Effects of ethanolic extract and naphthoquinones obtained from the bulbs of Cipura paludosa on short-term and long-term memory: involvement of adenosine A₁ and A₂A receptors.
Previous studies from our group have indicated important biological properties of the ethanolic extract and isolated compounds from the bulbs of Cipura paludosa (Iridaceae), a native plant widely distributed in northern Brazil, including antioxidant, neuroprotective and anti-nociceptive activities. In the present study, the effects of the ethanolic extract and its two naphthoquinones (eleutherine and isoeleutherine) on the short- and long-term memory of adult rodents were assessed in social recognition and inhibitory avoidance tasks. Acute pre-training oral administration of the ethanolic extract improved the short-term social memory in rats as well as facilitated the step-down inhibitory avoidance short- and long-term memory in mice. Moreover, the co-administration of 'non-effective' doses of the extract of Cipura paludosa and the adenosine receptor antagonists caffeine (non-selective), DPCPX (adenosine A1 receptor antagonist) and ZM241385 (adenosine A2A receptor antagonist) improved the social recognition memory of rats. In the inhibitory avoidance task, the co-administration of sub-effective doses of the extract with caffeine or ZM241385, but not with DPCPX, improved the short- and long-term memory of mice. Finally, the acute oral administration of eleutherine and isoeleutherine facilitated the inhibitory avoidance short- and long-term memory in mice. These results demonstrate for the first time the cognitive-enhancing properties of the extract and isolated compounds from the bulbs of Cipura paludosa in rodents and suggest a possible involvement of adenosine A1 and A2A receptors in these effects.
Faculdade de Ciências da Saúde, Universidade de Brasília (UnB), Brasília, DF, Brazil.
Greice M R S
GM
Lucena
Filipe C
FC
Matheus
Vania M
VM
Ferreira
Priscila B
PB
Tessele
Mariangela S
MS
Azevedo
Valdir
V
Cechinel-Filho
Rui D
RD
Prediger
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001938:Brazil; D002110:Caffeine / Q000494:pharmacology; D000431:Ethanol / Q000737:chemistry; D005663:Furans / Q000302:isolation & purification / Q000494:pharmacology; D027621:Iridaceae / Q000737:chemistry; D008297:Male; D057567:Memory, Long-Term / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects*; D051379:Mice; D009285:Naphthoquinones / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots; D058915:Purinergic P1 Receptor Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043682:Receptor, Adenosine A1 / Q000187:drug effects / Q000378:metabolism; D043683:Receptors, Adenosine A2 / Q000187:drug effects / Q000378:metabolism; D014227:Triazines / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D005663:Furans; D009285:Naphthoquinones; D010936:Plant Extracts; D058915:Purinergic P1 Receptor Antagonists; D043682:Receptor, Adenosine A1; D043683:Receptors, Adenosine A2; D014227:Triazines; D014230:Triazoles; D014970:Xanthines; C097270:ZM 241385; D002110:Caffeine; D000431:Ethanol; C415044:eleutherin; C051360:1,3-dipropyl-8-cyclopentylxanthine; C529519:isoeleutherin