Aqueous extract of Phyllanthus amarus inhibits chromium(VI)-induced toxicity in MDA-MB-435S cells.

Cr(VI) (hexavalent) is a very strong oxidant which causes high cytotoxicity through oxidative stress in tissue systems. Its abundance in groundwater and drinking water in several parts of the world has been noted to cause severe toxicity to both flora and fauna. This study evaluated the effects of aqueous extract of Phyllanthus amarus Schum. & Thon. against Cr(VI)-induced oxidative toxicity in vitro in MDA-MB-435S human breast carcinoma cells, along with an estimation of its antioxidant potential, inhibition of lipid peroxidation and determination of its polyphenolic composition. The extract showed significant (P<0.05) potential in scavenging free radicals (DPPH() and ABTS()(+)) and Fe(+3), and in inhibiting lipid peroxidation. A distinct decline in Cr(VI)-induced cytotoxicity was noticed in MDA-MB-435S cells with an increase in extract dosage. Furthermore, the extract proved to contain a high content of phenolic compounds which were found to have strong and significant (P<0.05) positive correlations to free-radical scavenging potential, lipid peroxidation inhibition capacity and cyto-protective efficiency against Cr(VI)-induced oxidative cellular damage. HPLC analysis identified some of the major phenolic compounds in it. It was concluded that P. amarus aqueous extract has high antioxidant potential (by virtue of its phenolic constituents) which simultaneously inhibits Cr(VI)-induced oxidative toxicity to MDA-MB-435S cells.