Antioxidant activity and evidence for synergism of Cannabis sativa (L.) essential oil with antimicrobial standards

•Antioxidant and antimicrobial activities of Moroccan Cannabis sativa essential oil were studied.•Synergistic effect of essential oil in combination with standard antibiotics was investigated.•(E)-caryophyllene, α-humulene and caryophyllene oxide were found as major compounds.•C. sativa oil displayed a moderate antimicrobial activity against the tested microorganisms.•Combination with antibiotics showed a significant decrease in the individual MICs by 2- to 64-fold.