This study focuses on the analysis of the chemical composition and the evaluation of the antioxidant and antibacterial activities of the essential oil of Hyptis spicigera from Niger.
Hyptis spicigera is a plant that belongs to the Lamiaceae family. Analysis of the chemical composition of this plant’s essential oil by using gas chromatography coupled with mass spectrometry allowed to the identification of 39 compounds with (E) -β-caryophyllene (38.04%) as the major constituent. The antioxidant activity of the oil essential was evaluated by using the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging method and expressed as CI50, and the iron reduction method and expressed as CE50. An CI50 value of 4.56 mg/mL and an CE50 value of 2.51 mg/mL were obtained. The antibacterial activity was studied using the disc diffusion method and the microdilution method on Gram-positive and Gram-negative bacteria. The essential oil showed good antibacterial activity on the bacterial strains tested, with an inhibition zone diameter of 35 ± 1.5 mm and a minimum inhibitory concentration (MIC) of 0.03 mg/mL for the Enterococcus faecium H3434 strain, and an inhibition zone diameter of 20 ± 1 mm and a minimum inhibitory concentration (MIC) of 0.5 mg/mL for the methicillin-resistant Staphylococcus aureus P1123 strain.