Antidepressant-Like Activity of the Ethanolic Extract from Uncaria lanosa Wallich var. appendiculata Ridsd in the Forced Swimming Test and in the Tail Suspension Test in Mice

Abstract

This study investigated the antidepressant activity of ethanolic extract of U. lanosa Wallich var. appendiculata Ridsd (UL _EtOH) for two-weeks administrations by using FST and TST on mice. In order to understand the probable mechanism of antidepressant-like activity of UL _EtOH in FST and TST, the researchers measured the levels of monoamines and monoamine oxidase activities in mice brain, and combined the antidepressant drugs (fluoxetine, imipramine, maprotiline, clorgyline, bupropion and ketanserin). Lastly, the researchers analyzed the content of RHY in the UL _EtOH. The results showed that UL _EtOH exhibited antidepressant-like activity in FST and TST in mice. UL _EtOH increased the levels of 5-HT and 5-HIAA in cortex, striatum, hippocampus, and hypothalamus, the levels of NE and MHPG in cortex and hippocampus, the level of NE in striatum, and the level of DOPAC in striatum. Two-week injection of IMI, CLO, FLU and KET enhanced the antidepressant-like activity of UL _EtOH. UL _EtOH inhibited the activity of MAO-A. The amount of RHY in UL _EtOH was 17.12 mg/g extract. Our findings support the view that UL _EtOH exerts antidepressant-like activity. The antidepressant-like mechanism of UL _EtOH may be related to the increase in monoamines levels in the hippocampus, cortex, striatum, and hypothalamus of mice.