Abstract: This study aimed to screen Blumea balsamifera oil (BBO) with good antibacterial activity, seek antibacterial active substance, and preliminarily analyze its antibacterial activity against Staphylococcus aureus (S. aureus). BBO from different sources (A1-A5) and home-made (B1-B9, T) were screened by antibacterial test to S. aureus, Escherichia coli (E. coli), Pseudomons adaceae (P. arugino.sa), Streptococcus agalactiae (GBS), Candida albicans in vitro, the main chemical constituents were analyzed by GC-MS, and its MIC and MBC was also evaluated. Also, the protective effects of BBO T in mice infected with S. aureus, and its effect on the bacterial growth curve and bacterial morphology were both determined. The results showed that BBO B9 and T had the best antibacterial effect. The MIC values for S. aureus and P. arugino.sa were 9.77, 13.68 μg·mL^-1, and MBC values were 19.54 and 27.35 μg·mL^-1, respectively. Thirty-six common chemical constituents were detected from BBO B5, B9 and T, in which α-Humulene, pinene and linalool had certain antibacterial activity. Different concentrations of BBO T solution could inhibit the death of mice induced by S. aureus in different degrees, and significantly reduce the splenomegaly, white spots in kidney and renal tissue necrosis in mice (P<0.01). The low concentration of BBO T solution could delay the strain to enter the logarithmic growth phase, and the high concentration could kill the bacteria, change the cell morphology and break up the cells. These results suggest that BBO T is of good quality and has good antibacterial activity in vivo and in vitro. It exerts antibacterial effect by destroying the structure of bacteria and inhibiting the growth of strains. α-Humulene, pinene and linalool in BBO may be the key antibacterial substances, which can be used for further development and research.

Key words: Blumea balsamifera oil, GC-MS, chemical composition, antibacterial activity