Memory retrieval improvement by Heteropterys aphrodisiaca in aging rats

Abstract

Few data exists about the pharmacological properties of Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), which is native to the scrubland regions of Brazil. The present study investigated the effects of oral treatment with H. aphrodisiaca extract (BST0298) on the learning and memory of young (3-6 months) and aged (21-23 months) rats, and compared the in vitro antioxidant activity of three lots collected in different years. An improvement in the number of sessions to learn the task was observed in the left/right discrimination test in aged rats treated for 45 days with 25 mg/kg (7.0 ± 0.5; p=0.005) or 50 mg/kg (7.6 ± 0.6; p=0.012) compared with control old rats (11.0 ± 1.6). On the other hand, pre-treatment did not improve the performance of scopolamine-treated mice in the passive avoidance test. The in vitro malondialdehyde test showed that all three different extracts presented similar antioxidant activity. The flavonoids astilbin, isoastilbin and neoastilbin were isolated from the extract and may contribute to the biological activity. These results suggest that repeated treatment with H. aphrodisiaca improves learning and memory, probably by a non-muscarinic mechanism.Uniterms: Heteropterys aphrodisiaca O. Mach/pharmacognosy. Heteropterys aphrodisiaca O. Mach/ antioxidant activity. Malpighiaceae/pharmacognosy. Antioxidants. Flavonoids. Plant extract.Existem poucos dados disponíveis sobre as propriedades farmacológicas da Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), nativa da região do pantanal brasileiro. O presente estudo investigou o efeito do tratamento oral com um extrato de H. aphrodisiaca (BST0298) sobre a memória e aprendizagem de ratos jovens (3-6 meses) e idosos (21-23 meses) e comparou a atividade antioxidante in vitro de três lotes, coletados em diferentes anos. Melhora quanto ao número de sessões necessárias para aprender a tarefa foi observada no teste de discriminação direita/esquerda em ratos idosos tratados por 45 dias com doses de 25 mg/kg (7,0 ± 0,5; p=0,005) e 50 mg/kg (7,6 ± 0,6; p=0,012) comparados com ratos idosos controle (11,0 ± 1,6). Por outro lado, o pré-tratamento com o extrato não melhorou o desempenho de camundongos tratados com escopolamina no teste da esquiva passiva. Em relação à avaliação da atividade antioxidante in vitro pelo teste do malonodialdeído, os três lotes analisados apresentaram atividade antioxidante semelhante. Os flavonóides astilbina, isoastilbina e neoastilbina foram isolados do extrato e podem contribuir para a atividade biológica. Estes resultados sugerem que a administração repetida de H. aphrodisiaca melhora a memória e aprendizagem provavelmente por um mecanismo não muscarínico. Unitermos

Comparison of the chemical composition and biological effects of the roots, branches and leaves of Heteropterys tomentosa A. Juss

“…In this study, old rats pre-treated for 80 consecutive days with 50 mg/kg of Heteropterys tomentosa root and branch extracts had no improvement in learning, as evaluated by the T-maze test. This result is contrary to those found in previous studies with the BST0298 extract (Galvão et al, 2002(Galvão et al, , 2011.…”

“…The discrepancy between these results and those obtained by Galvão et al (2002Galvão et al ( , 2011 may be due to differences in the chemical composition of the extracts because they were not collected in the same region. Some compounds had different concentrations and were slightly higher in the BST0298 extract, despite the similarity in the chromatographic profile from both botanical materials.…”

“…Old rats chronically treated with the extract also showed a positive effect on learning when evaluated in the T-maze test (Galvão et al, 2002). A similar effect was recently demonstrated in this experimental model using lower treatment doses and shorter times (Galvão et al, 2011).…”

Heteropterys Genus: A Review of its Phytochemistry and Pharmacology

“…The phytochemical characterization of the BST0298 extract showed the presence of the flavonoids astilbin, neoastilbin and isoastilbin, as well as an aliphatic nitro compound identified as 2, 3, 4, 6-tetra-O-(3nitropropanoyl)-O-β-D-glucopyranoside. Moreover, the BST0298 extract presented marked antioxidant activity by inhibition of lipid peroxidation, which can contribute for beneficial effect on memory (Galvao et al, 2011).…”

“…The roots of H. tomentosa are used as aphrodisiac, tonic or stimulant, as well as for nervous debility, vasodilatation and antiulcer in Brazil (Galvao et al, 2011;Veggi et al, 2011). Diverse studies for exploring the possible biological properties, in particular of the extracts of roots of H. tomentosa, have been carried out.…”