Effects of curcumin on the dorsal root ganglion structure and functional recovery after sciatic nerve crush in rat

Background: Curcumin has protective effects on a variety of CNS injury models. Our purpose was to assess the effects of curcumin on the dorsal root ganglion (DRG) and functional recovery in sciatic nerve crush (SNC) of rats. Methods: The fifth lumbar DRG was removed 28 days after SNC. Sciatic functional index (SFI) and also the DRG structure were evaluated, using stereological methods to assess the effects of curcumin. Results: The volume and number of A- and B-cells were reduced in the SNC as compared with the sham-operated animals. In curcumin treated rats, the volume decreased but in a lesser extent and it was similar to 10% and similar to 15% higher on the average in comparison with the non-treated SNC (P < 0.04). In curcumin treated rats, the number of cells also decreased but in a lesser extent and it was similar to 17% and similar to 36% higher in comparison with the non-treated crushed animals (P < 0.02). The surface area of A- and B-cells reduced in the SNC and SNC plus curcumin in comparison with the sham-operated rats (P < 0.01). The number of satellite cells was reduced in the SNC as compared with the sham-operated animals. In curcumin treated rats, the number of satellite cells decreased but in a lesser extent and the number of satellite cells was similar to 19% higher in comparison with the non-treated (P < 0.02). SFI test shows that the motor function of the rats treated with curcumin significantly improved at 21st days after sciatic nerve crush. Conclusion: The results demonstrate that curcumin promotes the functional recovery and has a neuroprotective effect on the DRG after sciatic nerve injury in the rats. (C) 2011 Elsevier Ltd. All rights reserved.