Antioxidant and anticoagulant properties of myo-inositol determined in an ex vivo studies and gas chromatography analysis

Myo-inositol plays a key role in the vasculature and may be beneficial for preventing harmful environmental effects. In this study aortic rings were isolated from middle-aged (12-month-old) male Wistar rats and preincubated with myo-inositol (0.01-100 mg/L) for 2 h. A stable thromboxane A₂ analog was added (0.1 nM, 2 h) to analyze vascular dysfunction. The concentration of myo-inositol in the organ baths was determined via gas chromatography. In another experiment, human blood plasma was subjected to pro-oxidant - hydrogen peroxide administration, and myo-inositol was added to analyze lipid and protein oxidation processes. The thromboplastin time, prothrombin time, and thrombin time were also studied. Myo-inositol administration protected thiol groups against oxidative stress, meanwhile decreased vascular contraction and potentiated vasodilation (concentrations 1-100 mg/L, but not ≤ 0.1 mg/L), and changed the level of 8-isoprostane (concentrations: 0.1-100 mg/L, but not 0.01 mg/L) in plasma treated with H₂O₂/Fe²⁺. A dose above 100 mg/L additionally protected lipids (measured as thiobarbituric acid reactive substances) and increased thrombin time. Moreover, significant differences in vascular relaxation were observed between the studied myo-inositol concentrations (1 vs. 10 vs. 100 mg/L), which was not detected under the 0.1 mg/L. The concentration of myo-inositol in the organ baths determined via gas chromatography revealed that this nutraceutical agent was not used by the aortic rings during the incubation period in physiological processes. A protective effect of myo-inositol against prooxidant damage to human plasma and rat thoracic arteries has been demonstrated.