SOLUBILIZED HYPERICIN AND PSEUDOHYPERICIN FROM HYPERICUM-PERFORATUM EXERT ANTIDEPRESSANT ACTIVITY IN THE FORCED SWIMMING TEST

It has been shown recently that the fraction IIIc of a crude extract o f Hypericum perforatum, (St. John's wort) that contained both hyperici n (1) and pseudohypericin (2), was remarkably active in the rats force d swimming test (FST) after Porsolt. However, neither of the naphthodi anthrones isolated from this fraction were sufficiently effective when administered suspended in water. The solubility of 1 and 2 is remarka bly increased in the presence of a fraction containing procyanidins, e specially procyanidin B2, which is present also in the active Hypericu m fraction IIIc. The cooperative effect of procyanidins significantly increased the in vivo effects of 1 and 2, which exhibited inverted U-s haped dose response curves, in the FST. The anti-immobility effect of solubilized 1 and 2 was antagonized by the dopamine antagonist sulpiri de. These data indicate that naphthodianthrones are antidepressant con stituents of H. perforatum and suggest that the dopaminergic system is involved in their action.