The reduction of arterial tension produced by stevioside is dependent on nitric oxide synthase activity when the endothelium is intact

Stevia as a Natural Sweetener: A Review

Stevia rebaudiana of the Asteraceae family is a perennial shrub. It is a sweetener herb also known as sweet weed, sweet leaf, sweet herbs and honey leaf, native to Argentina, Brazil and Paraguay. The leaves of stevia are sweeter than sucrose with zero calories. Steviol, a diterpenoid glycoside derivative identified from this plant, is sweeter than sucrose and is safe when used as a sweetening agent. Diabetic and obese people with hyperglycemia who are in a condition to follow a strict diet can use stevioside as an alternative sweetener. In addition to its hypoglycemic property, the plant also exhibits antibacterial, anti-inflammatory, hypotensive, antiseptic, diuretic, anti-fertility and cardiotonic properties. It has also been documented to show good effects on treating skin diseases such as dermatitis, acne, eczema etc. The leaves of stevia with enriched phytoconstituents could be an alternative natural sweetener for children, adults and old age persons who have a craze to drink beverages and eat sweetened food products in their habitual life.

Splenic Blood Flow Increases after Hypothermic Stimulus (Cold Pressor Test): A Perfusion Magnetic Resonance Study

The Cold Pressor Test (CPT) is a novel diagnostic strategy to noninvasively assess the myocardial microvascular endothelial-dependent function using perfusion magnetic resonance imaging (MRI). Spleen perfusion is modulated by a complex combination of several mechanisms involving the autonomic nervous system and vasoactive mediators release. In this context, the effects of cold temperature on splenic blood flow (SBF) still need to be clarified. Ten healthy subjects were studied by MRI. MRI protocol included the acquisition of GRE T1-weighted sequence ("first pass perfusion") during gadolinium administration (0.1mmol/kg of Gd-DOTA at flow of 3.0 ml/s), at rest and after CPT. Myocardial blood flow (MBF) and SBF were measured by applying Fermi function deconvolution, using the blood pool input function sampled from the left ventricle cavity. MBF and SBF values after performing CPT were significantly higher than rest values (SBF at rest: 0.65 ± 0.15 ml/min/g Vs. SBF after CPT: 0.90 ± 0.14 ml/min/g, p: <0.001; MBF at rest: 0.90 ± 0.068 ml/min/g Vs. MBF after CPT: 1.22 ± 0.098 ml/min/g, p<0.005). Both SBF and MBF increased in all patients during the CPT. In particular, the CPT-induced increase was 43% ± 29% for SBF and 36.5% ± 17% for MBF. CPT increases SBF in normal subjects. The characterization of a standard perfusion response to cold might allow the use of the spleen as reference marker for the adequacy of cold stimulation during myocardial perfusion MRI.