title: Effects of S-petasin on corticosterone release in rats.
abstract: Petasites hybridus is used in Chinese herbal medicine. S-petasin is a bioactive compound isolated from leaves or roots of Petasites hybridus. S-petasin has been used to relieve gastrointestinal pain, lung disease, and spasms of the urogenital tract. However, the side effect of S-petasin on endocrine systems are still not clear. This study explored the effects of S-petasin on the release of corticosterone in vivo and in vitro. An intravenous injection of S-petasin (10 microg/kg) decreased both basal and adrenocorticotropin (ACTH)-induced plasma corticosterone concentration in male rats. In vitro, S-petasin (3 x 10(-6) - 10(-4) M) caused a significant reduction of basal and ACTH-stimulated release of corticosterone from the enzymatically dispersed rat zona fasciculata-reticularis (ZFR) cells in a dose-dependent manner. In order to study possible mechanisms, ZFR cells were incubated with S-petasin (10(-5) M) in the presence or absence of forskolin (adenylate cyclase activator, 10(-6) - 10(-4) M), 8-Br-cAMP (a cAMP analogue, 10(-6) 10(-4) M), 25-OH-cholesterol (pregnenolone biosynthesis precursor, 10(-5) M) combined with trilostane (a blocker of 3beta-hydroxysteriod dehydrogenase, 3beta-HSD, 10(-6) M) and deoxycorticosterone (corticosterone biosynthesis precursor, 10(-9) - 10(-6) M) at 37 degrees C for 1h. The concentration of pregnenolone and corticosterone in media were measured by radioimmunoassay. The stimulatory effects of corticosterone secretion induced by forskolin (10(-5) - 10(-4) M), 8-Br-cAMP (10(-5) - 10(-4) M) and deoxycorticosterone (10(-7) - 10(-6) M) were reduced by S-petasin at 10(-5) M. The stimulatory effects of pregnenolone secretion induced by 25-OH-cholesterol combined with or without trilostane was reduced by S-petasin at 10(-5) M. These results suggest that S-petasin inhibits the production of corticosterone from rat ZFR cells in part through decreasing the activities of adenylyl cyclase, P450scc and 11beta-hydroxylase.
authors.affiliation: Department of Chemical Engineering, Chinese Culture University, Shih-Lin, Taipei, Taiwan, Republic of China. llchiang@staff.pccu.edu.tw
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Chang
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Tseng
authors.forename: Yun-Lian
authors.initials: YL
authors.lastname: Lin
authors.forename: Wan-Song Alfred
authors.initials: WS
authors.lastname: Wun
authors.forename: Paulus S
authors.initials: PS
authors.lastname: Wang
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D003345:Corticosterone / Q000096:biosynthesis / Q000097:blood* / Q000378:metabolism; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology*; D015383:Zona Fasciculata / Q000187:drug effects / Q000378:metabolism
chemical_list: D012717:Sesquiterpenes; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000324:Adrenocorticotropic Hormone; C418727:petasin; D003345:Corticosterone