Antinociceptive effect of ethanolic extract of Selaginella convoluta in mice

Abstract

BackgroundSelaginella 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.MethodsPreliminary 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.ResultsA 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.ConclusionOverall, 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.

Antinociceptive activity of the ethanolic extract from barks and leaves of Cnidoscolus quercifolius (Euphorbiaceae) in mice

“…*P < 0.05, signifi cantly different from control, analysis of variance followed Dunnett's test (n = 6, by group) to opioid analgesics, but INDO and acetylsalicylic acid respond better in the second phase. 16 The extracts showed effects in the second phase, indicating a possible anti-infl ammatory effect.…”

Evaluation of Analgesic, Anti-inflammatory and CNS Depressant Potential of Dendrophthoe falcata (Linn.) Leaves Extracts in Experimental Mice Model

“…More specifically, acetic acid injection induces a release of TNF-α, interleukin-1β (IL-1β) and interleukin-8(IL-8) by resident peritoneal macrophages, mast cells, prostanoids and bradykinin [28].These prostaglandin and lipoxygenase products are responsible for inflammation and pain. Substance(s) inhibiting the writhing response will have analgesic effect preferably by inhibition of prostaglandin synthesis, a peripheral mechanism of pain inhibition [30]. Non steroidal anti-inflammatory drugs (NSAIDs) can inhibit COX in peripheral tissues and therefore interfere with the mechanism of transduction of primary afferent nociceptors.…”

Antinociceptive and Anti-inflammatory Activities of Methanol Extract of Ormosia coccinea (Aubl.) Jacks in vivo

“…Intraplantar injection of formalin has been reported to produce a distinct biphasic nociceptive response [12,21], termed first and second phases [20]. The first phase, commonly denominated early or neurogenic phase (from 0 to 5 min after injection formalin) results from a direct stimulation of nociceptors (predominantly C-fibres) [22,23,27,28,31,32,34]. Substance P, glutamate and bradykinin are thought to participate in this phase, which is believed to be non-inflammatory pain [28].…”

“…Because this model is highly sensitive and also has the ability to detect antinociceptive effects of compounds at dose levels that may appear inactive in other models [20,21]. The intraperitoneal administration of agents that irritate serous membranes provokes a stereotyped behaviour in the mice which is characterized by abdominal contractions, movements of the body as a whole and twisting of the dorso-abdominal muscles [22] and a reduction in motor activity and motor incoordination [23]. It has been suggested that acetic acid injection into peritoneal cavity leads to increased levels of cyclooxygenases (COX) and lipoxygenase [24] and indirectly leads to the release of endogenous nociceptive mediators such as PGE 2 and PGF 2α [5,20,[25][26][27][28][29][30], serotonin [22,25,26,29,30], histamine [22,26,30,31], bradykinin [21,22,24], substance P [24,25], cytokines (TNF-α, IL-1β, IL-8) [21,24,25,29] and lipoxygenase products [20], which eventually excites the primary afferent nociceptors [25] that contribute to the development of inflammatory pain [22].…”

“…To provide a confirmation of the central antinociceptive activity of MEOC, we used the hot plate test, since this model is sensitive and specific for strong analgesics (opioids), while peripherally acting analgesics are inactive [23,26,28,35,36]. This model of nociception, predominantly a spinal reflex, is thought to involve supraspinal nociceptive processing [21,27] and has often been used to assess central antinociceptive activity [25,28].…”