Neuroprotective Effects of Guarana (Paullinia cupana Mart.) against Vincristine in Vitro Exposure.

BACKGROUND: Vincristine (VCR) is not a specific chemotherapeutic drug, responsible for cause several side effects. In this sense, many natural products have been studied to reduce this problem. Objetives: To examine the guarana neuroprotective effect in mice brain and cerebellum cells against vincristine (VCR) exposition. DESIGN: An in vitro study was performed using mice brain and cerebellum mice in monolayer culture. First, cells were exposed to VCR (0.009 µM for 24 hours and 0.0007 µM for 72 hours) to measure the cytotoxicity effect. Also, the cellular effect of hydroalcoholic extract of guarana (10; 30; 100 and 300 µg/mL) was evaluated in the same cells in 24 and 72 hours. After that, cells were exposed to VCR and guarana extract to evaluate the neuroprotective effect of guarana. MEASUREMENTS: Cell viability was analyzed by MTT, Free dsDNA and LHD Assays. Moreover, metabolism oxidative profile was evaluated by reactive oxygen species (ROS), lipoperoxidation (LPO) and catalase (CAT) levels through DCFH-DA, TBARS and Catalase Activity Assays, respectively. RESULTS: Our findings revealed that VCR caused neuronal cytotoxicity by reducing cell viability and increasing ROS and LPO levels. On the other hand, guarana did not cause cell damage in none of tested concentrations. In addition, guarana exhibited a notable protective effect on brain and cerebellum cells exposed to VCR by increasing cell viability, stimulating CAT activity, reducing levels of ROS and LPO. CONCLUSIONS: In this sense, guaraná is a remarkable antioxidant fruit that could be a target in new therapies development to reduce VCR neurotoxicity. .

Hypercholesterolemia and Ecto-enzymes of Purinergic System: Effects of Paullinia cupana.

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.