title: Antiallergic activity of tylogenin, a novel steroidal compound from Tylophora sylvatica.
abstract: Tylogenin, a steroidal aglycone generated by acid hydrolysis from two seasonal glycosides occurring in Tylophora sylvatica, inhibits IgE-induced basophil mediator release for allergic reactions. In the rabbit basophil-dependent serotonin release (BDSR) assay system, the inhibitory activity of tylogenin (geom mean IC50 = 39 microM) was significantly (P < 0.05) greater than that of its parent glycosides, tylophoroside (geom mean IC50 263 microM) and acetyltylophoroside (geom mean IC50 331 microM), and that of dexamethasone (geom mean IC50 = 912 microM). The activity of tylogenin was found to increase with the incubation time. In the human leukocyte-dependent histamine release (LDHR) test model, the glycosides had only a minimal activity. In contrast, tylogenin, with a geom mean IC50 = 49 microM, exerted a significantly (P < 0.05) greater potency than dexamethasone (IC50 = 257 microM). These results suggest that tylogenin could represent a new class of antiallergic agents.
authors.affiliation: Department of Biology, Johns Hopkins University, Baltimore, MD 21218.
authors.forename: J N
authors.initials: JN
authors.lastname: Gnabre
authors.forename: M J
authors.initials: MJ
authors.lastname: Halonen
authors.forename: D G
authors.initials: DG
authors.lastname: Martin
authors.forename: J L
authors.initials: JL
authors.lastname: Pinnas
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D015549:Basophil Degranulation Test; D002240:Carbohydrate Sequence; D003907:Dexamethasone / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010616:Phenanthrenes / Q000494:pharmacology*; D011446:Prospective Studies; D011817:Rabbits; D012503:Saponins / Q000494:pharmacology; D012632:Secosteroids; D012701:Serotonin / Q000378:metabolism; D013256:Steroids
chemical_list: D010616:Phenanthrenes; D012503:Saponins; D012632:Secosteroids; D013256:Steroids; C090836:tylophoroside; C085024:tylogenin; C085023:acetyltylophoroside; D012701:Serotonin; D003907:Dexamethasone; D015107:4-Butyrolactone