Digitaria ciliaris is widely reported to be a problematic weed in agricultural areas and is mainly used as an indicator plant for the development of herbicides. However, its bioactivities on skin regeneration and wound healing have not been investigated. In the present study, we investigated the effects of D. ciliaris flower absolute on skin wound healing and skin regeneration-related events, that is, proliferation, migration, and collagen biosynthesis, in human fibroblasts and keratinocytes. For this study, we extracted absolute from the D. ciliaris flower by solvent extraction and identified the composition of D. ciliaris flower absolute using GC/MS analysis. We also tested the effect of D. ciliaris flower absolute in CCD986sk fibroblasts and/or HaCaT keratinocytes using the WST assay and 5-bromo-2′-deoxyuridine incorporation assay, Boyden chamber assay, ELISA, sprouting assay, and immunoblotting. GC/MS analysis of D. ciliaris flower absolute revealed that it contained 15 compounds. The absolute increased the proliferations of keratinocytes and fibroblasts and the migration of fibroblasts but did not affect cell viabilities. In addition, it enhanced the syntheses of type I and IV collagen in fibroblasts, but not in keratinocytes. The sprouting assay showed increased sprout outgrowth of fibroblasts. In addition, D. ciliaris flower absolute induced the phosphorylation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase in fibroblasts. These results indicate that D. ciliaris flower absolute may promote skin wound healing/regeneration by inducing the proliferation, migration, and collagen synthesis of fibroblasts, as well as the proliferation of keratinocytes. Therefore, D. ciliaris flower absolute may be a potential natural source for cosmetic or pharmaceutical agents that promote skin wound healing/regeneration.

Patrinia scabiosifolia (PS) has bioactivities such as antitumor and anti‐inflammation effects. However, its effects on human skin physiological activities, such as skin regeneration and wound healing, remain unclear. In this study, we investigated the effects of absolute extracted from PS flower (PSF) on migration and proliferation of human dermal keratinocyte (HaCat). The yield of PSF absolute obtained by solvent extraction method was 0.105 % and its five constituents were found in GC/MS analysis. The PSF absolute induced the proliferation and migration of HaCats. The absolute increased the phosphorylation of serine/threonine‐specific protein kinase (Akt) and extracellular signal‐regulated kinase1/2 (Erk1/2) in HaCats. In addition, the absolute stimulated the outgrowth of collagen sprouting of HaCats. These results demonstrated, for the first time, that PSF absolute may have positive effects on skin regeneration and/or wound healing by inducing migration and proliferation of dermal keratinocytes via the Akt/Erk1/2 pathway. Therefore, PSF absolute may be a useful natural material for skin regeneration and/or wound healing.

Smilax china (SC) has pharmacological effects including anti‐inflammatory activity, but its effects on skin wound healing and skin barrier function have not been investigated. Here, we investigated the effects of absolute extracted from SC flowers (SCF) on skin wound healing‐linked responses and functional skin barrier proteins using human epidermal keratinocytes (HaCaT cells). SCF absolute contained 20 components and was non‐toxic to HaCaT cells. The absolute increased the proliferation, migration, and sprout outgrowth of HaCaT cells, and enhanced the activations of serine/threonine‐specific protein kinase and extracellular signal‐regulated kinase1/2. In addition, it increased the syntheses of type I and IV collagens and the expressions of skin barrier proteins (filaggrin and loricrin). These results indicate SCF absolute may has positive effects on skin wound healing by accelerating keratinocyte migration and proliferation activities and collagen synthesis, and on skin barrier function by upregulating barrier proteins in keratinocytes. We suggest SCF absolute to be considered as a potential means of promoting skin wound and barrier repair.

Salix koreensis Anderss (SKA) has been used traditionally to treat inflammation, pain, and edema. SKA has anti-inflammatory and antioxidant effects, but no study has examined its effects on skin wound healing. Here, we aimed to investigate the effects of the absolute extracted from SKA flower (SKAFAb) on skin wound healing-associated responses in keratinocytes. SKAFAb was produced using a solvent extraction method and its chemical composition was analyzed by gas chromatography/mass spectrometry. The effects of SKAFAb on HaCaT cells (a human epidermal keratinocyte cell line) were investigated using a Boyden chamber and 5-bromo-2′-deoxyuridine incorporation, sprout outgrowth, immunoblotting, enzyme-linked immunosorbent, and water-soluble tetrazolium salt assays. Sixteen constituents were identified in SKAFAb. SKAFAb promoted HaCaT cell proliferation, migration, and type I and IV collagen productions. SKAFAb increased sprout outgrowth and increased the phosphorylations of serine/threonine-specific protein kinase (Akt), c-Jun NH2-terminal kinase, extracellular signal-regulated kinase1/2, and p38 mitogen-activated protein kinase (MAPK) in HaCaT cells. These results indicate that SKAFAb promotes keratinocyte proliferation and migration, probably by activating Akt and MAPK signaling pathways, and induces collagen synthesis in keratinocytes. SKAFAb may be a promising material for promoting skin wound healing.

Zea mays L. (ZM) has cytotoxic and anti‐inflammatory activities, but its biological activities such as skin regeneration and wound healing in human skin have not been reported. In the present study, we tested the effects of ZM flower (ZMF) absolute on proliferation and migration of human keratinocytes (HaCaTs) and identified its components by using gas chromatography/mass spectrometry (GC/MS) analysis. GC/MS analysis revealed that the ZMF absolute contained 13 constituents, and it increased HaCaT proliferation and migration. The ZMF absolute enhanced the phosphorylation levels of serine/threonine‐specific protein kinase (Akt), p38 mitogen‐activated protein kinase (MAPK), and extracellular signal‐regulated kinase1/2 in HaCaTs. In addition, the absolute induced an increase in sprout outgrowth of HaCaTs. The present study reports for the first time that ZMF absolute may promote skin wound healing and/or skin regeneration by stimulating proliferative and migratory activities in dermal keratinocytes through the Akt/MAPK pathway. Therefore, ZMF absolute may be a promising natural material for the use in skin regeneration and/or wound healing applications.