Fig. 1

OE reduces inflammation in rabbit disc cells in vitro, increases collagen gene expression in vivo. A–C Rabbit disc cells were pretreated with different concentrations of OE and then stimulated with lipopolysaccharide (LPS) for 16 h. Gene expression of Interleukin-8 (IL-8) and nitric oxide synthase 2 (NOS2) was analyzed. Statistically significant differences between OE-treated and VC (saline) from LPS (P < 0.05) are indicated (*). Conditioned media was collected to quantify interleukin-8 (IL-8) protein. (Lower panel D) Rabbits (n = 8) underwent surgical disc injury and intradiscal treatment with OE or VC. After 3 weeks, intervertebral disc tissues were isolated for RNA analysis of phenotypic disc and inflammatory genes: collagen type I (COL1), collagen type II (COL2), chemokine C–C motif ligand (CCL)2, CCL5 and IL-8 (D). Cell culture experiment data were analyzed with One way ANOVA with multiple comparisons and included in the significant difference (*) on graphs. In vivo, rabbit disc gene expression was analyzed with multiple unpaired t-tests. Error bars represent SEM