Chemical Composition and Bioactivity of Extracts Obtained from Prunus spinosa Seeds by Supercritical CO2 Extraction

This study investigates the potential reuse of <i>Prunus spinosa</i> (blackthorn) seeds, a food industry by-product. Traditionally discarded, these seeds are now being explored for their bioactive compounds. In this work, seeds were used as raw material for supercritical CO₂ extraction. Two distinct extracts were obtained at low and high pressure (SFE90 and SFE200) and both extracts presented an aqueous phase (WE90 and WE200). SFE90 analysis by GC/MS allowed us to identify benzaldehyde and fatty acids (mainly oleic and linoleic acids). The fatty acid profile of SFE200, determined by HPLC-DAD/ELSD, showed that oleic and linoleic acids were predominant in supercritical oil. The phytochemical composition of the water extracts, analyzed via LC-DAD-ESI-MS, revealed that higher pressure enhanced the recovery of specific flavonols and anthocyanins, while lower pressure preserved various polyphenolic subclasses. WE90 was rich in 3-feruloylquinic acid and cyanidin-3-<i>O</i>-rutinoside, whereas WE200 was rich in caffeic acid hexoside 2 and dihydro-<i>o</i>-coumaric acid glucoside. Benzaldehyde was individuated in WE90 and WE200 by HPLC-DAD analysis. Cytotoxicity assays demonstrated that WE90, WE200 and SFE200 had anticancer effects on SH-SY5Y neuroblastoma cells, while all extracts did not remarkably affect the viability and morphology of human skin keratinocytes (HaCaT cells). These results suggest that <i>P. spinosa</i> seed extracts have potential nutraceutical and pharmaceutical applications.