Tetrahydroalstonine

Tetrahydroalstonine ((-)-Tetrahydroalstonine) is an indole alkaloid and a selective α₂-adrenergic receptor antagonist. Tetrahydroalstonine exhibits certain neuroprotective effects. Tetrahydroalstonine can regulate autophagy-lysosomal function by activating the Akt/mTOR pathway, significantly reducing OGD/R-induced primary cortical neuronal injury^[1][2][3]. In Vitro:Tetrahydroalstonine (0.75-3 µM; 3-26 h) improves cell viability and ameliorates abnormal expression of autophagic and lysosomal markers (LC3B-II/I, LAMP1, CSTB, TFEB) in primary cortical neurons treated with oxygen-glucose deprivation/reoxygenation (OGD/R). The mechanism involves activation of the Akt/mTOR pathway^[1]. In Vivo:Tetrahydroalstonine (0.5-4 mg/kg; intravenous injection; single dose) in pithed rats shows that low doses (0.5-2 mg/kg) enhance the pressor response induced by electrical stimulation of sympathetic nerves, while high dose (4 mg/kg) inhibits the response^[2].