Effects of Alcoholic Extract of Portulaca Oleracea on Modulation of Neuropathic and Acute Pain in Rats

Portulaca Oleracea is a medicinal plant with many effects including analgesic and anti-inflammatory properties. This study aimed to investigate the effect of alcoholic extract of Portulaca Olerecea on CCI model of neuropathic pain (Bennet & Xie model) and acute thermal pain induced by Tail Flick. Adult male Wistar rats weighing 200-250 g were used. Sensitivity to mechanical stimuli (mechanical allodynia) and noxious thermal stimuli were evaluated by Von Frey filaments and Tail Flick, respectively. In neuropathic pain studies, animals were randomly assigned to five groups of sham, CCI, two groups subjected to CCI and injected with extract (200 and 400 mg/kg, i.p.) and a group subjected to CCI and injected with normal saline. In these groups, mechanical allodynia was assessed on day 7 after surgery. In acute pain studies, animals were divided to three groups of a group that received normal saline and two groups that received extract (200 and 400 mg/kg, i.p.). In these groups, Tail Flick was measured 30 minutes after normal saline or extract administration. Data were analyzed by SPSS and appropriate statistical tests. All of the rats that had experienced CCI, exhibited mechanical allodynia after neuropathy.Portulaca oleracea could reduce the development of mechanical allodynia after CCI at 200 and 400 mg/kg doses. Thermal acute pain was reduced by 400 mg/kg of the extract. Our findings indicate that Portulaca Oleracea extract can reduce behavioral symptoms of
neuropathic and acute pain.