جستجوی مقالات مرتبط با کلیدواژه « allodynia » در نشریات گروه « پزشکی »

Chronic neuropathic pain is one of the common and debilitating problems of human societies and is a challenge in health care Valerian officinalis has been used in the treatment of pain and anxiety due to its antioxidant effects and multiple mechanisms. Also, the medicinal form of emulsion is studied to increase the bioavailability and absorption of herbal products. The present study was conducted to determine the analgesic and anti-anxiety effects of the oral emulsion of the extract and compare it with the effects of the extract in adult male rats. First, the oral emulsion of the extract was formulated with the help of similar studies and Design Expert software, and the best formulation was selected. Then, neuropathic pain was induced in the animals with the help of a sciatic nerve chronic obstructive lesion (CCI) neuropathy surgical model. The extract and emulsion were given orally (gastric gavage) to the animals for 30 days, after which behavioral tests were performed, to investigate thermal allodynia, and elevated plus maze (EPM), to investigate induced anxiety behaviors, one day before Induction of neuropathy and on days 2, 4, 6, 10, 14, 21, 30 after neuropathy were investigated, and at the end, the effects of oral emulsion gavage of extract and extract on lipid peroxidation of malondialdehyde (MDA) in brain tissue were investigated and compared. Separate administration of valerian extract and emulsion reduced cold allodynia in all days after CCI surgery compared to the neuropathy group (P<0.05). In addition, CCI surgery caused anxiety in rats. Administration of valerian emulsion and its extract were able to significantly reduce anxiety in the behavioral test of the plus-shaped elevated maze. The difference is that this reduction process started earlier with the administration of the extract emulsion (P<0.001). Also, the administration of the extract and emulsion significantly reduced the amount of malondialdehyde in the brain tissue in neuropathic rats compared to the neuropathy group (P<0.001), with the difference that the emulsion of the extract caused a greater decrease in the amount of malondialdehyde compared to the extract. Valerian extract and emulsion have analgesic and anti-anxiety effects. In addition, the administration of valerian emulsion in neuropathic rats has significantly more anti-anxiety and analgesic effects compared to the administration of valerian extract.

Background and

Inflammation plays an important role in the development of neuropathic pain (NP). Considering the anti-inflammatory effects of mesenchymal stem cells (MSCs) and their conditioned medium (CM), we aimed to investigate the effect of MSC-CM on the expression of CCL3 and CCL4 genes in the spinal cord of rats with NP.

In this experimental-interventional study, 28 male Wistar rats weighing 200-300 grams were included. NP was induced in male rats using the chronic constriction injury (CCI) model of the sciatic nerve. MSCs-CM was injected intraperitoneally (1ml) into each rat in the experimental group one day before surgery (-1), and 7 and 11 days after the surgery, while the rats of control group received DMEM. At the end of the study (day 15), the expression level of CCL3 and CCL4 genes in the animals’ spinal cord was measured using Real time PCR.

Molecular studies showed a significant decrease in CCL3 gene expression (P<0.05) in CM treated animals compared to the control group, but in term of CCL4 gene expression, there was no significant difference between the groups.

Anti-NP effects of MSCs-CM seem to be partly mediated through downregulation of CCL3 chemokine in the spinal cord.

Neuropathic pain due to chemotherapy is one of the most important types of chronic pain that despite the increasing advances in medical sciences, its treatment is associated with many problems. In this study, the effects of atomoxetine on paclitaxel-induced neuropathic pain and the effect of alpha-2 adrenergic receptor antagonist (yohimbine) on the analgesic effect of atomoxetine were investigated.

Male mice received paclitaxel (2 mg/kg i.p.) from the first to the fifth day and atomoxetine (5, 10, and 15 mg/kg p.o.) was administered from the day 6 to 10. Mice were divided into different groups (n=8) and each group received a unique dose of the drug. On days 9, 10 and 11, Von Frey and acetone tests were performed. Also, the effect of alpha-2 adrenergic receptor antagonist (yohimbine) on the analgesic effect of atomoxetine was investigated. For this purpose, after pain induction, mice received atomoxetine (15 mg/kg p.o) with yohimbine (5 mg/kg i.p. 5) from day 6 to 10.

Daily administration of atomoxetine (15 mg/kg p.o) effectively increased pain threshold in the cold and mechanical allodynia tests (P<0.01). Administration a single dose of atomoxetine on the 11th day did not alter behavioral tests.

According to these findings, it can be concluded that atomoxetine is able to reduce the severity of paclitaxel-induced neuropathic pain.

Neuropathic pain is a chronic pain that results from damage to the central and peripheral nerves. According to the previous studies, physical activity or progesterone can be an effective treatment for alleviating sensory neuropathic pain individually. In this way, the combined effect of chronic progesterone and forced exercise on behavioral pain responses in the neuropathic pain model of chronic constriction injury in rats was considered.

Eighty male Wistar rats were used in 8 groups (n=10). First, neuropathic pain was induced by CCI in the respective groups. For the treatment of neuropathic pain, animals in the groups received progesterone (6 mg/kg) started 12 days after the operation until day 26. In exercise groups, the exercise started 12 days after surgery until day 33. Behavioral tests were performed on days 12 and 33.

Interestingly, we found that CCI-induced neuropathy could produce thermal hyperalgesia and mechanical allodynia in experimental groups on day 12 before exercise and progesterone therapy. After the stabilization of neuropathic pain, co-administration of progesterone (6 mg/kg) for 14 days and moderate intensity exercise for 3 weeks in the respective group could alleviate neuropathic pain compared with the CCI and each of treated groups individually.

The findings of this study showed that co-administration of chronic progesterone and forced exercise after the stabilization of neuropathic pain may alleviate neuropathic pain

Damage to the central and peripheral nervous system causes neuropathic pain. Caffeine is a plant alkaloid and non-selective antagonist of A1, A2a and A2b adenosine receptors. It is reported that caffeine increases the threshold of pain. In this study, the effect of acute caffeine on behavioral responses of neuropathic pain was investigated.

The present study was conducted on 56 adult male Wistar rats in the weight range of 220-250 g. Neuropathic pain was induced by chronic constriction injury (CCI(. Animals were randomly divided into 7 groups (n = 8): Control, Sham, CCI, CCI + Saline, and CCI + Caffeine (10, 50 and 100 mg/kg). Thermal hyperalgesia, mechanical and thermal allodynia has been done on days 4 ,7, 14, 21, 28 after CCI.

Neuropathic rats desmostrated increased pain thresholds. Notably, caffeine at a dose of 10 mg/kg significantly increased the thermal allodynia., but at doses of 50 and 100 mg/kg, it significantly decreased the thermal hyperalgesia and mechanical allodynia.

Our findings indicated that the effects of caffeine on pain responses are dose-dependent. Probably the inhibition of adenosine A1 receptors by caffeine increases pain responses, while the inhibition of A2a and A2b adenosine receptors is associated with protective effect of caffeine against pain responses.

Background and Purpose: Chronic neuropathic pain caused by damage or disturbance of the functioning of the somatosensory system are one of the major health problems and many people suffer from such diseases. The aim of this study was to investigate the effect of Umbelliprenin (UMB) on the symptoms of neuropathic pain in chronic constriction injury model (CCI) of neuropathy in adult male rats. 24Wistar rats (250±20g) were randomly divided into 3 groups: sham, CCI and CCI+UMB (100μg/rat) groups. UMB was injected intrathecaly one day before surgery, and 3 days after surgery. Von Frey and Hot-Plate tests were performed one day before surgery and on days 2, 4, 7, 10 and 14 after surgery. The results were reported as mean and SEM (P

Role of NMDA receptors in persistence of pathological pain is not clear. In addition, long-term potentiation (LTP) has a crucial role in development and maintenance of neuropathic pain. The aim of this study was to investigate the role of glutamate NMDA receptor and electrophysiological changes in spinal dorsal horn following L5 spinal nerve ligation.

The model of spinal nerve  ligation (SNL) was used in this study. In behavioral experiments to evaluate mechanical allodynia, Von frey filaments were used from a day before induction of neuropathy up to 7 days after neuropathy. Memantin 10 mg/Kg, i.p.,  as NMDA antagonist, was injected one hour before SNL up to 7 days afer SNL. LTP induction  and dorsal horn WDR neurons recording was performed by spinal single unit set up on day 7 after high frequeny stimulus (HFS) induction.

SNL induced mechanical allodynia . Daily injection of memantin increased thershold of pain significantly (p < 0.01) at the period of maximum pain (days 5, 6 and 7). Electrophsiological recording showed a significant decrease in the thershold of activation of C and Aδ fibers or LTP induction (p < 0.001) 7 days after SNL, compared to sham group. Daily administration of memantin prevented  induction of LTP.

It seems that NMDA receptors are involved in development of plasticity during neuropathic pain. Control of neuropathic pain by memantin might open a new insight  in treatment of neuropathic pain.

Post-traumatic stress disorder (PTSD) symptoms and pain can be appeared repeatedly following traumatic events. Although in acute stress condition, pain perception significantly covered by stress, few studies have discussed the changes in pain perception in a PTSD stress conditioning. In the present study, changes of facial acute pain and allodynia have been investigated in an animal model of PTSD.

Male Wistar rats were divided to two groups as control and under stress. PTSD was induced by single prolonged stress (SPS) method and confirmed by elevated plus maze (EPM) and rats plasma corticostrone levels. Acute facial pain and allodynia were evaluated by the eye wiping test and von frey test in the experimental groups.

SPS rats spent less time and made a fewer entries into the open arms of EPM (p < 0.05). The corticostrone level was significantly decreased in Stress + DEXA group compared to the Control + DEXA (p < 0.05). The number of eye wiping was significantly decreased in SPS-induced rats compared to the control (p < 0.001). The response threshold of applying von frey filament in face of SPS-induced rats was significantly increased compared to the control (p < 0.001).

Acute pain perception and allodynia of face area of rats was reduced in SPS-induced animals. Increased endogenous opioids in PTSD condition may lead to this observation.

Neuropathic pain is a chronic pain that affects on the patient’s quality of life. Use of herbal instead of synthetic drugs recently has been increased due to side effects of synthetic drugs and herbal effective components. Flavonoids are herbal compounds that have analgesic and anti-inflammatory effects. Because Allium cepa L. has a great amount of flavonoids, this study has been designed to evaluate analgesic effects of alcoholic extract of Allium cepa L. on neuropathic pain behavior in chronic constriction injury model in rats.
In this experimental study, neuropathic pain induced by chronic constriction injury (CCI model) in Rats. Animals were randomly divided into 4 groups (n=10 for each): Sham, CCI model, receiving red onion hydroalcoholic extract at a dose of 100 mg/kg and a group receiving gabapentin (100 mg/kg). Red onion extract and gabapentin were administered by gavage for 21 days. Using thermal hyperalgesia, mechanical and thermal allodynia tests, the analgesic effects of extract have been measured.
Findings of this study revealed that CCI surgery on rats induced hyperalgesia, mechanical and thermal allodynia. Daily intakes of alcoholic extract of red onion and gabapentin significantly increase the paw withdrawal latency; increase the threshold to mechanical allodynia and decrease in response to acetone.
Oral use of alcoholic extract of Allium cepa L. reduces neuropathic pain behavior in CCI model in rats.

Neuropathic pain is one of the common complications of diabetes mellitus which is caused by impairment in nerve conductivity. The role of flavonoid and polyphenol compounds in treatment of neuropathic pain has been revealed، and extract of onion contains significant amounts of these compounds. The aim of this study was to investigate the effect of alcoholic extract of onion on diabetic neuropathic pain in streptozotocin-diabetic rats. In this experimental study، 40 male Wistar rats were divided into 5 groups: normal control، diabetic control and groups receiving alcoholic extract of onion (125، 250 and 500 mg/kg/day). After injection of streptozotocin (55 mg/kg)، the extract was administered for 3 weeks. At days 0، 7، 14 and 21 after injection of streptozotocin، assessment of neuropathic pain was performed by thermal allodynia، mechanical allodynia، hyperalgesia and formalin test. Behavioral responses to thermal and mechanical stimuli in diabetic control rats showed significant reduction (P<0. 05). Oral administration of alcoholic extract of onion at doses of 125 and 250 led to improvement in diabetic neuropathic pain in all 4 tests. However، dose of 500 mg didn’t improve neuropathic pain. Oral administration of alcoholic extract of Iranian red onion improves diabetic neuropathic pain in rats.