Antidepressant properties of some Hypericum canariense L. and Hypericum glandulosum Ait. extracts in the forced swimming test in mice.

It has been shown in a previous work that the methanol extract obtained from the aerial part in blossom of Hypericum canariense L. and Hypericum glandulosum Ait. was active in the tetrabenazine and forced swimming test. In the present study, the central nervous effect of the aqueous, butanol and chloroform fractions obtained from the methanol extracts of these Hypericum species was investigated in mice, particularly in animal models of depression. It was found that the immobility time in the forced swimming test was significantly reduced by the butanol and chloroform fraction of both species assayed, producing no effects or only a slight depression on spontaneous motor activity when assessed in a photocell activity meter. In this regard, the efficacy of the chloroform extract from Hypericum glandulosum Ait. (500 mg/kg p.o.) in the forced swimming test was comparable to that of the tricyclic antidepressant imipramine (50 mg/kg p.o.). In addition, the Hypericum glandulosum chloroform fraction was also effective in antagonizing the ptosis induced by tetrabenazine. Moreover, Hypericum canariense butanol fraction and Hypericum glandulosum chloroform fraction produced a slight but significant hypothermia. Taken together, these data demonstrate that the butanol and chloroform fractions from Hypericum canariense and Hypericum glandulosum possess antidepressant-like effects in mice, providing further support for the traditional use of these plants in the Canary Islands folk medicine against central nervous disorders.