Antinociceptive and Anti-Inflammatory Effects of <i>Stachytarpheta jamaicensis </i>(L.) Vahl (Verbenaceae)in Experimental Animal Models

Abstract

Objective: The present study was carried out to explore the antinociceptive as well as the anti-inflammatory effects of an ethanol extract of Stachytarpheta jamaicensis (L.) Vahl (EESJ) using 3 models of nociception and 2 models of inflammation in experimental animals. Materials and Methods: EESJ was prepared by overnight soaking of the oven-dried (50°C; 72 h) ground leaves (500 g) in 80% ethanol (1:5; w/v). The filtrate was evaporated to dryness (50°C), resuspended in distilled water at concentrations to provide the desired doses of 50, 100 and 150 mg/kg. For antinociceptive effects, 3 models were used: acetic acid-induced abdominal writhing, hot-plate- and formalin-induced paw-licking tests; for anti-inflammatory effects, 2 models were used – carrageenan-induced paw edema and cotton-pellet-induced granuloma tests. Appropriate doses were administered intraperitoneally (i.p.) to mice/rats prior to each test. The mechanisms of antinociceptive action of the extract were also investigated by pretreatment with naloxone (5 mg/kg, i.p.). Results: The extract exhibited significant (p < 0.05) antinociceptive activity in all nociceptive models tested with dose-dependent activity observed using the abdominal writhing and formalin tests. Pretreatment with naloxone partially, but significantly (p < 0.05) reversed the antinociceptive activity of the extract when assessed using the abdominal-writhing- and formalin-induced paw-licking tests, and completely inhibited its activity when the hot-plate test was used. The extract also showed significant (p < 0.05) anti-inflammatory activity in both the acute (carrageenan-induced paw edema test) and the chronic (cotton-pellet granuloma test) tests. Conclusion: This study showed the potential of EESJ to exert antinociceptive and anti-inflammatory activities, the former being modulated via peripheral and central mechanisms and involving, in part, activation of the opioid receptor system.

Antiinflammatory and Antinociceptive Activities of <i>Zingiber zerumbet </i>Methanol Extract in Experimental Model Systems

“…The activated mechanoinsensitive 'sleeping' nociceptors then transmit the response to the spinal cord where the noxious input can induce central sensitization to pain. Based on this association, Attaway and Zaborsky [2] claimed that agents with antiinflammatory activity, either derived from animals or plants, can also possess an antinociceptive activity, which is supported by various findings [3][4][5] .…”

In vivo Antinociceptive and Anti-inflammatory Activities of Dried and Fermented Processed Virgin Coconut Oil

“…The procedure described by Sulaiman et al [11] was used to study the anti-inflammatory activity of VCOs in this model of chronic inflammation. Cotton pellets, weighing approximately 50 mg each, were autoclaved for 2 h. The autoclaved cotton pellets were implanted at intrascapular distance, or dorsum region, aseptically under the skin on the shaved backs of rats anesthetized with 1 ml/kg avertin (i.p.).…”

In vivo Analgesic Effect of Aqueous Extract of <i>Tamarindus indica</i> L. Fruits

“…The antinociceptive activity seen could be due in part to inhibition of the release of inflammatory mediators or blockade of the peripheral cyclooxygenase activity [17] . Despite being claimed as a highly sensitive and useful model for analgesic drug development, this model of visceral pain is not a selective pain test [18,19] . The disadvantage of this model is that drugs such as muscle relaxants and sedatives can produce similar effects, leading to possible false-positive results [18] .…”

“…Based on the findings of both the hot plate and the formalin tests, TIAE seems to possess significant central and peripheral antinociceptive mechanisms that are partly mediated by the activation of opioid systems. The activity of TIAE is suggested to involve inhibition of both the inflammatory-and non-inflammatory-effect-mediated nociception [19] .…”