Abstract
Baicalin, a naturally occurring flavonoid, was previously reported to exert anxiolytic-like effects in the Vogel conflict test. In the present study, the anxiolytic effects of baicalin alone and in combination with other anxiolytics were tested in mice using the elevated plus-maze (EPM). Baicalin treatment (7.5 - 30 mg/kg) significantly increased entries into and time spent in open arms, indicative of an anxiolytic-like effect. Motor-depressive and myorelaxant side effects commonly associated with anxiolytics were not observed with baicalin at effective anxiolytic doses in the hole-board and horizontal wire tests, respectively. Co-administration of baicalin (3.75 mg/kg) with dl-tetrahydropalmatine (dl-THP; 0.25 mg/kg), an anxiolytic-hypnotic alkaloid, both at sub-effective doses, induced an additive effect resulting in considerable anxiolysis. Similarly, an additive anxiolytic-like effect was observed with baicalin (3.75 mg/kg) and diazepam (DZ; 0.5 mg/kg). Results obtained from this study demonstrate the potential of baicalin as a candidate anxiolytic and its possible application in multidrug therapy.
Abbreviations
BZS:benzodiazepine-binding site
EPM:elevated plus-maze
DZ:diazepam
GABAA:type A γ-aminobutyric acid
dl-THP:dl-tetrahydropalmatine
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Dr. Hong Xue
Department of Biochemistry
Hong Kong University of Science and Technology
Clear Water Bay
Hong Kong
People’s Republic of China
Telefon: +852-2358-8707
Fax: +852-2358-1552
eMail: hxue@ust.hk
