ABSTRACT
OBJECTIVES: We attempted to ascertain if bisbenzylisoquinoline alkaloids, liensinine and isoliensinine from Nelumbo nuciferaâ Gaertner have antidepressant-like effects and compare the effects with those previously obtained by their analogue neferine. METHODS: Using mice, the forced swimming test (FST) was carried out after treatment with liensinine, isoliensinine and neferine. KEY FINDINGS: Liensinine and isoliensinine elicited antidepressant-like effects in mice after the FST. Anti-immobility effects of liensinine and isoliensinine were antagonized by the 5-hydroxytryptamine1 A (5-HT1 A ) receptor antagonist WAY 100635, but not by the α1 -adrenoceptor antagonist prazosin. The anti-immobility effects of liensinine, isoliensinine and neferine were blocked by pretreatment with p-chlorophenylalanine (PCPA), which depletes serotonin (5-HT). CONCLUSIONS: These data suggest that liensinine and isoliensinine from Nelumbo nuciferaâ Gaertner have antidepressant-like effects and that antidepressant-like effects of liensinine and its analogues are closely related to serotonergic mechanisms.
Subject(s)
Antidepressive Agents/pharmacology , Behavior, Animal/drug effects , Benzylisoquinolines/pharmacology , Isoquinolines/pharmacology , Nelumbo/chemistry , Phenols/pharmacology , Plant Extracts/pharmacology , Serotonin Agents/pharmacology , Stress, Psychological/drug therapy , Animals , Antidepressive Agents/isolation & purification , Benzylisoquinolines/isolation & purification , Disease Models, Animal , Dose-Response Relationship, Drug , Isoquinolines/isolation & purification , Male , Mice, Inbred ICR , Motor Activity/drug effects , Nelumbo/embryology , Phenols/isolation & purification , Phytotherapy , Plant Extracts/isolation & purification , Plants, Medicinal , Seeds , Serotonergic Neurons/drug effects , Serotonergic Neurons/metabolism , Serotonin Agents/isolation & purification , Stress, Psychological/metabolism , Stress, Psychological/psychology , SwimmingABSTRACT
The effects of embryos of the seeds of Nelumbo nucifera on the central nervous system were studied in mice. MeOH extracts of embryos of Nelumbo nucifera seeds significantly inhibited locomotor activity in mice. The MeOH extract was successively partitioned between H(2)O and n-hexane, between H(2)O and CHCl(3), and between H(2)O and n-BuOH. CHCl(3) extracts strongly inhibited locomotor activity in mice, although other extracts had no effect on locomotor activity. The main alkaloid of CHCl(3) extracts, neferine, dose-dependently inhibited locomotor activity in mice. Neferine induced hypothermia in mice and apparently potentiated thiopental-induced sleeping time. An anxiolytic, diazepam, decreased locomotor activity, rectal temperature and enhanced sleep elicited by thiopental, similar to neferine. In addition, neferine and diazepam showed anti-anxiety effects in the elevated plus maze test. Neferine did not affect muscle coordination by the rota-rod test. Neferine did not affect strychnine- nor picrotoxin-induced seizure. In contrast, diazepam had apparent muscle relaxant and anti-convulsant effects. These results suggest that neferine has several central effects and that neferine may participate in the efficacy of the sedative effects of embryos of the seeds of Nelumbo nucifera. The mechanisms of the sedative effects of neferine are not similar to those of diazepam.