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Hypercholesterolemia is a metabolic disorder characterized by high levels of low-density lipoprotein and blood cholesterol, causing inflammatory lesion. Purinergic signaling modulates the inflammatory and immune responses through adenine nucleotides and nucleoside. Guaraná has hypocholesterolemic and antiinflammatory properties. Considering that there are few studies demonstrating the effects of guaraná powder on the metabolism of adenine nucleotides, we investigated its effects on the activity of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and ecto-adenosine deaminase activity in lymphocytes of rats with diet-induced hypercholesterolemia. The rats were divided into hypercholesterolemic and normal diet groups. Each group was subdivided by treatment: saline, guaraná powder 12.5, 25, or 50 mg/kg/day and caffeine concentration equivalent to highest dose of guaraná, fed orally for 30 days. An increase in adenosine triphosphate hydrolysis was observed in the lymphocytes of rats with hypercholesterolemia and treated with 25 or 50 mg/kg/day when compared with the other groups. The hypercholesterolemic group treated with the highest concentration of guaraná powder showed decreased ecto-adenosine deaminase activity compared with the normal diet groups. Guaraná was able to reduce the total cholesterol and low-density lipoprotein cholesterol to basal levels in hypercholesterolemic rats. High concentrations of guaraná associated with a hypercholesterolemic diet are likely to have contributed to the reduction of the inflammatory process.

The aim of the present study was to investigate the effect of curcumin (Cur) on the activity of ectonucleoside triphosphate diphosphohydrolase (CD39), 5'-nucleotidase (CD73) and adenosine deaminase in platelets of cigarette smoke-exposed rats. For that purpose, we subjected male Wistar rats to a treatment with Cur and cigarette smoke, once a day, 5 days each week, for 30 days. The rats were treated by gavage with Cur or corn oil and then exposed to cigarette smoke. The experimental procedures were divided into two sets of experiments. In the first, the animals were divided into four groups: vehicle (corn oil) or Cur 12·5, 25 or 50 mg·kg(-1) . In the second, the animals were divided into five groups: vehicle (corn oil), smoke, or smoke and Cur 12·5, 25 or 50 mg·kg(-1) . The results showed that treatment with Cur significantly prevented the increased adenosine triphosphate (ATP) (121%) and adenosine monophosphate (AMP) (159%) and the decreased adenosine diphosphate (ADP) (51%) hydrolysis observed in the cigarette smoke-exposed rats Our results suggest that those purinergic enzyme alterations observed in the cigarette smoke-exposed rats could be related to an excessive platelet aggregation and point toward the potential of Cur to modulate purinergic signalling and, consequently, regulate the thrombus formation.

Hyperlipidemia is a risk factor for the development of cognitive dysfunction and atherosclerosis. Natural compounds have recently received special attention in relation to the treatment of disease due to their low cost and wide margin of safety. Thus, the aim of this study was to determine the possible preventive effect of guarana powder (Paullinia cupana) on memory impairment and acetylcholinesterase (AChE) activity in the brain structures of rats with Poloxamer-407-induced hyperlipidemia. Adult male Wistar rats were pretreated with guarana (12.5, 25 and 50mg/kg/day) and caffeine (0.2mg/kg/day) by gavage for a period of 30days. Simvastatin (0.04mg/kg) was administered as a comparative standard. Acute hyperlipidemia was induced with intraperitoneal injections of 500mg/kg of Poloxamer-407. Memory tests and evaluations of anxiety were performed. The cortex, cerebellum, hippocampus, hypothalamus and striatum were separated to assess acetylcholinesterase activity. Our results revealed that guarana powder was able to reduce the levels of TC and LDL-C in a manner similar to simvastatin. Guarana powder also partially reduced the liver damage caused by hyperlipidemia. Guarana was able to prevent changes in the activity of AChE and improve memory impairment due to hyperlipidemia. Guarana powder may therefore be a source of promising phytochemicals that can be used as adjuvant therapy in the management of hyperlipidemia and cognitive disorders.