Pereskia aculeata Miller Flour: Metabolic Effects and Composition.

Pereskia aculeata Miller is known in Brazil as ora-pro-nobis (OPN) and has been used commonly in the folklore medicine. The purpose of our study was to evaluate the composition and the effects of OPN flour on the metabolic profile and intestinal motility of Wistar rats. Animals were divided randomly into five groups (n = 10): G1 (control group) and G2 (treated with OPN flour). For the intestinal motility: G3 (control group), G4 (treated with senne), and G5 (treated with OPN flour). After 40 days, G1 and G2 were euthanized and metabolic profiles were analyzed (glycemia, cholesterol, triglycerides, high density lipoprotein [HDL-c], C reactive protein, AST, ALT, Lee Index, weight, and visceral fat). The flour of OPN was effective in reducing percentage of weight gain, visceral fat, levels of total cholesterol, triglycerides, low density lipoprotein, very low density lipoprotein, and increased HDL-c. Significance was also found in the distance covered by the activated charcoal from the pylorus to the beginning of the cecum, which was higher in animals treated with OPN. Our results indicate that OPN flour may bring health benefits, as the improvement of the intestinal motility, and it is associated with reduction of visceral fat and lipid profile, as well as the increase of HDL-c levels. With these results, we may suggest that the incorporation of this flour in different industrial products may be a convenient and effective way for the intake of healthier products.

Mercury and DDT exposure risk to fish-eating human populations in Amazon.

In order to investigate the potential risk of mercury and DDTs exposure to fish-eating human populations in Samuel Reservoir, not affected directly by gold-mining activities, the axial muscle of Cichla monoculus was analyzed. Twenty-nine and thirty adults individuals were collected respectively on February (rainy season) and August (dry season) 2007. The specimens were sacrificed by spinal section before sex identification, body weight and total length determination. For total mercury, DDT and DDE quantifications and cholinesterase activity samples of the axial muscle were frozen at -20°C, and for histopathological studies gill and liver were fixed in ALFAC solution for 16 h. A value of 48.2% and 33% of the individuals, respectively from rainy and dry seasons, presented mercury concentrations higher than the maximum established for safe human consumption (0.5 µg g⁻¹) by World Health Organization. A positive correlation between body weight and Hg concentration was observed only in individuals from the rainy season, but no correlation was observed to DDT and DDE from both seasons. Differently from that observed to mercury, DDT levels presented a significant difference between both studied seasons, but no correlation was observed for both mercury and DDTs and sex. The levels of DDTs in muscle of C. monoculus are under the maximum established by FAO-Alimentarius CODEX and Swedish Food Regulation for human consumption. The histopathological and neurotoxic findings showed that the wild population of fish is affected by chronic exposure to mercury, meaning risk also to fish-eating populations. Finally, the results showed that C. monoculus is an important vehicle for human exposure to mercury and DDTs in Samuel Reservoir and that it is necessary a continuous biomonitoring of the levels of both pollutants in order to manage the risk of exposure to human populations.

Recovery of silver residues from dental amalgam.

UNLABELLED: Dental amalgam residues are probably the most important chemical residues generated from clinical dental practice because of the presence of heavy metals among its constituents, mainly mercury and silver. OBJECTIVE: The purpose of this study was to develop an alternative method for the recovery of silver residues from dental amalgam. MATERIAL AND METHODS: The residue generated after vacuum distillation of dental amalgam for the separation of mercury was initially diluted with 32.5% HNO3, followed by precipitation with 20% NaCl. Sequentially, under constant heating and agitation with NaOH and sucrose, the sample was reduced to metallic silver. However, the processing time was too long, which turned this procedure not viable. In another sequence of experiments, the dilution was accomplished with concentrated HNO3 at 90 degrees C, followed by precipitation with 20% NaCl. After washing, the pellet was diluted with concentrated NH4OH, water and more NaCl in order to facilitate the reaction with the reducer. RESULTS: Ascorbic acid was efficiently used as reducer, allowing a fast reduction, thus making the procedure viable. CONCLUSIONS: The proposed methodology is of easy application and does not require sophisticated equipment or expensive reagents.