Inhibition of fibrotic contraction by C-phycocyanin through modulation of connective tissue growth factor and α-smooth muscle actin expression

The effects of C-phycocyanin (C-pc), a phycobiliprotein, on the expression of pro-fibrotic mediators in hyper-tropic scarring such as connective tissue growth factor (CTGF) and alpha-smooth muscle actins (alpha-SMA) were investigated in relation to trans-differentiation of fibroblast to myo-fibroblast, an icon of scar formation. C-pc was isolated from Spirulina Platensis extract using sonication method and C-pc concentration was determined by Bennet and Bogorad equation. alpha-SMA and CTGF levels in wounded primary human dermal fibroblasts were determined by western blot analysis and immuno-fluorescence confocal microscope was employed. Fibroblast contractility was examined by three-dimensional collagen lattice contraction assay. There was an elevation of alpha-SMA (121%) and CTGF (143%) levels in wound cells as compared with non-wound cells. The does-response profiles of down regulation demonstrated that the maximum inhibitions of alpha-SMA by 63% (p < 0.05) and CTGF by 50% (p < 0.1) were achieved by C-pc (6 nM) treated cells. In confocal assay, non-wound fibroblasts exhibited basal level of alpha-SMA staining, while wounded cells without C-pc treatment showed strong up-regulation of alpha-SMA by 147% (p < 0.05). C-pc (6 nM) inhibited alpha-SMA expression by 70% (p < 0.05) and reduced collagen contraction by 29% (p < 0.05). C-pc seemed to lessen the over expression of CTGF, alpha-SMA, subsequently alleviating the fibrotic contracture. This study suggests the potential application of C-pc to regulation of the expression of pro-fibrotic mediators in scarring process and its potential usage as an efficient means for anti-fibrosis therapy.