Plantago holosteum Scop. as a potential natural antioxidant and antiinflammatory agent

Abstract

The genus Plantago L. (Plantaginaceae) comprises about 275 species found all over the world. Ancient use of plantains as herbal remedies is a consequence of their astringent, anti-toxic, antimicrobial, expectorant and diuretic properties. In order to valorize medicinal use of Plantago holosteum Scop., some tests on antioxidative and antiinflammatory activities of methanolic extract of P. holosteum, collected from mountain Kopaonik (Serbia) have been undertaken. The extract has been characterized regarding composition by LC-MS/MS and by different colorimetric techniques [1,2]. Flavonoids luteolin, luteolin-7-O-glc, apigenin and apigenin-7-O-glc, also iridoid aucubin were identified and quantified. The content of total phenolic compounds expressed as mg gallic acid equivalents/g of dry extract was 68.2±3 and flavonoids was 13.1±0.7mg quercetine equiv/g of d.e. The radical scavenger capacity (RSC) was evaluated towards several radicals using spectrophotometry [3] and following IC50 were found: diphenylpicrylhydrazyl (6.1±0.6µg/ml), hydroxyl (127.2±6.8µg/ml), superoxide anion (73.3±2.5µg/ml) and nitric oxide radical (0.67±0.06mg/ml), inhibition of lipid peroxidation (11.5±1.8µg/ml). These results indicate comparable or higher extract activity than activity of synthetic antioxidants as BHT or BHA (butylated hydroxytoluene/hydroxyanisol). Antiinflammatory activity was examined by means of 12-lipooxygenase (12-LO) and cyclooxygenase-1 (COX-1) inhibition, quantifying the 12-LO product 12-HETE (12-hydroxy-5,8,10,14-eicosatetraenoate) and COX-1 product 12-HHT (12-hydroxy-5,8,10-heptadecatrienoic acid) by RP-HPLC-MS/MS. At concentration of 4mg/ml extract showed 12-LO and COX-1 inhibitory activity of 60 and 42%.