Nuciferine

Nuciferine is an alkaloid found within the plants Nymphaea caerulea and Nelumbo nucifera.

Preliminary psychopharmacological research in 1978 was unable to conclusively determine the compound's classification regarding dopamine-receptor activity. On one hand, investigative studies found evidence of behavior traditionally associated with dopamine-receptor stimulation: stereotypy, increase in spontaneous motor activity, inhibition of conditioned avoidance response, and an increase in pain sensitivity resulting in an inhibition of morphine analgesia. On the other hand, these early investigative studies also found evidence of behavior traditionally associated with dopamine-receptor blockade: decrease of spontaneous motor activity, chills, catalepsy, trance-like states of consciousness.

Pharmacology
Nuciferine has been reported to have various anti-inflammatory, possibly mediated via PPAR delta activation Nuciferine suppresses the SOX2-AKT/STAT3 signaling pathway in animal models. Targeting SOX-2 pathways in human models with Nuciferine may offer a novel therapeutic approach for cancer treatment.

According to a newer study from 2016, Nuciferine acts as an antagonist at 5-HT2A, 5-HT2C, and 5-HT2B receptors, an inverse agonist at the 5-HT7 receptor, a partial agonist at D2, D5, and 5-HT6 receptors, and an agonist at 5-HT1A and D4 receptors. Additionally, it inhibits the dopamine transporter (DAT).

In rodent models relating to antipsychotic drug effects, Nuciferine has shown various actions such as blocking head-twitch responses and discriminative stimulus effects of a 5-HT2A agonist, enhancing amphetamine-induced locomotor activity, inhibiting phencyclidine (PCP)-induced locomotor activity, and restoring PCP-induced disruption of pre-pulse inhibition without inducing catalepsy.

Nuciferine may also potentiate morphine analgesia. The median lethal dose in mice is 289 mg/kg. It is structurally related to apomorphine and other aporphine derivatives.