Chemical characterization and in vitro evaluation of the antioxidant and antibacterial activity of pulicaria incisa (Lam.) DC. essential oil

Abstract

In the present study, in vitro antioxidant and antimicrobial activities of the essential oil of Pulicaria incisa (Lam.) DC., harvested from Oulad M’barek (Beni Mellal-Khenifra-Morocco) were evaluated. The essential oil obtained by hydrodistillation from the dried aerial parts was analysed by GC-MS. The major components were characterized as β-gurjunene (13.1%), β-bourbonene (11.5%), camphor (8.8%), γ-muurolene (7.9%), 1,8-cineole (eucalyptol) (6.1%), respectively. The P. incisa essential oil showed in the DPPH assay a value of IC50 105.99 ± 4.25 μg/mL and in the FRAP assay a value of EC50 87.21 ± 3.1 μg/mL, respectively. The antimicrobial activity of the oil was evaluated against five microorganisms using the in vitro paper disk diffusion for the determination of MIC and MBC values. The results obtained revealed different levels of sensitivity of the bacterial strains tested. The Allorhizobium vitis (S4) and Agrobacterium tumefaciens (C58) strains were the most sensitive to the investigated oil, with inhibition diameters >20 mm and a MIC and MBC of 0.25 (v/v) and 0.5 (v/v), respectively. Our results suggest that the essential oil of P. incisa contains bioactive compounds with antioxidant and antimicrobial properties supporting its traditional therapeutic use. This essential oil merits further study as a potential product for the management of phytopathogenic bacteria.