Abstract: Objective To explore the effect of capsaicin on inhibiting collagen expression, proliferation and migration ability of keloid fibroblasts in vitro and thus to provide scientific basis for clinical application of capsaicin in treatment of keloid. Methods The keloid tissues were harvested from 9 patients and digested with 0.3% collagenase to extract keloid fibroblasts. These cells were treated with different concentrations of capsaicin (0.5 μg/L and 5 μg/L) as the experiment group or without capsaicin treatment as the control group. CCK-8 assay was used to evaluate cell proliferation. Flow cytometry was also employed to evaluate cell cycle. Q-PCR assay was used to examine the gene expression levels of collagen and other extracellular matrices. In vitro wound scratch was also used to investigate cell migration ability. Results Capsaicin inhibited the proliferation of keloid fibroblasts, resulting in relative blockade of cell cycle in G0/G1 phase. It also inhibited the gene expression of collagens Ⅰ and Ⅲ and fibronectin. In addition, Capsaicin also inhibited the gene expression of IL-6, IL-8 and TNF-α, but had no effect on cell migration. Conclusion Capsaicin could inhibit the proliferation and gene expression of collagen and inflammatory cytokines of cultured fibroblasts in vitro.

Key words: Keloid, Fibroblasts, Capsaicin, Proliferation