The effects of Shikonin on the hypertrophic scar of rabbit ears via the TLR4/NF-κB signaling pathway

As a traditional Chinese medicine, Zihuang Shengji Ointment has obvious effects on promoting postoperative wound healing and reducing scar formation in clinical application. Shikonin is the major phytochemical in Zihuang Shengji Ointment. As a kind of naphquinone compound with anti-tumor, anti-viral, anti-inflammatory, anti-bacterial and other biological activities extracted from Lithospermum erythrorhizon, shikonin exerts an important role in many diseases. Shikonin has impacts on the development of hypertrophic scars (HS), however, these effects are yet mostly unknown. As a result, we created the Newland white rabbit ear HS model, administered shikonin to it, and then assessed scar hypertrophy using HE and VG staining. The degree of scarring is assessed by HI, NA, as well as AA. The expression levels of collagen I, collagen III, as well as α-SMA as well as fibroblast proliferation, are also measured using real-time PCR, immunohistochemistry, and western blot. TUNEL tests are used to assess fibroblast apoptosis. In our work, HE staining and VG staining showed that the shikonin-treated group had normal bundles of collagen fibers and regular fibroblasts. Shikonin suppresses the production of HS, according to histopathological features, HI, NA, and AA measures. Shikonin also causes fibroblast apoptosis and lowers the production of α-SMA, collagen I, as well as collagen III in the HS rat. Notably, we discover that NF-κB activation and TLR4 activity are inhibited by shikonin. Overall, the results show that the signaling pathway of TLR4/NF-κB is modulated by shikonin's inhibitory effect on scar formation, which represses the levels of collagen I, collagen III, α-SMA, as well as fibroblasts.