Dual effects of crude extracts obtained from Petiveria alliacea L. (Phytolaccaceae) on experimental anxiety in mice.

AIM OF THE STUDY: Different preparations obtained from P. alliacea have been traditionally used in South America and Brazil for many medical conditions. To investigate the effects of fresh whole plant (WP) extract, aerial part (AP) extract, and root (R) extract obtained from Petiveria alliacea using the elevated plus maze (EPM) model of anxiety in mice. Total flavonoid content present in Petiveria alliacea extracts was also determined. MATERIALS AND METHODS: WP, AP, or R (300-900 mg/kg) extracts were orally administered to mice 30 min before they were subjected to the EPM and open field test. Total flavonoid content present in the extracts was determined by spectrophotometry. RESULTS: The WP extract (300 and 900 mg/kg) caused anxiolytic-like effects, and the AP extract (300 mg/kg) induced anxiogenic-like effects in mice subjected to the EPM. No effect on anxiety-like behavior was observed with acute administration of the R extract. The content of flavonoids present in the AP extract (1.34%) was almost threefold higher than the flavonoid content present in the WP extract (0.52%). CONCLUSIONS: Preparations using different fresh parts of Petiveria alliacea caused opposite effects on experimental anxiety in mice. However, predicting the extent to which flavonoid content present in Petiveria alliacea extracts differentially induces anxiolysis or anxiogenesis in mice was not possible. Further studies will be necessary to elucidate the effects of flavonoids or other substances present in Petiveria alliacea extracts on experimental anxiety.

Possible involvement of GABA A-benzodiazepine receptor in the anxiolytic-like effect induced by Passiflora actinia extracts in mice.

Hydroethanol (HE) and methanol (ME) extracts obtained from the leaves of Passiflora actinia Hooker were evaluated for behavioral effects in mice. Single-dose oral administration of HE (300 and 600 mg/kg) or ME (100 and 300 mg/kg) resulted in anxiolytic-like effects in the elevated plus-maze. The anxiolytic-like effects were also seen after the repeated administration of the HE (100 and 300 mg/kg). Flumazenil (10mg/kg, i.p.), a GABA(A)-benzodiazepine receptor antagonist, blocked the effects of ME (300 mg/kg, p.o.) and HE (600 mg/kg). At higher doses, a sedative effect produced by acute administration of HE (600 mg/kg) or ME (300 mg/kg) was indicated by the potentiation of pentobarbital-induced sleep. With regard to memory-disrupting effects of anxiolytics, mice were evaluated by measuring the retest step-down latency 24h after foot-shock in a passive avoidance task. In contrast to diazepam (0.5mg/kg) or piracetam (200mg/kg), ME (30, 100 and 300 mg/kg) or HE (100, 300 and 600 mg/kg) did not influence the step-through latency in the acquisition or retention memory tasks. The present results show an anxiolytic profile for HE and ME of Passiflora actinia. There are also indications of an involvement of GABA(A) system in this effect.