Find in Library

Oxidative stress induces functional changes in arteries. Therefore, the effect of <i>myo</i>-inositol, a possible anti-inflammatory/antioxidant agent was studied on human plasma and rat thoracic arteries. Aortic rings from male Wistar rats (3 months of age) were incubated with <i>myo</i>-inositol (1, 10 and 100 μM, 120 min) and analyzed using the gas chromatography (GC) method. In another experiment, aortic rings were protected first with <i>myo</i>-inositol (1 µM, 60 min) and then subjected to a thromboxane receptor agonist (U-46619, 0.1 nM, 60 min). Therefore, these four groups under the following conditions were studied: (i) the control in the vehicle; (ii) <i>myo</i>-inositol; (iii) the vehicle plus U-46619; (iv) <i>myo</i>-inositol plus U-46619. The hemostatic parameters of human plasma and an H₂O₂/Fe²⁺ challenge for lipid and protein peroxidation were also performed. <i>Myo</i>-inositol was not absorbed into the pre-incubated aortic rings as measured by the GC method (0.040 µg/mg, <i>p</i> ≥ 0.8688). The effect of <i>myo</i>-inositol was more significant in the impaired arteries due to U-46619 incubation, which resulted in an improved response to acetylcholine (% Emax: 58.47 vs. 86.69), sodium nitroprusside (logEC₅₀: −7.478 vs. −8.076), CORM-2 (% Emax: 44.08 vs. 83.29), pinacidil (logEC₅₀: −6.489 vs. −6.988) and noradrenaline (logEC₅₀: −7.264 vs. −6.525). This was most likely a possible response to increased nitric oxide release (×2.6-fold, <i>p</i> < 0001), and decreased hydrogen peroxide production (×0.7-fold, <i>p</i> = 0.0012). KCl-induced membrane depolarization was not modified (<i>p</i> ≥ 0.4768). Both the plasma protein carbonylation (×0.7-fold, <i>p</i> = 0.0006), and the level of thiol groups (×3.2-fold, <i>p</i> = 0.0462) were also improved, which was not significant for TBARS (×0.8-fold, <i>p</i> = 0.0872). The hemostatic parameters were also not modified (<i>p</i> ≥ 0.8171). A protective effect of <i>myo</i>-inositol was demonstrated against prooxidant damage to human plasma and rat thoracic arteries, suggesting a strong role of this nutraceutical agent on vasculature which may be of benefit against harmful environmental effects.