Antioxidant and Acetylcholinesterase Inhibition Capacity of Hyrosols From Lamiaceae Plants for Biopesticide Use. The Role of Phenolic Compounds

Abstract

Background Hydrosols are aqueous solutions obtained as by-products after essential oil extraction from aromatic plants. However, they have been lately reconsidered for applications in ecological agriculture, cosmetic and food industry due to their valuable bioactive phytochemicals content. The aim of this study was to identify the main volatile and polyphenolic compounds in hydrosols extracted from three Romanian Lamiaceae plants, sage (Salvia officinalis), rosemary (Rosmarinus officinalis) and lavender (Lavandula angustifolia) and to analyse the correlation of their total phenolics content to the antioxidant and acetylcholinesterase inhibition capacity, in view of future development of novel biopesticides. Results Our results showed that sage and rosemary hydrosols presented better antioxidant activity than lavender hydrosol in all tested free radical scavenging and metal chelating assays. Good correlation of the antioxidant activity to hydrosols’ phenolics and flavonoids content was observed, except for DPPH assay. The same order was found for acetylcholinesterase activity inhibition, but this was partially related to phenolics content of hydrosols, suggesting that other components present in hydrosols were active compounds with synergistic role in this process. Conclusion These results indicated that Lamiaceae hydrosols could be recommended alone or as optimised mixtures to develop novel natural products for the control of pests in eco-agrosystems.