GCLC and Alzheimer disease: In vitro test: Cell viability, MMP ↑Apoptotic rate, ROS levels, intracellular Ca2+ ↓The expression of Bcl-2, HO-1, SOD1, GCLC and the Nrf2 levels in nucleus ↑The expression of Bax, cleaved caspase-3, Keap-1, cytochrome C and the Nrf2 levels in cytoplasm ↓In vivo test:AD-like behavior, Aβ1-42 level in brain, Aβ plaque, Ach and choline ChAT, SOD ↓Aβ1-42 level in serum, AChE, GSH-Px, SOD ↑