Fig. 7. HKL alleviates puncture-induced disc degeneration of rats in vivo.

a Radiographic images of rat tails with a needle-punctured disc at 2 and 4 weeks after surgery (white arrows). b Disc height index (DHI) of rat tail. c, d T2-weighted MRI of a rat tail with a needle-punctured disc preoperatively and at 2 and 4 weeks postoperatively. The Pfirrmann MRI grade scores were acquired from three groups at weeks 2 and 4. e, f The morphology of the disc was examined using H&E staining. Scale bar: 100 μM. g, h Immunofluorescence images of SIRT3 expression in the rat disc samples. Scale bar 100 μM. Each group consisted of 12 rats. ^*P < 0.05, ^**P < 0.01 compared with the control group. ^#P < 0.05, ^##P < 0.01 compared with the IVDD + vehicle group