A hydro-ethanolic extract of Synedrella nodiflora (L.) Gaertn ameliorates hyperalgesia and allodynia in vincristine-induced neuropathic pain in rats

Abstract

ackground: The hydro-ethanolic extract of Synedrella nodiflora (L.) Gaertn whole plant has demonstrated anal- gesic effects in acute pain models. The extract has also demonstrated anticonvulsant effects in murine models of experimental epilepsy. The present study illustrates an evaluation of the hydro-ethanolic extract of the plant for possible analgesic properties in hyperalgesia and allo- dynia associated with vincristine-induced neuropathy in rats. Method: Neuropathic pain was induced in Sprague-Daw- ley rats by injecting 100 μg/kg of vincristine sulphate on alternative days for 6 days (days 0, 2, 4, 8, 10 and 12). Vin- cristine-induced cold allodynia, mechanical hyperalgesia and thermal hyperalgesia were measured pre-vincristine administration and on days 15, 17 and 19 post-vincristine administration. The rats were then treated with S. nodi- flora extract (SNE) (100, 300 and 1000 mg/kg), pregabalin (10, 30 and 100 mg/kg) and distilled water as vehicle daily for 5 days and pain thresholds were measured on alternate days for 3 days. Results: SNE and pregabalin produced analgesic proper- ties observed as increased paw withdrawal latencies to mechanical, tactile, cold water stimuli and thermal hyper- algesic tests during the 5 days of treatment.

Conclusions: The findings suggest that hydro-ethanolic extract of S. nodiflora possesses anti-hyperalgesic and anti-allodynic effects in vincristine-induced neuropathic pain in rats.