Plants have been used in alternative medicine for centuries in the treatment of many diseases with the metabolites they contain. The goal of this work was to investigate the phenolic profile, antioxidant capacity and biological activity of I. helenium subsp. pseudohelenium extracts. Phe-nolic (HPLC) substances in leaf ethanol (L-EtOH), leaf pure water (L-PW), root ethanol (R-EtOH), and root pure water (R-PW) extracts of Inula helenium subsp. pseudohelenium plant were investi-gated. Also, in vitro the antimicrobial (hollow agar), antioxidant (DPPH, ABTS.+, FRAP, CU-PRAC), antiproliferative (MTT assay against HT-29, MCF-7 and L-929), and DNA (Agarose gel electrophoresis) protective activities of the samples were examined. Although gallic acid was not detected in the extracts, the presence of curcumin was detected only in EtOH extracts. L-EtOH exhibited the best antimicrobial activity. According to the antioxidant results, it was found that the L-EtOH extract had an activity profile close to the standard antioxidants in general. It was also found that the L-EtOH extract stabilized the DNA by disrupting the scavenging effect of H2O2+DMSO. According to the antiproliferative activity results, EtOH extracts exhibited the strongest effect, especially against MCF7. When evaluated in general terms, it was found that L-EtOH extract showed better activity than other extracts. It is important to conduct more in vivo and in vitro studies after isolating the active components of extracts e.g. L-EtOH, which have good effects in terms of biological activity.

Polyphenols are ubiquitous plant metabolites that demonstrate biological activities essential to the plant-environment interactions. They are of interest to plant food consumers, as well as to the food, pharmaceutical and cosmetic industry. The class of the plant metabolites comprises both widespread (chlorogenic acids, luteolin, quercetin) and unique compounds of diverse chemical structures but of the common biosynthetic origin. Polyphenols, next to sesquiterpenoids are regarded as the major class of the Inuleae-Inulinae metabolites responsible for the pharmacological activity of medicinal plants from the subtribe (Blumea spp., Dittrichia spp., Inula spp., Pulicaria spp. and others). Recent decades have brought a rapid development of molecular and analytical techniques which resulted in better understanding of the taxonomic relationships within the Inuleae tribe and in a plethora of data concerning the chemical constituents of the Inuleae-Inulinae. The current taxonomical classification has introduced changes in the well-established botanical names and rearranged the genera based on molecular plant genetic studies. The newly created chemical data together with the earlier phytochemical studies may provide some complementary information on biochemical relationships within the subtribe. Moreover, they may at least partly explain pharmacological activities of the plant preparations traditionally used in therapy. The current review aimed to systematize the knowledge on the polyphenols of the Inulae-Inulinae.