Lead (Pb) is an environmental contaminant that presents a high risk for human health. We aimed to investigate the possible alterations triggered by the exposure to Pb acetate for a long period in motor performance and the possible relationship with biochemical, proteomic and morphological alterations in the cerebellum of rats. Male Wistar rats were exposed for 55 days, at 50 mg/Kg of Pb acetate, and the control animals received distilled water. Open field (OF) and rotarod tests; biochemistry parameters (MDA and nitrite); staining/immunostaining of Purkinje cells (PC), mature neurons (MN), myelin sheath (MS) and synaptic vesicles (SYN) and proteomic profile were analyzed. Pb deposition on the cerebellum area and this study drove to exploratory and locomotion deficits and a decrease in the number of PC, MN, SYN and MS staining/immunostaining. The levels of MDA and nitrite remained unchanged. The proteomic profile showed alterations in proteins responsible for neurotransmitters release, as well as receptor function and second messengers signaling, and also proteins involved in the process of apoptosis. Thus, we conclude that the long-term exposure to low Pb dose promoted locomotion and histological tracings, associated with alterations in the process of cell signaling, as well as death by apoptosis.

Lead (Pb) is an environmental and occupational neurotoxicant after long-term exposure. This study aimed to investigate the effects of systemic Pb exposure in rats from adolescence to adulthood, evaluating molecular, morphologic and functional aspects of hippocampus. For this, male Wistar rats were exposed to 50 mg/kg of Pb acetate or distilled water for 55 days by intragastric gavage. For the evaluation of short-term and long-term memories, object recognition and step-down inhibitory avoidance tests were performed. At the end of the behavioral tests, the animals were euthanized and the hippocampus dissected and processed to the evaluation of: Pb content levels in hippocampal parenchyma; Trolox equivalent antioxidant capacity (TEAC), glutathione (GSH) and malondialdehyde (MDA) levels as parameters of oxidative stress and antioxidant status; global proteomic profile and neuronal degeneration by anti-NeuN immunohistochemistry analysis. Our results show the increase of Pb levels in the hippocampus of adult rats exposed from adolescence, increased MDA and GSH levels, modulation of proteins related to neural structure and physiology and reduced density of neurons, hence a poor cognitive performance on short and long-term memories. Then, the long-term exposure to Pb in this period of life may impair several biologic organizational levels of the hippocampal structure associated with functional damages.

The aim of this study was to determine the physicochemical composition and inorganic constituents of seventeen honey samples produced in Amazon region by different bee species (Scaptotrigona sp., Melipona fasciculata, Melipona flavolineata and Apis mellifera). The physicochemical parameters evaluated were pH, acidity, soluble solids, moisture, density, reducing sugars, apparent sucrose and hydroxymethylfurfural. Ba, Ca, Cd, Cu, Fe, Mg, Mn, P, Pb and Zn contents were determined in honey samples by inductively coupled plasma optical emission spectrometry. Na and K contents were measured in honeys by flame atomic absorption spectrometry. Honey samples were digested in a microwave oven using diluted nitric acid and hydrogen peroxide. The analytical results obtained in this study were evaluated by analysis of certified reference material (GBW 07604 Poplar leaves). The results of physicochemical analyzes showed significant differences (p < 0.05) among the species, mainly regarding moisture content, acidity, density and soluble solids. In general, the honeys from Scaptotrigona sp. showed the highest levels of minerals (Ca, Cu, K, Mg), being a good source of minerals, as well as presented significant differences (at 5% of significance) in relation to the other studied species. Thus, the results indicate new information about the composition of these honeys and emphasize the need for the implementation of specific legislation for quality assessing of honey from stingless bees.