Favorable effects of myo-inositol, selenomethionine or their combination on the hydrogen peroxide-induced oxidative stress of peripheral mononuclear cells from patients with Hashimoto's thyroiditis: preliminary in vitro studies.

OBJECTIVE: The aim of this study was to assess whether blood mononuclear cells (PBMC) from Hashimoto's thyroiditis (HT) and control women, were protected from in vitro H2O2-induced oxidative stress after addition of antioxidants. PATIENTS AND METHODS: PBMC, from 8 HT women and 3 healthy women (controls), were cultured in the presence of 200 µM H2O2 alone, with subsequent addition of myo-inositol (Myo) (0.25, 0.5, 1.0 µM), selenomethionine (SelMet) (0.25, 0.5, 1.0 µM), or their combination (0.25+0.25, 0.5+0.5, 1.0+1.0 µM). PBMC proliferation, vitality, genotoxicity (Comet score) and secretion in the medium of the chemokines CXCL10 [IP10], CCL2 e CXCL9 [MIG] were the indices measured. RESULTS: PBMC proliferation was decreased by H2O2 alone, and it decreased further and dose-dependently in either group (greatest decrease with Myo+SelMet in HT). H2O2 alone decreased vitality by 5% in controls and 10% in the HT group, but vitality was rescued by the three additions. The addition of H2O2 alone increased the Comet score at +505% above baseline in controls and +707% in HT women. In either group, each addition dose-dependently contrasted genotoxicity. Concentrations of chemokines in the medium were increased by H2O2 alone, and in HT women more than in controls. Each addition dose-dependently decreased these concentrations in either group, and often below baseline levels, with Myo+SelMet being the most potent addition (up to approximately -80% of baseline). CONCLUSIONS: The tested antioxidants exert beneficial effects on PBMC exposed in vitro to H2O2-induced oxidative stress in both control and HT women. Particularly, the association Myo+SelMet is the most effective. After the demonstration of a favorable in vitro outcomes in a large cohort of HT patients, we could predict favorable in vivo outcomes given by the same supplement. Thus, one can select HT patients with a high chance of benefit from supplementation.