A model of hypertriglyceridaemia in rats is described, which was used to investigate the hypolipidaemic effect of an intraperitoneal (i./p.) administration of a Ficus carica leaf decoction. Hypertriglyceridaemia was induced in rats following the protocol: a fasting period of 22 h, 2 h of oral (p.o.) administration of 20% emulsion of longchain triglycerides (LCT emulsion), both repeated once. The plasma triglyceride and total cholesterol levels obtained 2 h after the protocol were 5.7 +/- 2.5 mmol/L (p < 0.0001 vs basal levels) and 1.7 +/- 0.3 mmol/L, respectively, n = 10. The new model was used to test the hypotriglyceridaemic effect of a single dose of Ficus carica (fig tree) leaf decoction administered i./p. (50 g dry wt/kg body wt). After the i.p. injection of serum saline (control group, n = 10) or Ficus carica extract (group A, n = 10), plasma triglyceride levels in the control group and group A were 5.9 +/- 2.9 mmol/L and 5.5 +/- 2.9 mmol/L just after the LCT emulsion protocol; 4.7 +/- 2.7 mmol/L and 0.9 +/- 0.4 mmol/L, p < 0.005, 60 min after the LCT protocol; and 3.6 +/- 2.9 mmol/L and 1.0 +/- 0.4 mmol/L, p < 0.05, 90 min after the LCT protocol. The plasma total cholesterol levels, which were not modified in our experimental model, showed no significant differences in relation to baseline levels in the presence or absence of Ficus carica treatment either. The clearly positive results suggest the presence in the fig leaf decoction of a compound or compounds that influence lipid catabolism.