Hymenaea rubriflora Ducke stem bark extract has vasorelaxant and contractile inhibition capacity

Abstract We investigated the vasodilatory effects of Hymenaea rubriflora Ducke stem bark extract (HR- HAc). Vascular reactivity of the aortic rings of Wistar rats was tested by in vitro cumulative doses (0.1 - 729 μg/mL). Rats (n=5) were treated with 25 (G25), 50 (G50) and 100 (G100) mg/ kg of HR-HAc or saline (control group - CG) for four weeks. An in vitro assay resulted in dose-dependent relaxation of the aortic rings with functional endothelium, which was inhibited in the presence of L-NAME. Rings of the treated animals increased acetylcholine relaxing potency at all doses, with a greater effect on G50 (pD2 = 7.8±0.1, Emax = 95.6±1.1) and a decreased contractile potency to phenylephrine in G25 (pD2 = 6.9±0.06, Emax = 61.5±6.0%) and G50 (pD2= 6.6±0.06, Emax = 71.0±8.5%) when compared to the CG in the presence and absence of endothelium (pD2= 6.4± 0.1, 6.4±0.1 and 6.9±0.1, respectively). Cumulative doses of nitroprusside resulted in increased relaxing potency in all treated groups and maintained Emax at 100%. It is concluded that HR-HAc has vasorelaxant capacity and inhibitory vascular contraction activity applied either directly to aortic rings or after treatment with in vivo supplementation, which places this extract as a potential nutraceutical or pharmacological agent for treating diseases associated with vascular dysfunction.

Supplementation with Spirulina platensis Prevents Damage to Rat Erections in a Model of Erectile Dysfunction Promoted by Hypercaloric Diet-Induced Obesity.

Erectile dysfunction (ED) is the inability to achieve and/or maintain a penile erection sufficient for sexual satisfaction. Currently, many patients do not respond to the pharmacotherapy. The effects of a supplementation with Spirulina platensis, were evaluated in a model of ED induced by hypercaloric diet consumption. Wistar rats were divided into groups fed with standard diet (SD) or hypercaloric diet (HD) and supplemented with this alga at doses of 25, 50 or 100 mg/kg. Experimental adiposity parameters and erectile function were analyzed. In SD groups, Spirulina platensis reduced food intake, final body mass and adiposity index, and increased the total antioxidant capacity (TAC) of adipose tissue. However, no change was observed in erectile function. In the HD group, without Spirulina supplementation, a decrease in food intake was observed, in addition to an increase of final body mass, weight gain, adipose reserves, and adiposity index. Additionally, reduction in the number and increase in the latency of penile erection and adipose malondialdehyde levels, as well as a reduction in TCA was noted. Furthermore, cavernous contractility was increased, and the relaxing response was decreased. Interestingly, these deleterious effects were prevented by the algae at doses of 25, 50 and/or 100 mg/kg. Therefore, the supplementation with S. platensis prevents damages associated to a hypercaloric diet consumption and emerges as an adjuvant the prevention of ED.

Potential Therapeutic Role of Dietary Supplementation with Spirulina platensis on the Erectile Function of Obese Rats Fed a Hypercaloric Diet.

Spirulina platensis, an important source of bioactive compounds, is a multicellular, filamentous cyanobacterium rich in high-quality proteins, vitamins, minerals, and antioxidants. Due to its nutrient composition, the alga is considered a complete food and is recognized for its anti-inflammatory, antioxidant, antiobesity, and reproprotective effects. All of which are important for prevention and treatment of organic and metabolic disorders such as obesity and erectile dysfunction. The aim of this study was to investigate the modulatory role of Spirulina platensis food supplementation and the mechanisms of action involved in reversing the damage caused by a hypercaloric diet on the erectile function of rats. The animals were divided into a standard diet group (SD, n = 5); a hypercaloric diet group (HCD, n = 5); a hypercaloric diet group supplemented with S. platensis at doses of 25 (HCD+SP25, n = 5), 50 (HCD+SP50, n = 5), and 100 mg/kg (HCD+SP100, n = 5); and a hypercaloric diet group subsequently fed a standard diet (HCD+SD, n = 5). In the rats fed a hypercaloric diet, dietary supplementation with S. platensis effectively increased the number of erections while decreasing latency to initiate penile erection. Additionally, S. platensis increases NO bioavailability, reduces inflammation by reducing the release of contractile prostanoids, enhances the relaxation effect promoted by acetylcholine (ACh), restores contractile reactivity damage and cavernous relaxation, reduces reactive oxygen species (ROS), and increases cavernous total antioxidant capacity (TAC). Food supplementation with S. platensis thus restores erectile function in obese rats, reduces production of contractile prostanoids, reduces oxidative stress, and increases NO bioavailability. Food supplementation with S. platensis thus emerges as a promising new therapeutic alternative for the treatment of erectile dysfunction as induced by obesity.