Reducing effect of intragastrically administered saikosaponin A on alcohol and sucrose self-administration in rats

Saikosaponin A (SSA) is an active ingredient of the Asian medicinal herb, Bupleurum falcatum L. When administered via the intraperitoneal (i.p.) route, SSA suppressed multiple addictive-like behaviours, including operant alcohol self-administration, in rodents. It is unknown whether these effects are retained after intragastric (i.g.) administration, a desirable prerequisite for a compound with therapeutic potential. To fill this gap, i.g. SSA (0, 50, and 100 mg/kg) was tested in Sardinian alcohol-preferring (sP) rats trained to lever-respond for oral alcohol. SSA reduced lever-responding and amount of self-administered alcohol. However, when compared to i.p. SSA, i.g. SSA resulted to be markedly less potent and effective, suggestive of reduced bioavailability after i.g. treatment. Finally, and in agreement with previous data on the suppressing effect of i.p. SSA on behaviours motivated by highly palatable foods, i.g. SSA (0, 50, and 100 mg/kg) reduced oral sucrose self-administration in a separate set of sP rats.