Phytochemical composition and biological properties of a hydroalcoholic extract obtained from the aerial parts of Matthiola incana (L.) R. Br. (Brassicaceae) growing in Sicily

In continuation of our studies on species belonging to the Brassicaceae family growing in Sicily (Italy), this work aimed to characterize the phenolic profile and the volatile constituents and to evaluate some biological activities of a hydroalcoholic extract (80% methanol) obtained from the aerial parts (leaves and flower buds) of Matthiola incana (L.) R. Br. grown wild around Capo D’Orlando (Messina, Sicily). The HPLC-PDA/ESI-MS analysis led to the identification of twelve phenolic compounds, two phenolic acid derivatives (5.46 mg/g extract) and ten flavonoids (155.85 mg/g extract), being luteolin-glucoside the most abundant component (57.07 mg/g ± 0.87% RSD). By SPME/GC-MS fifty-one volatile constituents were fully characterized, and (Z)-9-Octadecen-1-ol turned out to be the most abundant one (24.35%). The antioxidant potential of M. incana extract was evaluated by in vitro methods based on different approaches and mechanisms: DPPH, reducing power, and ferrous ions chelating activity assays. The extract exhibited mild activity both in the DPPH and reducing power assays, whereas it was found to possess good chelating properties, reaching approximately 90% activity at the highest tested dose (2 mg/mL). In order to investigate the antioxidant efficacy of M. incana extract in a biological setting, the ability to protect bacterial growth and survival from the oxidative stress induced by hydrogen peroxide (H2O2) was evaluated on Escherichia coli. The extract displayed protective effect against H2O2-induced oxidative damage. The antimicrobial properties of M. incana extract against bacterial strains and yeasts were assayed by standard methods. The extract didn’t show activity against the tested strains (MICs > 500 µg/mL). Finally, the potential toxicity was investigated using Artemia salina lethality bioassay. The median lethal concentration value indicated that the extract did not display any toxicity against brine shrimps (LC50 > 1000 µg/mL). Acknowledgements: The authors wish to thank the Foundation “Prof. Antonio Imbesi” for financial support.