Authors
von Schonfeld J. Weisbrod B. Muller MK.
Institution
Department of Gastroenterology, Medical Clinic, Essen, Germany.
Title
Silibinin, a plant extract
with antioxidant and membrane stabilizing properties, protects exocrine
pancreas from cyclosporin A toxicity.
Source
Cellular & Molecular Life Sciences. 53(11-12):917-20, 1997 Dec.
Abstract
Silymarin can be extracted from the milk thistle, and
silibinin is the main component of the plant
extract. Possibly due to their antioxidant and
membrane-stabilizing properties, the compounds have been shown to protect
different organs and cells against a number of insults. Thus liver, kidney,
erythrocytes and platelets have been protected from the toxic effects of
ethanol, carbon tetrachloride, cold ischemia and drugs, respectively. The
effect of silibinin on endocrine and exocrine pancreas, however, has not been
studied. We therefore investigated whether silibinin treatment attenuates
cyclosporin A (CiA) toxicity on rat endocrine and exocrine pancreas. Groups
of 15 male Wistar rats were treated for 8 days with CiA and/or silibinin. On
day 9, endocrine and exocrine pancreatic functions were tested in vitro. At
the end of the treatment period, blood glucose levels in vivo were
significantly higher in rats treated with CiA while silibinin did not affect
glucose levels. In vitro, insulin secretion was inhibited after treatment
with silibinin, but amylase secretion was not affected.
After treatment with CiA both insulin and amylase secretion were reduced.
Silibinin and CiA had an additive inhibitory effect on insulin secretion, but
silibinin attenuated CiA-induced inhibition of amylase secretion. Despite CiA
treatment, amylase secretion was in fact restored to normal with the highest
dose of silibinin. Thus silibinin inhibits glucose-stimulated insulin release
in vitro, while not affecting blood glucose concentration in vivo. This
combination of effects could be useful in the treatment of
non-insulin-dependent diabetes mellitus. Furthermore, silibinin protects the
exocrine pancreas from CiA toxicity. As this inhibitory effect is probably
unspecific, silibinin may also protect the exocrine pancreas against other
insult principles, such as alcohol.