Artocarpin-enriched (Artocarpus altilis) Heartwood Extract Provides Protection Against UVB-induced Mechanical Damage in Dermal Fibroblasts

Collagen gel contraction assays: From modelling wound healing to quantifying cellular interactions with three-dimensional extracellular matrices

Cells respond to and actively remodel the extracellular matrix (ECM). The dynamic and bidirectional interaction between cells and ECM, especially their mechanical interactions, has been found to play an essential role in triggering a series of complex biochemical and biomechanical signal pathways and in regulating cellular functions and behaviours. The collagen gel contraction assay (CGCA) is a widely used method to investigate cell-ECM interactions in 3D environments and provides a mechanically associated readout reflecting 3D cellular contractility. In this review, we summarize various versions of CGCA, with an emphasis on recent high-throughput and low-consumption CGCA techniques. More importantly, we focus on the technique of force monitoring during the contraction of collagen gel, which provides a quantitative characterization of the overall forces generated by all the resident cells in the collagen hydrogel. Accordingly, we present recent biological applications of the CGCA, which have expanded from the initial wound healing model to other studies concerning cell-ECM interactions, including fibrosis, cancer, tissue repair and the preparation of biomimetic microtissues.

Curcuma aromatica and Curcuma comosa Extracts and Isolated Constituents Provide Protection against UVB-Induced Damage and Attenuate Matrix Metalloproteinase-1 Expression in HaCaT Cells

Ultraviolet-B (UVB) exposure is one of the primary extrinsic factors causing skin photoaging. It stimulates inflammatory responses and arrests the cell cycle. Matrix metalloproteinase-1 (MMP-1) secreted by keratinocytes is one of the important extracellular matrixes to attenuate UVB-induced skin aging via collagen degradation. Curcuma aromatica (CA) and Curcuma comosa (CC), the herbaceous plants in the Zingiberaceae family, are commonly used in Thai traditional women’s medicines. The present work was aimed to investigate the potential of the CA and CC extracts and their isolated compounds to attenuate UVB-induced MMP-1 and cell cycle arrest in HaCaT keratinocytes. Total phenolic contents and antioxidant capacities of the extracts were determined. CC extract contains more phenolic components and provides more potent antioxidant activities than CA extract. HaCaTs were pretreated with the extracts or their isolated constituents 1–4 for 24 h and then repeatedly exposed to UVB at 100 mJ/cm2 10 times. Both extracts and compounds 1–4 effectively reduce UVB-induced MMP-1 levels in HaCaT cells and restore cell cycle arrest. This is the first report on the potential of CA and CC extracts in reducing UVB-induced MMP-1 expression and regulating cell proliferation in HaCaT cells. Thus, CA and CC extracts might be used as alternative natural agents to prevent UVB-induced skin photoaging.