Figure 7
Antibacterial activity of spearmint extracts. Graph showing mean halo diameters +/- SEM from three disc diffusion assays to determine the effect of spearmint extracts made with various solvents on the growth of E. coli. Significance levels obtained from two-tailed t tests are denoted by stars: * = Significant, P < 0.05; ** = highly significant, P < 0.01; *** = very highly significant, P < 0.001. Significance levels for disc diffusion assays with peppermint essential oil were not determined.