stepholidine and Schizophrenia

Topics: Animals; Antipsychotic Agents; Basal Ganglia; Berberine; Clinical Trials as Topic; Dopamine; Dopamine Agents; Dopamine D2 Receptor Antagonists; Humans; Neurons; Nucleus Accumbens; Prefrontal Cortex; Receptors, Dopamine D1; Schizophrenia; Synaptic Transmission; Ventral Tegmental Area

An effective and rapid method for the microwave-assisted preparation of the key intermediate for the total synthesis of tetrahydroprotoberberines (THPBs) including l-stepholidine (l-SPD) was developed. Thirty-one THPB derivatives with diverse substituents on A and D ring were synthesized, and their binding affinity to dopamine D(1), D(2) and serotonin 5-HT(1A) and 5-HT(2A) receptors were determined. Compounds 18k and 18m were identified as partial agonists at the D(1) receptor with K(i) values of 50 and 6.3nM, while both compounds act as D(2) receptor antagonists (K(i)=305 and 145nM, respectively) and 5-HT(1A) receptor full agonists (K(i)=149 and 908nM, respectively). These two THPBs compounds exerted antipsychotic actions in animal models. Further electrophysiological studies employing single-unit recording in intact animals demonstrated that 18k-excited dopaminergic (DA) neurons are associated with its 5-HT(1A) receptor agonistic activity. These results suggest that these two compounds targeted to multiple neurotransmitter receptors may present novel lead drugs with new pharmacological profiles for the treatment of schizophrenia.

Topics: Animals; Antipsychotic Agents; Berberine; Berberine Alkaloids; CHO Cells; Cricetinae; Cricetulus; Dopamine D2 Receptor Antagonists; HEK293 Cells; Humans; Microwaves; Motor Activity; Protein Binding; Rats; Receptor, Serotonin, 5-HT1A; Receptor, Serotonin, 5-HT2A; Receptors, Dopamine D1; Receptors, Dopamine D2; Schizophrenia; Serotonin 5-HT1 Receptor Agonists; Structure-Activity Relationship

Bi-acetylated l-stepholidine (l-SPD-A), a novel derivate of l-stepholidine (l-SPD), possesses a pharmacological profile of D(1)/5-HT(1A) agonism and D(2) antagonism. In the present study, we examined the potential antipsychotic effect of l-SPD-A in a phencyclidine (PCP)-induced rat model of schizophrenia. Pretreatment with l-SPD-A blocked acute PCP-induced hyperlocomotion and reversed prepulse inhibition (PPI) deficits. Chronic l-SPD-A administration (i.p., 10mg/kg/day for 14 days) improved social interaction and novel object recognition impairments in rats that were pretreated with PCP (i.p., 5mg/kg/day for 14 days). Moreover, in a conditioned avoidance response (CAR) test, l-SPD-A, with either i.p. or oral administration, significantly decreased active avoidance without affecting the escape response of rats. Importantly, compared to that of the parent compound l-SPD, l-SPD-A showed stronger suppression of CARs. Lastly, using a [(35)S]GTPgammaS binding assay, we demonstrated that l-SPD-A improved impaired dopamine D(1) receptor function in the prefrontal cortex (PFC) in chronic PCP-treated rats. Taken together, these results indicate that l-SPD-A was not only effective against the hyperactivity, but also improved the sensorimotor gating deficit, social withdrawal and cognitive impairment in an animal model of schizophrenia. The present data suggest that l-SPD-A, a potential neurotransmitter stabilizer, is a promising novel candidate drug for the treatment of schizophrenia.

Topics: Acoustic Stimulation; Analysis of Variance; Animals; Antipsychotic Agents; Avoidance Learning; Berberine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Exploratory Behavior; Guanosine 5'-O-(3-Thiotriphosphate); Inhibition, Psychological; Interpersonal Relations; Locomotion; Male; Phencyclidine; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, Dopamine; Receptors, Serotonin; Recognition, Psychology; Reflex, Startle; Schizophrenia

(-)Stepholidine (SPD) is an active ingredient of the Chinese herb Stephania intermedia, which binds to the dopamine D(1) and D(2) like receptors. Biochemical, electrophysiological and behavioural experiments have provided strong evidence that SPD is both a D(1) and a D(2) antagonist, which could make SPD a unique antipsychotic drug. The present study aimed to investigate the antipsychotic properties of SPD in two animal models for schizophrenia.. The effects of SPD, clozapine and haloperidol in increasing forelimb and hindlimb retraction time in the paw test and in reversing the apomorphine and MK801-induced disruption of prepulse inhibition was investigated.. In the paw test, clozapine and SPD increased the hindlimb retraction time, with only a marginal effect on the forelimb retraction time, whereas haloperidol potently increased both. In the prepulse inhibition paradigm, all three drugs reverse the apomorphine-induced disruption in prepulse inhibition, while none of the drugs could reverse the MK801-induced disruption. SPD even slightly, but significantly, potentiated the effects of MK801.. The data show that SPD showed antipsychotic-like effects in both the prepulse inhibition paradigm and in the paw test. Moreover, the results of the paw test suggest that SPD has an atypical character with a relatively small potency to induce extrapyramidal side effects.

Topics: Animals; Antipsychotic Agents; Berberine; Clozapine; Dopamine D2 Receptor Antagonists; Haloperidol; Male; Motor Activity; Plants, Medicinal; Rats; Rats, Wistar; Receptors, Dopamine D1; Schizophrenia; Stephania