title: Modulation of sodium pumps by steroidal saponins.
abstract: Costus spicatus, used in Brazilian traditional medicine to expel kidney stones, contains steroidal saponins with different chemical characteristics. In spite of its popular utilization as potent diuretic, no scientific reports correlate this activity with the chemical constituents of the extract. Therefore, two steroidal saponins (3 beta,22 alpha,25R)-26-(beta-D-glucopyranosyloxy)-2-methoxyfurost-5-en-3-yl O-D-apio-beta-D-furanosyl-(1-->2)-O-[6-deoxy-alpha-L-mannopyranosyl-(1-->4)]-beta-D-glucopyranoside (1) and (3 beta,22 alpha,25R)-spirostan-3-yl O-D-apio-beta-D-furanosyl-(1-->2)-O-[6-deoxy-alpha-L-mannopyranosyl-(1-->4)]-beta-D-glucopyranoside (1a), were isolated from the rhizomes of this plant and their effects on the Na+-ATPase and (Na+ + K+)-ATPase activities of the proximal tubule from pig kidney were evaluated. It was observed that 1 and 1a inhibit specifically the Na+-ATPase activity.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil.
authors.forename: Aloa Machado
authors.initials: AM
authors.lastname: de Souza
authors.forename: Lucienne da Silva
authors.initials: Lda S
authors.lastname: Lara
authors.forename: Jose Osvaldo
authors.initials: JO
authors.lastname: Previato
authors.forename: Aníbal Gil
authors.initials: AG
authors.lastname: Lopes
authors.forename: Celso
authors.initials: C
authors.lastname: Caruso-Neves
authors.forename: Bernadete Pereira
authors.initials: BP
authors.lastname: da Silva
authors.forename: José Paz
authors.initials: JP
authors.lastname: Parente
mesh_terms: D000818:Animals; D000529:Complementary Therapies; D029770:Costus; D004285:Dogs; D007668:Kidney / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D007700:Kinetics; D008517:Phytotherapy; D012503:Saponins / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects* / Q000378:metabolism*; D013256:Steroids / Q000494:pharmacology*; D013552:Swine
chemical_list: D012503:Saponins; D013256:Steroids; D000254:Sodium-Potassium-Exchanging ATPase