Norboldine improves cognitive impairment and pathological features in Alzheimer's disease by activating AMPK/GSK3β/Nrf2 signaling pathway

Lindera aggregata (Sims) Kosterm is a common traditional herb that has multiple bioactivities. Radix Linderae (LR), the dry roots of Lindera aggregata (Sims) Kosterm., is a traditional Chinese herbal medicine with antioxidant, anti-inflammatory and immunomodulatory properties, first found in Kaibao Era. Norboldine (Nor) is an alkaloid extracted from LR and is one of the primary active ingredients of LR. However, the pharmacological functions of Nor in Alzheimer's disease (AD) and the mechanism of action are unknown.