Environmental Engineering Reference
In-Depth Information
6.6
Antihypercholesterolemic
Activity
diffusion agar method. From this group, 15 ethanol
extracts were tested against Entamoeba histolytica ,
and Giardia lamblia , Lithothamnium crassiuscula ,
Geodia sp., Pacifi gorgia sp. showed signifi cant
activity against Entamoeba histolytica , while
Myxilla incrustans and Muricea appressa were
active against Giardia lamblia. Lithothamnium
crassiuscula showed activity against both tro-
phozoites ( Matsubara et al. 2000 ).
In the right and left sides of the peritoneal cavity,
levels of total cholesterol and low-density lipo-
protein decreased to 37 % and 24 % due to sea-
weed. For histochemical changes, hepatic tissues
obtained at 40 h after injection of the triton and
the Porphyra yezoensis extract were fi xed in from
calcium solution. The number of lipid drops and
cholesterol particles decreased in the portal space
of the hepatic cytoplasm. This indicated that the
accumulation of lipid, including cholesterol,
caused by triton was prevented by the antihyper-
cholesterolemic effect of extract from the seaweed
P. yezoensis (Hong et al. 1998 ).
6.8
Immunosuppressive Activity
from Seaweeds
Water extracts of marine algae with immunosup-
pressive activity were investigated for in vivo
activity using murine models of collagen-induced
arthritis and skin transplantation. Eleven (three
brown and eight red algae) of them had suppres-
sive activity on the collagen-induced mouse
arthritis model. Of these, Eisenia bicyclis ,
Sargassum sagamianum , Amphiroa aberrans ,
and Gracilaria verrucosa , in particular, showed
high activity. On the other hand, treatment
with extracts from Codium fragile , C. intricatum ,
C. divaricatum , and Liagora sp. prolonged the
allograft survival time on the murine skin
rejection model. One of these algal extracts,
those from Liagora sp., markedly prolonged the
allograft survival time. These results suggest
that bioactive compounds with immunosuppres-
sive activity may be contained in these algae
(Mizukoshi et al. 1995 ).
6.7
Anticoagulant Substances
from Seaweeds
An anticoagulant isolated from the marine green
alga Codium pugniformis was composed mainly
of glucose with minor amounts of arabinose and
galactose. It was highly sulfated (326
mg poly-
saccharide) and contained protein (52
ʼ
mg
polysaccharide) and was thus a proteoglycan.
The anticoagulant properties of the purifi ed pro-
teoglycan were compared with those of heparin
by studying the activated partial thromboplastin
time (APTT), prothrombin time (PT), and throm-
bin time (TT) using normal human plasma.
The proteoglycan showed similar activities to
heparin, but was weaker than heparin. On the
other hand, the proteoglycan did not affect PT
even at the concentration at which APTT and TT
were prolonged. The anticoagulation mechanism
of this proteoglycan was due to the direct inhibi-
tion of thrombin and the potentiation of anti-
thrombin III. Ethanol extracts from a group of 53
marine organisms were evaluated for their anti-
microbial and antiparasitic activity. The activity
against Staphylococcus aureus , Streptococcus
faecalis , Bacillus subtilis (Gram-positive),
Escherichia coli (Gram-negative and Gram-
positive), Escherichia coli (Gram-negative), and
Candida albicans (yeast) was determined by the
ʼ
6.9
Antiulcer Substance
from Seaweeds
Porphyran inhibits Gram-negative bacterium
Helicobacter pylori colonization. This substance
can eliminate specifi cally H. pylori from the
stomach and used in the prevention or treatment
of gastritis, gastric ulcers, duodenal ulcers, and
gastric cancer. Oral administration of porphyran
prevents the adhesion of the urease on the H. pylori
cells so as to prevent several diseases associated
with it (Bhatia et al. 2003 ).
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