Neuroprotective Potential of Major Alkaloids from Nelumbo nucifera (Lotus): Mechanisms and Therapeutic Implications

Nelumbo nucifera (lotus) has long been used in traditional medicine across Asia, and its bioactive alkaloids have recently garnered attention for their neuroprotective properties. This review summarizes the current research on the mechanisms by which lotus-derived alkaloids, particularly neferine, nuciferine, liensinine, and isoliensinine, protect neural tissues. These compounds exhibit a wide range of pharmacological activities, including antioxidant and anti-inflammatory effects, regulation of calcium signaling and ion channels, promotion of neurogenesis, and modulation of key neurotransmitter systems, such as dopaminergic, cholinergic, and GABAergic pathways. Notably, they attenuate tau hyperphosphorylation, reduce oxidative stress-induced neuronal apoptosis, and enhance neurotrophic signaling via BDNF-related pathways. While antioxidant and anti-inflammatory actions are the most extensively studied, emerging evidence also highlights their roles in autophagy modulation and mitochondrial protection. Together, these findings suggest that lotus alkaloids are promising candidates for the prevention and treatment of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Further investigation is warranted to explore the synergistic mechanisms and potential clinical applications of these compounds.