Fig. 7

Oral NAC administration improves IVD degeneration in the rodent model. a Schematic representation of oral NAC administration experiment for IVD degenerative model. b Real-time RT-PCR analysis. NAC significantly abolished the induction of TNFα mRNA expression and reduction of aggrecan in punctured AF tissues. Data presented as mean ± SD of nine IVD discs derived from three independent rats performed in triplicate (n = 9); *p <0.05. c Western blotting. Protein expression of nitrotyrosine was clearly reduced by oral administration of NAC. d Densitometry confirmed that the protein level of nitrotyrosine was significantly abrogated by oral administration of NAC. e Western blotting. Phosphorylation of p38 was significantly attenuated by treatment of NAC. f Histological examination of H&E staining showed that oral administration of NAC improved the reduction of NP size and the disorganization of the AF in this degenerative model. Scale bars, 300 μm. g Mid-sagittal T2-weighted MRI. Area of T2 high intensity was increased by oral administration of NAC in the degenerative group. Representative data are shown. h The T2-weighted high-intensity area to IVD ratio was significantly improved by NAC administration. Data presented as mean ± SD; *p <0.05. COX cyclooxygenase, ERK extracellular signal-regulated kinase, H/E hematoxylin and eosin, JNK c-Jun N-terminal kinase, MMP matrix metalloprotease, MRI magnetic resonance imaging, NAC N-acetyl cysteine, ns not significant, TNF tumor necrosis factor