Anti-oxidation properties of leaves, skin, pulp, and seeds extracts from green papaya and their anti-cancer activities in breast cancer cells

Abstract

Aim: Breast cancer is typically detected either during a screening examination or after a woman notices a lump. Breast cancers have different phenotypes depending on the presence/absence of an estrogen receptor (ER) and/or an epidermal growth factor (Her-2) receptor. The objective of the present investigation was to investigate growth inhibitory activity of methanol-, ethanol-, and water-extracts from papaya fruit and leaves on MDA-MB-231 (ER-/Her-2-), MCF-7 (ER+/Her-2-), SK-BR- 3 (ER-/Her-2+) and MDA-MB-361, AU565 (ER+/Her-2+) breast cancer cells.Methods: The anti-oxidation potential of papaya extracts was determined by assessing their total polyphenol content, total flavonoid content and by assaying their anti-oxidation capacity. The effects on breast cancer cells proliferation were determined using a WST-1 assay.Results: The seeds and leaves contained higher anti-oxidation potential than that of the skin and pulp fractions. Our data indicate that methanol- and ethanol-extracts of papaya leaves, skin, pulp, and seeds have no effect on any of the breast cancer cell lines, whereas water-extract of leaves and seeds caused low to modest cytotoxic effects only on ER-negative breast cancer cell lines.Conclusion: Our data suggest that bioactive compound in papaya leaves can be potentially used to develop anti-cancer agents for ER-negative breast cancer.