Human skin fibroblast response is differentially regulated by galactofucan and low molecular weight galactofucan

•High molecular weight crude galactofucans (>600 kDa) are efficient antiproliferative agents for fibroblasts.•Crude galactofucans possibly increase extracellular matrix degradation by fibroblasts caused by increased secretion of matrix metalloproteinase.•Radically depolymerized (RDP) galactofucan increases collagen secretion without affecting fibroblast growth.

Wound healing is a sum of mechanisms that have to be finely modulated to reconstitute a tissue similar to the original. Several pathologies induce a decrease of healing rate and patients have to be treated to help the closure of wound. Glycosaminoglycan (GAG) mimetics have proven to be valuable in stimulating wound healing. In this study, galactofucan (fucoidan) was extracted from the brown seaweed Saccharina longicruris during two harvest periods (M05 and N05 fractions). Crude galactofucan M05 and N05 were subjected to radical depolymerization (RDP) for 4 h to obtain 2 RDP fractions (M05 RDP and N05 RDP fractions). Each fraction was added on cultured dermal fibroblasts and growth rate, collagen and MMP secretion were analyzed after treatment. Crude and RDP galactofucan influenced fibroblast growth, apoptosis and the synthesis of matrix metalloproteinase (MMP) and collagen according to the molecular weight of the polymer. Both crude galactofucan extracts reduced cell growth and increased MMP secretion, whereas only M05 stimulated apoptosis. By contrast, RDP fractions significantly increased collagen-I secretion and have no negative effect on fibroblast proliferation. Thus, crude and RDP galactofucan exhibit different metabolic activities on fibroblasts, which may be of interest in the area of wound healing.

Graphical abstractCell proliferation of human dermal fibroblasts treated with crude (M05 and N05) and radically depolymerized (RDP) galactofucan extracts with different structures. Cell proliferation was evaluated after 6 days in culture with galactofucan treatment at 1 mg/mL. Dotted lines indicate the control without extract (FBS 0.5%). (⁎P<0.05 and ⁎⁎P<0.01)The molecular weight and sulfate groups results were previously presented in Rioux, Turgeon, and Beaulieu 2010 Phytochemistry 71, 1586–1595.Figure optionsDownload full-size imageDownload as PowerPoint slide