Natriuretic and diuretic effects of Tropaeolum majus (Tropaeolaceae) in rats.
Tropaeolum majus L. (Tropaeolaceae), popularly known as "chaguinha", is well recognized in Brazilian traditional medicine as diuretic agent, although no scientific data have been published to support this effect.


OBJECTIVE
To evaluate the diuretic activity of the infusion and the hydroethanolic extract (HETM) of Tropaeolum majus, and possible mechanism of action.


METHODS
The infusions (2,5 - 10%) and the HETM doses (150, 300 mg/kg) were orally administered to rats. Urinary excretion, the electrolytes levels, and urea and creatinine were measured in of saline-loaded rats.


RESULTS
The oral administration of 10% (corresponding to 500 mg/kg) of the infusion increased significantly the urinary Na(+) excretion. Only the oral administration of 300 mg/kg of HETM increased significantly the urinary and Na(+) excretion. Prolonged administration of the HETM (300 mg/kg) significantly increased diuresis and the urinary excretion of Na(+), but others parameters were unaffected. To gain some evidence in possible involvement of prostaglandins system in diuretic action, the oral administration of HETM (300 mg/kg) in association indomethacin (5mg/kg) reduced the urinary and sodium excretion when compared only HETM group.


CONCLUSIONS
The results suggest that HETM could present compound(s) responsible for diuretic activities with no signs of toxicity, and the mechanism could involve prostaglandin system.
Department of Pharmacology, Universidade Paranaense, Umuarama, PR, Brazil.
Arquimedes
A
Gasparotto
Marcos Aurelio
MA
Boffo
Emerson Luiz Botelho
EL
Lourenço
Maria Elida Alves
ME
Stefanello
Cândida Aparecida Leite
CA
Kassuya
Maria Consuelo Andrade
MC
Marques
D000284:Administration, Oral; D000818:Animals; D003404:Creatinine / Q000097:blood; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004232:Diuretics / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004573:Electrolytes / Q000652:urine; D005665:Furosemide / Q000494:pharmacology; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018515:Plant Leaves; D011453:Prostaglandins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000652:urine*; D013997:Time Factors; D032388:Tropaeolum; D014508:Urea / Q000097:blood; D014554:Urination / Q000187:drug effects*
D016861:Cyclooxygenase Inhibitors; D004232:Diuretics; D004573:Electrolytes; D010936:Plant Extracts; D011453:Prostaglandins; D005665:Furosemide; D014508:Urea; D012964:Sodium; D003404:Creatinine; D007213:Indomethacin