Suplementação alimentar com Spirulina platensis previne o desenvolvimento da disfunção erétil em ratos Wistar alimentados com dieta hipercalórica

• Autor(a) principal: Souza, Iara Leão Luna de
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/13653
• topic: Spirulina platensis; Disfunção erétil; Dieta hipercalórica; Rho cinase; Óxido nítrico; Prostanoides; Estresse oxidativo; Erectile dysfunction; Hypercaloric diet; Rho kinase; Nitric oxide; Prostanoids; Oxidative stress; CNPQ::CIENCIAS BIOLOGICAS::FARMACOLOGIA

Erectile dysfunction is defined as the inability to achieve and/or maintain a penile erection sufficient for sexual satisfaction, with obesity, a chronic inflammatory disease, characterized by adipose tissue accumulation as a risk factor. Currently, many patients do not respond appropriately to ED pharmacotherapy. Therefore, the possible effects of a food supplementation with Spirulina platensis, algae with potential vasodilator and antioxidant, were evaluated in a model of ED induced by the hypercaloric diet consumption. The experimental procedures were approved by the UFPB Ethics Committee on Animal Use (certificate 0201/14). Wistar rats were divided into groups fed with a standard diet that receive saline solution (CSG), that were supplemented with the algae at doses of 25 (CG + SP25), 50 (CG + SP50) or 100 mg/kg/day (CG + SP100) and treated with sildenafil at dose of 1.5 mg/kg/day (CG + Sild) or in groups fed with a hypercaloric diet that receive saline solution (OSG), that were supplemented with the algae at doses of 25 (OG + SP25), 50 (OG + SP50) or 100 mg/kg/day (OG + SP100) and treated with sildenafil at dose of 1.5 mg/kg/day (OG + Sild). The nutritional and morphometric parameters, erectile function, in vivo, functional mechanisms involved in the alterations of the corpus cavernosum contractile and relaxing reactivity, in vitro, and the systemic and tissue oxidative stress were analyzed. Spirulina platensis at the dose of 50 mg/kg reduced food intake and final body mass of rats fed with a standard diet, while at the dose of 100 mg/kg promoted a reduction in the mass and diameter of adipocytes from the inguinal adipose tissue and, consequently, in the adiposity index. In addition, no change was observed in the basal erectile function of these rats. However, the hypercaloric diet consumption resulted in a decrease in food intake, but, there was an increase in the final body mass, as a result of the increase in dietary efficacy and weight gain due to caloric intake coefficients, besides the increase in epididymal, retroperitoneal and inguinal reserves, and adiposity index. Additionally, a reduction in number and an increase in latency for penile erection were correlated with hypercaloric diet consumption. Interestingly, these deleterious effects of hypercaloric diet consumption on body adiposity and erectile function, in vivo, were prevented by food supplementation with S. platensis. Regarding cavernous reactivity, rats (CG + SP100) showed reduction of the contraction of KCl (electromechanical coupling). However, the contractile efficacy of phenylephrine (Phe) (pharmacomechanical coupling) was potentialized (CG + SP50), which was associated to a positive modulation of the Rho kinase pathway (ROCK) and contractile prostanoids. Besides that, positive regulation of the nitric oxide (NO) pathway, reduction of reactive oxygen species (ROS) and potentiation of the relaxing effect promoted by acetylcholine (ACh) were observed. Integration of pathways that promote contraction and relaxation of rat corpus cavernous may underlie the non-change in the erectile function of these rats, in vivo. On the other hand, the hypercaloric diet consumption resulted in an increase in the contractile efficacy of KCl and Phe, and attenuation of the relaxing response induced by ACh, indicating the compromise of the electro- and pharmacomechanical couplings of cavernous contraction. The deleterious effects on cavernosal reactivity are due to ROCK pathway activation, ROS increase, negative modulation of NO pathway and the imbalance of the relaxing/contractile prostanoids. In this context, food supplementation with S. platensis in rats fed with a hypercaloric diet prevented damages to contractile and relaxation cavernous reactivity. In the analysis of oxidative stress, total antioxidant capacity (TAC) was increased in tissue by the supplementation with the algae at a dose of 50 mg/kg in rats fed with a standard diet. In rats fed with a hypercaloric diet, there was an increase in the levels of systemic and tissue malondialdehyde (MDA), as well as a reduction in systemic TCA, resulting in oxidative damage to rats. This alteration in the oxidative stress was prevented by the algae supplementation. Therefore, food supplementation with S. platensis prevents damages associated to a hypercaloric diet consumption and emerges as an adjuvant for the ED treatment.