This study was aimed at providing a comprehensive phytochemical characterization and multi-biological assessment of Symphytum officinale L., a medicinal plant with a noteworthy traditional use, and Anchusa ochroleuca M. Bieb., a Boraginaceae species from the Romanian flora. The dichloromethane, methanol and 65 % ethanol extracts obtained from the roots and aerial parts of both plants revealed the presence of numerous phenolic acids, oxygenated fatty acids, pyrrolizidine alkaloids (PAs) and flavonoids, as assessed by LC-HRMS/MS analysis. Consistent with their higher total phenolic content, the polar aerial part extracts of S. officinale and root extracts of A. ochroleuca showed the most significant antioxidant activities, as evaluated by DPPH (173.22-216.98 mg TE/g) and ABTS (219.41-311.97 mg TE/g) radical scavenging, CUPRAC (387.18-626.40 mg TE/g), FRAP (199.36-299.86 mg TE/g) and total antioxidant capacity (2.28-2.68 mmol TE/g). Furthermore, both plants exhibited good tyrosinase (19.11-43.89 mg KAE/g) and α-glucosidase (2.45-12.54 mmol ACAE/g) inhibitory effects. The orthogonal projections to latent structures discriminant analysis (OPLS-DA) allowed the objective differentiation between the roots and aerial parts of the two investigated species based on their phytochemical and biological profiles. The partial least square (PLS) analysis showed that several individual phenolic acids, such as danshensu, rabdosiin and rosmarinic acid, significantly contributed to the antioxidant potential of both Boraginaceae species, whilst the relative levels of sucrose were positively correlated with the anti-enzymatic properties. Overall, S. officinale and A. ochroleuca could be regarded as rich sources of bioactive phytochemicals that could further lead to developing novel phyto-pharmaceutical commodities.
Keywords: Anchusa ochroleuca; Antioxidant; Comfrey; Enzyme inhibitors; LC-HRMS/MS; Symphytum officinale.
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