title: Influence of OSW-1 [3 beta,16 beta,17 alpha-trihydroxycholest-5-en-22-one 16-O-(2-O-4-methoxybenzoyl-beta-D-xylopyranosyl)-(1--> 3)-(2-O-acetyl-alpha-L-arabinopyranoside)], a steroidal saponin, on endothelium dependent relaxation caused by acetylcholine in rat aorta.
abstract: The tension of isolated ring preparation of the aorta from rats was measured isometrically to study the influence of OSW-1 [3 beta,16 beta,17 alpha-trihydroxycholest-5-en-22-one 16-O-(2-O-4-methoxybenzoyl-beta-D-xylopyranosyl)-(1 right arrow 3)-(2-O-acetyl-alpha-L-arabinopyranoside)], a steroidal saponin, on the endothelium dependent and independent relaxation caused by acetylcholin (ACh) and sodium nitroprusside (SNP), respectively. OSW-1 (10(-7) M), which has more than 100 times higher concentration for anti-tumor activity, had no influence on either the endothelium dependent or independent relaxation. OSW-1 (10(-6) M, 0.9 microgram/ml) slightly reduced the endothelium dependent relaxation caused by ACh but did not affect the SNP-induced relaxation. In contrast to OSW-1, 1 mg/ml of saponin significantly suppressed the ACh-induced relaxation and shifted the dose-relaxation curve for SNP to the right. OSW-1 (10(-7) and 10(-6) M) did not affect the norepinephrine-induced contraction but 1 mg/ml of saponin significantly attenuated it. The results suggest that though the higher concentration of OSW-1 shows weaker influence on the endothelium function compared with saponin, OSW-1 at an anti-tumor dose has no influence on either endothelium or smooth muscle function.
authors.affiliation: Department of Pharmacology, Tokyo University of Pharmacy and Life Science, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Honda
authors.forename: Y
authors.initials: Y
authors.lastname: Mimaki
authors.forename: Y
authors.initials: Y
authors.lastname: Sashida
authors.forename: H
authors.initials: H
authors.lastname: Kogo
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D002783:Cholestenones; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012503:Saponins / Q000494:pharmacology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002783:Cholestenones; D012503:Saponins; D014662:Vasoconstrictor Agents; C106408:OSW 1; D000109:Acetylcholine; D009638:Norepinephrine