Reference Sample size Animal type Method of SCI Treatment groups Route & timing of curcumin administration Pathological findings Outcomes/results Ormond et al. [36 ] 14 Sprague-Dawley rats Weight drop After SCI: curcumin versus DMSO Epidural injection within 30 minutes of SCI & weekly thereafter, until sixth week Curcumin group with greater spinal cord tissue sparing & neuronal tissue sparing In curcumin group, improved functional scores after 3 weeks and greater soleus weight Kim et al. [37 ] 36 Sprague-Dawley rats Clipping for 120 seconds Sham, SCI/vehicle, and SCI/curcumin Seven consecutive days of intraperitoneal injections after SCI Curcumin group with decreased cavity size two weeks after SCI In curcumin group, higher neuromotor scores after 7 days; increased SOD and decreased MDA and macrophage markers Zhang et al. [38 ] 30 Sprague-Dawley rats Permanent ligation of lumbar artery Sham, SCI/saline, and SCI/curcumin Intraperitoneal injection daily for 7 days starting 24 hours after SCI Curcumin group with decreased iNOS and NMDA expression as compared with saline group Higher hind limb motor function in curcumin group at 7 days
Sun and Xu [39 ] 200 Rats, unknown type Not specified Sham, SCI/saline, SCI/low-dose curcumin, and SCI/high-dose curcumin Intraperitoneal injection immediately after SCI Curcumin group with increase in CGRP+ cells, starting at 3 days, with dose response Enhanced motor scores of curcumin-treated groups starting at 3 days; dose response between high- and low-dose curcumin groups starting at 7 days Lee et al. [40 ] 40 ICR mice Monofilament-based chronic constriction injury Vehicle, gabapentin (positive control), and KMS4034 (0.1, 1, and 10 mg/kg) Not specified 10 mg/kg KMS4034 group with decrease in CGRP+ cells KMS4034 and gabapentin groups with decreased postnoxious stimulus paw licking, flinching, and withdrawal latency Zhao et al. [41 ] Not specified C57BL/6J mice Chronic constrictive injury of sciatic nerve Vehicle, curcumin at various dose levels (5, 15, and 45 mg/kg) Orally, twice daily for three weeks starting 10 days after SCI — Decreased mechanical allodynia and thermal hyperalgesia in curcumin groups with dose response; effects abrogated with impedance of monoamine signaling Joseph et al. [42 ] 52 C57BL/6J mice Spinal cord transection Control diet/sedentary, control diet/exercise, DHA/curcumin/sedentary, and DHA/curcumin/exercise 21 days prior to intervention; diet ad libitum — Enhanced spinal cord motor learning in both curcumin/DHA groups and highest in group with exercise; effects mediated by several signaling factors including neurotrophic factors Holly et al. [43 ] 27 Sprague-Dawley rats Placement of paraspinal nonresorbable polymer Control (no SCI), SCI/Western diet, and SCI/DHA/curcumin Diet ad libitum and for 6 weeks after procedure — Improved gait at 3 & 6 weeks in the DHA/curcumin groups; potential mediation via neurotrophic factors Di et al. [44 ] 72 Sprague-Dawley rats Chronic constrictive injury of sciatic nerve Sham, SCI only, SCI/vehicle, and SCI/curcumin Intraperitoneal injection daily for 14 days, starting 1 day after SCI Decreased corticosteroid synthesis/expression in curcumin group Curcumin group with improved withdrawal to thermal stimulation, starting at 7 days Ormond et al. [45 ] 63 Sprague-Dawley rats Weight drop from close (moderate SCI) or afar (severe SCI) SCI only ( = 18), SCI/curcumin ( = 10), SCI/NSCs ( = 16), and SCI/curcumin/NSCs ( = 19) Intramuscular injection near site of injury, within 20 minutes Numerically greatest spinal cord parenchymal sparing with curcumin/NSCs Synergistic effect of curcumin and NSCs in neuromotor recovery, along with body weight after SCI and soleus muscle weight (after severe SCI)