Does Chlorella vulgaris modulates the expression of COL and MMP genes in skin ageing?

Chlorella vulgaris, a unicellular microalgae, produces many intracellular phytochemi­cals namely carotenoids, tocopherols, ubiquinone and protein. Skin ageing which is induced by oxidative stress involves decreased extracellular matrix synthesis and in­creased expression of enzymes that degrade the collagenous matrix. The objective of this study was to determine the effect of C. vulgaris on the expression of genes en­coded for collagen (COL) and matrix metalloproteinases (MMPs) which are involved in skin ageing. Human diploid fibroblasts (HDFs) were obtained from circumcision fo­reskin of 8-12 year-old boys. HDFs were cultured into 3 groups: untreated control cells, cells with stress-induced premature senescence (SIPS; cells were induced with H2O2 at passage 6 for 2 weeks) and SIPS treated with C. vulgaris (prolonged C. vulgaris treatment started at passage 4 and combined treatment with H2O2 at passage 6 for 2 weeks). Senescence-associated ß-galactosidase (SA ß-gal) was de­termined using senescent cells histochemical staining kit (Sigma, USA). Expression of COLI, COLIII, COLIV, MMPI, MMPII and MMPIII genes was quantitatively analysed with real-time RT-PCR method (iScript™ One Step real-time PCR with SYBR® Green; Biorad). HDFs treated with H2O2 (SIPS) exhibited senescent morphological features of flatten­ing and enlarged with increased expression of SA ß-gal (p<0.05). Gene expres­sion analysis showed COLI was downregulated in SIPS and SIPS treated with C. vulgaris (p<0.05)while COLIII decreased in SIPS and increased in SIPS treated with C. vulga­ris (p<0.05). Expression of MMPI was increased in SIPS and SIPS treated with C. vul­garis (p<0.05) indicating its synergistic effect with H2O2 treatment. In conclusion, in skin ageing,COLI and COLIII genes were downre­gulated while MMPI was upregu­lated. C. vulgaris modulated the expression of COL and MMP genes by downregulat­ing COLI and upregulating COLIII and MMPI but it did not exert anti-ageing effect.