(p-ClPhSe)2 reversed DM+ mice DLB but did not alter mouse spontaneous behaviour; hyperglycaemia; counteracted DM-induced cortical oxidative damage. It did not reverse the ↑ in adrenal gland weight and the DM-induced decrease in GR content. It modulated the Keap1/Nrf2/HO-1 signalling pathway in DM mice and ↓ FJC+ cells (a measure of neurodegeneration) in the cerebral cortex of diabetic mice. Here, GSR is linked to Lewy body dementia.