Ação da uleína sobre a produção de óxido nítrico em células RAEC e B16F10

Abstract

RESUMO:Foi investigada a infl uência da fração rica em alcalóides e da substância majoritária desta fração, uleína, isolada das cascas de Himatanthus lancifolius (Muell. Arg.) Woodson, Apocynaceae, popularmente conhecida como agoniada, sobre a produção de óxido nítrico em células RAEC e B16F10 e a correlação com a atividade antioxidante. Os ensaios de atividade antioxidante foram realizados utilizando os métodos de redução do complexo fosfomolibdênico e o da redução do radical livre DPPH. Os resultados demonstraram uma atividade antioxidante de 59,3 ± 0,8% para a fração alcaloídica, enquanto que, para a uleína, esse efeito foi de 0,5 ± 0,1% no ensaio de redução do complexo fosfomolibdênico. No ensaio do DPPH, a fração alcaloídica apresentou IC 50 = 196,3 ± 8,9 μg/mL e para a uleína 6475,0 ± 25,0 μg/mL. A uleína, principal alcalóide da fração, estimulou uma produção máxima de óxido nítrico nas concentrações de 0,1 μg/ ml (20,9 ± 1,4 μM) e 1 μg/ml (41,1 ± 0,2 μM) utilizando células RAEC e B16F10, respectivamente, demonstrando que o efeito da uleína nas células ocorre através de estímulos nas vias de produção de óxido nítrico e não por um efeito sequestrante de radical livre. Unitermos:Himatanthus lancifolius, Apocynaceae, agoniada, antioxidante, óxido nítrico, uleína.ABSTRACT: "Uleine effect on the production of nitric oxide in RAEC and B16F10 cells". The infl uence of the rich alkaloidal fraction and of the major substance in this fraction, uleine, isolated from the barks of Himatanthus lancifolius (Muell. Arg.) Woodson, Apocynaceae, popularly known as agoniada, on the nitric oxide production in RAEC and B16F10 cells and its correlation with the antioxidant activity, were investigated. For the antioxidant activity the methods of formation of a phosphomolybdenum complex and the reduction of the free radical DPPH were used. The results demonstrated an antioxidant activity of 59.3 ± 0.8% for the alkaloidal fraction, while for uleine the effect was of 0.5 ± 0.1% in the reduction of the phosphomolibdenium method. In the assay of DPPH, the alkaloidal fraction presented IC 50 = 196.3 ± 8.9 μg/mL and for uleine, 6475.0 ± 25.0 μg/mL. Uleine also stimulated a maximum nitric oxide production in the concentrations of 0.1 μg/mL (20.9 ± 1.4 μM) and 1 μg/mL (41.1 ± 0.2 μM) using RAEC and B16F10 cells, respectively, demonstrating that the effect of uleine in the cells occurs by promoting the nitric oxide production pathway, but not through a free radical scavenger effect.

Influence of the preparation method on the low efficacy of multi-herb commercial products: the example of João da Costa e Associações

“…Previous studies showed a significant activity of this alkaloid in smooth muscle and in production of nitric oxide (Souza, 2007;Franca et al, 2000;Rattmann et al, 2005). Recent study also shown a marked antinociceptive activity of extracts from Rosmarinus officinalis, including that induced by formalin (González-Trujano et al, 2007).…”

Antiproliferative effect of a traditional remedy, Himatanthus articulatus bark, on human cancer cell lines

“…The best example is the Vinca alkaloids, vinblastine and vincristine, isolated from Catharanthus roseus (Apocynaceae). Also, alkaloids such as uleine and demethoxyaspidormine have been isolated from bark extracts of Himatanthus lancifolius (Baggio et al, 2005;Rattmann et al, 2005;Souza et al, 2007). Moreover, we can not exclude the presence of terpenoids (stigmasterol, sitosterol and lupeol derivatives) in the apolar fraction from the bark extract (Barreto et al, 1998).…”

Aspidosperma subincanum II. Usefulness of uleine and ribonucleic fragments in the treatment of AIDS patients

“…DC., Apocynaceae, have been extensively studied (Seidl et al, 2010). Its capacity to promote the synthesis of nitric oxide (Souza et al, 2007) makes of these plants candidates for use as an adjuvant in the treatment of patients suffering from an immune-depression. The bark of Aspidosperma subincanum has been purified and the food supplement rich in uleine so obtained has been demonstrated innocuous (Federlin et al, 2014).…”