Secondary Metabolites from Pollino National Park Native Plants: Gentiana Lutea and Hypericum Perforatum

Background: Plants are able to synthetize a wide variety of organic molecules, called Secondary Metabolites (SMs) composed of very complex carbon skeleton structures. Plant SMs have protective actions to abiotic/biotic stresses. Within the OnFoods project (www.onfoods.it), two native species from Pollino National Park, in the Mediterranean area, Hypericum perforatum and Gentiana lutea were analyzed for the SMs content. Methods: Hypericum perforatum and Gentiana lutea were collected at different altitudes and geopedological characteristics of sampling site were analyzed. Plant samples were subjected to drying in controlled condition, matrix was pounded and extracted in EtOH 80% The phytochemical profile was investigated through TLC, HPLC analyses and the Folin-Ciocalteau method. The potential antioxidant activity was examined through ABTS assay. Results: The phytochemical profile of both spontaneous and cultivated H. perforatum tissues was analyzed and compared. TLC analyses of extracts showed different patterns of SMs, indicating that different altitudes induced the formation of specific biotypes adapted to the environment. The HPLC analyses confirmed that the relative concentration of some components such as hypericin and pseudohypericin were altitude dependent. The highest polyphenol content was in leaves, followed by flowers and fruits. These data were consistent with the potential mesured antioxidant activity. On the contrary,in Gentiana lutea, both total polyphenol content and the antioxidant potential seemed to decrease as the altitude of the collection site increases. Conclusions: The different strategies adopted by Hypericum perforatum and Gentiana lutea can be observed. While Gentiana lutea SMs content is stable, Hypericum perforatum showed significant differences in the SMs content, for the adaptative and plastic responses to the changing conditions of the environments. These findings suggest that these plants could be used as an ecological bioindicator and a potential candidate for further studies