Seasonal Variation of Lavandula angustifolia Mill. Antioxidant Capacity

Abstract

Lavandula angustifolia Mill. is one of the most widely used medicinal and aromatic plants, known for its diverse biological activities attributed to its secondary metabolites. The present study aimed to evaluate the total polyphenol content (TPC), total flavonoid content (TFC), total phenolic acid content (TPAC), as well as antioxidant activity determined by the DPPH radical scavenging assay (FRSA) and molybdenum-reducing power (MRP) in ethanol extracts of different plant parts of L. angustifolia during the vegetation period. Plant material was collected from experimental fields of the Institute of Climate Smart Agriculture of the National Academy of Agrarian Sciences of Ukraine during 2024–2025. The ethanol extracts exhibited considerable variation depending on growth stages and plant organs. Specifically, TPC ranged from 22.02 to 80.84 mg GAE g⁻¹, TFC from 10.27 to 36.18 mg QE g⁻¹, TPAC from 4.61 to 39.04 mg CAE g⁻¹, MRP from 26.97 to 172.94 mg TE g⁻¹, and FRSA from 3.64 to 9.20 mg TE g⁻¹. The highest levels of phenolic compounds and antioxidant activity were observed in bud extracts, indicating that the budding stage is the most favorable period for harvesting biologically active raw material. Strong correlations between phenolic content and antioxidant activity further confirmed the key role of polyphenols in the antioxidant potential of L. angustifolia extracts. Overall, the obtained results suggest that bud-derived material of L. angustifolia represents a promising source for pharmacological and breeding applications. These findings also provide a basis for further biochemical investigations of Lavandula species across different stages of vegetation.