Intradiscal injection of crocin retards lesion induced intervertebral disc degeneration

Intervertebral disc degenerative diseases have become a serious social health problem. However, there is no clinical treatment effectively retarding the progression of intervertebral disc degeneration. Crocin, which is extracted from saffron, has been proved to exert anti-inflammatory and anti-catabolic effects on intervertebral disc in vitro and ex vivo. In the present study, effects of crocin on lesion induced rat intervertebral disc degeneration were investigated. As shown by results, intradiscal crocin injection rescued the MRI signal loss of nucleus pulposus in T2weighted images. The excessive mRNA expression of MMP-3 and ADAMTS-5 induced by puncture lesion was significantly suppressed by crocin injection. Meanwhile, crocin treatment partly recued the impaired mRNA expression of type II collagen and aggrecan. Obviously, crocin injection maintained the normal morphology of disc and alleviated lesion induced degeneration related histological changes reducing histological scores. Immunohistochemical assay showed that the upregulation of MMP-3 and ADAMTS-5 protein expression in nucleus pulposus was also inhibited by crocin treatment. According to biochemical assay, crocin injection suppressed the lesion induced decrease of proteoglycan content in nucleus pulposus, which is consistent with mRNA expression analysis. Our results further prove the protective effects of crocin on intervertebral disc degeneration, suggesting that crocin is promising for retarding the progression of intervertebral disc degeneration.