Serotonin receptors contribute to the promnesic effects of P. olacoides (Marapuama).
Nootropic, antioxidant, and neuroprotective properties have been shown in a standardized ethanol extract of Ptychopetalum olacoides (POEE), a medicinal plant traditionally used by the Amazonian elderly population. It has been revealed that POEE mechanisms of action include anticholinesterase effects, and involve beta-adrenergic and dopamine D(1) receptors. The purpose of this study was to verify the role of serotonin receptors in the promnesic effects of this standardized extract. The step-down task in mice and selective serotonin antagonists were used. The study reveals that POEE promnesic effects on short-term (acquisition, consolidation and retrieval) and long-term (retrieval) declarative aversive memories are increased by 5HT(2A) (but not 5HT(1A)) serotonin antagonists (spiperone and pindolol, respectively). The observed synergism between POEE and spiperone can be interpreted as the combined effects of two subeffective doses of two 5HT antagonists, or the known synergism between an acetylcholinesterase inhibitor (POEE) and a 5HT antagonist. In conclusion it is suggested that 5HT(2A) serotonin receptors are relevant for the promnesic effects of this extract, adding to its multiple mechanisms of action.
Laboratório de Etnofarmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Av. Sarmento Leite 500/202, Porto Alegre, RS, 90046-900, Brazil. adrilourenco@gmail.com
Adriana Lourenço
AL
da Silva
Juliana G
JG
Ferreira
Bárbara
B
da Silva Martins
Sabrina
S
Oliveira
Nathalia
N
Mai
Domingos S
DS
Nunes
Elaine
E
Elisabetsky
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D008568:Memory / Q000145:classification / Q000187:drug effects; D051379:Mice; D031656:Olacaceae / Q000737:chemistry*; D010869:Pindolol / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D011985:Receptors, Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013134:Spiperone / Q000494:pharmacology; D018709:Statistics, Nonparametric
D010936:Plant Extracts; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D013134:Spiperone; D010869:Pindolol