Investigation of phenolic contents and in vitro biological activities of Inula helenium subsp. pseudohelenium extracts

The purpose of the present study was to investigate the phenolic profile, antioxidant capacity, and biological activity of Inula helenium subsp. pseudohelenium extracts, for the first time. Phenolic substances in leaf ethanol (L-EtOH), leaf pure water (L-PW), root ethanol (R-EtOH), and root pure water (R-PW) extracts of I. helenium subsp. pseudohelenium plant were investigated by HPLC. Also, the antimicrobial (hollow agar), antioxidant, antiproliferative, and DNA protective activities of the samples were examined in vitro. 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, the L-EtOH extract had an activity profile close to the standard antioxidants in general. It was also found that the L-EtOH extract stabilised 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 cancer cell lines. 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.