The Therapeutic Effects of Seven Lycopodium Compounds on Cell Models of Alzheimer's Disease.

Abstract

As an acetylcholinesterase inhibitor (AChEI), Huperzine-A (Hup-A) is marketed for treatment of mild to moderate Alzheimer's disease (AD) for decades in China. However, Hup-A causes some side effects. To search for new analogs or derivatives of Hup-A, we produced five Lycopodium alkaloids and two analogues by chemical synthesis: Lyconadins A-E, H-R-NOB, and 2JY-OBZ4. To systematically evaluate the therapeutic effects of the seven compounds on AD cell models. We assessed the effects of the seven compounds on cell viability via CCK-8 kit and used HEK293-hTau cells and N2a-hAPP cells as AD cell models to evaluate their potential therapeutic effects. We examined their effects on cholinesterase activity by employing the mice primary neuron. All compounds did not affect cell viability; in addition, Lyconadin A and 2JY-OBZ4 particularly increased cell viability. Lyconadin D and Lyconadin E restored tau phosphorylation at Thr231, and H-R-NOB and 2JY-OBZ4 restored tau phosphorylation at Thr231 and Ser396 in GSK-3β-transfected HEK293-hTau cells. 2JY-OBZ4 decreased the level of PP2Ac-pY307 and increased the level of PP2Ac-mL309, supporting that 2JY-OBZ4 may activate PP2A. Lyconadin B, Lyconadin D, Lyconadin E, H-R-NOB, and 2JY-OBZ4 increased sAβPPα level in N2a-hAPP cells. 2JY-OBZ4 decreased the levels of BACE1 and sAβPPβ, thereby reduced Aβ production. Seven compounds exhibited weaker AChE activity inhibition efficiency than Hup-A. Among them, 2JY-OBZ4 showed the strongest AChE inhibition activity with an inhibition rate of 17% at 10μM. Among the seven Lycopodium compounds, 2JY-OBZ4 showed the most expected effects on promoting cell viability, downregulating tau hyperphosphorylation, and Aβ production and inhibiting AChE in AD.