[Effect of liquorice decoction on rat intestinal P-glycoprotein].

OBJECTIVE: To investigate the effect of liquorice in functional modulation of intestinal P-glycoprotein (P-gp) in rats. METHODS: An in vitro diffusion chamber system (Ussing chamber) was used to examine the direct effect of liquorice decoction on rhodamine 123 (a subtrate of P-gp) transport and evaluate the permeability of rhodamine 123 or fluorescein sodium through rat jejunum membranes after oral administration of liquorice decoction. RESULTS: Direct application of liquorice decoction did not obviously affect rhodamine 123 transport across the intestinal mucosa. Oral administration of liquorice decoction (10 g/kg, twice daily for a week) significantly increased the absorption of rhodamine 123 and also enhanced rhodamine 123 secretion across the jejunum mucosa. Liquorice had no obvious effect on the transport of CF across the jejunum mucosa. CONCLUSION: Liquorice may slightly inhibit P-gp function in the intestinal mucosa to increase the intestinal absorption of rhodamine 123.