Abstract:
Former studies have shown that curcumin, which can be extracted from different Curcuma species, is able to stimulate bile flow in rats,
whereas bisdemethoxycurcumin, which is mainly found in rhizomes of
Curcuma longa, is believed to inhibit bile flow. To reevaluate this observation
we investigated the influence of both curcuminoids on bile flow, bile acid
concentration and excretion over a time period of 180 min in the bile
fistula model in rats. Furthermore, we tested the ability of both curcuminoids
to reduce cyclosporin-induced cholestasis. 30 min after intravenous
injection of 25 mg/kg of curcumin and bisdemethoxycurcumin bile flow
was enhanced from 500 μl/kg/15 min (100 %) to 180 %
and to 220 %, respectively. The choleretic effect of bisdemethoxycurcumin
lasted longer than that of curcumin. Following intravenous injection of 30 mg/kg
of cyclosporin, which reduced bile flow, bile acid concentration (15 mmol/l)
and excretion (12.5 μmol/kg/15 min) to 40 % of the
initial value, administration of curcumin and bisdemethoxycurcumin transiently
increased bile flow to 100 % and to 125 % of the starting value,
respectively. However, only bisdemethoxycurcumin statistically significantly
attenuated cyclosporin-induced reduction of bile acid excretion. We conclude
that the beneficial properties of curcuminoids for the therapy of cyclosporin-induced
cholestasis still remain to be proven.
Key words:
Curcumin - bisdemethoxycurcumin - cyclosporin - cholestasis -
Curcuma spec. - Zingiberaceae
