Neuropathy can induce inflammation that results in muscle atrophy. Curcumin has been shown to exert an anti-inflammatory effect, preserving muscle mass in diabetic rats. However, the mechanism of curcumin to preserve muscle mass in neuropathy is not known. PURPOSE: To examine the effect of curcumin on the intramuscular inflammation and muscle cross-sectional area (CSA) in a neuropathy rodent model. METHODS: Twelve rats were randomly assigned to three groups: sham (CON), spinal nerve ligation (SNL), and SNL+100curcumin/kg BW (100CUR). The right (R) lumbosacral section (i.e., L5/L6) of the spinal cord was ligated (SNL and 100CUR) or sham surgery (CON) was performed, whereas the contralateral side (left: L) was served as their own control. Rats were fed with a control diet without (i.e., CON and SNL) or with (i.e., 100CUR) curcumin supplementation for 4 weeks. Plantaris (left and right) and tibialis anterior (TA; right) muscles were collected. TA was stained for dystrophin to measure CSA. Left and right plantaris were analyzed for protein content for AChR, CaMK2, CaMK2Thr286, CaMK2Thr286/CaMK2, NF-κB, NF-κBSer536, NF-κBSer536/NF-κB, IL-1β, and GAPDH. Each protein was normalized to GAPDH then to the CON. RESULTS: A significant (p ≤ 0.05) group effect was observed for TA CSA and a group x leg interaction effect was observed for CaMK2Thr286/CaMK2, NF-κBSer536, IL-1β protein content. For muscle CSA, CON (9027.33 ± 603.39 μm2) and 100CUR (8853.68 ± 696.73 μm2) were larger than SNL (4771.01 ± 539.69 μm2). No difference was observed in CSA between CON and 100CUR. Additionally, when compared between left and right plantaris muscles, only SNL had greater CaMK2Thr286/CaMK2 (R: 2.63 ± 1.87 vs. L: 1.56 ± 1.65), NF-κBSer536 (R: 1.85 ± 0.83 vs. L: 0.55 ± 0.33), and IL-1β (R: 2.11 ± 1.32 vs. L: 0.65 ± 0.29) protein content in the right than the left leg, whereas, no difference was observed for left leg among groups. For NF-κBSer536, SNL (1.85 ± 0.83) was greater than 100CUR (0.91 ± 0.52) in the right leg. No significant differences were observed for AChR, CaMK2, CaMK2Thr286, and NF-κBSer536/NF-κB. CONCLUSION: In a neuropathic model, muscle atrophy was observed with concomitant increase in CaMK2/NF-κB/IL-1β activation in the ipsilateral plantaris. Curcumin supplementation appears to mitigate this inflammatory response and muscle mass loss.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.