Phytochemical screening and antioxidant activity of four Moroccan aromatic plant methanolic extracts and essential oils

Abstract

This work aimed to evaluate and to compare the antioxidant potential between essential oils (EOs) and methanolic extracts (MEs) of Anthemis tenuisecta, Cladanthus arabicus Cass., Ismelia carinata Schousb., and Thymus broussonetii Boiss subsp. broussonetii collected from Morocco. The EOs used in this study were isolated by hydrodistillation using a Clevenger-type apparatus. The MEs were obtained by methanol maceration. The main compounds of EOs were identified using gas chromatography-mass spectrometry. The MEs of the four plant species were tested for total phenolics and total flavonoids. The in vitro antioxidant activity of EOs and MEs was carried out using diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activity of MEs showed high correlations with phenolic compounds. For both fractions, the best IC₅₀ values were given by T. broussonetii. The MEs revealed significantly (p ≤ 0.05) better antioxidant activity than EOs. The results suggest that A. tenuisecta, C. arabicus, I. carinata, and T. broussonetii may be potential sources of natural antioxidants.