Pyrostegia venusta attenuate the sickness behavior induced by lipopolysaccharide in mice

Pyrostegia venusta (Ker.) Miers (Bignoniaceae) is native to the Brazilian Cerrado and popularly known as "cipó-de-são-joão." In traditional Brazilian medicine, the Pyrostegia venusta are used as a general tonic as well as a treatment for diarrhea, vitiligo, cough, and common diseases of the respiratory system related to infections, such as bronchitis, flu and cold. This study was conducted to evaluate the effects of a hydroethanolic extract of flowers of Pyrostegia venusta on sickness behaviors induced by lipopolysaccharide in mice.

To evaluate the effects of orally administered Pyrostegia venusta hydroethanolic extract (PvHE) on lipopolysaccharide-induced sickness behaviors, mice were submitted to the forced swim test (FST) and the open field test.

Lipopolysaccharide (LPS, 100 μg/kg, i.p.) administration increased the time spent floating in the FST and depressed locomotor activity in the open field. Pretreatment with PvHE at test doses of 100 and 300 mg/kg, p.o. attenuated the behavioral changes induced by LPS in the FST and open field test. This effect was similar to pretreatment with dexamethasone (1 mg/kg), which is a steroidal drug that inhibits immune and inflammatory responses, including cytokine production.

The extract of Pyrostegia venusta attenuated the depressive-like and exploratory behaviors induced by lipopolysaccharide. Thus, our results supported previous claims of the usefulness of these plants in traditional therapies and suggest that these plants may be useful in the treatment of disorders that induced sickness behavior, such as flu and cold.