METHODS: Thirty-two Sprague-Dawley male rats were randomly allocated into four groups (n=8): control, diabetes mellitus (DM) rats and diabetic rats treated with ifenprodil at a lower dose (0.5 μg/day) (I 0.5) or higher dose (1.0 μg/day) (I 1.0). DM was induced by a single injection of streptozotocin at 60 mg/kg on day 0 of experimentation. Diabetic status was assessed on day 3 of the experimentation. The responses on both tactile and thermal stimuli were assessed on day 0 (baseline), day 14 (pre-intervention), and day 22 (post-intervention). Ifenprodil was given intrathecally for 7 days from day 15 until day 21. On day 23, 5% formalin was injected into the rats' hind paw and the nociceptive responses were recorded for 1 hour. The rats were sacrificed 72 hours post-formalin injection and an analysis of the spinal NR2B expression was performed.
RESULTS: DM rats showed a significant reduction in pain threshold in response to the tactile and thermal stimuli and higher nociceptive response during the formalin test accompanied by the higher expression of phosphorylated spinal NR2B in both sides of the spinal cord. Ifenprodil treatment for both doses showed anti-allodynic and anti-nociceptive effects with lower expression of phosphorylated and total spinal NR2B.
CONCLUSION: We suggest that the pain process in the streptozotocin-induced diabetic rat that has been modulated is associated with the higher phosphorylation of the spinal NR2B expression in the development of PDN, which is similar to other models of neuropathic rats.
AIM: This study aims to evaluate the anti-inflammation an analgesic activity of the aqueous extract of Launaea arborescens (AqELA) and its pathway of action.
METHODS: the investigation of anti-inflammatory and analgesic effects were done using formalin test, acetic acid test. For mechanism investigation, it was used hot plate test to induce opioid receptors, a histamine and serotonin test to induce edema paw, finally, for the TRPV1 receptor, it was used the capsaicin test.
RESULTS: The aqueous extract of Launaea arborescens showed a significant inhibition of abdominal writhing test 95% and 100% inhibition of licking paw using acid acetic test and formalin test respectively (EC: 47 mg/kg and 104 mg/kg). The analgesic effect of the aqueous extract of Launaea arborescens showed inhibition of sensation of pain after 120 min compared to morphine effect. The aqueous extract of Launaea arborescens reduced paw volume after 180 min and 120 min for histamine and serotonin respectively with dose-dependent. Concerning of TRPV1 receptors, the inhibition was showed at doses 100 mg and 300 mg.
CONCLUSION: Our results contribute towards validation of the traditional use of Launaea arborescens for inflammation ailment.