Chemical Composition and Bioactivity of the Essential Oils of Heracleum pyrenaicum subsp. pollinianum and Heracleum orphanidis

The objective of this research was to analyze the chemical composition, antimicrobial and cytotoxic activity of Heracleum pyrenaicum subsp. pollinianum (Bertol.) F. Pedrotti & Pignatti (HPP) and H. orphanidis Boiss. (HO) essential oils. The composition of the oils was analyzed by GC and GC-MS. β-Pinene (35.1%) was the most abundant compound in HPP root oil, while (Z)-falcarinol (80.0%) dominated in HO root oil. (E)-Nerolidol (28.5%) was the main constituent in HPP leaf oil. HPP fruit oil, as well as HO leaf and fruit oils mainly contained aliphatic esters, mostly octyl acetate (50.5-84.5%). Antimicrobial screening was performed by microdilution method against eight bacterial and eight fungal strains. The strongest antibacterial activity was shown by both root oils (MICs 0.02-0.60 mg/mL and MBCs 0.04-2.50 mg/mL for HPP, and MICs 0.02-1.25 mg/mL and MBCs 0.04-2.50 mg/mL for HO), while the best antifungal potential was exhibited by HPP fruit oil (MICs 0.30-0.60 mg/mL and MFCs 0.60-1.25 mg/mL) and HO leaf oil (MICs 0.15-0.63 mg/mL and MFCs 0.30-1.25 mg/mL). The tested root and fruit oils exhibited strong cytotoxic effect, which was determined by MTT test against HeLa (IC50 7.53-21.07 μg/mL) and LS174 (IC50 24.16-58.86 μg/mL) cell lines.