Antimicrobial Activity of the Essential Oil of Plectranthus neochilus against Cariogenic Bacteria

Table 1

Minimum inhibitory concentration (MIC) values (μg/mL) obtained for the essential oil of P. neochilus (PN-EO), compounds 1, 2, 3, and 4, and the mixture 1 + 2 + 3 + 4 against selected cariogenic bacteria.

Microorganisms	PN-EO	CHD^a	1^b	2^b	3^b	4^b	1 + 2 + 3 + 4^c
E. faecalis	250.0	14.8	>4000	>4000	>4000	>4000	>4000
S. salivarius	250.0	7.4	4000	4000	4000	4000	4000
S. mutans	3.9	1.8	>4000	>4000	>4000	>4000	1000
S. mitis	31.3	14.8	4000	4000	4000	4000	4000
S. sobrinus	62.5	1.8	>4000	>4000	>4000	>4000	4000
S. sanguinis	62.5	7.4	4000	>4000	>4000	>4000	>4000
L. casei	31.3	3.7	4000	4000	4000	4000	500

Chlorhexidine dihydrochloride.
^bFor compounds 1, 2, 3, and 4, the concentration of 4000 g/mL corresponds to 29.4, 29.4, 19.6, and 18.1 mM, respectively.
^c1 + 2 + 3 + 4: mixture of α-pinene, β-pinene, trans-caryophyllene, and caryophyllene oxide.