HMOX1 and Lewy body dementia: Catalpol reversed TST, FST, and OFT abnormalities and abnormal PI3K and Akt phosphorylation; ↑Nrf2-HO1, SOD, GPX and GSTs; ↓ GSH and MDA in hippoc and frontal cortex of STZ-induced hyperglycaemic mice with DLB