title: The inhibitory activities of the components of Huang-Lian-Jie-Du-Tang (HLJDT) on eicosanoid generation via lipoxygenase pathway.
abstract: OBJECTIVE
  Huang-Lian-Jie-Du-Tang (HLJDT) is a traditional Chinese medicine with anti-inflammatory use. In the present study, the effects of its component herbs and pure components were observed on eicosanoid generation to find out the contributory components and their precise targets on arachidonic acid (AA) cascade.
  
  
  METHODS
  By monitoring leukotriene B(4) (LTB(4)), 5-hydroxyeicosatetraenoic acid (5-HETE), and 12-hydroxy-5,8,10-heptadecatrienoic acid (12-HHT), we compared the effects of HLJDT, HLJDT free of one or two component herbs, and water extract of four single component herbs of HLJDT (Rhizoma coptidis, Radix scutellariae, Cortex phellodendri and Fructus gardeniae) on eicosanoid generation in rat elicited peritoneal macrophages. In addition, thirteen pure compounds from HLJDT (baicalin, baicalein, wogonoside, wogonin, berberine, magnoflorine, phellodendrine, coptisine, palmatine, jateorrhizine, crocin, chlorogenic acid, and geniposide) were tested in the macrophages. Furthermore, the efficacies of these thirteen compounds were evaluated on cell-free purified enzymes: leukotriene A(4) hydrolase (LTA(4)H), 5-, 15-lipoxygenase (5-, 15-LO), and cyclo-oxygenase-1/2 (COX-1/2). Moreover, the possible synergetic effect on LO pathway derived LTB(4) generation between the active components was also tested in rat peritoneal macrophages.
  
  
  RESULTS
  Our experiments showed that Rhizoma coptidis and Radix scutellariae were responsible for the suppressive effect of HLJDT on eicosanoid generation. Some of the pure components including baicalein, baicalin, wogonoside, wogonin, coptisine, and magnoflorine inhibited eicosanoid generation in rat macrophages via LO pathway of AA cascade. Further experiments on cell-free purified enzymes confirmed that Radix scutellariae derived baicalein and baicalin showed significant inhibition on 5-LO and 15-LO, while Rhizoma coptidis derived coptisine showed medium inhibition on LTA(4)H. On the other hand, no significant inhibition of thirteen components on COX-1/2 was observed. Moreover, the slight synergetic inhibition on LTB(4) between baicalein and coptisine was proved in the rat peritoneal macrophages.
  
  
  CONCLUSIONS
  Baicalein and coptisine, the active components of HLJDT, for the first time are found to interfere with arachidonic acid cascade via inhibition on different points of LO pathway. This finding makes the mechanism of HLJDT clearer and achieves its safer therapeutic application.
authors.affiliation: Department of Natural Product Chemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Huawu
authors.initials: H
authors.lastname: Zeng
authors.forename: Shengshan
authors.initials: S
authors.lastname: Dou
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Siyang
authors.initials: S
authors.lastname: Fan
authors.forename: Xing
authors.initials: X
authors.lastname: Yuan
authors.forename: Shuanglai
authors.initials: S
authors.lastname: Zhu
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhang
authors.forename: Runhui
authors.initials: R
authors.lastname: Liu
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D015777:Eicosanoids / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D058945:Lipoxygenases / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004365:Drugs, Chinese Herbal; D015777:Eicosanoids; C045607:huang-lien-chieh-tu-tang; D058945:Lipoxygenases