Multiple causes of neuropathic pain have been identified and its incidence is likely to increase owing to the ageing global population. Glycyrrhiza glabra (licorice) is a medicinal plant known to be a highly efficacious medicinal herb with several pharmacological effects. Few researchers have demonstrated anti-nociceptive activity of licorice acute pain. The aim of this study was to investigate the anti-nociceptive effect of prepared aqueous extract of Glycyrrhiza glabra root administration on chronic constriction injury (CCI) of sciatic nerve induced neuropathic pain and some selected inflammatory biomarkers in adult male wistar rats. Seven groups of 5 rats per group were used. Groups 1 and 2 were controls. Administration started in groups 3, 4, and 5 three days after surgery and continued for 18 days. Group 3 received 10mg/kg of Imipramine. Groups 4 and 5 received 75mg/kg and 150mg/kg of licorice respectively. Groups 6 and 7 received 75mg/kg and 150mg/kg respectively for 10 days before surgery. Paw withdrawal thresholds were assessed using hot plate method on days 3, 7, 14, and 21. On day 21, plasma level of tumor necrotic factor (TNF-α) and C-reactive protein (CRP) were determined using appropriate ELISA kits. There was significant change in pain threshold in the extract treated ameliorative groups when compared with the control and the ameliorative reference drug. TNF- alpha and CRP concentrations were significantly reduced in groups 6 and 7, compared with groups 1, 2 and 3. In conclusion, anti-nociceptive activity of licorice and its effect on TNF-α, and CRP are dose dependent and administration before surgery was more effective.

Sleep deprivation can be described as inadequate quantity or quality of sleep characterized by insufficient sleep duration, delayed sleep onset, and occurrence of napping episodes during the day. Sleep deprivation in animals and obstructive sleep apnea syndrome in human was reported to be associated with increased oxidative stress. Glycyrrizha glabra (licorice) is a medicinal plant known to be a highly efficacious medicinal herb with several pharmacological effects. Hence, the aim of this study was to demonstrate whether or not licorice root extract will regulate the imbalance between the reactive oxygen species and production of antioxidant enzymes in the brain of sleep deprived rats. Twenty - five 6-week-old male Wistar rats were randomly divided into five groups to undergo sleep deprivation and recovery for 5 days each. Group I (Control): Group II: sleep deprivation (SD); Group III: sleep deprivation and recovery (SD+SR) all received distill water (10ml/kg) orally; Group IV: sleep deprivation and licorice (SD+Lic), Group V: sleep deprivation, recovery with licorice (SD+SR+Lic) both received licorice (150mg/kg) orally once daily. MDA concentration among rats in Groups II (51%), III (46.7%) and IV (31.3%) were significantly higher when compared with control. Rats in Group III (20.5%), Group IV (24.6%) and Group V (30.8%) showed increased significant change in GSH concentration when compared with Group II. The concentration of CAT among rats in Group II was significantly lower than those rats in Group III (43.8%), Group IV (53.8%) and Group V (72.9%). These results clearly show that sleep deprivation significantly affects the oxidative status of rats. In conclusion, licorice root extract has ameliorative effect on the imbalance between the reactive oxygen species and production of antioxidant enzymes in the brain of sleep deprived rats.
Sleep ; Sleep Deprivation ; Oxidative Stress, Rats