alves R.J.,Federal University of Minas Gerais | Menezes R.R.,Laboratorio Of Toxicologia Experimental | And 5 more authors.
Current Topics in Toxicology | Year: 2012

Metronidazole (MTZ) is an antibacterial/antiprotozoal drug used to treat infections. This study aimed to assess the safety of two pharmacologically active MTZ analogs, MTZ-Ms and MTZ-I, in an attempt to provide scientific evidences that justify further investments in these drugs. The acute toxicity studies were performed using 300 or 2000 mg/kg doses. No treatment-related mortality occurred in MTZ and MTZ-Ms groups. By contrast, one death was detected when using 2000 mg/kg of MTZ-I. In the subacute toxicity studies, 200, 400, or 600 mg/kg doses of MTZ and MTZ-I, and a 1000 mg/kg dose of MTZ-Ms, were applied. No abnormal behavior was observed in the MTZ and MTZ-Ms group. Two deaths in the MTZ-I (600 mg/kg) group were identified. Changes in clinical biochemistry parameters were of minor nature and occurred in the absence of a clear dose-related distribution. Lymphocytes and leukocytes increased in the MTZ and MTZ-Ms groups, suggesting immunostimulation. Histopathological examination revealed hyperplasia of intestinal epithelium along with alterations in spleen and testis in rats treated with MTZ (600 mg/kg) and MTZ-Ms (1000 mg/kg). In MTZ-I groups, mortality was considered to be related to treatment with test substance in both acute and subacute toxicity assays. The results suggest that MTZ and MTZ-Ms have similar toxicological profile. However, further investigations are warranted. Source

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