The proliferation of keratinocytes is one of the important steps in the wound-healing process, which is regulated by various signals. Prior studies have shown that Trichosanthes kirilowii extract has the ability to promote angiogenesis. Therefore, in this study, we tested the wound-healing efficacy of Trichosanthes kirilowii extract with respect to promoting keratinocyte proliferation. A total of 100 μg/mL of Trichosanthes kirilowii extract treatment improved 145.38% of keratinocyte proliferation compared with DMSO-treated control in an MTT assay and increased 238.2% of wound closure by re-epithelialization in an in vitro wound-healing assay. Trichosanthes kirilowii extract promoted ERK1/2 phosphorylation in western blot analysis and induced the expression of the c-fos and c-jun (AP-1 transcription factors), cyclins (cell cycle regulator), and growth factors CTGF and VEGF (stimulator of angiogenesis) in qRT-PCR analysis. An in vivo wound-healing assay showed that Trichosanthes kirilowii extract improved wound healing, and the significant difference in wound closure compared with DMSO-treated control was shown on days 6 and 7 with a mouse model. Taken together, we demonstrate that Trichosanthes kirilowii extract promotes the proliferation of keratinocytes by activating ERK1/2 and increasing the mRNA expression of c-fos, c-jun, CTGF, and VEGF. Therefore, we suggest Trichosanthes kirilowii extract as a new component for skin care and as a wound-healing substance.
Keywords: AP-1 transcription factor; HaCaT cell; MAP kinase pathway; angiogenesis; growth factor; wound healing.