Effect of triterpene saponins from roots of Ampelozizyphus amazonicus Ducke on diuresis in rats.
BACKGROUND
Ampelozizyphus amazonicus Ducke is a plant used in Brazilian folk medicine to both prevent malaria and act as a depurative.


OBJECTIVE
We have investigated the effects of an ethanol crude extract of roots of Ampelozizyphus amazonicus (CEAaD), a chemically characterized saponin mixture (SAPAaD), as well as a saponin-free fraction (SAPAaD-free) obtained from CEAaD on diuresis in rats.


METHODS
Wistar rats under ad libitum water conditions or water deprivation for 12h prior to the start of the experiment were volume-expanded with 0.9% NaCl (4% body weight, by gavage) containing either CEAaD, SAPAaD, or SAPAaD-free at the doses indicated in the text. Rats were individually housed in metabolic cages, and urine volume was measured every 30 min throughout the experiment (3 h).


RESULTS
CEAaD increased urine volume in rats under conditions of both free access to water and under water deprivation. In the latter condition, CEAaD (150 mg/kg) increased the urine volume from zero to 0.9+/-0.1 ml/120 min, n=6). Similarly, the SAPAaD-free (50-200 mg/kg) mixture also increased the urine volume. In contrast, SAPAaD (12.5-1000 mg/kg) produced a significant reduction (p<0.01) in diuresis under conditions of both water deprivation and with free access to water prior to the start of the experiment.


CONCLUSIONS
Our data indicate that CEAaD contains compounds that cause both diuresis and antidiuresis and that the antidiuretic effect is due mainly to the presence of saponins.
Department of Physiology and Biophysics, Institute of Biological Science, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
Lúcio Ricardo Leite
LR
Diniz
Paula Carvalho
PC
Santana
Ana Paula Araújo Ferreira
AP
Ribeiro
Viviane Gomes
VG
Portella
Lílian Fernanda
LF
Pacheco
Nádia Burkowski
NB
Meyer
Isabela Costa
IC
César
Gustavo Pereira
GP
Cosenza
Maria das Graças Lins
Md
Brandão
Maria Aparecida Ribeiro
MA
Vieira
D000818:Animals; D050034:Antidiuretic Agents / Q000302:isolation & purification / Q000494:pharmacology; D001938:Brazil; D004231:Diuresis / Q000187:drug effects; D004232:Diuretics / Q000302:isolation & purification / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D008519:Medicine, Traditional; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots; D010946:Plants, Medicinal; D051381:Rats; D017208:Rats, Wistar; D027823:Rhamnaceae / Q000737:chemistry*; D012503:Saponins / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D014315:Triterpenes / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*
D050034:Antidiuretic Agents; D004232:Diuretics; D010936:Plant Extracts; D012503:Saponins; D014315:Triterpenes