Medicinal and aromatic plants – industrial profiles

Results of the studies
Monoterpenes versus contractions of smooth muscle
Previous comparisons of the pharmacological activity of many components and essential oils
suggested that monoterpenes were responsible for contractions in the guinea-pig ileum 
in vitro
(Lis-Balchin 
et al
., 1996a,b).
This was best illustrated by work on two New Zealand essential oils Manuka and Kanuka.
The former was largely composed of sesquiterpenes and produced a relaxation in the gut, while
the latter was composed largely of monoterpenes and produced a contraction (Lis-Balchin 
et al
.,
1996a). Further, work on over seventy essential oils suggested that there was a considerable cor-
relation of contraction of the small intestine with a high percentage of monoterpenes (but not
sesquiterepenes) (Lis-Balchin 
et al
., 1996b; 1998).
Table 23.1
The predicted effect on guinea-pig ileum based on the
percentage of components at different retention time
intervals
RT
10
11–15
16–20
21–30
30
Effect
a
19
66
—
5
—
R
b
13
64
12
7
—
R
c
—
3
—
47
45
R
d
82
1
—
5
—
S
e
97
3
—
—
—
S
f
57
—
—
32
—
S/R
g
69
25
2
2
—
S/r
h
2
—
85
2
—
R
i
82
—
—
4
—
S
j
6
41
45
5
—
R
k
46
22
30
—
—
S/R
l
8
30
5
39
10
R
m
—
—
—
59
48
R
n
—
—
—
78
34
R
o
7
29
58
—
—
R
p
—
92
2
—
—
R
q
—
52
37
6
—
R
r
99
—
—
—
—
S
s
1
30
51
5
—
R
t
14
—
1
69
—
S/R
u
16
—
76
—
—
S/R
v
67
7
2
9
—
S
w
1
—
34
56
—
R
x
—
—
—
89
4
R
y
58
32
—
—
—
S/R
z
4
—
1
76
1
R

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Chemical profiles of lavender oils and pharmacology
247
These results therefore suggested that it was simply the actual percentage composition of the
monoterpenes which determined whether the effect on the smooth intestinal muscle would be
contractile or relaxant. This was therefore investigated further.