| Title |
Genistein, a protein tyrosine kinase inhibitor, ameliorates
retinal degeneration after ischemia-reperfusion injury in rat. |
Author |
Hayashi A, Weinberger AW, Kim HC, de Juan E Jr. |
Bio |
Wilmer Ophthalmological Institute, Johns Hopkins University,
School of Medicine, Baltimore, Maryland 21287, USA. |
| Abstract |
PURPOSE: The authors sought to determine the effect of
genistein, a naturally occurring protein tyrosine kinase
inhibitor, in a model of ischemia-reperfusion injury in the rat
retina. METHODS: Ischemia-reperfusion injury was induced by
temporary optic nerve ligation. A dose of 0.034 mg, 0.34 mg, and
3.4 mg of genistein or dimethyl sulfoxide (DMSO) alone was
injected intraperitoneally 1 hour before the ligation of the optic
nerve and just after the start of reperfusion. After 48 hours of
reperfusion, the effect of genistein on overall protein tyrosine
phosphorylation in the retina was studied using Western blot
analysis. After 168 hours, the effect of increasing doses of
genistein on retinal degeneration was examined by quantitative
morphometric analysis of histologic sections of the retina.
RESULTS: The authors found that tyrosine phosphorylation was
increased after 48 hours of reperfusion in the
ischemia-reperfusion-injured eyes treated with DMSO alone. A
severe inner retinal degeneration was observed in the animals
treated with DMSO alone after 168 hours of reperfusion. The
treatment with 3.4 mg genistein inhibited the increase in tyrosine
phosphorylation and protected the eyes significantly from the
induced ischemic retinal degeneration by morphometric analysis of
the mean thickness of the inner limiting membrane to the outer
limiting membrane, the inner plexiform layer, and the inner
nuclear layer (P < 0.02). Treatments with lower amounts of
genistein (0.034 mg and 0.34 mg) did not show a significant
protection of retinal degeneration after the injury. CONCLUSIONS:
Systemic administration of high dose of genistein, a
dietary-derived isoflavone, can ameliorate an
ischemia-reperfusion-induced retinal degeneration. Genistein may
be useful to prevent neuronal degeneration in the inner retina as
a result of ischemic injury. PMID: 9152239 [PubMed - indexed for MEDLINE]
|
| This 1997 article
from Johns Hopkins University was one of the earlier articles to
show not only Genistein's ability to protect cells of the eye from
stroke-like conditions, but to also show how the basic mechanism
is applicable to many other kinds of cells. Protein tyrosine
kinase is a big player in cancer as well as in oxidative stress
and radiation effects. Genistein inhibits protein kinase and this
prevents much of the cascade leading to premature aging, radiation
damage, and malignancy. In time you will see more and more human
application of Genistein. |
