000 naa a22 7ar4500
016 _a000307981500002
022 _a1572-3887
040 _aNEU
041 _aeng
050 _aQU4.3
100 1 _9574912
_aDalmızrak, Özlem,
_cProf. Dr.
_
245 1 0 _aEvaluation of the in vitro Inhibitory Impact of Hypericin on Placental Glutathione S-Transferase pi.
_cOzlem Dalmizrak, Gulnihal Kulaksiz, Erkmen Nazmi Ozer.
260 _c2012.
_bSpringer,
_aNew York :
520 _aSt John's Wort (SJW) extracts are herbal products which are available without prescription in most countries and widely used in the treatment of mild to moderate depression. Since it is a herbal product and available without prescription, use of SJW is common among pregnant and/or lactating woman. The principal of the study was to clarify the effects of hypericin, one of the components of SJW, on glutathione S-transferase-pi (GST-pi) purified from human placenta. The K (m) values of GST-pi were 0.21 +/- A 0.03 mM for glutathione (GSH) and 2.29 +/- A 0.54 mM for 1-chloro-2,4-dinitrobenzene (CDNB). At fixed [GSH], the V (m) value calculated was about 3 times higher than the conditions in which [CDNB] was fixed; 201 +/- A 30 U/mg protein versus 74 +/- A 3 U/mg protein. At constant substrate concentrations (1 mM), an average IC (50) value of 0.70 +/- A 0.02 mu M was obtained. Hypericin inhibited GST-pi competitively with respect to both substrates. When GSH was the varied substrate a K (i) value of 0.31 +/- A 0.05 mu M was found; when CDNB was the varied substrate, a K (i) value of 0.85 +/- A 0.02 mu M was obtained. On the basis of these data considering transplacental transfer of hypericin and immature hepatic clearance of the baby, using this herbal product may cause abnormalites due to the inhibition of one of the most important placental detoxification enzymes, GST-pi.
650 0 _9117600
_aBiochemistry
650 0 _9572720
_aNear East University Article
650 0 _9572723
_aYakın Doğu Üniversitesi Makale
650 0 _9576675
_aInhibition kinetics
650 0 _9576676
_aSt John's Wort
650 0 _9576677
_aTransplacental transfer
773 _aProtein Journal
_gOCT 2012, Vol 31 Issue 7, p544-549
_x15723887
856 _uhttp://library.neu.edu.tr:2048/login?url=http://dx.doi.org/10.1007/s10930-012-9433-6
942 _x1000007
_kQU00000043E932012
_cOED
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999 _c244376