Beneficial In Vitro Effects of a Low Myo-Inositol Dose in the Regulation of Vascular Resistance and Protein Peroxidation under Inflammatory Conditions

Oxidative stress induces functional changes in arteries. Therefore, the effect of myo-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 myo-inositol (1, 10 and 100 mu M, 120 min) and analyzed using the gas chromatography (GC) method. In another experiment, aortic rings were protected first with myo-inositol (1 mu M, 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) myo-inositol; (iii) the vehicle plus U-46619; (iv) myo-inositol plus U-46619. The hemostatic parameters of human plasma and an H2O2/Fe2+ challenge for lipid and protein peroxidation were also performed. Myo-inositol was not absorbed into the pre-incubated aortic rings as measured by the GC method (0.040 mu g/mg, p >= 0.8688). The effect of myo-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 (logEC(50): -7.478 vs. -8.076), CORM-2 (% Emax: 44.08 vs. 83.29), pinacidil (logEC(50): -6.489 vs. -6.988) and noradrenaline (logEC(50): -7.264 vs. -6.525). This was most likely a possible response to increased nitric oxide release (x2.6-fold, p < 0001), and decreased hydrogen peroxide production (x0.7-fold, p = 0.0012). KCl-induced membrane depolarization was not modified (p >= 0.4768). Both the plasma protein carbonylation (x0.7-fold, p = 0.0006), and the level of thiol groups (x3.2-fold, p = 0.0462) were also improved, which was not significant for TBARS (x0.8-fold, p = 0.0872). The hemostatic parameters were also not modified (p >= 0.8171). A protective effect of myo-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.

Automated summary

The study investigated the effect of myo-inositol as a possible anti-inflammatory/antioxidant agent on human plasma and rat thoracic arteries. The results showed that myo-inositol had a protective effect, improving the response of impaired arteries and reducing oxidative stress.