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. .

Influence of protein supplementation on the resistance and resilience on young hair sheep naturally infected with gastrointestinal nematodes during rainy and dry seasons.

Thirty, 4-month-old entire Santa Ines lambs were grazed on an Andropogon gayanus pasture, during a 34-week period (rainy season weeks 0-20 and dry season weeks 21-34) and allocated in two treatment groups (n = 15) each with different protein supplementation: high protein (HP-19% CP) and low protein (LP-11% CP). These were subdivided into those receiving anthelmintic treatment (c) (n = 7) and without anthelmintic treatment (i) (n = 8). The objective was to evaluate the effects of supplementation with protein on resistance and resilience to natural helminth infection of hair breed lambs. Lamb weight, blood collection and faecal egg counts (FEC) were carried out monthly. The lambs were slaughtered after 34 weeks, when worm burdens, worm length and eosinophil cell counts were taken. The sheep on treatments HPc and HPi were heavier in live weight than those from LPi and LPc (P < 0.05) at the end of the rainy period. The HPc group finished heavier (P < 0.05) than the other groups in the dry season, which had no significant differences between them. The predominant species of nematode found was T. colubriformis followed by H. contortus, Trichuris globulosa and Moniezia expansa. Animals on HPi had lower FEC than LPi (P < 0.05). The number of worms was lower for both HP groups (P < 0.05) with worm length shorter in the HPc group (P < 0.05) compared with all other groups. The number of eosinophils was higher in animals in the LPi group, which also showed anaemia and lower plasma urea at the end of the dry season. Diet supplementation with high protein was able to improve resilience and resistance to natural infection by endoparasites during the rainy season. In the dry season there was a decrease in both of these traits, which were intimately linked to the quality of available forage under tropical conditions.