Super Blue Green (registered trademark, Cell Tech brand) algae is the species known as _Aphanizomenon_flos-aquae_.
The remainder of this file is divided into five parts:
PART I. What are microcystins?
Quoting from _Toxicon_, volume 32, number 12, "Use of
a Colorimetric Protein Phosphatase Inhibition Assay and
Enzyme Linked Immunosorbent Assay for the Study of
Microcystins and Nodularins.", by An and Carmichael,
1994, pages 1495 and 1496:
"Microcystins are monocyclic heptapeptide liver toxins
produced by species of cyanobacteria within the genera
_Microcystis_, _Anabaena_, _Oscillatoria_, and _Nostoc_
(Carmichael, 1992). The toxins contain two variable
L-amino acids plus three D-amino acids plus the unusual
amino acids, N-methyldehydroalanine and 3-amino-9-methoxy-
10-phenyl-2,6,8-trimethyl-deca-4(E)6(E)-dienoic acid
(Adda) (Reinhart _et_al_, 1988)."
[A peptide is a small protein. A heptapeptide is a
protein composed of seven amino acids. Monocyclic means
it's a one-ring loop. A microcystin is a seven-member
ring of amino acids, containing three D-amino acids and
two weird amino acids, neither kind normally being found
in human food. Amino acids can have two mirror-image
forms, called D and L. All amino acids used to build
proteins in the human body are L-amino acids, except
glycine which is reflection-symmetric (i.e. neither
D nor L). D-amino acids are nutritionally inert, and
they may contribute towards the ability of microcystins
to survive the digestive process intact and get absorbed.]
Quoting from page 1497:
"Recently, both microcystin and nodularin have been found
to be potent inhibitors of protein phosphatase types 1 and
2A (Yoshizawa _et_al_, 1990) as well as tumor promoters
in laboratory animals (Nishiwaka-Matsushima _et_al_,
1992b; Falconer, 1991). They are also suspected to be
involved with promotion of primary liver cancer in humans
exposed to long-term low doses of these cyclic peptide
toxins through drinking water (Carmichael, 1994;
Yu, 1989)."
PART II. Where do microcystins come from?
Quoting from "A Cell Tech Statement Regarding
_Microcystis_ in Klamath and Agency Lakes", Cell Tech
press release, September 1996:
"Cell Tech also closely monitors algal blooms in Klamath
and Agency Lakes by regularly performing species
identification and quantification."
"Our test results indicate that there is currently a high
level of _Microcystis_aeruginosa_ in certain parts of the
lake, particularly Agency Lake."
[Cell Tech claims their standard is no more than 1%
non-_Aphanizomenon_ species in SBGA.]
Quoting from "A Message from Christian Drapeau", a file
posted by Jim Fentress (jim@frii.com) on April 8, 1996,:
"Microcystins are regularly found, but only in non-
significant amounts (specifically, 0.1-0.2 mcg/g of
SBGA)."
Quoting from a posting made on May 25, 1997,
<19970525172900.NAA00137@ladder01.news.aol.com>,
from Bluuegreen
[Note that these numbers are about ten times higher
than those admitted in the previous quote.]
Quoting from "Response to Vegetarian Times", a letter from
Marta Kollman, October 31, 1996, available on Cell Tech's
fax-on-demand service (800/565-5092) as document #151:
"We know from rigorous testing over the years that
_Microcystis_ has always existed in Klamath Lake at very
low levels."
[But how low is low enough? Read on!]
PART III. What do microcystins do?
Quoting from _Journal_of_Cancer_Research_and_Clinical_
_Oncology_, volume 118, "Liver Tumor Promotion by the
Cyanobacterial Peptide Toxin Microcystin-LR", by
Nishiwaki-Matsushima, Ohta, Nishiwaki, Suganuma, Kohyama,
Ishikawa, Carmichael, and Fujiki, 1992, page 421:
"In two experiments, we found that microcystin-LR has
a potent tumor-promoting activity in rat liver initiated
with diethylnitrosamine (DEN) below the concentrations
that do not release aminotransferase (transaminase)
from the liver into the blood serum. Microcystin acts
on the liver through the okadaic acid pathway and is one
of the strongest liver tumor promoters found to date."
[DEN is a carcinogen used to seed cancer foci in the
experimental animals. Once seeded, the experiment
measured the promotion of these cancer foci by various
suspected tumor promoters. Release of aminotransferase
into the blood would be a sign of an acutely hepatotoxic
reaction, which microcystins may cause. This set of
experiments found potent liver tumor promotion at levels
below those which are acutely or sub-acutely toxic
to the liver, as indicated by the lack of release of
aminotransferase.]
Quoting from page 423:
"The mechanism of action of microcystin in liver cells
is similar to that of okadaic acid, and therefore most
likely expressed through the okadaic pathway. We have
found that the okadaic pathway, involving inhibition of
protein phosphatase 1 and 2A activities, is a general
mechanism of tumor promotion in various organs."
[Inhibition of PP1 and PP2A ain't good!]
From Wright State University, Dept. of Bio. Sciences,
10/28/96.
(513-873-2655 FAX: 513-873-3320)
ELISA assay for ... microcystins:
Measurable levels of microsystin or nodularin were found
in samples QA-9638 - QA-9643 (ug/g):
638 1.1
639 0.4
640 1.3
641 1.0
642 1.7
643 0.7