Assessment of polyphenol content, in vitro antioxidant, antimicrobial and toxic potentials of wild growing and cultured rue

Abstract

 Ruta graveolens L. (rue) is edible medicinal plant that is traditionally used in various countries. This study aimed to investigate and compare the phenolic content, antioxidant capacity, antibacterial and cytotoxic activities of the methanolic and ethanolic extracts of wild growing and cultured rue. The total phenolic content of the tested extracts varied from 57.90 to 166.91 mg of catechin equivalent (CE)/g of extract and the total flavonoid content from 4.18 to 26.87 mg of rutin equivalent (Ru)/g of extract.  All the tested samples exhibited significant antioxidant potential in DPPH radicals scavenging and lipid peroxidation inhibition assays (comparable with activity of rutin in the same test systems), antimicrobial activity determined by microdilution method (particularly against Gram (+) bacteria strains) and ability to induce inhibition of HeLa cells growth and proliferation (up to 71.81%). In addition, rue-treated HeLa cells showed various morphological changes after 72 h of incubation with rue extracts. Extracts from wild growing rue with the highest polyphenol, tannin and flavonoid contents demonstrated the strongest activities in all tested systems. The present study also emphasized the fact that the rue leaves and herb should be harvested at the beginning of blossoming stage in order to achieve the maximal level of secondary metabolites and optimal pharmacological effects.