RESUMEN
The aim of this study was to evaluate the in vitro antioxidant activity of the methanol extract of Plantago bellardii All. aerial parts. This was assessed by two different tests, scavenging of 1,1-diphenyl-2-picrylhydrazil (DPPH) radical, and inhibition of lipid peroxidation on liposomes prepared from bovine brain extract. In both tests the extract showed a potent antioxidant effect. The characterization of the major compounds in the extract as rutin, geniposide and verbascoside was performed by isolation and HPLC comparison with authentic samples. They were quantified by HPLC for the flavonoids and colorimetry for iridoids. The compounds that contribute most to the antioxidant activity were shown to be verbascoside and rutin.
Asunto(s)
Antioxidantes/química , Extractos Vegetales/química , Plantago/química , Glucósidos/química , Glucósidos Iridoides , Iridoides/química , Estructura Molecular , Fenoles/química , Piranos/química , Rutina/químicaRESUMEN
Antioxidative activities of methanol extracts from five Plantago species (P. afra, P. coronopus, P. lagopus, P. lanceolata, and P. serraria) were characterized by the DPPH scavenging test and the inhibition of Fe2+/ascorbate-induced lipid peroxidation on bovine brain liposomes. All extracts showed antioxidant activity in both methods. Whereas P. serraria exhibited the strongest activity as a DPPH scavenger, P. lanceolata and P. serraria were found to be the most active in the lipid peroxidation inhibition assay. The extracts were investigated regarding their composition by different colorimetric techniques, such as the content of total phenolic compounds by the Folin-Ciocalteu assay, flavonoids by AlCl3 reagent, phenylpropanoid glycosides (PPGs) by Arnow reagent, and iridoids by Trim-Hill assay. A high correlation was found between the scavenging potency and the total phenolic and phenylpropanoid content of the extracts but not between the lipid peroxidation potency and the extract composition. P. serraria is presented as a possible new source of natural antioxidants.
Asunto(s)
Antioxidantes/análisis , Antioxidantes/farmacología , Extractos Vegetales/química , Plantago/química , Compuestos de Bifenilo , Colorimetría , Flavonoides/análisis , Depuradores de Radicales Libres , Glicósidos/análisis , Iridoides/análisis , Metanol , Fenoles/análisis , PicratosRESUMEN
Methanolic extracts from seven Plantago species used in traditional medicine for the treatment of cancer, were evaluated for cytotoxic activity against three human cancer cell lines recommended by the National Cancer Institute (NCI, USA). The results showed that Plantago species exhibited cytotoxic activity, showing a certain degree of selectivity against the tested cells in culture. Since the flavonoids are able to strongly inhibit the proliferation of human cancer cell lines, we have identified luteolin-7-O-beta-glucoside as major flavonoid present in most of the Plantago species. Also, we have evaluated this compound and its aglycon, luteolin, for their cytotoxic and DNA topoisomerase I poisons activities. These results could justify the traditional use of the Plantago species and topoisomerase-mediated DNA damage might be a possible mechanism by which flavonoids of Plantago exert their cytotoxicity potential.