IJCS | Volume 32, Nº2, May/June 2019

DOI: 10.5935/2359-4802.20180097 238 ORIGINAL ARTICLE International Journal of Cardiovascular Sciences. 2019;32(3)238-246 Mailing Address: Matheus Lavorenti Rocha Rua 240, s/n - Setor Leste Universitário. Postal Code: 74605-170, Goiânia, GO - Brazil. E-mail: matheusroch@yahoo.com.br, rochaml@ufg.br Antioxidant and Vasodilatory Action of Grape Juices Produced in Different Regions of Brazil José Britto Junio r, K arla Carneiro Siqueira Leit e, Eric de Souza Gi l, Matheus Lavorenti Roch a Universidade Federal de Goiás (FF/UFG), Goiás, GO - Brazil Manuscript received on November 30, 2017, revised manuscript on July 20, 2018, accepted on August 07, 2018. Abstract Background: Grapes and its derivatives (wines and juices) are rich in polyphenols that have high antioxidant and vasodilator capacity. These biological activities may vary in the juices marketed and produced in different regions of Brazil. Objectives: To determine the antioxidant and vasorelaxant effects of grape juice samples produced in different regions of Brazil. Methods: The content of phenolic compounds and antioxidant capacity were evaluated by the methods of Folin- Ciocalteau, DPPH, ABTS and a new electroanalytical approach (differential pulse voltammetry - DPV). Vasodilator effects were analyzed in isolated aorta from rats in an organ bath. Results: The samples from RJ and SP presented respectively the higher and lower phenolic content and also antioxidant capacity by the methods used (ABTS and DPPH). The results of the electrochemical index corroborate to the other tests, with the best results to RJ (21.69 ± 3.15 µA/V) and worse to the SP sample (11.30 ± 0.52 µA/V). In the vascular reactivity studies, the relaxation induced by each sample presented more distinct differences, following the order: RJ (87.9 ± 4.8%) > RS1 (71.6 ± 8.6%) > GO (56.2 ± 7.2%) > SP (39.9 ± 7.8%) > PR (39.4 ± 9.5%) > RS2 (19.5 ± 6.2%). Inhibition of endothelial NO practically abolished (p < 0.001) the relaxation for all samples, except one. Conclusion: The phenolic content and antioxidant capacity vary greatly among samples. The results obtained for the order of antioxidant activity were: RJ > RS1 > GO > RS2 > PR > SP. The juices were able to induce vascular relaxation at quite varied levels, and the RJ sample the most effective. The L-NAME practically blocked all samples except one (RS2). (Int J Cardiovasc Sci. 2019;32(3)238-246) Keywords: Antioxidants/pharmacology; Vasodilatation; Vasodilatador Agents/analysis; Vitis; Fruit and Vegetable Juices/analysis; Epidemiology; Cardiovascular Diseases/prevention and control; Neoplasms/prevention and control. Introduction Epidemiological evidence shows that the ingestion of foods rich in polyphenols (such as grapes and grape products) is associated with decreased mortality worldwide due to reduced cases of cancer and cardiovascular diseases. 1 Polyphenols have beneficial antioxidant effects against oxidative stress, themain pathophysiological mechanism in the development of cardiovascular diseases, such as hypertension, diabetes and atherosclerosis. 2 They cause vasodilation by increasing the production of vasodilatory agents produced by the vascular endothelium (as NO) and decreasing vasoconstricting agents, such as endothelin-1. 2,3 In addition, there is a direct correlation between the number of polyphenols in red wine and its capacity to induce endothelium-dependent vasodilation. 4 Despite the great benefit of chronic red wine consumption, the alcohol present in the drink generates some limitations of use, mainly in psychiatric patients,