Chemical composition, antimicrobial activities and synergistic effects of essential oil from Senecio anteuphorbium, a Moroccan endemic plant

•Essential oil (EO) extracted from Senecio anteuphorbium, a Moroccan endemic plant.•The EO was characterized by the abundance of γ-selinene, cyperene and γ-cadinene.•The EO displayed antimicrobial activities against human pathogen microorganisms.•The combination of the EO with antimicrobials showed a decrease in their MICs.•The studied EO contributed to the decrease of antimicrobial MICs by 4- to 64- fold.