
Anthocyanins and flavonoids are polyphenolic compounds and capable of inhibiting the growth of human cancer cells. It is mainly responsible for cyanic colors ranging from salmon pink through red and violet to dark blue of most flowers, fruits, leaves and stems. Quercetin, a novel flavonoid, was present in the onion peel (Allium cepa). In the present study, we explored the cytotoxic effects of anthocyanin on human epithelial cells and the Breast cancer cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The HEp-2 and MCF-7 cells were seeded in 96-well culture plates in different concentrations of red onion and big onion peel extracts of Allium cepa to determine their anticancer effects using the MTT assay. Anthocyanin extracted from big onion peel showed approximately 92% inhibition on HEp-2cells at 1000 µg/ml (table 1). When compared with anthocyanin extracted from red onion peel, big onion peel showed a highest inhibition. The anthocyanin extracted from red onion peel and big onion peel was tested against MCF-7 cell lines. Red onion peel showed higher activity around 78% inhibitions than big onion peel. So we can assume that, the anthocyanin compounds present in red onion peel are inhibiting the proliferation of cells. So the anthocyanins extracted from easily available onion peel would be a valuable source for antiproliferative activity in food industry.