Rui Li1, Le Shen1, Xuerong Yu1, Chao Ma2, Yuguang Huang3. 1. Department of Anesthesiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, China. 2. Department of Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, China. 3. Department of Anesthesiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, China. Electronic address: huangyuguanglab@163.com.
Abstract
AIMS: Gabapentin (Gap) relieves neuropathic pain, but it has several adverse effects as well. We aimed to investigate whether vitamin C (VitC) supplementation would reduce the effective dose of Gap for analgesia in rats with chronic constriction injury (CCI). MAIN METHODS: Rats were randomly assigned to Sham, CCI, VitC, Gap, and VitC+Gap treatment groups. CCI, involving the left sciatic nerve, was induced in all animals except the Sham group. VitC (500mg/kg (body weight)), Gap (10, 30, or 100mg/kg), or VitC (500mg/kg)+Gap (10, 30, or 100mg/kg) were injected intraperitoneally twice daily for a week from 7days after sham or CCI surgery. Mechanical paw withdrawal threshold (PWT), thermal paw withdrawal latency (PWL) and malondialdehyde (MDA) content in serum or spinal cord tissues were all measured. The expression of sodium dependent vitamin C transporter 2 (SVCT2) and glucose transporter 3 (GLUT3) in dorsal root ganglion (DRG) were detected by quantitative real-time PCR, Western blot and immunohistochemistry. KEY FINDINGS: No more than 30mg/kg Gap could restore the decrease of PWT or PWL induced by CCI so long as combined with 500mg/kg VitC. For mechanism study, we found that VitC supplementation would remarkedly ameliorate oxidative stress in peripheral blood, and possibly cause a positive feedback in VitC uptake of neurons in DRG by promoting SVCT2 expression. SIGNIFICANCE: Vitamin C can enhance gabapentin's analgesic effect. And the underlying mechanism may be concerned with antioxidative responses which were more obvious in peripheral blood than in the neurons.
AIMS: Gabapentin (Gap) relieves neuropathic pain, but it has several adverse effects as well. We aimed to investigate whether vitamin C (VitC) supplementation would reduce the effective dose of Gap for analgesia in rats with chronic constriction injury (CCI). MAIN METHODS:Rats were randomly assigned to Sham, CCI, VitC, Gap, and VitC+Gap treatment groups. CCI, involving the left sciatic nerve, was induced in all animals except the Sham group. VitC (500mg/kg (body weight)), Gap (10, 30, or 100mg/kg), or VitC (500mg/kg)+Gap (10, 30, or 100mg/kg) were injected intraperitoneally twice daily for a week from 7days after sham or CCI surgery. Mechanical paw withdrawal threshold (PWT), thermal paw withdrawal latency (PWL) and malondialdehyde (MDA) content in serum or spinal cord tissues were all measured. The expression of sodium dependent vitamin C transporter 2 (SVCT2) and glucose transporter 3 (GLUT3) in dorsal root ganglion (DRG) were detected by quantitative real-time PCR, Western blot and immunohistochemistry. KEY FINDINGS: No more than 30mg/kg Gap could restore the decrease of PWT or PWL induced by CCI so long as combined with 500mg/kg VitC. For mechanism study, we found that VitC supplementation would remarkedly ameliorate oxidative stress in peripheral blood, and possibly cause a positive feedback in VitC uptake of neurons in DRG by promoting SVCT2 expression. SIGNIFICANCE: Vitamin C can enhance gabapentin's analgesic effect. And the underlying mechanism may be concerned with antioxidative responses which were more obvious in peripheral blood than in the neurons.
Authors: Farah M Abdulkhaleq; Tawfiq M Alhussainy; Mujtaba M Badr; Asad A Abu Khalil; Omar Gammoh; Bayan Y Ghanim; Nidal A Qinna Journal: Drug Des Devel Ther Date: 2018-10-18 Impact factor: 4.162