title: Inhibitory effect of alkaloids extracted from the stem bark of Hunteria zeylanica on 5-lipoxygenase activity in vitro.
abstract: The effects of alkaloid extract from the stem bark of Hunteria zeylanica Gard. (H. zeylanica) on the activities of cyclooxygenase and 5-lipoxygenase in A23187-stimulated rat mast cells were investigated. H. zeylanica alkaloid extract (0.3-300 micrograms/ml) inhibited leukotriene C4 (LTC4) production by 5-lipoxygenase in a concentration-dependent manner and it blocked the production by 50% at 300 micrograms/ml. On the other hand, the extract had no effect on prostaglandin D2 (PGD2) production by cyclooxygenase. Neither (-)-eburnamine nor pleiomutinine, major constituents of H. zeylanica alkaloid extract, inhibited the production of PGD2 and LTC4 in the A23187-stimulated mast cells. The inhibition of arachidonic acid metabolism via 5-lipoxygenase pathway may be due to minute amounts of other components as stated in the Discussion.
authors.affiliation: Division of Pharmacology, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: W
authors.initials: W
authors.lastname: Reanmongkol
authors.forename: M
authors.initials: M
authors.lastname: Tohda
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: S
authors.initials: S
authors.lastname: Subhadhirasakul
authors.forename: H
authors.initials: H
authors.lastname: Takayama
authors.forename: S
authors.initials: S
authors.lastname: Sakai
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000470:Alkaloids / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D017997:Leukotriene C4 / Q000096:biosynthesis; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D015230:Prostaglandin D2 / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000470:Alkaloids; D000894:Anti-Inflammatory Agents, Non-Steroidal; D016859:Lipoxygenase Inhibitors; D017997:Leukotriene C4; D000001:Calcimycin; D015230:Prostaglandin D2