Radix Dipsaci does not improve tendon healing in a rat model of patellar tendon donor site injury

Abstract

To explore whether Radix Dipsaci (RD) exhibits beneficial effects on tendon healing. An attempt was made to explore the in vitro effects of a hot water extract of RD on gene expression of procollagen Type I (COL1A1), procollagen Type III (COL3A1) and decorin in cultured tendon fibroblasts, and its in vivo effects in a well-established rat model of patellar tendon donor site injury. It was found that gene expression of COL3A1 and decorin in cultured tendon fibroblasts was significantly increased by RD, but that COL1A1 was not affected. In vivo studies showed that RD increased blood vessels in the wound but did not significantly affect the expression of COL1A1, COL3A1 and decorin at day 14 post-injury. The ultimate tensile stress of the healing tendon was not significantly improved by either local injection or oral administration of hot water extract of RD (P > 0.05). The present findings imply that RD per se does not significantly improve tendon healing. Further investigation of RD in a herbal formula may be necessary to test its efficacy in tendon injuries.