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The crude extracts of Hypericum species native to South Brazil showed analgesic and antidepressant-like effects in rodents. The chemical characterization of these species revealed that they are rich in flavonoids and phloroglucinol derivatives. In the present study a detailed investigation was performed on the activities of hyperoside (HYP), a common flavonoid in the genus Hypericum. Hyperoside was obtained from the aerial parts of H. caprifoliatum by chromatographic procedures. Mice treated with single doses (10, 20 and 40 mg/kg i.p.) did not present signs of toxicity or weight loss. At 20 and 40 mg/kg i.p. the mice exploratory behavior in the open field test was reduced. At 20 mg/kg i. p. the pentobarbital sleeping time increased, but not the sleeping latency. No activity was found on the hot-plate (10 and 20 mg/kg i.p.) or in the acetic acid-induced writhing test (20 and 40 mg/kg p.o.). Nevertheless, an antidepressant-like effect in the forced swimming test in mice and rats was observed (HYP 10 and 20 mg/kg i.p. in mice; HYP 1.8 mg/kg/day p.o. in rats). The antidepressant-like effect in rats was prevented by the administration of sulpiride (50 mg/kg i.p.) a D2 antagonist. In conclusion, hyperoside was found to present a depressor effect on the central nervous system as well as an antidepressant-like effect in rodents which is, at least in part, mediated by the dopaminergic system.

An isocratic HPLC system is described which allows the separation of the iridoid and indole precursors of terpenoid indole alkaloids, which are present in a single crude extract. The system consists of a column of LiChrospher 60 RP select B 5 μm, 250 x 4 mm (Merck) with an eluent of 1 % formic acid-acetonitrile-trichloroacetic acid (100 :10 :0.25, v :v :w) at a flow of 1.2 ml/min. In the suspension cultures of Catharanthus roseus secologanin and tryptophan were detected. In the cultures of Tabernaemontana divaricata loganin, tryptophan, and tryptamine accumulated.