Ethnobotanical, metabolomic and bioactivity study of Italian alimurgic plant species traditionally used in folk medicine

Traditional medicine is the oldest form of health care, used to prevent/treat human illnesses, born by the experiences of different cultures, orally transmitted until today. The aim of this work was to analyse alimurgic plants used in Italian folk medicine, to acquire preliminary scientific data to link their traditionally reported effectiveness in treating human diseases. B.officinalis, C.dactylon, F.vulgare, H.perforatum, M.sylvestris, S.nigra, U.dioica were collected in three Italian regions. Polyphenols, reducing sugars, proteins and antioxidant activity were quantified with spectrophotometric techniques and resulted to be higher in flowers and leaves respect to stems and roots. Next, B.officinalis, F.vulgare, H.perforatum and S.nigra infusions and decoctions were subjected to an in vitro simulated digestion, to verify how plant metabolites and their biological activities are affected by human digestion. Phenols and antioxidant activity decreased after digestion, while reducing sugars and proteins increased. H.perforatum phenolic profile was analysed with HPLC-DAD and resulted to be composed by rutin, epicatechin, epigallocatechin, catechin and caffeic acid. H.perforatum and B.officinalis extracts were chemically characterized with NMR, resulting three main classes of molecules, aliphatic, proteins, aromatic compounds. The preparations efficacy in external treatments against skin diseases was finally tested. Infusions/decoctions showed anti-tyrosinase activity (probably due to phenolics in not digested and bioactive peptides in digestates); not digested showed antimicrobial activity (they could be effective for topical applications) and anti-inflammatory activity and did not exert any toxicity (potential hormetic effect). The analysed alimurgic species preparations showed high concentrations of phytochemicals and demonstrated to have significant biological activities: not digested showed evidences linked to their traditional topical uses, and digestates mimicking the traditional use through oral ingestion. Many other variables acting in the human organism could not be replicated in laboratory during the present thesis work, so further analyses are needed to justify the folk medicinal uses of these plant preparations.