Biological potentialities and chemical composition of Tarenaya aculeata roots and stems

Plant extracts are rich in secondary metabolites responsible for numerous biological activities. This study aimed to evaluate the antioxidant, antibacterial and photoprotective potentials, toxicity and chemical composition of extracts and fractions of stems and roots of Tarenaya aculeata. Phytochemical analyses were performed at qualitative and quantitative levels to evaluate the classes of secondary metabolites. The sun protection factor (SPF) and antioxidant potentials were determined spectrophotometrically, the antibacterial activity was tested against seven bacteria and the toxicity was evaluated using Artemia salina assay. Phytochemical screening revealed the presence of alkaloids, phenolic compounds, flavonoids, glycosides, tannins and saponins. The levels of phenolic compounds, tannins and alkaloids, SPF and antioxidant potentials showed greater results in the stem (SF) and root (RF) fractions in relation to the stem (SE) and root (RE) extracts. All samples exhibited a broad spectrum of antibacterial activity, with MIC values ranging from 31.25 to 250 Hg mL-1. SE, SF and RF caused mortality in A. salina larvae, with LC50 of 347.06, 34.71 and 85.39 ng mL-1, respectively, whereas RE was non-toxic. Thus, T. aculeata is rich in bioactive secondary metabolites, although further studies will be needed to characterize its chemical constituents and investigate their adverse effects.

Los extractos de plantas son ricos en metabolitos secundarios responsables de numerosas actividades biológicas. Este estudio tuvo como objetivo evaluar el potencial antioxidante, antibacteriano y fotoprotector, ademas de la toxicidad y la composición química de extractos y fracciones de tallos y raíces de Tarenaya aculeata. Se realizaron análisis fitoquímicos a nivel cualitativo y cuantitativo para evaluar las clases de metabolitos secundarios. El factor de protección solar (SPF) y los potenciales antioxidantes se determinaron espectrofotométricamente, la actividad antibacteriana se probó contra siete bacterias y la toxicidad se evaluó mediante el ensayo con Artemia salina. El tamizaje fitoquímico reveló la presencia de alcaloides, compuestos fenólicos, flavonoides, glucósidos, taninos y saponinas. Los niveles de compuestos fenólicos, taninos y alcaloides, SPF y potencial antioxidante mostraron mayores resultados en las fracciones de tallo (SF) y raíz (RF) en relación a los extractos de tallo (SE) y raíz (RE). Todas las muestras exhibieron actividad antibacteriana de amplio espectro, con valores de MIC que oscilaron entre 31,25 y 250 Hg mL-1. SE, SF y RF causaron mortalidad en larvas de A. salina, con CL50 de 347,06; 34,71 y 85,39 µg mL-1, respectivamente, mientras que RE no fue tóxico. Por tanto, T. aculeata es rica en metabolitos secundarios bioactivos, aunque se necesitarán más estudios para caracterizar sus componentes químicos e investigar sus efectos adversos.

Extratos vegetais são ricos em metabólitos secundários responsáveis por inúmeras atividades biológicas. Este estudo teve como objetivo avaliar os potenciais antioxidante, antibacteriano e fotoprotetor, toxicidade e composição química de extratos e frações de caules e raízes de Tarenaya aculeata. Análises fitoquímicas foram realizadas em níveis qualitativo e quantitativo para avaliar as classes de metabólitos secundários. Fator de proteção solar (FPS) e potenciais antioxidantes foram determinados espectrofotometricamente, a atividade antibacteriana testada contra sete bactérias e a toxicidade avaliada pelo ensaio com Artemia salina. A triagem fitoquímica revelou a presença de alcaloides, compostos fenólicos, flavonoides, glicosídeos, taninos e saponinas. Os teores de compostos fenólicos, taninos e alcaloides, FPS e potencial antioxidante apresentaram maiores resultados nas frações caule (SF) e raiz (RF) em relação aos extratos de caule (SE) e raiz (RE). Todas as amostras exibiram atividade antibacteriana de amplo espectro, com valores de MIC variando de 31,25 a 250 µg mL-1. SE, SF e RF causaram mortalidade em larvas de A. salina, com LC50 de 347,06, 34,71 e 85,39 Hg mL-1, respectivamente, enquanto RE não foi tóxico. Portanto, T. aculeata é rico em metabólitos secundários bioativos, embora mais estudos sejam necessários para caracterizar seus constituintes químicos e investigar seus efeitos adversos.

Cytotoxicity and the bioconversion strategy of Aristolochia spp

Aristolochia plants are notable from an ethnopharmacological viewpoint, but the relevance of these species for medicinal purposes has been debated because of their inherent toxicity. The convergence of these contrasting realities can be readily achieved using bioconversion methods, which have been shown to be useful tools for numerous applications, including the detoxification of biomass. In this context, methanolic extracts of leaves from Aristolochia triangularis and Aristolochia gibertii, as well as the feces of Battus polydamas larvae fed with leaves from these plants, were prepared, and their cytotoxic activities were evaluated on a human fibroblast cell line (GM07492). The leaf extracts were found to be cytotoxic, leading to reductions of 42.1 and 33.8% on cell viability, respectively, while the fecal extracts were considered inactive. In addition to evidencing the cytotoxicity of A. triangularis and A. gibertii, these findings demonstrated a potential bioconversion strategy for obtaining aristolochiaceous extracts with reduced toxicity using the larvae of a specialist phytophagous insect, thus renewing expectations in relation to the pharmacological importance of Aristolochia spp. The results were also ecologically relevant, as B. polydamas larvae were found to be able to detoxify compounds from host plants.(AU)

Toxicological properties of an aqueous extract of Aristolochia triangularis leaves, using the brine shrimp lethality and Allium cepa bioassays / Propriedades toxicológicas de um extrato aquoso de folhas de Aristolochia triangularis utilizando os bioensaios de letalidade com Artemia salina e Allium cepa

ABSTRACT: The aqueous extract of Aristolochia triangularis leaves showed activity against Artemia salina larvae, with an LD50 of 370.6 µg/mL. In experiments with Allium cepa seeds, the extract caused a 51.26% reduction in the germination index, inhibited mean root growth, and was cytotoxic at concentrations of 668 and 2,000 µg/mL. Its antioxidant activity was additionally assessed in this research and the ferric reducing antioxidant power value was found to be 391.2 µM/g. Such health-beneficial property can be attributed partly to the total phenolic content, spectrophotometrically determined as 52.67 mg/g. The occurrence of cytotoxicity suggested caution when consuming teas from A. triangularis leaves for medicinal purposes, and equally reveals the need for further studies to investigate their adverse effects.

RESUMO: O extrato aquoso de folhas de Aristolochia triangularis mostrou atividade sobre larvas de Artemia salina, com um DL50 de 370,6 µg/mL. Em experimentos com sementes de Allium cepa, o extrato provocou uma redução de 51,26% no índice de germinação, inibiu o crescimento radicular médio e foi citotóxico nas concentrações de 668 e 2.000 µg/mL. Sua atividade antioxidante foi adicionalmente avaliada nesta pesquisa e o valor de poder redutor de íons férrico foi de 391,2 µM/g. Tal propriedade benéfica para a saúde pode ser parcialmente atribuída ao conteúdo de compostos fenólicos totais, espectrofotometricamente determinada como 52,67 mg/g. A ocorrência de citotoxicidade sugeriu cautela ao consumir chás de folhas de A. triangularis para propósitos medicinais, e igualmente revela a necessidade por estudos adicionais para investigar os efeitos adversos deles.