Cultivated Parsnip and Its Two Wild Relatives as Sources of Polyphenols with Antioxidant and Antimicrobial Activities

The composition and bioactivities of dry methanol extracts from roots, leaves and fruits of cultivated Pastinaca sativa subsp. sativa (Ps) and wild-growing P. sativa subsp. urens (Pu) and P. hirsuta (Ph) were investigated. Their compositions were analyzed by LC-DAD-QTOF-MS/MS, total phenolics and antioxidant activity were measured spectrophotometrically, antimicrobial activity was assessed by microdilution (14 strains), and cytotoxicity was evaluated by the MTT assay (four cell lines). Chemical analysis revealed 45 compounds. While Ps leaf extract had the highest rutin content (13.21 mg/g), Ph leaf and fruit extracts were the richest in total quercetin glycosides and their derivatives (103.70 and 163.93 mg/g); Ph leaf extract was also rich in chlorogenic acid (58.08 mg/g). Extract amounts corresponding to established furanocoumarin intake thresholds were calculated (e.g., regarding leaf extracts, up to 5.46 g for Ph). Ph leaf extract showed the highest total phenolic content (70.07 mg quercetin equivalents/g), FRAP value (0.97 mmol Fe2+/g) and anti-DPPH activity (64.56 mg quercetin equivalents/g). The best antimicrobial activity was observed against Micrococcus luteus (MIC = 0.156–2.5 mg/mL; MBC = 5–10 mg/mL), a known food spoilage bacterium, with Ps leaf extract being the most active. Ps fruit extract showed weak-to-moderate cytotoxicity; others were generally non-cytotoxic. The investigated parsnips, including Ps agricultural waste, represent potential sources of bioactive polyphenols for food applications.