Antiradical activity of seven Plantago species from Serbia and Montenegro

Abstract

Plantago species are widely distributed in Europe and 14 species are described in the Flora of Serbia [1]. In Asia and Europe, Plantago species have been used in folk medicine for the treatment of certain respiratory and digestive diseases, and wound healing [2]. Phytochemical investigation of the genus revealed the presence of iridoid glycosides and various phenolics [3]. In our study, 50% ethanolic extracts of Plantago lanceolata, P. atrata, P. bellardii, P. coronopus, P. holosteum, P. reniformis, and P. schwarzenbergiana leaves were investigated regarding the contents of total phenolics, phenylpropanoid glycosides (PPG), and iridoids. Antiradical activity of extracts was characterized by the DPPH scavenging test. The amount of total phenolics varied from 9.28–24.98mg GAE/g DW, and decreasing order was P. lanceolata > P. schwarzenbergiana > P. holosteum > P. atrata > P. reniformis > P. bellardii > P. coronopus. Regarding the PPG content, the highest amount was present in P. lanceolata (8.88%), and P. atrata contained the lowest amounts of PPG (1.55%). The most abundant in iridoids were P. holosteum, P. atrata and P. lanceolata (14.54, 12.52 and 12.25mg/g, respectively). The highest scavenging activity toward DPPH radical was observed in P. lanceolata (IC50=0.25mg/ml), while the lowest activity was shown by P. coronopus (IC50=0.77mg/ml). The scavenging effect of extracts decreased in the same order as with total phenolic content, and the relationship between total phenolic content and antiradical activity of extracts was observed with statistically significant correlation (r=–0.95).