Fig. 1: LBP induces intrinsic growth capacity of axotomized dorsal root ganglion (DRG) neurons in ex vivo explant cultures.

Adult male C57BL/6 mice were orally administrated with 100 mg/kg LBP (or PBS as vehicle controls) for 9 and 13 consecutive days. For pre-conditioning DRG explant cultures, the left sciatic nerve was transected, and lumbar 3, 4, and 5 (L3/4/5) ipsilateral DRGs were harvested at 5 days post-injury, and cultured on a poly-D-lysine-coated 8-well chamber with a thin layer of Matrigel for 48 h. Cultures were fixed and immunostained with anti-βIII-tubulin antibodies for neurite outgrowth assay. a Representative fluorescent micrographs showed that DRG explants treated with LBP for 9 and 13 days induced robust neurite extension compared to the PBS-treated controls. Scale bar: 500μm. b The average total neurite length was quantified by automated WIS-Neuromath software. LBP increased neurite outgrowth of DRG explants significantly, with its maximal effect at day 13. The total neurite length of LBP-treated DRG explants (13-day treatment) was comparable with pre-conditioned DRG explants. Mean ± SEM (n = 6–8 per group); *P < 0.05, one-way ANOVA followed by post hoc Bonferroni test.