In Vitro TNF-α Inhibition Elicited by Extracts from Echinodorus grandiflorus Leaves and Correlation with Their Phytochemical Composition.

This study aimed to evaluate the effect of various extracts and fractions obtained from Echinodorus grandiflorus leaves on tumor necrosis factor-α release by lipopolysaccharide-stimulated THP-1 cells, as well as to look at the association between bioactivity and phytochemical composition. To this end, a high-performance liquid chromatography with diode-array detection method was developed and validated, enabling the quantification of seven compounds in E. grandiflorus extracts and fractions. All of these samples showed antitumor necrosis factor-α activity, however, extracts prepared from 50% EtOH, water and dichloromethane, and a flavonoid-rich fraction elicited the most potent responses. trans-Aconitic acid and isoorientin were the major compounds in some preparations. Polynomial regression analysis showed the association between the contents of swertiajaponin, swertisin, trans-aconitic, and chicoric acids with the antitumor necrosis factor-α activity of the extracts and fractions. None of the compounds tested alone abolished tumor necrosis factor-α release completely, however, some extracts and fractions reached this result, suggesting a synergistic effect between the constituents. Therefore, it is clearly shown that the species E. grandiflorus has significant in vitro antitumor necrosis factor-α activity, a promising characteristic that deserves further investigations in the search for new anti-inflammatory agents from plants.