Biology Reference
In-Depth Information
(EC
50
0.5 μg/mL), cytotoxicity against human oral squamous cell
carcinoma and salivary gland tumor cells, antihistamine, and oxidative
activities (Kolodziej
et al.
, 2001, Kanoh
et al.
, 2000, Barbehenn
et al.
,
2006 a/b, Sakagami
et al.
, 2000).
Several other tannins (Figs. 6.13 and 6.14) have been examined for
their IL-1β inducing ability with macrophages. Simple tannins such as
(-)-epicatechin gallate (
77
, ECG) and (-)-epigallocatechin gallate (
74
)
generated only a slight amount of the cytokine (35 and 44% increases
over control, respectively). Monomeric ellagitannins such as
tellimagrandin I (
64
) (162%), tellimagrandin II (
65
) (198%), and rugosin
A (
68
) (209%) were found to stimulate much more IL-1β compared to
the control (305 pg/mL). Oligomeric tannins including agrimoniin (
61
)
(359%), oenothein A (
69
) (254%), and oenothein B (
67
) (293%) induced
2 to 4 times more of the cytokine over basal levels. Similarly to the direct
antitumor activity experiments, higher molecular weight tannins were not
necessarily the most potent inducers of IL-1β. For example, the large
ellagitannins euphorbin C-Hy (
73
) (108%), laevigatin B (
75
) (125%),
and laevigatin C (
76
) (130%) were less potent than the monomers
tellimagrandins I and II. In addition, a correlation between anticancer
activity and IL-1β generating abilities of the tannins could not be
established. It was suggested that perhaps this lack of correlation was
due to either tannin instability in the host or differences between human
macrophages and whole mice.
In addition, Okuda and co-workers also have reported the release of
an IL-1-like cytokine (a more specific characterization was not
forthcoming) from human monocytes incubated with 50 μg/mL of one of
four condensed tannins: ECG
77
(produced 39 times more IL-1 than
the blank control), ECG-dimer
78
(141 times more), ECG-trimer
79
(201 times more), and ECG-tetramer
80
(162 times more) (Sakagami
et al.
, 1992). The amounts of IL-1 generated were indirectly measured by
observing the proliferation response ([
3
H]-thymidine incorporation into
cell) of mouse thymocytes incubated with the monocyte supernatant.
