Bioavailability and Brain-Targeting of Geniposide in Gardenia-Borneol Co-Compound by Different Administration Routes in Mice

Both geniposide (Ge) and borneol (Bo) are bioactive substances derived from traditional Chinese medicine. Injections containing co-compound of Gardenia-Borneol are widely used for stroke treatment in China, such as "Xingnaojing" multi-component injection. As more and more adverse reactions (especially drug allergy) were reported, it is urgent to find more effective and safer routes of administration for such kinds of medicines. In this paper, bioavailabilities and brain-target effects of geniposide in Gardenia-Borneol co-compound through different administration routes in mice were investigated. Geniposide concentrations in plasma and in brain of mice were determined by reversed-phase high-performance liquid chromatography. The pharmacokinetics parameters of intranasal (i.n.) and intragastric (i.g.) administration were compared with intravenous (i.v.) administration. The bioavailabilities of Ge were 85.38% and 28.76% for i.n. and i.g. while T(max) were 1 min and 30 min. C(max) were 21.881 ± 5.398, 1.914 ± 0.327 and 42.410 ± 6.268 μg/mL for i.n., i.g. and i.v., respectively. The AUC of Ge in brain were 32413.6 ± 4573.9, 6440.1 ± 863.7 and 37270.5 ± 4160.6 ng/g ·min for i.n., i.g. and i.v., respectively. The drug target indexes (DTI) were 1.02 and 0.60 for i.n. and i.g. The results demonstrated that geniposide could be absorbed promptly and thoroughly by i.n. administration in mice and basically transported into the brain though blood vessel passways.