Chemical composition of Crithmum maritimum L. essential oil and hydrodistillation residual water by GC-MS and HPLC-DAD-MS/MS, and their biological activities

Abstract

Aromatic and medicinal plants, such as those from the Apiaceae family, and their metabolites, namely essential oils are of great industrial interest and a source of biologically relevant compounds.Essential oils are the major resource obtained during the hydrodistillation of aromatic plants, however, this process also originates high amounts of residual water. Although this by-product is discarded, it is conceivable that this water may be rich in non-volatile compounds which possess interesting biological properties. Therefore, the aim of this work is to analyze the oil and the hydrodistillation residual water of Crithmum maritimum L. (sea fennel), a highly aromatic plant widely used in many European countries and highlight the bioactive potential of both products. High performance liquid chromatography-photodiode array detector-mass spectrometry (HPLC-DAD-MS/MS) analysis of the hydrodistillation residual water showed a profile rich in hydroxycinnamic acids and small amounts of flavone and flavonol glycosides. Chemical analysis of the essential oil by gas chromatography coupled with mass spectrometry (GC-–MS) has revealed that γ-terpinene (33.6 %), sabinene (32.0 %) and thymol methyl ether (15.7 %) are the major compounds.The antioxidant potential of the residual water was disclosed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and a composition-activity relationship was unveiled by thin layer chromatography (TLC). The anti-inflammatory potential was demonstrated by using an in vitro model of inflammation (lipopolysaccharide (LPS)-stimulated macrophages). Furthermore, the antifungal potential was evaluated by the capacity to inhibit two important virulence factors in Candida albicans.Our results show that the residual water have a promising antioxidant potential as measured by DPPH scavenging assay (IC50 of 650 ± 160 μg/mL). Chlorogenic acid and quercetin derivatives found in the hydrodistillation residual water are the mainly contributors for this activity. The essential oil of C. maritimum (3.125 μg/mL) decreases the production of nitric oxide in LPS-stimulated macrophages by 37 % without affecting cell viability. In addition, the essential oil has a strong effect on virulence factors of C. albicans through inhibiting the formation of the germ tube by more than 50 % at 30 μg/mL besides, it is able to inhibit biofilm formation by decreasing both the biomass and the cell viability.Summing up, the present work highlights that the essential oil of Crithmum maritimum and the non-volatile extract rich in hydroxycinnamic acids and flavonoid glycosides, obtained after the hydrodistillation process have important biological activities, thus endorsing the industrial exploitation of this plant.