Antiproliferative Effect of Carrageenans on Epidermoid Carcinoma (A431NS) Cells Through Inhibition of DNA Synthesis and Translationally- Controlled Tumour Protein (TPT1) Gene Expression

Carrageenans are polysaccharide constituents of red seaweed cell walls used in food and medicine as well as thickening agents and excipients in cosmetics and skincare products. Carrageenans have antioxidants, anti-inflammatory and pro-apoptotic properties that could potentially cause antiproliferative effects against cancer cells. The primary aim of this study was to assess the antiproliferative effect of iota (ι) and kappa (κ)-carrageenan as well as their combination with α-tocopherol on epidermoid carcinoma (A431NS) cells concerning DNA synthesis and translationally-controlled tumour protein (TPT1) gene expression. Carrageenans exhibited cytotoxic effects against A431NS cells with CD50<100ug/ml and an antiproliferative effect in a concentration-dependent manner after 24, 48 and 72 hours of treatment by inhibiting DNA synthesis in these cells. The expression of the TPT1 gene increased significantly (p<0.05) in untreated A431NS cells. However, the expression was either lowered or completely suppressed in groups treated with carrageenans and/or α-tocopherol compared to the untreated cells. This study indicates that carrageenans can exhibit an antiproliferative effect via inhibition of DNA synthesis and downregulation of TPT1 gene expression in A431NS cells. The anticancer activity of carrageenans deserves further studies to explore their potential applications as an ingredient in cosmetics or skin care products for the prevention of skin cancer.