Antinociceptive effect of ethanolic extract of Selaginella convoluta in mice.
BACKGROUND
Selaginella convoluta (Arn.) Spring (Selaginellaceae), commonly known as "jericó", is a medicinal plant found in northeastern Brazil. S. convoluta is used in folk medicine as an antidepressant, aphrodisiac, diuretic, analgesic, anti-inflammatory and it is used to combat amenorrhea, coughing and bleeding. This study was performed to evaluate the antinociceptive effects of ethanolic extract from S. convoluta in mice exposed to chemical and thermal models of nociception.


METHODS
Preliminary phytochemical analysis of the ethanolic extract was performed. The ethanolic extract from Selaginella convoluta (Sc-EtOH) was examined for its intraperitoneal (i.p.) antinociceptive activity at the doses of 100, 200 and 400 mg/kg body weight. Acetic acid-induced writhing, formalin injection and hot plate tests were used to evaluate the antinociceptive activity of Sc-EtOH extract. The rota-rod test was used to evaluate motor coordination.


RESULTS
A preliminary analysis of Sc-EtOH revealed that it contained phenols, steroids, terpenoids and flavonoids. In the acetic acid-induced writhing test, mice treated with Sc-EtOH (100, 200 and 400 mg/kg, i.p.) exhibited reduced writhing (58.46, 75.63 and 82.23%, respectively). Secondly, Sc-EtOH treatment (100, 200 and 400 mg/kg, i.p.) decreased the paw licking time in mice during the first phase of the formalin test (by 44.90, 33.33 and 34.16%, respectively), as well as during the second phase of the test (by 86.44, 56.20 and 94.95%, respectively). Additionally, Sc-EtOH treatment at doses of 200 and 400 mg/kg increased the latency time in the hot plate test after 60 and 90 minutes, respectively. In addition, Sc-EtOH did not impair motor coordination.


CONCLUSIONS
Overall, these results indicate that Sc-EtOH is effective as an analgesic agent in various pain models. The activity of Sc-EtOH is most likely mediated via the inhibition of peripheral mediators and central inhibitory mechanisms. This study supports previous claims of traditional uses for S. convoluta.
Núcleo de Estudos e Pesquisas de Plantas Medicinais, Universidade Federal do Vale do São Francisco, Petrolina, Pernambuco 56.304-205, Brazil.
Pedro Guilherme S
PG
de Sá
Xirley Pereira
XP
Nunes
Julianeli Tolentino
JT
de Lima
José Alves
JA
de Siqueira Filho
André Paviotti
AP
Fontana
Jullyana de Souza
Jde S
Siqueira
Lucindo José
LJ
Quintans-Júnior
Patrícia Kauanna Fonseca
PK
Damasceno
Carla Rodrigues Cardoso
CR
Branco
Alexsandro
A
Branco
Jackson Roberto Guedes da Silva
JR
Almeida
D000700:Analgesics / Q000008:administration & dosage* / Q000009:adverse effects / Q000302:isolation & purification; D000818:Animals; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D059225:Nociception / Q000187:drug effects; D010146:Pain / Q000188:drug therapy*; D010936:Plant Extracts / Q000008:administration & dosage* / Q000009:adverse effects / Q000302:isolation & purification; D032503:Selaginellaceae / Q000737:chemistry*
D000700:Analgesics; D010936:Plant Extracts