RESUMO
This paper deals with determination of potential carcinogenic and inhibitory activity of 10 compounds isolated from the ethanolic extract of Lilium candidum L. perfonned by DC polarography. The series of investigated compounds consisted of two spirostanol saponins, two pyroline derivatives, jatropham and its glucoside, flavonol kaempferol, 2-fenylethyl-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside, 2-phenylethylpalmitate and methylsuccinic acid. Carcinogenic, resp. mutagenic activity data for these compounds, with the exception of kaempferol, are not available in scientific literature. All tested compounds were reduced in N,N-dimethylformamide in one or two well defined steps. They also fonned a reversible complex with alpha-lipoic acid, a compound serving as an indicator of carcinogenic activity. The marginal diffuse current values of these complexes served as a criterion of a very low potential carcinogenicity. The inhibitory activity of isolates were studied in the presence of 12-O-tetradecanoylphorbol-13-acetate, a specific tumor promoter for an epidermal carcinogenesis, and in the presence of a polyaromatic substance 7,12-dimetylbenz(a)anthracene known as a carcinogen. The spirostanol saponins possessed the highest inhibitory activity (> 70%) and jatropham (66%). The inhibitory activity of jatropham glucoside was significantly lower (49%). Practically zero inhibitory activity was measured for the 2-phenylethylpalmitate and methylsuccinic acid.
Assuntos
Anticarcinógenos/isolamento & purificação , Carcinógenos/isolamento & purificação , Liliaceae , Extratos Vegetais/química , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Anticarcinógenos/química , Anticarcinógenos/toxicidade , Carcinógenos/química , Carcinógenos/toxicidade , Etanol , Camundongos , Mutagênicos/química , Mutagênicos/isolamento & purificação , Mutagênicos/farmacologia , Polarografia , Pirróis/farmacologia , Saponinas/farmacologia , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/prevenção & controle , Acetato de Tetradecanoilforbol/toxicidadeRESUMO
Apigenin (4',5,7-trihydroxyflavone, AP) belongs to a less-toxic and non-mutagenic flavone subclass of flavonoids, the biotransformation and metabolism of which have been little studied until now. Therefore, this study is focussed on the determination of AP in free form. AP was administered to rats via the i.p. route (25 mg kg(-1)) and then the blood was collected at 10, 15, 30 and 45 min after injection. Methanol was used for rat plasma deproteinization. The HPLC assay (mobile phase, 2% formic acid-acetonitrile-methanol, 40:35:25, v/v; flow-rate, 1 ml min(-1); UV detection at 349 nm) for AP determination was validated and used for the quantification of AP in rat plasma. The unknown concentration was calculated from the equation obtained by the least-squares regression analysis (y = 0.521x + 1.130, r2 = 0.998). The highest concentration of AP in plasma was found to be 30 min after injection. The concentration profile of AP obtained here may contribute to until known results about AP metabolism. They could be applied to other studies of AP or related flavonoids because of favourable effects on human health.