Inhibition characteristics of hypericin on rat small intestine glutathione-S-transferases

TUNA G., KULAKSIZ ERKMEN G., DALMIZRAK Ö., Dogan A., ÖĞÜŞ İ. H., Ozer N.

CHEMICO-BIOLOGICAL INTERACTIONS, vol.188, no.1, pp.59-65, 2010 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 188 Issue: 1
  • Publication Date: 2010
  • Doi Number: 10.1016/j.cbi.2010.07.007
  • Journal Name: CHEMICO-BIOLOGICAL INTERACTIONS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.59-65
  • Keywords: St John's Wort, Hypericin, GST-alpha, GST-pi, Rat small intestine, PHOTODYNAMIC THERAPY, JOHNS-WORT, BREAST-CANCER, EXPRESSION, CELLS, PI, CONSTITUENTS, ISOENZYMES, BINDING, KINASE
  • Hacettepe University Affiliated: Yes

Abstract

Glutathione-S-transferases constitute a family of enzymes involving in the detoxification of xenobiotics, signalling cascades and serving as ligandins or/and catalyzing the conjugation of various chemicals and drugs. The widely expressed cytosolic GST-pi is a marker protein in various cancers and its increased concentration is linked to drug resistance. GST-pi is autoregulated by S-glutathionylation and it catalyzes the S-glutathionylation of other proteins in response to oxidative or nitrosative stress. S-glutathionylation of GST-pi results in multimer formation and the breakage of ligand binding interactions with c-Jun NH(2)-terminal kinase (JNK). Another widely expressed GST enzyme, GST-alpha is assumed as a marker in hepatocellular damage, is implicated in cancer, asthma, cardiovascular disease and response to chemotherapy.