Plantago altissima L. as a potential natural antioxidant and anti-inflammatory agent

Abstract

Ancient use of plantains (genus Plantago L., Plantaginaceae) as herbal remedies is a consequence of their astringent, anti-toxic, antimicrobial, expectorant and diuretic properties. P. altissima L. is broadly distributed in Southern Europe and the Balkan Peninsula. As there are no data about biological activity of this species, some tests on activities of methanolic extracts have been undertaken. The extract has been characterized by LC-MS/MS [1] and several flavonoids as luteolin-7-O-glc and apigenin could be detected. The content of total phenolics (82.7±3.7mg gallic acid equiv/g of d. e.) and flavonoids (7.7±0.2mg quercetine equiv/g of d.e.) was determined by colorimetric techniques [1]. The radical scavenger capacity (RSC) was evaluated using various radicals and spectrophotometry [1] and the following IC50-values were found: diphenylpicrylhydrazyl (10.7±0.8µg/ml), hydroxyl (312.5±15.8µg/ml), superoxide anion (27.2±1. 7µg/ml) and nitric oxide radical (1.3±0.1mg/ml). Inhibition of lipid peroxidation could be proven (IC50=177.7±9.5µg/ml). The results indicate comparable or higher extract activity than that of synthetic antioxidants as BHT or BHA (butylated hydroxytoluene/hydroxyanisol). Anti-inflammatory activity was examined by means of cyclooxygenase-1 (COX-1) and 12-lipooxygenase (12-LOX) inhibition and quantifying the COX-1 product 12-HHT (12-hydroxy-5,8,10-heptadecatrienoic acid) and 12-LOX product 12-HETE (12-hydroxy-5,8,10,14-eicosatetraenoate) by RP-HPLC-MS/MS [2]. Extracts inhibited both, COX-1 and 12-LOX (IC50=4.4±0.3 and 3.6±0.3mg/mL, respectively). In this study, we report for the first time an antioxidant and anti-inflammatory activity of P. altissima, and accordingly consider this species as a promising source of natural antioxidant and anti-inflammatory agents.