Behavioral, Biochemical and Molecular modulation in Brain and Spinal cord : A potential antinociceptive‐antidepressant mechanism of Xanthophylls

Abstract

AimThe present study was designed to investigate the antinociceptive‐antidepressant effects of xanthophylls, Lutein and in chronic pain‐depression dyed.MethodsSD rats (230‐250 g) were anesthetized under ketamine‐xylazine (80 ‐ 20 mg/kg, intraperitoneally) and chronic constriction injury (CCI) was performed (Bennett and Xie, 1988). Vehicle‐olive oil (0.5 ml), Lutein (LT 20 & 40 mg/kg), Zeaxanthin (ZX 20 & 40 mg/kg) and Lutein‐Zeaxanthin (LZ 25 & 50 mg/kg) were administered from day 14 to day 38. Behavioural observations were recorded on 0, 7, 14, 21, 28 & 35th day. Animals were sacrificed on 36th day; sciatic nerve, spinal cord and brain were isolated for biochemical estimations (Brain monoamines, spinal GABA, total ROS in brain, spinal cord and sciatic nerve)and molecular expression.ResultPain, anxiety and depression (increased immobility at expenses of climbing behaviour) were significantly increased in CCI animals. Decreased brain noradrenalin and increased spinal ROS was observed in CCI animals compared to sham. LT 40, ZX 40 and LZ 25 and 50 decreased the mechanical allodynia, thermal hyperalgesia and allodynia. Similarly, LT (40 mg/kg), ZX (40 mg/kg) and their combination LZ (25 and 50 mg/kg) showed reduction in depression behaviour i.e. decreased time of immobility and increased climbing in FST. Modulation in brain monoamine levels and decreased spinal ROS were observed in LT 40, ZX 40, LZ 25 and LZ 50 treated animals. Similarly, modulation in protein and mRNA expression at Spinal cord were observed.Conclusionxanthophylls LT, ZX and LZ play their antinociceptive‐antidepressant role by modulating ROS & monoamines level at brain along with the protein and mRNA expression and ROS at spinal cord.