Metabolite profiling of sea buckthorn dried fruits (Hippophae rhamnoides L.) by unconventional methods through UHPLC-Q-Exactive-MS/MS analysis

In Europe and Asia, Hippophae rhamnoides L. (Elaeagnaceae) fruit has been recognized for centuries as a food with important nutritional and medicinal properties. It is a source of nutrients and active compounds, with many health benefits such as anti-inflammatory, antioxidant, hepatoprotective, hypoglycaemic, hypolipidaemic, and neuroprotective. The objective of the present study was the investigation of metabolite profiling of sea buckthorn dried fruits from different Countries (Italy, Poland, Russia) using an LC-ESI/(HR)MS system consisting of a UHPLC coupled to a Q-Exactive hybrid quadrupole Orbitrap high-resolution mass spectrometer (UHPLC-Q-Exactive), operating in positive ionization mode. Amino acids, carboxylic acid derivatives, fatty acids, phenolic acids, flavonoids, and terpene derivatives were identified in sea buckthorn fruit extracts. Unconventional extraction techniques such as microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and conventional extraction technique such as decoction (Dec) were carried out on dried fruits. A comparative analysis of fruit extracts was carried out using multivariate statistical analysis (PLS-DA). The total phenolic content of H. rhamnoides extracts was studied together with the antioxidant activity tested by TEAC assay. Decoctions showed the highest antioxidant activity (TEAC value ranging from 2.084 to 2.543 mM). Finally, the tyrosinase inhibition assay was carried out to demonstrate the potential sea buckthorn fruit extracts in dermocosmetic applications. Among the varieties, the Italian one showed an interesting tyrosinase inhibitory activity (IC50 in the range from 45.414 to 69.222 mu g/mL).