WNK2 and memory impairment: (9) Dendrobium alkaloids, extracted from Dendrobium nobile Lindl., can improve lipopolysaccharide- (LPS-) induced memory impairment in rats, and this effect is related to prevent overexpression of tumor necrosis factor receptor 1 via inhibition of phosphorylated p38 mitogen-activated protein kinases and the downstream nuclear factor kappa-B signal pathway [36].