d-chiro-Inositol (DCI), an isomer of inositol, possesses antioxidative and endothelial protective properties. Possibly due to a deficiency of insulin mediators, polycystic ovary syndrome (PCOS) is often associated with insulin resistance (IR) and hyperinsulinemia, likely responsible for an elevated production of reactive oxygen species. We investigated oxidative-related alterations of inositol in the blood of women with PCOS before and after treatment with DCI. A total of 38 normal-weight PCOS women were investigated before and after DCI administration (500 mg/day for 12 weeks; n = 38) by evaluating serum testosterone, serum androstenedione, fasting serum insulin, fasting serum glucose, and parameters of IR. From the blood, we determined biomarkers of oxidative stress: superoxide anion radicals, hydrogen peroxide, nitric oxide, and the index of lipid peroxidation. The activity of catalase and superoxide dismutase and the reduced glutathione (GSH) content in the hemolysate were also assessed. Data showed that PCOS patients' plasma underwent oxidative stress, as indicated by the higher level of prooxidants and reduced cytosolic GSH content. DCI treatment significantly improved the metabolic parameters. Also, serum values of testosterone were reduced. In conclusion, PCOS patients suffer from a systemic oxidative stress that induces endothelial dysfunction. Treatment with DCI is effective in reducing hormonal, metabolic, and oxidative abnormalities in PCOS patients by improving IR.
Keywords: d-chiro-inositol; insulin resistance; oxidative stress; polycystic ovary syndrome; résistance à l’insuline; stress oxydatif; syndrome des ovaires polykystiques.