Résumé
Pseudobrickellia brasiliensis (Asteraceae) is a plant commonly known as arnica-do-campo and belongs to the native flora of the Brazilian Cerrado. The alcoholic extract of the plant has been used as an anti-inflammatory agent in folk medicine, but the biological mechanism of action has not been elucidated. The present study evaluated the composition of P. brasiliensis aqueous extract and its effects on pro-inflammatory cytokine production and lymphocyte proliferation. The extracts were prepared by sequential maceration of P. brasiliensis leaves in ethanol, ethyl acetate, and water. Extract cytotoxicity was evaluated by trypan blue exclusion assay, and apoptosis and necrosis were measured by staining with annexin V-FITC and propidium iodide. The ethanolic (ETA) and acetate (ACE) extracts showed cytotoxic effects. The aqueous extract (AQU) was not cytotoxic. Peripheral blood mononuclear cells stimulated with phorbol myristate acetate and ionomycin and treated with AQU (100 μg/mL) showed reduced interferon (IFN)-γ and tumor necrosis factor (TNF)-α expression. AQU also inhibited lymphocyte proliferative response after nonspecific stimulation with phytohemagglutinin. The aqueous extract was analyzed by liquid chromatography coupled with photodiode array detection and mass spectrometry. Quinic acid and its derivatives 5-caffeoylquinic acid and 3,5-dicaffeoylquinic acid, as well as the flavonoids luteolin and luteolin dihexoside, were detected. All these compounds are known to exhibit anti-inflammatory activity. Taken together, these findings demonstrate that P. brasiliensis aqueous extract can inhibit the pro-inflammatory cytokine production and proliferative response of lymphocytes. These effects may be related to the presence of chemical substances with anti-inflammatory actions previously reported in scientific literature.
Sujets)
Humains , Anti-inflammatoires/pharmacologie , Asteraceae/composition chimique , Prolifération cellulaire/effets des médicaments et des substances chimiques , Interféron gamma/effets des médicaments et des substances chimiques , Lymphocytes/effets des médicaments et des substances chimiques , Extraits de plantes/pharmacologie , Facteur de nécrose tumorale alpha/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Chromatographie en phase liquide à haute performance , Interféron gamma/métabolisme , Agranulocytes/effets des médicaments et des substances chimiques , Agranulocytes/métabolisme , Extraits de plantes/composition chimique , Facteurs temps , Facteur de nécrose tumorale alpha/métabolismeRésumé
ABSTRACT Pseudobrickelliabrasiliensisis aspecies endemic toBrazil, popularlyknown as “arnica”/ “arnica-do-campo”/ “arnica-do-mato” and used for itsanalgesicand anti-inflammatoryproperties. The objective of this research was thephytochemical studyof the essential oilandhexaneandethyl acetateextracts of the leaves of this species. The essential oilwasextracted byhydrodistillation using a Clevengerapparatusand was analyzed byGC/MS, 25components were identified, with a predominance ofmonoterpenes. The extractswere subjected toclassicalchromatographyand the fractionswere analyzed byGC/MS, 1D 1H-NMR, 13C-NMR and 13C-NMR-DEPT 135.α-amyrin, α-amyrin acetate, β-amyrin, β-amyrin acetate, lupeol, lupeolacetate, pseudotaraxasterol andtaraxasterol (triterpenes), andkaurenoicacid (diterpene) were identified.Theseterpenesarechemo-taxonomicallyrelated to theEupatorieaetribe(Asteraceae) and may be responsible for the anti-inflammatory activity attributed to the plant.
RESUMO Pseudobrickellia brasiliensis é uma espécie endêmica do Brasil, popularmente conhecida como “arnica”/ “arnica-do-campo”/ “arnica-do-mato” e usada por suas propriedades analgésica e antiinflamatória. O objetivo do trabalho foi o estudo fitoquímico do óleo essencial e dos extratos hexânico e em acetato de etila das folhas dessa espécie. O óleo essencial foi extraído por hidrodestilação em aparato de Clevenger e foi analisado por CG/EM, sendo identificados 25 componentes, com predomínio de monoterpenos. Os extratos foram submetidos a cromatografia clássica, e as frações foram analisadas por CG/EM, 1D 1H-RMN, 13C-RMN e 13C-RMN-DEPT 135. Foram identificados α-amirina, acetato de α-amirina, β-amirina, acetato de β-amirina, lupeol, acetato de lupeol, pseudotaraxasterol e taraxasterol (triterpenos) e o ácido caurenóico (diterpeno). Estes terpenos estão quimiotaxonomicamente relacionados a tribo Eupatorieae (Asteraceae) e podem ser responsáveis pela atividade antiinflamatória atribuída a planta.