Biology Reference
In-Depth Information
In this vein of investigation, geraniin and corilagin were identified as
potent inhibitors (Okabe
et al
., 2001).
1.7.2.3
Host-mediated antitumor activity
Several oligomeric ellagitannins specifically inhibited tumor (Sarcoma-
180 and MM2) growth after having been administrated either before or
after intraperitoneal inoculation of tumor cells into mice abdomen. This
effect was found only for
these oligomers among over a hundred tannins
and related polyphenols thus screened. Among these active oligomers
were macrocyclic oligomers, such as oenothein B and woodfordin C
(dimers), oenothein A and woodfordin D (trimers), and woodfordin F
(tetramer) (Miyamoto
et al
., 1997). This effect was attributed to an
enhancement of the immune response of host animals, which was
supported by their stimulation of IL-1 production from human peripheral
macrophages (Miyamoto
et al
., 1993, see Chapter 6).
1.7.3 Induction of apoptosis
Ellagitannins induced apoptotic cell death, which was characterized by
internucleosomal DNA cleavage and apoptotic body in human
promyelocytic leukemic HL-60 cells and evaluated by agarose gel
electrophoresis and fluorescence activated cell sorter, at levels of potency
higher than those determined for condensed tannins. However, the most
active compound thus screened was the simple phenol gallic acid (Inoue
et al
., 1994, Sakagami
et al
., 1995, 1999).
1.7.4 Effects on liver functions and others
Intramuscular administration of geraniin siginificantly lowered levels of
glutamyl oxaloacetic transaminase (GOT), glutamyl pyruvic
transaminase (GPT) and lipid peroxides in serum (Nakanishi
et al
.,
1999). Intramuscular injection of geraniin and ellagic acid significantly
suppressed experimental hepatic injuries induced by carbon tetrachloride,
D
-galactosamine, and thioacetamide in rats, and a protective effect
against liver damages was confirmed by histological observation (Hikino
