Table 3

Antimicrobial activity of 21 essential oils against P. vulgaris, P. aeruginosa and E. coli using disc diffusion method
Oil Name
 P. vulgaris
 P. aeruginosa
 E. coli
Concentration
 1:1
 1:5
 1:10
 1:20
 1:1
 1:5
 1:10
 1:20
 1:1
 1:5
 1:10
 1:20
Aniseed oil
 -
 -
 -
 -
 -
 -
 -
 -
 -
 -
 -
 -
Calamus oil
 11.1 ± 0.7gh
 9.2 ± 0.5h
 -
 -
 13.8 ± 0.5ef
 12.8 ± 0.4f
 9.2 ± 0.7 d
 8.3 ± 0.5 d
 -
 -
 -
 -
Camphor oil
 8.8 ± 0.7 hi
 -
 -
 -
 10 ± 0.5gh
 -
 -
 -
 8.8 ± 1d
 -
 -
 -
Cedar wood
 14.1 ± 1.1f
 12.9 ± 0.5g
 8.2 ± 0.5f
 -
 15.6 ± 0.5de
 14.1 ± 0.9ef
 8.23 ± 0.5d
 -
 -
 -
 -
 -
Cinnamon oil
 29.4 ± 0.5a
 27 ± 0a
 18.6 ± 1.52a
 14.1 ± 0.4b
 33.3 ± 1.6a
 32.2 ± 0.5a
 24.4 ± 0.5a
 21 ± 0a
 29.8 ± 0.7a
 26 ± 1a
 23.8 ± 1a
 21 ± 0.2a
Citronella oil
 19.5 ± 0.5cd
 11.3 ± 0.7g
 -
 -
 12.1 ± 0.5fg
 10.4 ± 0.5g
 -
 -
 -
 -
 -
 -
Clove oil
 20.1 ± 1c
 18.2 ± 0.5d
 11.8 ± 0.5d
 8 ± 0e
 17.4 ± 0.7d
 15.5 ± 0.2e
 8.5 ± 0.5d
 -
 17.4 ± 2c
 15.1 ± 0.5c
 10.8 ± 0.5e
 8 ± 0c
Eucalyptus oil
 -
 -
 -
 -
 -
 -
 -
 -
 8.5 ± 1d
 -
 -
 -
Geranium oil
 19 ± 0.2de
 14.6 ± 0.2e
 11 ± 1.5ef
 8.3 ± 0e
 21.5 ± 0.2c
 19.2 ± 1.2d
 9.4 ± 0.5d
 -
 14.1 ± 1c
 10.4 ± 1d
 -
 -
Lavender
 10.8 ± 0.5ghi
 9.3 ± 0.5h
 -
 -
 12.1 ± 0.9fg
 9.9 ± 0.7g
 -
 -
 -
 -
 -
 -
Lemon oil
 22.5 ± 0.5b
 18.9 ± 0.5d
 15.5 ± 0.5c
 10.7 ± 0.2d
 21.4 ± 1.1c
 19.9 ± 0.7cd
 9.1 ± 0.2d
 -
 21.6 ± 0.5b
 18.9 ± 0.5b
 10.6 ± 0.2e
 -
Lemongrass oil
 14.6 ± 0.7f
 12.1 ± 0.2g
 9.5 ± 0.5ef
 -
 23.4 ± 1c
 19.6 ± 0.5d
 9.1 ± 0.5d
 -
 -
 -
 -
 -
Lime oil
 27.8 ± 0.5a
 24 ± 0b
 17.9 ± 0.1ab
 13 ± 1c
 25.5 ± 1b
 23.5 ± 0.5b
 13.6 ± 0.7c
 9.3 ± 0.8c
 22.7 ± 0.5b
 18.9 ± 1b
 15.6 ± 0.5c
 17.6 ± 1.5b
Nutmeg
 14.5 ± 0.7f
 11.9 ± 0.2g
 8 ± 0 f
 -
 15.5 ± 0.5de
 12.9 ± 1f
 -
 -
 -
 -
 -
 -
Orange oil
 23.7 ± 0.7b
 22.2 ± 0.7 c
 16.5 ± 0.2bc
 10.7 ± 0.5d
 21.6 ± 0.2c
 18.8 ± 0.2d
 9.4 ± 0.5d
 -
 22.9 ± 0.5b
 19.4 ± 0.7b
 12.4 ± 0.2d
 -
Palmarosa oil
 19 ± 0cd
 15.8 ± 0.2 e
 9.9 ± 0.2 def
 -
 14.4 ± 0.5ef
 13.2 ± 0.5ef
 9.2 ± 0.2d
 -
 8.2 ± 0.5d
 -
 -
 -
Peppermint oil
 8.5 ± 0.2i
 -
 -
 -
 13.4 ± .52ef
 11.2 ± 0.8g
 -
 -
 -
 -
 -
 -
Rosemary oil
 17.4 ± 1cd
 15.9 ± 0.5ef
 9.7 ± 0de
 -
 23.4 ± 0.2c
 21.9 ± 0.5c
 14.5 ± 0.5b
 8.3 ± 0.5d
 17.5 ± 1c
 15.1 ± 0.7c
 9.1 ± 0.2f
 -
Basil oil
 8.9 ± 0.7ghi
 -
 -
 -
 8.23 ± 0.5h
 -
 -
 -
 10.5 ± 0.5d
 8.2 ± 0.5e
 -
 -
Vetiver oil
 11.5 ± 0.5g
 10.3 ± 0.2
 11.4 ± 0.5de
 -
 13.5 ± 0.5ef
 11.7 ± 0.5g
 8.2 ± 0.2d
 -
 -
 -
 -
 -
Wintergreen
 15.8 ± 0.7ef
 14.8 ± 0.5 f
 9.5 ± 1 def
 -
 10.2
 -
 -
 -
 8.9 ± 1d
 -
 -
 -
Streptomycin**
 18.4 ± 0.7


16.4 ± 0.2


21.2 ± 0.1


Vehicle control
 -


-


-


** Streptomycin disc (25 μg) as a positive reference standard; Values are mean inhibition zone(mm) ± S.D of three replicates

Means within a column followed by different letters are statistically significant by tukey's test at p = 0.05; - no activity.

Prabuseenivasan et al. BMC Complementary and Alternative Medicine 2006 6:39   doi:10.1186/1472-6882-6-39