Assessment of the antinociceptive and anti-inflammatory activities of the stem methanol extract of Diplotropis purpurea

Abstract

Context: Since there is still a great need to search for plant species with antinociceptive and anti-inflammatory activities, Diploptropis purpurea (Rich.) Amshoff (Fabaceae) is studied for the first time.

Objective: This evaluates the analgesic and anti-inflammatory activities of the stem methanol extract of Diplotropis purpurea (MEDP).

Material and methods: The anti-inflammatory and analgesic effects of MEDP of D. purpurea were evaluated in vivo. The antinociceptive activity was assessed in CD1 male mice were treated by oral gavage with 500 mg/kg of MEDP 30 min before submitting to acetic acid-induced abdominal writhing, hot-plate, and formalin tests. Paws oedema induced by carrageenan, histamine or serotonin were performed in male Sprague–Dawley rats to determinate the anti-inflammatory activity.

Results: Oral administration of MEDP produced significant antinociceptive effects on the inflammatory phase in the formalin test [12.0 s versus 72.5 s in carboxymethyl cellulose (CMC) control group]. MEDP produced an analgesic effect in the hot-plate model, although the effect was modest compared to tramadol (40 and 60%, respectively). The oral administration of MEDP in a dose of 500 mg/kg showed maximum inhibition (75.1%) after 0.5 h in carrageenan-induced oedema, but it did not modify histamine or serotonin-induced oedemas.

Discussion and conclusion: In the peripheral nociception model, acetic acid-induced abdominal writhing, the MEDP did not show a protective effect, but its analgesic effects were evident in the inflammatory phase of the formalin test and in the hot-plate model. These results show that the anti-inflammatory effect was accompanied by a reduction in the perception of painful stimuli.

Keywords:

• Fabaceae
• carrageenan
• paw oedema
• hot plate
• formalin test
• writhing test

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by SENACYT (National Secretariat for Science, Technology and Innovation of Panama) through projects FID11-090 and INF11-054, and MPG thanks the SNI program of research incentives.