Pharmacology, Toxicology and Therapeutics : Faculty & Graduate Students : Hyoungwoo Bai
Research Interests
Under the supervision of Dr. Bao Ting Zhu, I am studying the effects of various endogenous and exogenous factors that modulate the catalytic activity of the human cyclooxygenase (COX) 1 and COX 2.
Briefly, COX I and II are enzymes that catalyze the metabolism of arachidonic acid (AA), resulting in the formation of prostaglandins (PGs), thromboxanes (TXs), and hydroxyeicosateraenoic acids (HETEs). It is well known that abnormally-elevated levels of these autacoids mediate inflammation, and pharmacological inhibition of pathologically-elevated COX I and/or II activity is highly effective in treatment of various inflammatory diseases. On the other hand, normal levels of these same autacoids that are formed by constitutively-expressed COX enzymes (mostly CO X I) also exert many important physiological functions. For instance, in the cardiovascular system, PGD2 and PGE2 can cause strong vasodilation, while in the gastrointestinal track, PGE2 is a protective factor that decreases gastric acid secretion and increases mucus secretion. Consistent with these well-known physiological functions of PGs, chronic use of selective COX II inhibitors (e.g., Rofecoxib) is associated with an elevated cardiovascular risk.
My recent studies showed that some of the dietary polyphenols can strongly activate the catalytic activity of COX I and II, resulting in increased biosynthesis of PGs both in vitro. Given the important physiological functions of various PG products, I believe it is critically important to determine whether these naturally-occurring compounds are physiological cofactors that are used by COX I and II in vivo to support their normal catalytic activity for PG biosynthesis.
Also, I am studying the biochemical characteristics of the recombinant human catechol-O-methyltransferase for the O-methylation of various endogenous and exogenous catechol substrates.
Publications
Bai HW and Zhu BT. Strong activation of cyclooxygenase I and II by bioflavonoids. 2008, Journal of Lipid Research (In press).
Bai HW, Wang P and Zhu BT. Biochemical characterization of a mutant form of the human catechol-O-Methyltransferase. 2008, International Journal of Molecular Medicine (In press).
Bai HW and Zhu BT. Identification of a novel haplotype of the human catechol-O-methyltransferase gene. 2008, Pharmacogenetics and Genomics (In press).
Zhu BT, Shim J-Y, Nagai M, and Bai HW. Molecular modeling study of the mechanism of high-potency inhibition of human catechol-O-methyltransferase by (-)-epigallocatechin-3-O-gallate. 2008, Xenobiotica, 38, 130-146.
Zhu BT, Wang P, Nagai M, Wen Y and Bai HW. Inhibition of human catechol-O-methyltransferase (COMT)-mediated O-methylation of catechol estrogens by major polyphenolic components present in coffee. 2008, Journal of Steroid Biochemistry and Molecular Biolog (submitted).
Bai HW, Shim JY and Zhu BT. Biochemical and molecular modeling studies of the O-methylation of various endogenous and exogenous catechol substrates catalyzed by recombinant human soluble and membrane-bound catechol-O-methyltransferases. 2007, Chemical Research in Toxicology 20: 1409-1425.
Hyoungwoo Bai
Department of Pharmacology, Toxicology, and Therapeutics
The University of Kansas Medical Center
MS1018, KLSIC 4036
2146 W. 39th Ave.
Kansas City, KS 66160
Phone: (913) 588-9180
Fax: (913) 588-7501
E-Mail: hbai@kumc.edu
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The University of Kansas Medical Center