Evaluation of effects of N-(2-hydroxybenzoyl) tyramine (riparin II) from Aniba riparia (NEES) MEZ (Lauracea) in anxiety models in mice.

In order to evaluate the effects produced by N-(2-hydroxybenzoyl) tyramine (riparin II) isolated from the unripe fruit of Aniba riparia (NEES) MEZ (Lauraceae) on the central nervous system, different behavioral tests were performed. Riparin II (rip II) was administered orally (p.o.) and intraperitoneally (i.p.) in male mice, at doses of 25, 50 and 75 mg/kg, and tested on elevated plus maze (EPM), open field, rota rod and hole board tests. The results revealed that rip II caused considered increase of the number of head dips in hole board test and increased the number of entries and the time of permanence in the open arms in plus maze test in both routes. No significant effect was evidenced on rota rod and open field test, except an increase observed in the number of rearing. These results showed that riparin II presents anxiolytic-like effects in the plus maze and hole board tests which are not influenced by the locomotor activity as detected in the open field test.

Anxiolytic-like effects of (O-methyl)-N-2,6-dihydroxybenzoyl-tyramine (riparin III) from Aniba riparia (Nees) Mez (Lauraceae) in mice.

This work presents behavioral effects of (O-methyl)-N-2,6-dihydroxybenzoyl-tyramine (riparin III) isolated from the unripe fruit of Aniba riparia (Nees) Mez (Lauraceae) in animal models of open field, rota rod, elevated plus maze and hole board tests in mice. Riparin III (ripIII) was administered orally, in male mice, at single doses of 25 and 50 mg/kg. The results showed that ripIII, at both doses, had no effects on the spontaneous motor activity in the rota rod test nor in the number of squares crossed in the open field test. However, riparin III decreased the number of grooming and rearing. In the plus maze test, ripIII, at both doses increased the following parameters: percentage of entries in the open arms (PEOA), time of permanence in the open arms (TPOA) and percentage of time of permanence in the open arms (PTOA) and at the dose of 50 mg/kg, increased the number of entries in the open arms (NEOA). Similarly, ripIII, at both doses, showed an increase in the number of head dips into the holes of the hole board test. These results show that riparin III presents anxiolytic effects in the plus maze and hole board tests which are not influenced by the locomotor activity in the open field test.