Modulation of sodium pumps by steroidal saponins.
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.
de Souza
Aloa Machado
AM
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil.
Lara
Lucienne da Silva
Lda S
Previato
Jose Osvaldo
JO
Lopes
Aníbal Gil
AG
Caruso-Neves
Celso
C
da Silva
Bernadete Pereira
BP
Parente
José Paz
JP
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
D012503:Saponins; D013256:Steroids; D000254:Sodium-Potassium-Exchanging ATPase