Phytochemical Composition and Cytoprotective Properties of the Endemic Sideritis sipylea Boiss Greek Species: A Valorization Study.

Sideritis sipylea Boiss. (Fam. Lamiaceae) is an endemic plant of the North Aegean Islands (Greece), commonly known as ironwort. Traditionally, its aerial parts have been used to relieve several ailments, especially gastrointestinal disorders, however, with scant knowledge about the pharmacological basis. In the present study, an endemic S. sipylea Greek species from Lesvos Island has been characterized for phytochemical composition and biological activities, in order to give a possible scientific basis to its traditional use and to highlight a further nutraceutical interest as a source of bioactive phytochemicals and extracts. Three different fractions obtained from a methanolic extract of S. sipylea aerial parts by using ethyl acetate with 10 (S10), 20 (S20), and 50% (S50) methanol as fractionation solvents were phytochemically characterized. Moreover, their antioxidant power and cytoprotective activity in different human cell lines were evaluated. The phytochemical analysis highlighted the presence of flavonoids, iridoids, and phenolic acids in all the tested samples. Particularly, the S10 fraction mainly contained iridoids, while S20 and S50 lavandulifolioside and chlorogenic acid, respectively. The fractions also showed antioxidant properties, S10 and S20 being the most potent. When assessed in human cholangiocytes, they counteracted the cytotoxicity of the tBOOH pro-oxidant agent, by reducing ROS levels and affecting GSH antioxidant system. The present findings highlight a possible interest in S10 and S20 fractions from S. sipylea as sources of bioactive molecules and stimulate further studies in order to characterize their possible application for nutraceutical and pharmaceutical purposes.

Phytochemical Profile and Biological Activity of Endemic Sideritis sipylea Boiss. in North Aegean Greek Islands.

Sideritis sipylea Boiss. is an endemic plant of the Mediterranean basin that is distributed in the Greek islands of the North Aegean Sea, i.e., Lesvos, Chios, Samos, and Ikaria, and in the West and Middle peninsula of Turkey. It is considered an endangered species because of its uncontrolled collection from its original habitat. Although the antioxidant, anti-inflammatory and antimicrobial properties have been previously reported, the total chemical profile has not yet been explored. In this context, the chemical profiles of the water/methanol (HA), methanol (ME), and ethyl acetate (EtOAc) extracts were analyzed using ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS). In parallel, analysis by gas chromatography-mass spectrometry (GC-MS) was employed for the dichloromethane extract (DCM) as well as for the essential oil (EO) and the extract obtained by supercritical fluid extraction (SFE). Furthermore, the total phenolic content (TPC) along with the in vitro tyrosinase and elastase enzyme inhibitory activity of different extracts was evaluated, towards the discovery of new active agents for cosmetic formulations. These activities are in accordance with its well-known antioxidant and anti-inflammatory properties, confirming the importance of ethnopharmacological references for S. sipylea in Greece and Turkey.

An Ethnobotanical Study of Medicinal Plants in the Greek Islands of North Aegean Region.

Greek islands of the North Aegean Region are a group of nine inhabited islands (Lemnos, Agios Efstratios, Lesvos, Chios, Psara, Oinousses, Samos, Ikaria, and Fourni) located in the northern part of the Aegean Sea, close to Asia Minor. Each island of this region can be considered autonomous in terms of culture and biodiversity. With this work we try to evaluate the status of the traditional uses of medicinal plants in this region. Endemic and endangered species such as Sideritis sipylea Boiss., Origanum sipyleum L., Thymus sipyleus Boiss., Pistacia lentiscus L., Verbascum ikaricum Murb., are still used by locals to treat different ailments. Moreover, the use of some species for the treatment of specific diseases has been reported for the first time. We report about 109 wild plants of medicinal importance, from 52 families, listing their uses for therapeutic purposes and galenic preparations provided by local medical doctors and pharmacists. The information we include was derived from literature sources and additionally collected through semi-structured interviews conducted on 200 informants (100 men and 100 women). Additionally, informant consensus factor (FIC) and UV value were calculated for the medicinal plants in the current study in relation with the diseases treated. This research confirms the importance of the medicinal plants and the diffusion of their use in traditional medicine within this region. This ethnopharmacological survey is a fundamental step for the preservation of the local knowledge both for further scientific research and for the protection of endangered and endemic medicinal plants.